WO2019220710A1 - Physical quantity measuring device - Google Patents

Physical quantity measuring device Download PDF

Info

Publication number
WO2019220710A1
WO2019220710A1 PCT/JP2019/004958 JP2019004958W WO2019220710A1 WO 2019220710 A1 WO2019220710 A1 WO 2019220710A1 JP 2019004958 W JP2019004958 W JP 2019004958W WO 2019220710 A1 WO2019220710 A1 WO 2019220710A1
Authority
WO
WIPO (PCT)
Prior art keywords
physical quantity
quantity measuring
bonding layer
measuring device
semiconductor element
Prior art date
Application number
PCT/JP2019/004958
Other languages
French (fr)
Japanese (ja)
Inventor
拓也 青柳
望 八文字
大介 寺田
健悟 鈴木
阿部　博幸
彰夫 保川
隆史 松村
穣二 市野沢
Original Assignee
日立オートモティブシステムズ株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 日立オートモティブシステムズ株式会社 filed Critical 日立オートモティブシステムズ株式会社
Priority to JP2020518978A priority Critical patent/JP6909354B2/en
Publication of WO2019220710A1 publication Critical patent/WO2019220710A1/en

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L9/00—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L29/00—Semiconductor devices specially adapted for rectifying, amplifying, oscillating or switching and having potential barriers; Capacitors or resistors having potential barriers, e.g. a PN-junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
    • H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
    • H01L29/84—Types of semiconductor device ; Multistep manufacturing processes therefor controllable by variation of applied mechanical force, e.g. of pressure

Definitions

  • the present invention relates to a physical quantity measuring device that measures a physical quantity such as pressure.
  • the physical quantity measuring device refers to, for example, a pressure sensor, a torque sensor, a load sensor, a thrust sensor, etc. mounted on a vehicle or the like, and is configured by mounting a semiconductor element made of silicon or silicon carbide. Used for measurement of brake pressure, various gas pressures, load pressure, etc.
  • Conventional semiconductor sensors are usually mounted on a metal diaphragm with a semiconductor element.
  • a metal diaphragm As the material of this diaphragm, there may be used an Fe—Ni alloy having a thermal expansion coefficient close to that of silicon, but it is required to use a stainless steel diaphragm from the viewpoint of proof stress and corrosion resistance.
  • Patent Document 1 discloses that a stress absorbing material whose main component is an inorganic glass is provided in a ring shape on a bonding member at a position located on the outer peripheral side of a semiconductor element.
  • the physical quantity measuring device is a physical quantity measuring device having a semiconductor element, a base, and a bonding layer connecting the semiconductor element and the base, wherein at least a part of the side surface of the bonding layer is a stress relaxation material. It is characterized by being in contact.
  • the present invention it is possible to sufficiently relax the thermal stress of the physical quantity measuring device, and to provide a highly reliable device in the long term.
  • the present invention is not particularly limited as long as it is a physical quantity detected using a semiconductor element, but a pressure measuring device will be described below as an example of a physical quantity to be detected.
  • FIG. 1 is a cross-sectional view of the pressure measuring device 100.
  • the pressure measuring device 100 is electrically connected to the metal housing 10 in which the pressure port 11, the base 14, and the flange 13 are formed, the semiconductor element 15 that measures the pressure in the pressure port 11, and the semiconductor element 15. Board 16, cover 18, and connector 19 for electrical connection to the outside.
  • the pressure port 11 has a hollow cylindrical pressure introduction part 12ha in which a pressure introduction port 12a is formed on one end side (lower side in the drawing) in the axial direction and the other end side (upper side in the drawing) in the axial direction of the pressure introduction part 12ha. And a formed cylindrical flange 13.
  • a base 14 is erected at the central portion of the flange 13 so as to be deformed and deformed by pressure.
  • the base 14 has a pressure receiving surface that receives the pressure introduced from the pressure introducing port 12a, and a sensor mounting surface on the opposite side of the pressure receiving surface.
  • the tip portion 12hat of the pressure introducing portion 12ha of the pressure port 11 facing the semiconductor element 15 on the base 14 side has a rectangular shape and is a central portion of the flange 13 and is slightly lower than the upper surface of the base 14. This part is continuously drilled. Due to the rectangular shape of the distal end portion 12hat, a distortion difference in the x direction and the y direction occurs in the base 14.
  • the semiconductor element 15 is bonded to a substantially central portion on the sensor mounting surface of the base 14 via a bonding layer described later.
  • the semiconductor element 15 is configured as a semiconductor chip including one or more strain resistance bridges 30a to 30c that output an electrical signal corresponding to deformation (strain) of the base 14 on a silicon chip.
  • the substrate 16 includes an amplifier that amplifies each detection signal output from the semiconductor element 15, an AD converter that converts an analog output signal of the amplifier into a digital signal, and a digital that performs a correction operation described later based on the digital signal.
  • a signal arithmetic processing circuit, a memory storing various data, a capacitor 17 and the like are mounted.
  • a predetermined diameter range from the center of the closing plate 18a that closes the other end of the cover 18 in the axial direction is cut out, and the detected pressure detected by the pressure measuring device 100 is formed by, for example, resin in the cutout portion.
  • a connector 19 for outputting the value to the outside is inserted.
  • One end of the connector 19 is fixed to the cover 18 in the cover 18, and the other end of the connector 19 is exposed from the cover 18 to the outside.
  • the connector 19 has a rod-like terminal 20 inserted by, for example, insert molding.
  • the terminal 20 is composed of, for example, three terminals for power supply, grounding, and signal output. One end of each terminal 20 is connected to the substrate 16 and the other end is connected to an external connector (not shown). It is electrically connected to the ECU of the automobile via a wiring member.
  • FIG. 2 is a circuit diagram of the pressure measuring device 100.
  • a plurality of strain resistance bridges of the semiconductor element 15 and circuit components mounted on the substrate 16 are shown.
  • Each of the strain resistance bridges 30a to 30c is configured by bridge-connecting resistance gauges whose resistance values change by being distorted in accordance with the deformation of the base 14. Power is supplied from the voltage source 35 to the strain resistance bridges 30a to 30c.
  • the output signals (bridge signals corresponding to pressure) of the strain resistance bridges 30a to 30c are amplified by amplifiers (AMP) 31a to 31c, and the amplified output signals are converted from analog to digital (AD) converters (ADC) 32a to 32a. It is converted into a digital signal by 32c.
  • AMP amplifiers
  • AD analog to digital converters
  • the digital signal arithmetic processing circuit (Digital Signal Processor) 33 converts the pressure value detected by, for example, one strain resistance bridge 30a into the other strain resistance bridges 30b and 30c. An arithmetic process for correcting the detected pressure value is performed, and the corrected pressure value is output as a detected value of the pressure measuring device.
  • a non-volatile memory 34 is connected to the digital signal arithmetic processing circuit 33.
  • the digital signal arithmetic processing circuit 33 is not limited to the correction arithmetic processing, but compares the detected pressure values of a plurality of strain resistance bridges with each other, or the preliminarily stored in the nonvolatile memory 34 with the detected pressure values of the strain resistance bridges. Comparison with the pressure value is performed to determine whether the measurement target device is deteriorated or the semiconductor element 15 is deteriorated, and processing such as outputting a failure signal at the time of the determination is also performed.
  • the power supply from the voltage source 35 to the strain resistance bridges 30a to 30c and the output of each signal from the digital signal arithmetic processing circuit 33 are performed via the terminal 20 in FIG.
  • the non-volatile memory 34 may be mounted on a circuit chip different from the circuit components mounted on the substrate 16. Further, instead of the digital signal calculation processing circuit 33, the correction calculation may be performed by an analog circuit. *
  • the base 14 and the semiconductor element 15 are bonded via a bonding layer 21.
  • the entire side surface of the bonding layer 21 is covered with the stress relaxation material 22.
  • the side surface of the bonding layer 21 refers to a surface positioned in a vertical direction from the mounting surface of the base 14 when the semiconductor element 15 is viewed from the base 14.
  • the stress relaxation material 22 in contact with at least a part of the side surface of the bonding layer 21 relaxes the thermal stress generated by the difference in thermal expansion coefficient between the semiconductor element 15 and the base 14, thereby improving the bonding reliability. .
  • the bonding layer 21 does not need to be formed of a single layer, and may be formed of a plurality of layers.
  • a bonding layer 21 a having a role of bonding the semiconductor element 15 at a temperature lower than the heat resistant temperature of the semiconductor element 15, a high Young's modulus, and a high insulation property.
  • the bonding layer 21b can be configured to share the role.
  • the bonding layer 21a may not be insulating.
  • the joining layer constituted by being divided into a plurality of layers may be composed of at least two layers or more and a brittle material.
  • the bonding layer has at least one insulating layer.
  • a bonding layer 21c having a role of bonding to the base 14 may be added. 4 and 5, the thermal stress generated in the bonding layer 21 can be well dispersed, so that the bonding reliability can be further improved.
  • These bonding layers 21 are preferably made of a lead-free material in consideration of the environment.
  • the term “lead-free” as used in this embodiment means that a prohibited substance in the RoHS directive (Restriction of Hazardous Substances: effective July 1, 2006) is contained within a specified value or less.
  • the thickness of the bonding layer 21 is not particularly limited and can be widely used in the range of about 5 to 500 ⁇ m, but is particularly preferably 20 ⁇ m or more and 300 ⁇ m or less from the relationship between reliability and sensor output.
  • FIG. 6 is a top view of the joined body. This is an example in which the joined body of the semiconductor element 15, the joining layer 21, and the base 14 shown in FIGS. 3 to 5 is observed from the upper surface.
  • the entire bonding layer 21 is covered with the stress relaxation material 22 around the bonding layer 21.
  • the entire side surface of the bonding layer 21 is covered with the stress relaxation material 22, but a part of the side surface of the bonding layer 21 may be in contact with the stress relaxation material 22.
  • the entire side surface of the bonding layer 21 is in contact with the stress relaxation material 22, and more desirably, the entire side surface of the bonding layer 21 is covered as shown in FIGS. It is in a state. More desirably, as shown in FIG. 6, the entire bonding layer 21 is covered with the stress relaxation material 22. Since the stress relaxation material 22 covers the bonding layer 21, thermal contraction of the bonding layer 21 is relaxed by a tensile force. Further, at least a part of the side surface of the semiconductor element 15 is in contact with the stress relaxation material 22. Thereby, the thermal stress generated in the semiconductor element 15 can be relaxed.
  • the material of the semiconductor element 15 is not particularly limited, but silicon or silicon carbide which are general materials can be used.
  • a thin film layer can also be formed on the back surface of the semiconductor element 15 in order to improve the adhesive strength with the bonding layer 21 and relieve thermal stress during bonding.
  • the thin film layer preferably contains at least Al, Ni, Ti, Mo, Ag, and SiN. As a result, even if the material of the semiconductor element 15 is changed, the bonding can be performed according to the bonding layer 21.
  • the material of the base 14 is required to have a high yield strength so as to cope with high pressure and repeated stress, and to have a low thermal expansion characteristic in order to reduce the difference in thermal expansion coefficient from the semiconductor element 15. Therefore, for example, SUS630, SUS430, SUS420J2, etc. are adopted in the SUS system. Moreover, cast iron, chromium molybdenum steel, carbon tool steel, etc. can be used in the iron system. In the case of using an iron-based material, a treatment such as plating may be performed to improve the corrosion resistance. The type of plating is not particularly limited, but zinc nickel alloy plating or the like can be applied.
  • the yield strength of the base 14 is preferably 400 MPa (megapascal) or more.
  • the thermal expansion coefficient of the base 14 is preferably 140 ⁇ 10 ⁇ 7 / ° C. or less. In the case of more than this, it becomes difficult to relieve the thermal stress at the bonding layer 21 due to the large difference in thermal expansion coefficient with the semiconductor element 15 and the reliability is lowered.
  • the thermal expansion coefficient in the present embodiment refers to a value measured in a temperature range of room temperature to 250 ° C.
  • the bonding layer 21 is not particularly limited as long as it has insulating properties and low creep characteristics, and a resin material can also be used, but from the viewpoint of low creep characteristics, brittle materials such as glass are included. It is preferable.
  • the reason why insulation is necessary is that noise applied from the base 14 to the semiconductor element 15 during mounting in an automobile or the like can be suppressed, and the reason why low creep characteristics are necessary is to the semiconductor element 15 that measures physical quantities. This is because the physical quantity does not change.
  • the insulating property in the present embodiment refers to a volume resistivity of 10 10 ⁇ cm or more.
  • the thermal expansion coefficient ( ⁇ 21 ) of the bonding layer 21 is preferably not less than the thermal expansion coefficient ( ⁇ 15 ) of the semiconductor element 15 and not more than the thermal expansion coefficient ( ⁇ 14 ) of the base 14 from the viewpoint of thermal stress relaxation. That is, the relationship of ⁇ 14 ⁇ ⁇ 21 ⁇ ⁇ 15 is satisfied. Further, when the bonding layer is a plurality of layers as described above, alpha 21a thermal expansion coefficient of each layer from the top layer in this order, alpha 21b, when the ⁇ 21c ⁇ , ⁇ 14 ⁇ ⁇ ⁇ 21c It is preferable that the relationship of ⁇ ⁇ 21b ⁇ ⁇ 21a ⁇ ⁇ 15 is satisfied.
  • the stress relaxation material 22 is not particularly limited as long as it does not react with the semiconductor element 15, the bonding layer 21, and the base 14, but preferably includes a ductile material such as a resin material. When formed with only a brittle material such as low melting point glass, the stress relaxation material 22 itself may be damaged by the stress generated in the stress relaxation material 22. In that case, since it may cause damage to the bonding layer 21 and the semiconductor element 15, it is desirable to be composed of a ductile material such as a resin material from the viewpoint of reliability. Further, a protective member that protects the circuit on the substrate 16 may be used as the stress relaxation material 22.
  • one containing vanadium is selected as a glass composition that can be bonded at a temperature lower than the heat resistance temperature of the semiconductor element 15.
  • the side surface of the bonding layer 21 is covered with the stress relaxation material 22. Insulation cannot be ensured when covered.
  • the stress relaxation material 22 is required to have insulating properties.
  • the merit of including the resin material is that the resin material can be formed at a temperature lower than the bonding temperature of the bonding layer 21, so that the reaction with the bonding layer 21 can be suppressed. That is, the bonding temperature of the bonding layer is lower than the heat resistance temperature of the semiconductor element. Thereby, a stress relaxation material can be formed on the side surface of the bonding layer 21 and the side surface of the semiconductor element 15 where the thermal stress increases, and the thermal stress generated in the bonding layer 21 and the semiconductor element 15 can be effectively reduced. Can do.
  • the thermal expansion coefficient ( ⁇ 22 ) of the stress relaxation material 22 is desirably equal to or less than the thermal expansion coefficient ( ⁇ 14 ) of the base 14. More desirably, it is not less than the thermal expansion coefficient ( ⁇ 21 ) of the bonding layer 21. That is, it is desirable to satisfy the relationship of ⁇ 14 ⁇ ⁇ 22 . More desirably, ⁇ 14 ⁇ ⁇ 22 ⁇ ⁇ 21 . By setting the thermal expansion coefficient in the above range, it is possible to effectively relieve the thermal stress generated at the time of joining.
  • the stress relaxation material 22 has a Young's modulus of 1.9 GPa or more. More desirably, it is 3.9 GPa or more. When this is satisfied, the thermal stress generated at the time of joining can be effectively relieved.
  • the resin material contained in the stress relaxation material 22 may be either crystalline or amorphous, and may be used in combination of several types instead of one.
  • the resin material include polyethylene, polyvinyl chloride, polypropylene, polystyrene, polyvinyl acetate, ABS resin, AS resin, acrylic resin, polyacetal resin, polyimide, polycarbonate, modified polyphenylene ether (PPE), polybutylene terephthalate (PBT), Polyarylate, polysulfone, polyphenylene sulfide, polyether ether ketone, polyimide resin, fluorine resin, polyamide imide, polyether ether ketone, epoxy resin, phenol resin, polyester, polyvinyl ester, and the like can be used.
  • the rubber resins such as fluoro rubber, silicone rubber, and acrylic rubber can be used.
  • the glass transition temperature is preferably 130 ° C. or higher from the viewpoint of heat resistance. Below this temperature, sensor characteristics may change due to resin degradation depending on the external temperature.
  • a filler material such as ceramics may be included in addition to the resin material in order to adjust the thermal expansion coefficient and Young's modulus.
  • filler materials include wollastonite, potassium titanate, zonotlite, gypsum fiber, aluminum borate, aramid fiber, fibrous magnesium compound, carbon fiber, glass fiber, talc, mica, glass flake, polyoxybegin zoyl whisker, etc. Can be used. A combination of these can also be used.
  • the above resin material and filler material can be used in combination in order to obtain a preferable thermal expansion coefficient and Young's modulus.
  • the stress relieving material 22 may be a common member for joining and sealing other members when forming the physical quantity measuring device. In that case, since the number of steps can be reduced, it is also possible to select a resin material and a filler material from that viewpoint.
  • Example 1-3 Comparative Example 1
  • measured values based on the types of stress relaxation materials and the like will be described using examples.
  • the present invention is not limited to the description of the examples taken up here, and may be combined as appropriate.
  • Examples 1 to 3 shown in FIG. 7A are examples in which the type of the stress relaxation material is changed from the material A to the material C, and the comparative example shows a case where the stress relaxation material is not used.
  • CAE analysis is performed on the thermal stress generated at the bonding surface of the semiconductor element 15 with the bonding layer 21a when a temperature change between 130 ° C. and ⁇ 40 ° C. is applied in the bonding structure shown in FIG. It is.
  • the thermal expansion coefficient ⁇ ( ⁇ ppm / ° C.) was 10
  • the Young's modulus (GPa) was 22.8
  • the maximum principal stress change rate (%) applied to the semiconductor element 15 was 29.
  • Example 2 the thermal expansion coefficient ⁇ ( ⁇ ppm / ° C.) was 41, the Young's modulus (GPa) was 3.9, and the principal stress change rate (%) was 37.
  • Example 3 the thermal expansion coefficient ⁇ ( ⁇ ppm / ° C.) was 89, the Young's modulus (GPa) was 1.9, and the main stress change rate (%) was 92.
  • FIG. 8A is a graph in which the thermal expansion coefficient is plotted on the horizontal axis and the main stress change rate is plotted on the vertical axis for Examples 1 to 3 shown in FIG. 7A.
  • FIG. 8B is a graph in which Young's modulus is plotted on the horizontal axis and principal stress change rate is plotted on the vertical axis for Examples 1 to 3 shown in FIG.
  • FIG. 7B shows the semiconductor element 15, the bonding layer 21a, the bonding layer 21b, the bonding layer 21c, and the base shown in FIG. 5 used in the analysis of Examples 1 to 3 shown in FIG. 14 physical property values are shown.
  • the thermal expansion coefficient ⁇ ( ⁇ ppm / ° C.) is 3.0, 6.0, 7.2, and 11.6 in the order of the semiconductor element 15, the bonding layer 21a, the bonding layer 21b, the bonding layer 21c, and the base 14, respectively. 11.3.
  • the Young's modulus (GPa) is 170, 53, 73, 53, and 205 in the order of the semiconductor element 15, the bonding layer 21a, the bonding layer 21b, the bonding layer 21c, and the base 14.
  • Example 4-6 Comparative Example 2
  • the reliability of the joint structure shown in FIG. 5 is examined by experiment.
  • ⁇ Production of bonding material> In producing the bonding material, a glass plate (D263 made by SCHOTT) was used for the bonding layer 21b. The bonding layers 21a and 21c forming paste were applied on the upper and lower sides of the glass plate using screen printing, dried at 150 ° C. for 30 minutes, and then pre-baked to obtain a bonding material.
  • ⁇ Prototype of joined body> As the materials to be joined, a semiconductor element 15 (160 ⁇ m thick) and a SUS630 base 14 having a Ti and Al metallization treatment on the back surface were used. The bonding layer 21 manufactured as described above was placed between the semiconductor element 15 and the base 14, a load was applied from the upper surface of the semiconductor element 15, and the bonded body was manufactured by heating. At this time, the heating condition was maintained at 400 ° C. for 10 minutes.
  • the stress relaxation material 22 was formed by using the materials A, B, and C described in Examples 1 to 3 and holding the stress relaxation material 22 at 100 to 160 ° C. for 1 to 2 hours.
  • Examples 4 to 6 shown in FIG. 7C are examples in which the type of the stress relaxation material is changed from the material A to the material C, and the comparative example shows a case where the stress relaxation material is not used.
  • the average joint strength was 198, and the Weibull coefficient m was 5.1.
  • the average joint strength was 157, and the Weibull coefficient m was 6.6.
  • the average joint strength was 109 and the Weibull coefficient m was 4.5.
  • the average joint strength is 100 and the Weibull coefficient m is 3.0.
  • the average bonding strength (MPa) is an average of stress when the bonded body breaks. From the above results, it was confirmed that the bonding strength of the bonded body was actually improved by forming the stress relaxation material 22 in the bonded structure shown in FIG. It has also been found that the Weibull coefficient indicating the variation in bonding strength can be improved.
  • Example 7 Comparative Example 3
  • the bonding layer 21a forming paste the same paste as in Example 4-6 was used.
  • the bonding layer 21b was formed using a bonding layer 21b forming paste.
  • the bonding layer 21b was formed by printing the bonding layer 21b forming paste on the base using screen printing, drying at 150 ° C. for 30 minutes, and baking at 850 ° C.
  • Example 4 The bonding layer 21a-forming paste prepared in Example 4-6 was similarly applied to the upper surface of the bonding layer 21b by screen printing, and pre-baked by holding at 400 ° C. for 30 minutes to obtain a bonding layer of about 20 ⁇ m. 21a was formed. Thereafter, the semiconductor element 15 was placed on the upper surface of the bonding layer 21a in the same manner as in Example 4-6, a load was applied, and the bonded body was maintained at 400 ° C. for 10 minutes.
  • the stress relaxation material 22 used in Example 4 was similarly formed on the fabricated joined body. Further, as Comparative Example 3, a material in which the stress relaxation material 22 was not formed was also produced.
  • Example 4-6 A four-point bending test was performed on the fabricated joined body in the same manner as in Example 4-6. As a result, it was found that the joint strength could be improved and the variation could be reduced as in Example 4-6. From the above results, it has been found that the present invention has an effect of relieving thermal stress generated during bonding regardless of the structure of the bonding layer 21.
  • Example 8-10 Comparative Example 4
  • the joining structure was the same as in Example 4.
  • the form of the stress relaxation material 22 as shown in FIG. 7D, in Example 8, a part of the side surface of the bonding layer was coated, and in Example 9, the whole side surface of the bonding layer was coated.
  • Example 10 the entire bonding layer and the entire side surface of the semiconductor element (corresponding to FIG. 6) were produced.
  • Comparative Example 4 a material in which the stress relaxation material 22 was not formed was also produced.
  • the pressure range of 0 to 20 MPa was set to 0.5 to 4.5 V in full scale (FS) for the manufactured pressure sensor, and the following reliability test was performed.
  • the thermal shock shown in FIG. 7D is a reliability test of 2000 cycles of a thermal shock test at 130 ° C. to ⁇ 40 ° C.
  • the -40 ° C. standing shown in FIG. 7D is an evaluation of the drift characteristics of the sensor output value by conducting a 2000 hour standing test at -40 ° C.
  • the 130 ° C. standing condition shown in FIG. 7D is an evaluation of the drift characteristic of the sensor output value by conducting a standing test at 130 ° C. for 2000 hours.
  • the evaluation result shows that the change in the output value at 20 ° C. before and after the test is 2% F.S. S.
  • Example 10 showed the most excellent reliability, and Example 9 and Example 8 also showed good reliability.
  • the long-term reliability was improved by forming the stress relaxation material 22.
  • the stress relaxation material can relieve the stress of the entire joint structure, so that a larger covering area is desirable.
  • the side surfaces of the semiconductor element are also in good contact with each other.
  • the physical quantity measuring apparatus 100 includes a semiconductor element 15, a base 14, and a bonding layer 21 that connects the semiconductor element 15 and the base 14, and at least a part of the side surface of the bonding layer 21 is stressed. It is in contact with the moderating material 22. Thereby, the thermal stress of the physical quantity measuring apparatus 100 can be sufficiently relaxed, and a highly reliable apparatus can be provided in the long term.
  • the present invention is not limited to the above-described embodiment, and other forms conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention as long as the characteristics of the present invention are not impaired. . Moreover, it is good also as a structure which combined the above-mentioned embodiment.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Ceramic Engineering (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Computer Hardware Design (AREA)
  • Measuring Fluid Pressure (AREA)
  • Pressure Sensors (AREA)

Abstract

Since it is not possible to form a stress absorption material to form at a bonding layer site around the lower part of a semiconductor element and the ends (side surfaces) of a bonding layer, thermal stress is not fully absorbed, posing a problem with bonding site reliability. This physical quantity measuring device is provided with a semiconductor element, a base, and a bonding layer that connects the semiconductor element and the base, wherein the side surfaces of the bonding layer at least partially contact a stress relaxation material.

Description

物理量測定装置Physical quantity measuring device
　本発明は、たとえば圧力等の物理量を測定する物理量測定装置に関する。 The present invention relates to a physical quantity measuring device that measures a physical quantity such as pressure.
　物理量測定装置とは、例えば車両などに搭載される圧力センサ、トルクセンサ、荷重センサ、推力センサなどを指し、シリコンや炭化ケイ素からなる半導体素子を実装されることで構成され、エンジンの燃料圧、ブレーキ圧、各種ガス圧、荷重圧等の測定に用いられる。 The physical quantity measuring device refers to, for example, a pressure sensor, a torque sensor, a load sensor, a thrust sensor, etc. mounted on a vehicle or the like, and is configured by mounting a semiconductor element made of silicon or silicon carbide. Used for measurement of brake pressure, various gas pressures, load pressure, etc.
　従来の圧力センサは、通常、金属のダイアフラムに半導体素子が実装される。このダイアフラムの材質としては、シリコンに近い熱膨張係数を有するＦｅ－Ｎｉ系合金などが使用される場合もあるが、耐力や腐食性などの観点からステンレス系のダイアフラムを使用することが求められる。 Conventional semiconductor sensors are usually mounted on a metal diaphragm with a semiconductor element. As the material of this diaphragm, there may be used an Fe—Ni alloy having a thermal expansion coefficient close to that of silicon, but it is required to use a stainless steel diaphragm from the viewpoint of proof stress and corrosion resistance.
　また、半導体素子とダイアフラムの接合に関しては、ガラスなどの脆性材を用いて、もしくは直接接合されることが望ましい。これは、一般的な樹脂やはんだ等で接合する場合には、接合層のクリープが問題となり半導体素子上で測定する物理量が変化してしまうためである。しかしながら、ステンレスと半導体素子とは、熱膨張係数が大きく異なるため、加熱して接合後の冷却工程で接合層に大きな熱応力が発生する。この熱応力によって接合層や半導体素子の破損が発生するため、接合時にかかる熱応力をいかに緩和して接合するかが問題となっている。
　上記の問題を解決するため、例えば特許文献１では、接合部材上で、半導体素子の外周側に位置する部位に主成分が無機ガラスの応力吸収材を環状に設けることが開示されている。 In addition, it is desirable that the semiconductor element and the diaphragm are bonded using a brittle material such as glass or directly. This is because, when bonding with a general resin or solder, the creep of the bonding layer becomes a problem, and the physical quantity measured on the semiconductor element changes. However, since the thermal expansion coefficient differs significantly between stainless steel and semiconductor elements, a large thermal stress is generated in the bonding layer in the cooling step after heating and bonding. Since the thermal stress causes damage to the bonding layer and the semiconductor element, there is a problem of how to relax the thermal stress applied at the time of bonding.
In order to solve the above problem, for example, Patent Document 1 discloses that a stress absorbing material whose main component is an inorganic glass is provided in a ring shape on a bonding member at a position located on the outer peripheral side of a semiconductor element.
特開２０１３－２３４９５５公報JP 2013-234955 A
　しかしながら、特許文献１の方法では、環状に設けた応力吸収材の内周部位の下部に位置する接合層に信頼性を低下させる引張応力が発生してしまう。また、半導体素子とダイアフラムの接合において、最も熱応力の大きくなる部位は半導体素子の下部周辺の接合層部位と接合層の端部（側面）であるが、この部位には応力吸収材を形成できず熱応力を吸収しきれないため、接合部位の信頼性に課題があった。 However, in the method of Patent Document 1, a tensile stress that reduces reliability is generated in the bonding layer located below the inner peripheral portion of the annular stress absorbing material. In the bonding of the semiconductor element and the diaphragm, the portion where the thermal stress is greatest is the bonding layer portion around the lower portion of the semiconductor element and the end portion (side surface) of the bonding layer, but a stress absorbing material can be formed in this portion. Since the thermal stress could not be absorbed, there was a problem in the reliability of the joint part.
　本発明に係る物理量測定装置は、半導体素子と、基台と、半導体素子と基台とを接続する接合層と、を有する物理量測定装置において、少なくとも前記接合層側面の一部が応力緩和材と接触していることを特徴とする。 The physical quantity measuring device according to the present invention is a physical quantity measuring device having a semiconductor element, a base, and a bonding layer connecting the semiconductor element and the base, wherein at least a part of the side surface of the bonding layer is a stress relaxation material. It is characterized by being in contact.
　本発明によれば、物理量測定装置の熱応力を十分に緩和することができ、長期的に信頼性の高い装置を提供することができる。 According to the present invention, it is possible to sufficiently relax the thermal stress of the physical quantity measuring device, and to provide a highly reliable device in the long term.
圧力測定装置の断面図である。It is sectional drawing of a pressure measuring device. 圧力測定装置の回路図である。It is a circuit diagram of a pressure measuring device. 接合体の断面図である。It is sectional drawing of a conjugate | zygote. 接合体の断面図である。It is sectional drawing of a conjugate | zygote. 接合体の断面図である。It is sectional drawing of a conjugate | zygote. 接合体の上面図である。It is a top view of a joined body. 応力緩和材の種類等に基づく解析値及び測定値を示す図である。It is a figure which shows the analytical value and measured value based on the kind etc. of stress relaxation material. 応力緩和材の種類等に基づく解析値を示すグラフである。It is a graph which shows the analysis value based on the kind etc. of stress relaxation material.
　以下、本発明の実施形態について図１から図８を用いて詳細に説明する。本発明は、半導体素子を使用して検出する物理量であれば特に制限されるものではないが、以下では検出する物理量の一例として、圧力測定装置について述べる。 Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. The present invention is not particularly limited as long as it is a physical quantity detected using a semiconductor element, but a pressure measuring device will be described below as an example of a physical quantity to be detected.
　（圧力測定装置）
　図１は、圧力測定装置１００の断面図である。
　圧力測定装置１００は、圧力ポート１１と基台１４とフランジ１３とが形成される金属筐体１０と、圧力ポート１１内の圧力を測定する半導体素子１５と、半導体素子１５と電気的に接続される基板１６と、カバー１８と、外部と電気的に接続するためのコネクタ１９とを備える。 (Pressure measuring device)
FIG. 1 is a cross-sectional view of the pressure measuring device 100.
The pressure measuring device 100 is electrically connected to the metal housing 10 in which the pressure port 11, the base 14, and the flange 13 are formed, the semiconductor element 15 that measures the pressure in the pressure port 11, and the semiconductor element 15. Board 16, cover 18, and connector 19 for electrical connection to the outside.
　圧力ポート１１は、軸方向の一端側（図面下側）に圧力導入口１２ａが形成された中空筒状の圧力導入部１２ｈａと、圧力導入部１２ｈａの軸方向の他端側（図面上側）に形成された円筒状のフランジ１３とを備えている。フランジ１３の中央部位には、圧力によって変形し歪を生じる基台１４が立設されている。 The pressure port 11 has a hollow cylindrical pressure introduction part 12ha in which a pressure introduction port 12a is formed on one end side (lower side in the drawing) in the axial direction and the other end side (upper side in the drawing) in the axial direction of the pressure introduction part 12ha. And a formed cylindrical flange 13. A base 14 is erected at the central portion of the flange 13 so as to be deformed and deformed by pressure.
　基台１４は、圧力導入口１２ａから導入された圧力を受ける受圧面と、受圧面とは反対の面にセンサ搭載面とを有する。 The base 14 has a pressure receiving surface that receives the pressure introduced from the pressure introducing port 12a, and a sensor mounting surface on the opposite side of the pressure receiving surface.
　圧力ポート１１の圧力導入部１２ｈａの、基台１４側の半導体素子１５に対向する先端部１２ｈａｔは矩形形状になっており、フランジ１３の中央部であって基台１４の上部表面より若干低い高さの部位まで連続して穿設されている。この先端部１２ｈａｔの矩形形状によって、基台１４にはｘ方向－ｙ方向の歪差が生じる。 The tip portion 12hat of the pressure introducing portion 12ha of the pressure port 11 facing the semiconductor element 15 on the base 14 side has a rectangular shape and is a central portion of the flange 13 and is slightly lower than the upper surface of the base 14. This part is continuously drilled. Due to the rectangular shape of the distal end portion 12hat, a distortion difference in the x direction and the y direction occurs in the base 14.
　半導体素子１５は、基台１４のセンサ搭載面上のほぼ中央部に後述する接合層を介して接合されている。半導体素子１５は、シリコンチップ上に基台１４の変形（歪）に応じた電気信号を出力する１つ以上の歪抵抗ブリッジ３０ａ～３０ｃを備える半導体チップとして構成される。 The semiconductor element 15 is bonded to a substantially central portion on the sensor mounting surface of the base 14 via a bonding layer described later. The semiconductor element 15 is configured as a semiconductor chip including one or more strain resistance bridges 30a to 30c that output an electrical signal corresponding to deformation (strain) of the base 14 on a silicon chip.
　基板１６は、半導体素子１５から出力された各検出信号を増幅するアンプ、そのアンプのアナログ出力信号をデジタル信号に変換するＡ－Ｄ変換器、そのデジタル信号に基づいて後述する補正演算を行うデジタル信号演算処理回路、各種データが格納されたメモリおよびコンデンサ１７等が搭載されている。 The substrate 16 includes an amplifier that amplifies each detection signal output from the semiconductor element 15, an AD converter that converts an analog output signal of the amplifier into a digital signal, and a digital that performs a correction operation described later based on the digital signal. A signal arithmetic processing circuit, a memory storing various data, a capacitor 17 and the like are mounted.
　カバー１８の軸方向他端を閉塞する閉塞板１８ａの、中央よりの所定径範囲は切り欠かれており、その切欠部には例えば樹脂等により形成され、圧力測定装置１００で検出された検出圧力値を外部に出力するためのコネクタ１９が挿入されている。 A predetermined diameter range from the center of the closing plate 18a that closes the other end of the cover 18 in the axial direction is cut out, and the detected pressure detected by the pressure measuring device 100 is formed by, for example, resin in the cutout portion. A connector 19 for outputting the value to the outside is inserted.
　コネクタ１９の一端はカバー１８内においてカバー１８に固定され、コネクタ１９の他端はカバー１８から外部へ露出している。 One end of the connector 19 is fixed to the cover 18 in the cover 18, and the other end of the connector 19 is exposed from the cover 18 to the outside.
　このコネクタ１９の内部には、例えばインサート成型により挿入された棒状のターミナル２０を有している。このターミナル２０は、例えば電源用、接地用、信号出力用の３本で構成され、各ターミナル２０の一端は基板１６に接続されており、他端が図示省略の外部コネクタに接続されることによって、自動車のＥＣＵ等へ配線部材を介して電気的に接続される。 The connector 19 has a rod-like terminal 20 inserted by, for example, insert molding. The terminal 20 is composed of, for example, three terminals for power supply, grounding, and signal output. One end of each terminal 20 is connected to the substrate 16 and the other end is connected to an external connector (not shown). It is electrically connected to the ECU of the automobile via a wiring member.
　図２は、圧力測定装置１００の回路図である。半導体素子１５の複数の歪抵抗ブリッジと基板１６に搭載された各回路部品を示す。
　歪抵抗ブリッジ３０ａ～３０ｃは、それぞれ基台１４の変形に応じて歪むことで抵抗値が変化する抵抗ゲージをブリッジ接続して構成されている。歪抵抗ブリッジ３０ａ～３０ｃには電圧源３５から電力が供給される。 FIG. 2 is a circuit diagram of the pressure measuring device 100. A plurality of strain resistance bridges of the semiconductor element 15 and circuit components mounted on the substrate 16 are shown.
Each of the strain resistance bridges 30a to 30c is configured by bridge-connecting resistance gauges whose resistance values change by being distorted in accordance with the deformation of the base 14. Power is supplied from the voltage source 35 to the strain resistance bridges 30a to 30c.
　歪抵抗ブリッジ３０ａ～３０ｃの出力信号（圧力に相当するブリッジ信号）は、アンプ（ＡＭＰ）３１ａ～３１ｃによって増幅され、その増幅出力信号はＡ－Ｄ（アナログ－デジタル）変換器（ＡＤＣ）３２ａ～３２ｃによってデジタル信号に変換される。 The output signals (bridge signals corresponding to pressure) of the strain resistance bridges 30a to 30c are amplified by amplifiers (AMP) 31a to 31c, and the amplified output signals are converted from analog to digital (AD) converters (ADC) 32a to 32a. It is converted into a digital signal by 32c.
　デジタル信号演算処理回路（Digital Signal Processor）３３は、Ａ－Ｄ変換器３２ａ～３２ｃの出力信号に基づいて、例えば１つの歪抵抗ブリッジ３０ａで検出された圧力値をその他の歪抵抗ブリッジ３０ｂ、３０ｃの検出圧力値によって補正する演算処理を行って、その補正した圧力値を圧力測定装置の検出値として出力する。デジタル信号演算処理回路３３には、不揮発性メモリ３４が接続されている。 Based on the output signals of the AD converters 32a to 32c, the digital signal arithmetic processing circuit (Digital Signal Processor) 33 converts the pressure value detected by, for example, one strain resistance bridge 30a into the other strain resistance bridges 30b and 30c. An arithmetic process for correcting the detected pressure value is performed, and the corrected pressure value is output as a detected value of the pressure measuring device. A non-volatile memory 34 is connected to the digital signal arithmetic processing circuit 33.
　このデジタル信号演算処理回路３３は、補正演算処理に限らず、複数の歪抵抗ブリッジの検出圧力値同士の比較や、歪抵抗ブリッジの検出圧力値と予め不揮発性メモリ３４に記憶しておいた規定圧力値との比較を行って、測定対象機器の劣化や半導体素子１５の劣化を判定し、その判定時に故障信号を出力する等の処理も行う。 The digital signal arithmetic processing circuit 33 is not limited to the correction arithmetic processing, but compares the detected pressure values of a plurality of strain resistance bridges with each other, or the preliminarily stored in the nonvolatile memory 34 with the detected pressure values of the strain resistance bridges. Comparison with the pressure value is performed to determine whether the measurement target device is deteriorated or the semiconductor element 15 is deteriorated, and processing such as outputting a failure signal at the time of the determination is also performed.
　尚、電圧源３５から歪抵抗ブリッジ３０ａ～３０ｃへの電力の供給およびデジタル信号演算処理回路３３からの各信号の出力は、図１のターミナル２０を介して行われる。 The power supply from the voltage source 35 to the strain resistance bridges 30a to 30c and the output of each signal from the digital signal arithmetic processing circuit 33 are performed via the terminal 20 in FIG.
　不揮発性メモリ３４は、基板１６に搭載された回路部品とは異なる回路チップに搭載されていてもよい。また、デジタル信号演算処理回路３３の代わりに補正演算をアナログ回路で行うように構成してもよい。　 The non-volatile memory 34 may be mounted on a circuit chip different from the circuit components mounted on the substrate 16. Further, instead of the digital signal calculation processing circuit 33, the correction calculation may be performed by an analog circuit. *
（半導体素子と基台との接合部）
　図３～図５は、半導体素子１５と、接合層２１と、基台１４との接合体の断面を示す一例である。 (Junction between semiconductor element and base)
3 to 5 are examples showing a cross section of a joined body of the semiconductor element 15, the bonding layer 21, and the base 14.
　図３に示すように、基台１４と半導体素子１５とは、接合層２１を介して接合されている。この例では、接合層２１の側面全体が応力緩和材２２で被覆されている。なお、接合層２１の少なくとも側面の一部が応力緩和材２２と接触する構成であってもよい。ここで接合層２１の側面とは、基台１４から半導体素子１５を見た場合に基台１４の実装面から垂直方向に位置する面のことを指す。接合層２１の少なくとも側面の一部と接触する応力緩和材２２が、半導体素子１５と基台１４の熱膨張係数差によって発生する熱応力を緩和することで、接合の信頼性を向上させている。 As shown in FIG. 3, the base 14 and the semiconductor element 15 are bonded via a bonding layer 21. In this example, the entire side surface of the bonding layer 21 is covered with the stress relaxation material 22. Note that at least part of the side surface of the bonding layer 21 may be in contact with the stress relaxation material 22. Here, the side surface of the bonding layer 21 refers to a surface positioned in a vertical direction from the mounting surface of the base 14 when the semiconductor element 15 is viewed from the base 14. The stress relaxation material 22 in contact with at least a part of the side surface of the bonding layer 21 relaxes the thermal stress generated by the difference in thermal expansion coefficient between the semiconductor element 15 and the base 14, thereby improving the bonding reliability. .
　接合層２１は図４、図５に示すように一層で構成する必要はなく、複数層に分けて構成することも可能である。複数層に分けて構成する場合には、例えば、図４に示すように半導体素子１５の耐熱温度以下で半導体素子１５を接合する役割を有する接合層２１aと、高ヤング率、且つ高絶縁性を有する接合層２１ｂというように役割を分担して構成することができる。この場合、接合層２１aは絶縁性でなくても良い。複数層に分けて構成される接合層は、少なくとも２層以上であり、かつ脆性材料で構成されもよい。接合層は、少なくとも１層以上の絶縁層を有する。 As shown in FIGS. 4 and 5, the bonding layer 21 does not need to be formed of a single layer, and may be formed of a plurality of layers. In the case of being divided into a plurality of layers, for example, as shown in FIG. 4, a bonding layer 21 a having a role of bonding the semiconductor element 15 at a temperature lower than the heat resistant temperature of the semiconductor element 15, a high Young's modulus, and a high insulation property. The bonding layer 21b can be configured to share the role. In this case, the bonding layer 21a may not be insulating. The joining layer constituted by being divided into a plurality of layers may be composed of at least two layers or more and a brittle material. The bonding layer has at least one insulating layer.
　また、図５に示すように、さらに接合層２１a、接合層２１ｂに加えて、基台１４と接合する役割を有する接合層２１ｃを加えて構成することもできる。図４、図５のように複数層で構成することによって、接合層２１に発生する熱応力をうまく分散できるため、接合の信頼性をさらに向上させることができる。これら接合層２１は、環境への配慮から無鉛の材料で構成されることが望ましい。本実施形態でいう無鉛とは、ＲｏＨＳ指令（Ｒｅｓｔｒｉｃｔｉｏｎ ｏｆ Ｈａｚａｒｄｏｕｓ Ｓｕｂｓｔａｎｃｅｓ：２００６年７月１日施行）における禁止物質を指定値以下の範囲で含有することを容認するものとする。接合層２１の厚みは、特に規定されるものではなく、５～５００μｍ程度まで幅広く使用できるが、信頼性とセンサとしての出力の関係から特に好ましいのは２０μｍ以上３００μｍ以下である。 Further, as shown in FIG. 5, in addition to the bonding layer 21a and the bonding layer 21b, a bonding layer 21c having a role of bonding to the base 14 may be added. 4 and 5, the thermal stress generated in the bonding layer 21 can be well dispersed, so that the bonding reliability can be further improved. These bonding layers 21 are preferably made of a lead-free material in consideration of the environment. The term “lead-free” as used in this embodiment means that a prohibited substance in the RoHS directive (Restriction of Hazardous Substances: effective July 1, 2006) is contained within a specified value or less. The thickness of the bonding layer 21 is not particularly limited and can be widely used in the range of about 5 to 500 μm, but is particularly preferably 20 μm or more and 300 μm or less from the relationship between reliability and sensor output.
　また、図６は接合体の上面図である。図３～図５に示した、半導体素子１５と、接合層２１と、基台１４との接合体を上面から観察した場合の一例である。この例では、接合層２１の周囲であって、接合層２１全体が応力緩和材２２で被覆されている。図６では、接合層２１の側面全体が応力緩和材２２で被覆されているが、接合層２１の側面の一部が応力緩和材２２と接触するようにしてもよい。 FIG. 6 is a top view of the joined body. This is an example in which the joined body of the semiconductor element 15, the joining layer 21, and the base 14 shown in FIGS. 3 to 5 is observed from the upper surface. In this example, the entire bonding layer 21 is covered with the stress relaxation material 22 around the bonding layer 21. In FIG. 6, the entire side surface of the bonding layer 21 is covered with the stress relaxation material 22, but a part of the side surface of the bonding layer 21 may be in contact with the stress relaxation material 22.
　このように、接合層２１の少なくとも側面の一部が応力緩和材２２と接触する構成であり、より望ましくは、図３～図５に示したように、接合層２１の側面全体が被覆されている状態である。さらに望ましくは、図６に示したように、接合層２１全体が応力緩和材２２で被覆されている状態である。応力緩和材２２が接合層２１を覆うことで、接合層２１の熱収縮を、引っ張り力で緩和する。また、半導体素子１５の少なくとも側面の一部が応力緩和材２２と接触している。これにより、半導体素子１５に発生する熱応力を緩和することができる。 As described above, at least a part of the side surface of the bonding layer 21 is in contact with the stress relaxation material 22, and more desirably, the entire side surface of the bonding layer 21 is covered as shown in FIGS. It is in a state. More desirably, as shown in FIG. 6, the entire bonding layer 21 is covered with the stress relaxation material 22. Since the stress relaxation material 22 covers the bonding layer 21, thermal contraction of the bonding layer 21 is relaxed by a tensile force. Further, at least a part of the side surface of the semiconductor element 15 is in contact with the stress relaxation material 22. Thereby, the thermal stress generated in the semiconductor element 15 can be relaxed.
　半導体素子１５の材料としては、特に限定されるところではないが、一般的な材料であるシリコンや炭化ケイ素を用いることができる。この際、半導体素子１５の裏面には、接合層２１との接着強度向上や接合時の熱応力を緩和するために薄膜層を成膜することもできる。薄膜層としては、少なくともＡｌ、Ｎｉ、Ｔｉ、Ｍｏ、Ａｇ、ＳｉＮが含まれることが望ましい。これによって、半導体素子１５の材質が変わっても接合層２１に合わせて接合することが可能となる。 The material of the semiconductor element 15 is not particularly limited, but silicon or silicon carbide which are general materials can be used. At this time, a thin film layer can also be formed on the back surface of the semiconductor element 15 in order to improve the adhesive strength with the bonding layer 21 and relieve thermal stress during bonding. The thin film layer preferably contains at least Al, Ni, Ti, Mo, Ag, and SiN. As a result, even if the material of the semiconductor element 15 is changed, the bonding can be performed according to the bonding layer 21.
　基台１４の材質には、高圧や繰り返し応力にも対応できるように高耐力であること、さらに半導体素子１５との熱膨張係数差を小さくするために低熱膨張特性であることが求められる。そのため、例えば、ＳＵＳ系ではＳＵＳ６３０やＳＵＳ４３０、ＳＵＳ４２０Ｊ２などが採用される。また、鉄系では鋳鉄、クロムモリブデン鋼、炭素工具鋼などを用いることができる。鉄系の材料を用いる場合には、耐食性を向上させるためにメッキなどの処理を施しても良い。メッキの種類としては特に限定されるところではないが、亜鉛ニッケル合金メッキなどが適用できる。基台１４の耐力としては、４００ＭＰa（メガパスカル）以上あることが好ましい。これ以下の場合には、基台１４に繰り返しの応力が発生することによって基台１４の信頼性が低下する。また、基台１４の熱膨張係数としては、１４０×１０－７／℃以下であることが好ましい。これ以上の場合には、半導体素子１５との熱膨張係数差が大きくなることによって接合層２１で熱応力を緩和するのが難しくなり、信頼性が低下する。ここで、本実施形態における熱膨張係数とは、室温～２５０℃の温度範囲での測定した値のことを指す。 The material of the base 14 is required to have a high yield strength so as to cope with high pressure and repeated stress, and to have a low thermal expansion characteristic in order to reduce the difference in thermal expansion coefficient from the semiconductor element 15. Therefore, for example, SUS630, SUS430, SUS420J2, etc. are adopted in the SUS system. Moreover, cast iron, chromium molybdenum steel, carbon tool steel, etc. can be used in the iron system. In the case of using an iron-based material, a treatment such as plating may be performed to improve the corrosion resistance. The type of plating is not particularly limited, but zinc nickel alloy plating or the like can be applied. The yield strength of the base 14 is preferably 400 MPa (megapascal) or more. In the case of less than this, the reliability of the base 14 is lowered due to repeated stress generated in the base 14. Further, the thermal expansion coefficient of the base 14 is preferably 140 × 10 −7 / ° C. or less. In the case of more than this, it becomes difficult to relieve the thermal stress at the bonding layer 21 due to the large difference in thermal expansion coefficient with the semiconductor element 15 and the reliability is lowered. Here, the thermal expansion coefficient in the present embodiment refers to a value measured in a temperature range of room temperature to 250 ° C.
　接合層２１は、絶縁性、且つ低クリープ特性を有するものであれば特に限定されるところではなく、樹脂材料も用いることができるが、低クリープ特性の観点からはガラスなどの脆性材が含まれることが好ましい。絶縁性が必要な理由は、自動車等へ実装時に基台１４から半導体素子１５へかかるノイズを抑制することができるためであり、低クリープ特性が必要な理由は、物理量を測定する半導体素子１５へかかる物理量が変化しないためである。ここで、本実施形態における絶縁性とは、体積抵抗率で１０１０Ωｃｍ以上のことを指す。 The bonding layer 21 is not particularly limited as long as it has insulating properties and low creep characteristics, and a resin material can also be used, but from the viewpoint of low creep characteristics, brittle materials such as glass are included. It is preferable. The reason why insulation is necessary is that noise applied from the base 14 to the semiconductor element 15 during mounting in an automobile or the like can be suppressed, and the reason why low creep characteristics are necessary is to the semiconductor element 15 that measures physical quantities. This is because the physical quantity does not change. Here, the insulating property in the present embodiment refers to a volume resistivity of 10 10 Ωcm or more.
　接合層２１の熱膨張係数（α２１）は、熱応力緩和の観点から半導体素子１５の熱膨張係数（α１５）以上、基台１４の熱膨張係数（α１４）以下であることが望ましい。すなわち、α１４≧α２１≧α１５の関係性を満たす。また、接合層が上記のように複数層になる場合には、各層の熱膨張係数を層の上から順にα２１ａ、α２１ｂ、α２１ｃ・・・とすると、α１４≧・・・α２１ｃ≧α２１ｂ≧α２１ａ≧α１５の関係を満たすことが好ましい。 The thermal expansion coefficient (α 21 ) of the bonding layer 21 is preferably not less than the thermal expansion coefficient (α 15 ) of the semiconductor element 15 and not more than the thermal expansion coefficient (α 14 ) of the base 14 from the viewpoint of thermal stress relaxation. That is, the relationship of α 14 ≧ α 21 ≧ α 15 is satisfied. Further, when the bonding layer is a plurality of layers as described above, alpha 21a thermal expansion coefficient of each layer from the top layer in this order, alpha 21b, when the α 21c ···, α 14 ≧ ··· α 21c It is preferable that the relationship of ≧ α 21b ≧ α 21a ≧ α 15 is satisfied.
　応力緩和材２２は、半導体素子１５や接合層２１、基台１４と反応しないものであれば特に限定されるところではないが、樹脂材料のような延性材料を含むことが望ましい。低融点ガラスのような脆性材料のみで形成した場合には、応力緩和材２２に発生する応力によって応力緩和材２２そのものが破損する場合がある。その場合、それが接合層２１や半導体素子１５にも破損をもたらす場合があるため、信頼性の観点から樹脂材料のような延性材料を含むもので構成されることが望ましい。また、応力緩和材２２として、基板１６上の回路を保護する保護部材を援用してもよい。 The stress relaxation material 22 is not particularly limited as long as it does not react with the semiconductor element 15, the bonding layer 21, and the base 14, but preferably includes a ductile material such as a resin material. When formed with only a brittle material such as low melting point glass, the stress relaxation material 22 itself may be damaged by the stress generated in the stress relaxation material 22. In that case, since it may cause damage to the bonding layer 21 and the semiconductor element 15, it is desirable to be composed of a ductile material such as a resin material from the viewpoint of reliability. Further, a protective member that protects the circuit on the substrate 16 may be used as the stress relaxation material 22.
　また、無鉛の低融点ガラスの場合には、半導体素子１５の耐熱温度以下で接合できるガラス組成としてバナジウムを含むものが選択されるが、この場合には接合層２１の側面を応力緩和材２２で被覆した場合に絶縁性を担保できなくなる。同様の観点から、応力緩和材２２は絶縁性を有することが求められる。また、樹脂材料を含むことのメリットは、樹脂材料を含むことで接合層２１の接合温度よりも低温で形成できるため、接合層２１との反応を抑えることができるためである。すなわち、接合層の接合温度は半導体素子の耐熱温度以下である。これにより、熱応力の大きくなる接合層２１の側面や半導体素子１５の側面にも応力緩和材を形成することができ、効果的に接合層２１や半導体素子１５に発生する熱応力を緩和することができる。 In the case of lead-free low-melting glass, one containing vanadium is selected as a glass composition that can be bonded at a temperature lower than the heat resistance temperature of the semiconductor element 15. In this case, the side surface of the bonding layer 21 is covered with the stress relaxation material 22. Insulation cannot be ensured when covered. From the same viewpoint, the stress relaxation material 22 is required to have insulating properties. In addition, the merit of including the resin material is that the resin material can be formed at a temperature lower than the bonding temperature of the bonding layer 21, so that the reaction with the bonding layer 21 can be suppressed. That is, the bonding temperature of the bonding layer is lower than the heat resistance temperature of the semiconductor element. Thereby, a stress relaxation material can be formed on the side surface of the bonding layer 21 and the side surface of the semiconductor element 15 where the thermal stress increases, and the thermal stress generated in the bonding layer 21 and the semiconductor element 15 can be effectively reduced. Can do.
　応力緩和材２２の熱膨張係数（α２２）は、基台１４の熱膨張係数（α１４）以下であることが望ましい。より望ましくは、接合層２１の熱膨張係数（α２１）以上である。すなわち、α１４≧α２２の関係性を満たすことが望ましい。より望ましくは、α１４≧α２２≧α２１である。熱膨張係数を上記範囲にすることで、接合時に発生する熱応力を効果的に緩和することができる。 The thermal expansion coefficient (α 22 ) of the stress relaxation material 22 is desirably equal to or less than the thermal expansion coefficient (α 14 ) of the base 14. More desirably, it is not less than the thermal expansion coefficient (α 21 ) of the bonding layer 21. That is, it is desirable to satisfy the relationship of α 14 ≧ α 22 . More desirably, α 14 ≧ α 22 ≧ α 21 . By setting the thermal expansion coefficient in the above range, it is possible to effectively relieve the thermal stress generated at the time of joining.
　応力緩和材２２のヤング率は、１．９ＧＰａ以上であることが望ましい。より望ましくは、３．９ＧＰａ以上である。これを満たすとき、接合時に発生する熱応力を効果的に緩和することができる。 It is desirable that the stress relaxation material 22 has a Young's modulus of 1.9 GPa or more. More desirably, it is 3.9 GPa or more. When this is satisfied, the thermal stress generated at the time of joining can be effectively relieved.
　応力緩和材２２に含まれる樹脂材料は、結晶質あるいは非晶質どちらでも良く、また１種類でなく数種類組み合わせて使用することも可能である。樹脂材料としては、例えばポリエチレン、ポリ塩化ビニル、ポリプロピレン、ポリスチレン、ポリ酢酸ビニル、ＡＢＳ樹脂、ＡＳ樹脂、アクリル樹脂、ポリアセタール樹脂、ポリイミド、ポリカーボネート、変性ポリフェニレンエーテル（ＰＰＥ）、ポリブチレンテレフタレート（ＰＢＴ）、ポリアリレート、ポリサルホン、ポリフェニレンスルフィド、ポリエーテルエーテルケトン、ポリイミド樹脂、フッ素樹脂、ポリアミドイミド、ポリエーテルエーテルケトン、エポキシ樹脂、フェノール樹脂、ポリエステル、ポリビニルエステル等が使用できる。また、ゴムとしては、フッ素ゴム、シリコーンゴム、アクリルゴム等の樹脂が使用できる。ただし、耐熱性の観点からガラス転移温度が１３０℃以上であることが好ましい。これ以下の温度では、外部温度によって樹脂劣化によるセンサ特性変化の可能性がある。 The resin material contained in the stress relaxation material 22 may be either crystalline or amorphous, and may be used in combination of several types instead of one. Examples of the resin material include polyethylene, polyvinyl chloride, polypropylene, polystyrene, polyvinyl acetate, ABS resin, AS resin, acrylic resin, polyacetal resin, polyimide, polycarbonate, modified polyphenylene ether (PPE), polybutylene terephthalate (PBT), Polyarylate, polysulfone, polyphenylene sulfide, polyether ether ketone, polyimide resin, fluorine resin, polyamide imide, polyether ether ketone, epoxy resin, phenol resin, polyester, polyvinyl ester, and the like can be used. Further, as the rubber, resins such as fluoro rubber, silicone rubber, and acrylic rubber can be used. However, the glass transition temperature is preferably 130 ° C. or higher from the viewpoint of heat resistance. Below this temperature, sensor characteristics may change due to resin degradation depending on the external temperature.
　応力緩和材２２に含まれる部材としては、樹脂材料の他に熱膨張係数やヤング率を調整するためにセラミックスなどのフィラ材が含まれていても良い。フィラ材としては、例えばウォラストナイト、チタン酸カリウム、ゾノトライト、石膏繊維、アルミボレート、アラミド繊維、繊維状マグネシウム化合物、炭素繊維、ガラス繊維、タルク、マイカ、ガラスフレーク、ポリオキシベジンゾイルウイスカなどを使用することができる。また、これらを複数組み合わせて使用することもできる。 As the member included in the stress relaxation material 22, a filler material such as ceramics may be included in addition to the resin material in order to adjust the thermal expansion coefficient and Young's modulus. Examples of filler materials include wollastonite, potassium titanate, zonotlite, gypsum fiber, aluminum borate, aramid fiber, fibrous magnesium compound, carbon fiber, glass fiber, talc, mica, glass flake, polyoxybegin zoyl whisker, etc. Can be used. A combination of these can also be used.
　上記の樹脂材料とフィラ材を好ましい熱膨張係数、ヤング率とするために組み合わせて使用することができる。また、上記の応力緩和材２２は、物理量測定装置を形成する際に、他の部材を接合・封止するのと共通部材とすることもできる。その場合、工程数を削減することもできるため、その観点から樹脂材料とフィラ材を選定することも可能である。 The above resin material and filler material can be used in combination in order to obtain a preferable thermal expansion coefficient and Young's modulus. Further, the stress relieving material 22 may be a common member for joining and sealing other members when forming the physical quantity measuring device. In that case, since the number of steps can be reduced, it is also possible to select a resin material and a filler material from that viewpoint.
（例１－３、比較例１）
　以下、例を用いて応力緩和材の種類等に基づく測定値について説明する。ただし、本発明は、ここで取り上げた例の記載に限定されることはなく、適宜組み合わせてもよい。 (Example 1-3, Comparative Example 1)
Hereinafter, measured values based on the types of stress relaxation materials and the like will be described using examples. However, the present invention is not limited to the description of the examples taken up here, and may be combined as appropriate.
　図７（Ａ）に示す例１から例３は、応力緩和材の種類を材料Ａから材料Ｃとした場合の例であり、比較例は応力緩和材を用いない場合を示す。これらの例では、図５に示した接合構造において、１３０℃から－４０℃の間の温度変化を与えた場合の半導体素子１５の接合層２１ａとの接合面における発生熱応力をＣＡＥ解析したものである。例１では、熱膨張係数α（×ｐｐｍ／℃）は１０、ヤング率（ＧＰａ）は２２．８、半導体素子１５にかかる最大主応力変化率（％）は２９であった。例２では、熱膨張係数α（×ｐｐｍ／℃）は４１、ヤング率（ＧＰａ）は３．９、主応力変化率（％）は３７であった。例３では、熱膨張係数α（×ｐｐｍ／℃）は８９、ヤング率（ＧＰａ）は１．９、主応力変化率（％）は９２であった。 Examples 1 to 3 shown in FIG. 7A are examples in which the type of the stress relaxation material is changed from the material A to the material C, and the comparative example shows a case where the stress relaxation material is not used. In these examples, CAE analysis is performed on the thermal stress generated at the bonding surface of the semiconductor element 15 with the bonding layer 21a when a temperature change between 130 ° C. and −40 ° C. is applied in the bonding structure shown in FIG. It is. In Example 1, the thermal expansion coefficient α (× ppm / ° C.) was 10, the Young's modulus (GPa) was 22.8, and the maximum principal stress change rate (%) applied to the semiconductor element 15 was 29. In Example 2, the thermal expansion coefficient α (× ppm / ° C.) was 41, the Young's modulus (GPa) was 3.9, and the principal stress change rate (%) was 37. In Example 3, the thermal expansion coefficient α (× ppm / ° C.) was 89, the Young's modulus (GPa) was 1.9, and the main stress change rate (%) was 92.
　図８（Ａ）は、図７（Ａ）に示す例１から例３について、横軸に熱膨張係数を縦軸に主応力変化率をプロットしたグラフである。図８（Ｂ）は、図７（Ａ）に示す例１から例３について、横軸にヤング率を縦軸に主応力変化率をプロットしたグラフである。 FIG. 8A is a graph in which the thermal expansion coefficient is plotted on the horizontal axis and the main stress change rate is plotted on the vertical axis for Examples 1 to 3 shown in FIG. 7A. FIG. 8B is a graph in which Young's modulus is plotted on the horizontal axis and principal stress change rate is plotted on the vertical axis for Examples 1 to 3 shown in FIG.
　なお、図７（Ｂ）は、図７（Ａ）に示す例１から例３の解析において使用した、図５に示した半導体素子１５、接合層２１ａ、接合層２１ｂ、接合層２１ｃ、基台１４の物性値を示す。熱膨張係数α（×ｐｐｍ／℃）は、半導体素子１５、接合層２１ａ、接合層２１ｂ、接合層２１ｃ、基台１４の順にそれぞれ、３．０、６．０、７．２、１１．６、１１．３である。ヤング率（ＧＰａ）は、半導体素子１５、接合層２１ａ、接合層２１ｂ、接合層２１ｃ、基台１４の順にそれぞれ、１７０、５３、７３、５３、２０５である。 7B shows the semiconductor element 15, the bonding layer 21a, the bonding layer 21b, the bonding layer 21c, and the base shown in FIG. 5 used in the analysis of Examples 1 to 3 shown in FIG. 14 physical property values are shown. The thermal expansion coefficient α (× ppm / ° C.) is 3.0, 6.0, 7.2, and 11.6 in the order of the semiconductor element 15, the bonding layer 21a, the bonding layer 21b, the bonding layer 21c, and the base 14, respectively. 11.3. The Young's modulus (GPa) is 170, 53, 73, 53, and 205 in the order of the semiconductor element 15, the bonding layer 21a, the bonding layer 21b, the bonding layer 21c, and the base 14.
　図７（Ａ）、図８（Ａ）、図８（Ｂ）より、図５に示すように応力緩和材２２を形成することで熱応力を低減できることが判明した。また、図７（Ｂ）、図８（Ａ）より、熱応力を効果的に低減させるためには応力緩和材２２の熱膨張係数は、基台１４の熱膨張係数以下程度になると効果が大きくなることが分かった。また、図７（Ａ）、図８（Ｂ）より、応力緩和材２２のヤング率は１．９ＧＰａ以上であるときに効果が大きくなり、より効果的なのは３．９ＧＰａ以上であった。 7 (A), 8 (A), and 8 (B), it was found that the thermal stress can be reduced by forming the stress relaxation material 22 as shown in FIG. Further, from FIGS. 7B and 8A, in order to effectively reduce the thermal stress, the effect is large when the thermal expansion coefficient of the stress relaxation material 22 is less than or equal to the thermal expansion coefficient of the base 14. I found out that Further, from FIGS. 7A and 8B, the effect is increased when the Young's modulus of the stress relaxation material 22 is 1.9 GPa or more, and more effective is 3.9 GPa or more.
（例４－６、比較例２）
　本例は、図５に示す接合構造の信頼性を実験にて検討したものである。
＜接合材の作製＞
　接合材を作製するに当たり、接合層２１ｂにはガラス板（ＳＣＨＯＴＴ製Ｄ２６３）を用いた。このガラス板の上下に接合層２１ａ、２１ｃ形成ペーストをスクリーン印刷を用いて塗布し、１５０℃にて３０分乾燥した後、仮焼成を実施することで接合材を得た。なお、接合層２１ａには、Ｖ２Ｏ５－Ｐ２Ｏ５－ＴｅＯ２－Ｆｅ２Ｏ３系ガラス（熱膨張係数α＝６．０ｐｐｍ／℃）、接合層２１ｃにはＶ２Ｏ５－Ｐ２Ｏ５－ＴｅＯ２－ＢａＯ－Ｋ２Ｏ系ガラス（熱膨張係数α＝１１．６ｐｐｍ／℃）を用いた。 (Example 4-6, Comparative Example 2)
In this example, the reliability of the joint structure shown in FIG. 5 is examined by experiment.
<Production of bonding material>
In producing the bonding material, a glass plate (D263 made by SCHOTT) was used for the bonding layer 21b. The bonding layers 21a and 21c forming paste were applied on the upper and lower sides of the glass plate using screen printing, dried at 150 ° C. for 30 minutes, and then pre-baked to obtain a bonding material. The bonding layer 21a has a V 2 O 5 —P 2 O 5 —TeO 2 —Fe 2 O 3 glass (thermal expansion coefficient α = 6.0 ppm / ° C.), and the bonding layer 21c has a V 2 O 5 − P 2 O 5 —TeO 2 —BaO—K 2 O glass (thermal expansion coefficient α = 11.6 ppm / ° C.) was used.
＜接合体の試作＞
　被接合材として、裏面にＴｉとＡｌのメタライズ処理をした半導体素子１５（160μｍ厚）とＳＵＳ６３０製基台１４を用いた。半導体素子１５と基台１４の間に上述のようにして作製した接合層２１を設置し、半導体素子１５の上面から荷重を付加し、加熱することで接合体を作製した。このとき、加熱条件は４００℃にて１０分間保持した。 <Prototype of joined body>
As the materials to be joined, a semiconductor element 15 (160 μm thick) and a SUS630 base 14 having a Ti and Al metallization treatment on the back surface were used. The bonding layer 21 manufactured as described above was placed between the semiconductor element 15 and the base 14, a load was applied from the upper surface of the semiconductor element 15, and the bonded body was manufactured by heating. At this time, the heating condition was maintained at 400 ° C. for 10 minutes.
＜応力緩和材２２の形成＞
　応力緩和材２２として、例１～例３に記載の材料Ａ、Ｂ、Ｃを用いて応力緩和材２２を１００～１６０℃で１～２ｈ保持することで形成した。 <Formation of stress relaxation material 22>
The stress relaxation material 22 was formed by using the materials A, B, and C described in Examples 1 to 3 and holding the stress relaxation material 22 at 100 to 160 ° C. for 1 to 2 hours.
＜接合の信頼性評価＞
　接合体の信頼性評価として、４点曲げ試験を実施した。４点曲げ試験では、接合体が破壊する際の応力を計測することで接合強度を測定した。その結果を図７（Ｃ）に示す。 <Joint reliability evaluation>
As a reliability evaluation of the joined body, a four-point bending test was performed. In the 4-point bending test, the bonding strength was measured by measuring the stress when the bonded body was broken. The result is shown in FIG.
　図７（Ｃ）に示す例４から例６は、応力緩和材の種類を材料Ａから材料Ｃとした場合の例であり、比較例は応力緩和材を用いない場合を示す。例４では、平均接合強度は１９８、ワイブル係数ｍは５．１であった。例５では、平均接合強度は１５７、ワイブル係数ｍは６．６であった。例６では、平均接合強度は１０９、ワイブル係数ｍは４．５であった。応力緩和材を用いない比較例では、平均接合強度は１００、ワイブル係数ｍは３．０である。平均接合強度（ＭＰａ）とは接合体が破壊する際の応力の平均である。　以上の結果より、図５に示す接合構造において、応力緩和材２２を形成することで実際に接合体の接合強度が向上することが確認できた。また、接合強度のバラツキを示すワイブル係数も改善できることが判明した。 Examples 4 to 6 shown in FIG. 7C are examples in which the type of the stress relaxation material is changed from the material A to the material C, and the comparative example shows a case where the stress relaxation material is not used. In Example 4, the average joint strength was 198, and the Weibull coefficient m was 5.1. In Example 5, the average joint strength was 157, and the Weibull coefficient m was 6.6. In Example 6, the average joint strength was 109 and the Weibull coefficient m was 4.5. In the comparative example using no stress relaxation material, the average joint strength is 100 and the Weibull coefficient m is 3.0. The average bonding strength (MPa) is an average of stress when the bonded body breaks. From the above results, it was confirmed that the bonding strength of the bonded body was actually improved by forming the stress relaxation material 22 in the bonded structure shown in FIG. It has also been found that the Weibull coefficient indicating the variation in bonding strength can be improved.
（例７、比較例３）
　本例では、図４に示す接合構造の信頼性を実験した例について記載する。
　接合層２１ａ形成ペーストとしては、例４－６と同様のものを使用した。接合層２１ｂの形成には、接合層２１ｂ形成ペーストを用いて形成した。接合層２１ｂ形成ペーストは、ＳｉＯ２－Ａｌ２Ｏ３－ＢａＯ系ガラスペースト（熱膨張係数α＝７．１ｐｐｍ／℃）を用いた。接合層２１ｂの形成は、スクリーン印刷を用いて基台上に接合層２１ｂ形成ペーストを印刷後、１５０℃で３０ｍｉｎ乾燥後、８５０℃にて１０ｍｉｎ焼成することで約２０μｍの接合層２１ｂを形成した。この接合層２１ｂの上面に、例４－６で作製した接合層２１ａ形成ペーストを同様にスクリーン印刷にて塗布し、４００℃にて３０ｍｉｎ保持することで仮焼成を実施して約２０μｍの接合層２１ａを形成した。その後、この接合層２１ａの上面に例４－６と同様に半導体素子１５を設置して荷重を付加し、４００℃にて１０ｍｉｎ保持することで接合体を作製した。作製した接合体に対し、例４で使用した応力緩和材２２を同様に形成した。また、比較例３として応力緩和材２２を形成しないものも作製した。 (Example 7, Comparative Example 3)
In this example, an example in which the reliability of the joint structure shown in FIG. 4 is tested will be described.
As the bonding layer 21a forming paste, the same paste as in Example 4-6 was used. The bonding layer 21b was formed using a bonding layer 21b forming paste. As the paste for forming the bonding layer 21b, SiO 2 —Al 2 O 3 —BaO glass paste (thermal expansion coefficient α = 7.1 ppm / ° C.) was used. The bonding layer 21b was formed by printing the bonding layer 21b forming paste on the base using screen printing, drying at 150 ° C. for 30 minutes, and baking at 850 ° C. for 10 minutes to form the bonding layer 21b of about 20 μm. . The bonding layer 21a-forming paste prepared in Example 4-6 was similarly applied to the upper surface of the bonding layer 21b by screen printing, and pre-baked by holding at 400 ° C. for 30 minutes to obtain a bonding layer of about 20 μm. 21a was formed. Thereafter, the semiconductor element 15 was placed on the upper surface of the bonding layer 21a in the same manner as in Example 4-6, a load was applied, and the bonded body was maintained at 400 ° C. for 10 minutes. The stress relaxation material 22 used in Example 4 was similarly formed on the fabricated joined body. Further, as Comparative Example 3, a material in which the stress relaxation material 22 was not formed was also produced.
　作製した接合体に対して、例４－６と同様に４点曲げ試験を実施した。結果は、例４－６と同様に接合強度向上およびバラツキが低減できることが分かった。以上の結果より、本発明は接合層２１の構造に関わらず、接合時に発生する熱応力を緩和する効果があることが判明した。 A four-point bending test was performed on the fabricated joined body in the same manner as in Example 4-6. As a result, it was found that the joint strength could be improved and the variation could be reduced as in Example 4-6. From the above results, it has been found that the present invention has an effect of relieving thermal stress generated during bonding regardless of the structure of the bonding layer 21.
（例８―１０、比較例４）
　本例では、図１に示す圧力センサの信頼性を検討した例について記載する。なお、接合構造は例４と同様のものとした。ただし、応力緩和材２２の形態については、図７（Ｄ）に示すように、例８では、接合層の側面の一部を被覆したもの、例９では、接合層の側面全体を被覆したもの、例１０では、接合層全体と半導体素子側面全体（図６相当）としたものを作製した。また、比較例４として応力緩和材２２を形成しないものも作製した。 (Example 8-10, Comparative Example 4)
In this example, an example in which the reliability of the pressure sensor shown in FIG. 1 is studied will be described. The joining structure was the same as in Example 4. However, as to the form of the stress relaxation material 22, as shown in FIG. 7D, in Example 8, a part of the side surface of the bonding layer was coated, and in Example 9, the whole side surface of the bonding layer was coated. In Example 10, the entire bonding layer and the entire side surface of the semiconductor element (corresponding to FIG. 6) were produced. Further, as Comparative Example 4, a material in which the stress relaxation material 22 was not formed was also produced.
　作製した圧力センサに対して、０～２０ＭＰaの圧力レンジをフルスケール（Ｆ．Ｓ．）で０．５～４．５Ｖと設定し、以下の信頼性試験を実施した。図７（Ｄ）に示す熱衝撃は、１３０℃～－４０℃での熱衝撃試験２０００サイクルの信頼性試験である。図７（Ｄ）に示す－４０℃放置は、－４０℃での２０００時間放置試験することによってセンサ出力値のドリフト特性を評価したものである。図７（Ｄ）に示す１３０℃放置は、１３０℃での２０００時間放置試験することによってセンサ出力値のドリフト特性を評価したものである。評価結果は、試験前後で２０℃での値の出力値の変化が２％Ｆ．Ｓ．未満のものを優、２％以上３％Ｆ．Ｓ．未満のものを良、３％以上４％未満Ｆ．Ｓ．のものを可とした。ただし、割れ等により評価できなかったものが存在した場合には不可とした。その結果、図７（Ｄ）に示すように、例１０が最も優れた信頼性を示し、例９、例８も良好な信頼性を示した。 The pressure range of 0 to 20 MPa was set to 0.5 to 4.5 V in full scale (FS) for the manufactured pressure sensor, and the following reliability test was performed. The thermal shock shown in FIG. 7D is a reliability test of 2000 cycles of a thermal shock test at 130 ° C. to −40 ° C. The -40 ° C. standing shown in FIG. 7D is an evaluation of the drift characteristics of the sensor output value by conducting a 2000 hour standing test at -40 ° C. The 130 ° C. standing condition shown in FIG. 7D is an evaluation of the drift characteristic of the sensor output value by conducting a standing test at 130 ° C. for 2000 hours. The evaluation result shows that the change in the output value at 20 ° C. before and after the test is 2% F.S. S. Less than 2% to 3% F. S. Less than 3% or more and less than 4%. S. The thing was acceptable. However, when there was something that could not be evaluated due to cracks or the like, it was deemed impossible. As a result, as shown in FIG. 7D, Example 10 showed the most excellent reliability, and Example 9 and Example 8 also showed good reliability.
　以上の結果より、応力緩和材２２を形成することで、長期的な信頼性においても向上することが確認できた。ここで、接合層の全面が被覆されている場合と一部しか接触していない場合では、接合層の全面が被覆されている場合の方が出力値変化が小さい傾向にあった。したがって、応力緩和材は接合構造全体の応力を緩和できるため、被覆面積が大きい方が望ましいことが分かった。もっとも望ましくは、半導体素子の側面も全面接触することが良好である。 From the above results, it was confirmed that the long-term reliability was improved by forming the stress relaxation material 22. Here, when the entire surface of the bonding layer is covered and when only a part of the bonding layer is in contact, the change in the output value tends to be smaller when the entire surface of the bonding layer is covered. Therefore, it has been found that the stress relaxation material can relieve the stress of the entire joint structure, so that a larger covering area is desirable. Most preferably, the side surfaces of the semiconductor element are also in good contact with each other.
　以上説明した実施形態によれば、次の作用効果が得られる。
（１）物理量測定装置１００は、半導体素子１５と、基台１４と、半導体素子１５と基台１４とを接続する接合層２１と、を有し、少なくとも接合層２１の側面の一部が応力緩和材２２と接触していることを特徴とする。これにより、物理量測定装置１００の熱応力を十分に緩和することができ、長期的に信頼性の高い装置を提供することができる。 According to the embodiment described above, the following operational effects can be obtained.
(1) The physical quantity measuring apparatus 100 includes a semiconductor element 15, a base 14, and a bonding layer 21 that connects the semiconductor element 15 and the base 14, and at least a part of the side surface of the bonding layer 21 is stressed. It is in contact with the moderating material 22. Thereby, the thermal stress of the physical quantity measuring apparatus 100 can be sufficiently relaxed, and a highly reliable apparatus can be provided in the long term.
　本発明は、上記の実施形態に限定されるものではなく、本発明の特徴を損なわない限り、本発明の技術思想の範囲内で考えられるその他の形態についても、本発明の範囲内に含まれる。また、上述の実施形態を組み合わせた構成としてもよい。 The present invention is not limited to the above-described embodiment, and other forms conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention as long as the characteristics of the present invention are not impaired. . Moreover, it is good also as a structure which combined the above-mentioned embodiment.
　１０…金属筐体
　１１…圧力ポート
　１２…圧力導入部
　１２ａ…圧力導入口
　１２ｈａ…圧力導入部
　１２ｈａｔ…先端部
　１３…フランジ
　１４…基台
　１５…半導体素子
　１６…基板
　１７…コンデンサ
　１８…カバー
　１８ａ…閉塞板
　１９…コネクタ
　２０…ターミナル
　２１、 ２１ａ～２１ｃ…接合層
　２２…応力緩和材
　３０ａ～３０ｃ…歪抵抗ブリッジ
　３１ａ～３１ｃ…アンプ
　３２ａ～３２ｃ…Ａ－Ｄ変換器
　３３…デジタル信号演算処理回路
　３４…不揮発性メモリ
　３５…電圧源
　１００…圧力測定装置 DESCRIPTION OF SYMBOLS 10 ... Metal casing 11 ... Pressure port 12 ... Pressure introduction part 12a ... Pressure introduction port 12ha ... Pressure introduction part 12hat ... Tip part 13 ... Flange 14 ... Base 15 ... Semiconductor element 16 ... Substrate 17 ... Capacitor 18 ... Cover 18a ... Blocking plate 19 ... Connector 20 ... Terminal 21, 21a-21c ... Junction layer 22 ... Stress relaxation material 30a-30c ... Strain resistance bridge 31a-31c ... Amplifier 32a-32c ... AD converter 33 ... Digital signal arithmetic processing circuit 34 ... Non-volatile memory 35 ... Voltage source 100 ... Pressure measuring device

Claims (15)

  1. 　半導体素子と、基台と、前記半導体素子と前記基台とを接続する接合層と、を有する物理量測定装置において、少なくとも前記接合層側面の一部が応力緩和材と接触していることを特徴とする物理量測定装置。 In the physical quantity measuring device having a semiconductor element, a base, and a bonding layer connecting the semiconductor element and the base, at least a part of the side surface of the bonding layer is in contact with the stress relaxation material. A physical quantity measuring device.
  2. 　請求項１に記載の物理量測定装置において、
    　前記接合層の側面全体が前記応力緩和材で被覆されていることを特徴とする物理量測定装置。     The physical quantity measuring device according to claim 1,
    The physical quantity measuring device, wherein the entire side surface of the bonding layer is covered with the stress relaxation material.
  3. 　請求項１または請求項２に記載の物理量測定装置において、
    　前記接合層全体が応力緩和層で被覆されていることを特徴とする物理量測定装置。     In the physical quantity measuring device according to claim 1 or 2,
    The physical quantity measuring apparatus characterized in that the entire bonding layer is covered with a stress relaxation layer.
  4. 　請求項１から請求項３までのいずれか一項に記載の物理量測定装置において、
    　前記半導体素子の側面にも前記応力緩和材が接触していることを特徴とする物理量測定装置。     In the physical-quantity measuring apparatus as described in any one of Claim 1- Claim 3,
    The physical quantity measuring apparatus, wherein the stress relaxation material is also in contact with a side surface of the semiconductor element.
  5. 　請求項１から請求項４までのいずれか一項に記載の物理量測定装置において、
    　前記応力緩和材は、延性材料を含むことを特徴とする物理量測定装置。     In the physical quantity measuring device according to any one of claims 1 to 4,
    The physical quantity measuring apparatus, wherein the stress relaxation material includes a ductile material.
  6. 　請求項１から請求項５までのいずれか一項に記載の物理量測定装置において、
    　前記応力緩和材は、樹脂材料を含むこと特徴とする物理量測定装置。     In the physical quantity measuring device according to any one of claims 1 to 5,
    The physical quantity measuring apparatus, wherein the stress relaxation material includes a resin material.
  7. 　請求項１から請求項６までのいずれか一項に記載の物理量測定装置において、
    　前記応力緩和材のガラス転移温度は、１３０℃以上であることを特徴とする物理量測定装置。     In the physical-quantity measuring apparatus as described in any one of Claim 1- Claim 6,
    The physical quantity measuring device, wherein the stress relaxation material has a glass transition temperature of 130 ° C. or higher.
  8. 　請求項１から請求項７までのいずれか一項に記載の物理量測定装置において、
    　前記応力緩和材のヤング率は、１．９ＧＰａ以上であることを特徴とする物理量測定装置。     In the physical quantity measuring device according to any one of claims 1 to 7,
    The physical quantity measuring device, wherein the stress relaxation material has a Young's modulus of 1.9 GPa or more.
  9. 　請求項１から請求項８までのいずれか一項に記載の物理量測定装置において、
    　前記応力緩和材の熱膨張係数は、前記基台の熱膨張係数以下であることを特徴とする物理量測定装置。     In the physical quantity measuring device according to any one of claims 1 to 8,
    The physical quantity measuring device according to claim 1, wherein a thermal expansion coefficient of the stress relaxation material is equal to or less than a thermal expansion coefficient of the base.
  10. 　請求項９に記載の物理量測定装置において、
    　前記応力緩和材の熱膨張係数は、前記基台の熱膨張係数以下であり、かつ前記接合層の熱膨張係数以上であることを特徴とする物理量測定装置。     The physical quantity measuring device according to claim 9,
    The physical quantity measuring device according to claim 1, wherein a thermal expansion coefficient of the stress relaxation material is equal to or lower than a thermal expansion coefficient of the base and equal to or higher than a thermal expansion coefficient of the bonding layer.
  11. 　請求項１から請求項１０までのいずれか一項に記載の物理量測定装置において、
    　前記接合層は、少なくとも２層以上であり、かつ脆性材料で構成されていることを特徴とする物理量測定装置。     In the physical quantity measuring device according to any one of claims 1 to 10,
    2. The physical quantity measuring apparatus according to claim 1, wherein the bonding layer includes at least two layers and is made of a brittle material.
  12. 　請求項１から請求項１１までのいずれか一項に記載の物理量測定装置において、
    　前記接合層は、３層で構成されていることを特徴とする物理量測定装置。     In the physical quantity measuring device according to any one of claims 1 to 11,
    The physical quantity measuring device, wherein the bonding layer is composed of three layers.
  13. 　請求項１から請求項１２までのいずれか一項に記載の物理量測定装置において、
    　前記接合層は、少なくとも１層以上の絶縁層を有することを特徴とする物理量測定装置。     In the physical quantity measuring device according to any one of claims 1 to 12,
    The physical quantity measuring device, wherein the bonding layer has at least one insulating layer.
  14. 　請求項１から請求項１３までのいずれか一項に記載の物理量測定装置において、
    　前記接合層の熱膨張係数は、前記基台の熱膨張係数以下と前記半導体素子の熱膨張係数以上の間の特性を有することを特徴とする物理量測定装置。     In the physical quantity measuring device according to any one of claims 1 to 13,
    The physical quantity measuring device characterized in that the thermal expansion coefficient of the bonding layer has a characteristic that is between the thermal expansion coefficient of the base and the thermal expansion coefficient of the semiconductor element.
  15. 　請求項１から請求項１４までのいずれか一項に記載の物理量測定装置において、
    　前記接合層の接合温度は前記半導体素子の耐熱温度以下であることを特徴とする物理量測定装置。     In the physical quantity measuring device according to any one of claims 1 to 14,
    The physical quantity measuring apparatus according to claim 1, wherein a bonding temperature of the bonding layer is equal to or lower than a heat resistant temperature of the semiconductor element.
PCT/JP2019/004958 2018-05-14 2019-02-13 Physical quantity measuring device WO2019220710A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2020518978A JP6909354B2 (en) 2018-05-14 2019-02-13 Physical quantity measuring device

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2018093124 2018-05-14
JP2018-093124 2018-05-14

Publications (1)

Publication Number Publication Date
WO2019220710A1 true WO2019220710A1 (en) 2019-11-21

Family

ID=68540067

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2019/004958 WO2019220710A1 (en) 2018-05-14 2019-02-13 Physical quantity measuring device

Country Status (2)

Country Link
JP (1) JP6909354B2 (en)
WO (1) WO2019220710A1 (en)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10132677A (en) * 1996-10-31 1998-05-22 Matsushita Electric Works Ltd Pressure sensor
JP2000100836A (en) * 1998-09-28 2000-04-07 Rohm Co Ltd Method of mounting semiconductor chip
JP2000114424A (en) * 1998-09-29 2000-04-21 Kyocera Corp Semiconductor device mounting board
JP2008064526A (en) * 2006-09-06 2008-03-21 Denso Corp Pressure sensor and its manufacturing method
DE102006053538A1 (en) * 2006-11-09 2008-05-15 I2S Intelligente Sensorsysteme Dresden Gmbh Fluid/liquid e.g. water, pressure sensor for internal combustion engine, has sensor unit wrapped radially outwards by deformable unit that is held in pre-stressed manner against inner wall of housing and outer wall of sensor unit
WO2015098324A1 (en) * 2013-12-25 2015-07-02 日立オートモティブシステムズ株式会社 Pressure measurement device

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10132677A (en) * 1996-10-31 1998-05-22 Matsushita Electric Works Ltd Pressure sensor
JP2000100836A (en) * 1998-09-28 2000-04-07 Rohm Co Ltd Method of mounting semiconductor chip
JP2000114424A (en) * 1998-09-29 2000-04-21 Kyocera Corp Semiconductor device mounting board
JP2008064526A (en) * 2006-09-06 2008-03-21 Denso Corp Pressure sensor and its manufacturing method
DE102006053538A1 (en) * 2006-11-09 2008-05-15 I2S Intelligente Sensorsysteme Dresden Gmbh Fluid/liquid e.g. water, pressure sensor for internal combustion engine, has sensor unit wrapped radially outwards by deformable unit that is held in pre-stressed manner against inner wall of housing and outer wall of sensor unit
WO2015098324A1 (en) * 2013-12-25 2015-07-02 日立オートモティブシステムズ株式会社 Pressure measurement device

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
ICHIMURA, YUJI ET AL.: "Semiconductor Product Resin Technologies and Analysis", FUJI ELECTRIC JOURNAL, vol. 75, no. 9, 10 September 2002 (2002-09-10), pages 509 - 510 *

Also Published As

Publication number Publication date
JPWO2019220710A1 (en) 2021-04-30
JP6909354B2 (en) 2021-07-28

Similar Documents

Publication Publication Date Title
JP6154488B2 (en) Pressure measuring device
KR101109282B1 (en) Pressure sensor device
JP5153126B2 (en) Sensor device for measuring fluid pressure and temperature
KR101236678B1 (en) Pressure sensor device
CN101983303B (en) Pressure-measuring glow plug
JP4075776B2 (en) Physical quantity sensor and pressure sensor
JP5748257B2 (en) High-temperature pressure sensor element for measuring the internal pressure of the engine, its manufacturing method, and engine parts
US5503023A (en) Pressure sensor for detecting the pressure in the combustion chamber of internal-combustion engines
JPH11211592A (en) High-pressure sensor and its manufacture
BR112012030407B1 (en) GENERAL PRESSURE SENSOR FOR AUTOMOBILE
JPH10148591A (en) Pressure detector
JP3671563B2 (en) Semiconductor device having a structure in which a mold IC is fixed to a case
JP4353251B2 (en) Pressure sensor
JP2016540986A (en) Pressure sensor
JP4185478B2 (en) Strain detector and manufacturing method thereof
WO2019220710A1 (en) Physical quantity measuring device
US6649988B2 (en) Semiconductor pressure sensor decreasing creep stress in &lt;110&gt; crystalline axis direction
JP4720451B2 (en) Pressure sensor
JP2010145341A (en) Pressure sensor module
WO2021126261A1 (en) Strain gages and methods for manufacturing thereof
JPS5936835B2 (en) Semiconductor pressure/differential pressure transmitter
JP2018115987A (en) Joining element of silicon and conductor, and pressure sensor using the same
KR20090117548A (en) Pressure sensor and apparatus for detecting pressure having the same
JP4882682B2 (en) Pressure sensor device
JPWO2018163632A1 (en) PHYSICAL QUANTITY MEASURING DEVICE, ITS MANUFACTURING METHOD, AND PHYSICAL QUANTITY MEASURING DEVICE

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 19803956

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2020518978

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 19803956

Country of ref document: EP

Kind code of ref document: A1