CN113148941A

CN113148941A - Pressure sensor packaging module

Info

Publication number: CN113148941A
Application number: CN202110318464.7A
Authority: CN
Inventors: 于成奇; 陈利宏; 王悦锋
Original assignee: Suzhou Novosense Microelectronics Co ltd
Current assignee: Suzhou Novosense Microelectronics Co ltd
Priority date: 2021-03-25
Filing date: 2021-03-25
Publication date: 2021-07-23

Abstract

The invention discloses a pressure sensor packaging module, which comprises a PCB substrate, an ASIC chip, an MEMS pressure sensing chip and an MEMS base, wherein the ASIC chip is arranged on the PCB substrate; the ASIC chip is fixedly connected to the PCB substrate; the PCB substrate comprises a preset through hole matched with the MEMS base, and the MEMS base penetrates through the PCB substrate through the preset through hole; the MEMS pressure sensing chip is arranged on the MEMS base and is arranged on the same side of the PCB substrate with the ASIC; the MEMS base comprises a contact through hole, and fluid to be tested exerts pressure on the MEMS pressure sensing chip through the contact through hole; the MEMS base is a corrosion-resistant base. The invention simplifies the manufacturing process of the packaging piece, improves the production efficiency, reduces the consumption of corrosion-resistant materials, further saves the cost and improves the protection effect on the MEMS pressure sensing chip.

Description

Pressure sensor packaging module

Technical Field

The invention relates to the field of chip packaging, in particular to a pressure sensor packaging module.

Background

With the development of intelligent machinery and the progress of science and technology, sensors are used as important devices for machines to autonomously sense the surrounding environment, and the development of the sensors is more and more concerned by various fields.

Specifically, in a pressure sensor, a conventional packaging structure of the pressure sensor generally includes wiring and gold plating on a corrosion-resistant ceramic substrate to obtain a ceramic substrate, fixing a pressure sensing chip on the ceramic substrate to obtain a package precursor, connecting the package precursor to a PCB board through a reflow soldering via a metal wire, and finally forming a hole in the ceramic substrate to allow the pressure sensing chip to contact a fluid to be measured. However, the prior art also has a plurality of problems, such as complex packaging process caused by high difficulty of wiring and gold plating on the ceramic substrate and high difficulty of reflow soldering among the ceramic substrate, the pressure sensing chip and the PCB; the production cost is increased due to the need of large-area ceramic as a substrate; the ceramic substrate and the PCB are not tightly sealed, and the protection effect on the pressure sensing chip is poor.

In summary, how to solve the problems of the prior art, such as complicated packaging process, high cost and poor chip protection effect of the pressure sensor, is a problem to be solved urgently by those skilled in the art.

Disclosure of Invention

The invention aims to provide a pressure sensor packaging module to solve the problems that in the prior art, a pressure sensor packaging process is complex, cost is high, and a chip protection effect is poor.

In order to solve the technical problem, the invention provides a pressure sensor packaging module, which comprises a PCB substrate, an ASIC chip, an MEMS pressure sensing chip and an MEMS base;

the ASIC chip is fixedly connected to the PCB substrate;

the PCB substrate comprises a preset through hole matched with the MEMS base, and the MEMS base penetrates through the PCB substrate through the preset through hole;

the MEMS pressure sensing chip is arranged on the MEMS base and is arranged on the same side of the PCB substrate with the ASIC;

the MEMS base comprises a contact through hole, and fluid to be tested exerts pressure on the MEMS pressure sensing chip through the contact through hole;

the MEMS base is a corrosion-resistant base.

Optionally, in the pressure sensor packaging module, the pressure sensor packaging module further includes a protection frame disposed on the same side as the MEMS pressure sensing chip;

the protection frame body, the PCB substrate and the MEMS base enclose a protection cavity, and the MEMS pressure sensing chip is arranged at the bottom of the protection cavity.

Optionally, in the pressure sensor package module, the pressure sensor package module further includes a front potting adhesive layer;

the front side close potting adhesive layer is arranged in the protection cavity and covers the front side of the MEMS pressure sensing chip.

Optionally, in the pressure sensor package module, an inner wall of the protective frame includes an anti-creeping groove.

Optionally, in the pressure sensor package module, the pressure sensor package module further includes a back potting adhesive layer;

the back pouring sealant layer is arranged at the bottom of the contact through hole and covers the back of the MEMS pressure sensing chip.

Optionally, in the pressure sensor package module, the MEMS base includes a step-shaped extension portion;

the step-shaped extension part is attached to the back face of the PCB substrate.

Optionally, in the pressure sensor package module, the MEMS base is fixed to the PCB substrate by bonding.

Optionally, in the pressure sensor package module, the opening of the contact through hole, which is far away from the MEMS pressure sensing chip, is a gradually constricted opening.

Optionally, in the pressure sensor package module, the MEMS base is any one of a ceramic base, a metal base, or an LCP base.

Optionally, in the pressure sensor package module, the pressure sensor package module further includes a test pad;

the test pad is arranged on the back surface of the PCB substrate.

The pressure sensor packaging module provided by the invention comprises a PCB substrate, an ASIC chip, an MEMS pressure sensing chip and an MEMS base; the ASIC chip is fixedly connected to the PCB substrate; the PCB substrate comprises a preset through hole matched with the MEMS base, and the MEMS base penetrates through the PCB substrate through the preset through hole; the MEMS pressure sensing chip is arranged on the MEMS base and is arranged on the same side of the PCB substrate with the ASIC; the MEMS base comprises a contact through hole, and fluid to be tested exerts pressure on the MEMS pressure sensing chip through the contact through hole; the MEMS base is a corrosion-resistant base.

According to the invention, the PCB substrate is perforated, and the MEMS base is embedded on the PCB substrate through the preset through hole, so that double-sided reflow soldering in the prior art is avoided, the manufacturing process of a packaging piece is greatly simplified, the production efficiency is improved, meanwhile, as the MEMS base is only arranged at the preset through hole, expensive corrosion-resistant materials are prevented from being paved on the whole surface, the consumption of the corrosion-resistant materials is reduced, and the cost is further saved.

Drawings

In order to more clearly illustrate the embodiments or technical solutions of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of an embodiment of a pressure sensor package module according to the present invention;

FIG. 2 is an exploded view of another embodiment of a pressure sensor package module according to the present invention;

FIG. 3 is a cross-sectional view of another embodiment of a pressure sensor package module according to the present invention;

FIG. 4 is a schematic structural diagram of an opposite side of another embodiment of a pressure sensor package module according to the present invention;

FIG. 5 is a schematic structural diagram of a pressure sensor package module according to another embodiment of the present invention;

fig. 6 is a partial schematic structural diagram of a pressure sensor package module according to still another embodiment of the present invention.

Detailed Description

In order that those skilled in the art will better understand the disclosure, the invention will be described in further detail with reference to the accompanying drawings and specific embodiments. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The core of the present invention is to provide a pressure sensor package module, wherein a schematic structural diagram of one embodiment is shown in fig. 1, which is referred to as a first embodiment, and includes a PCB substrate 100, an ASIC chip 200, an MEMS pressure sensing chip 300, and an MEMS base 400;

the ASIC chip 200 is fixedly connected to the PCB substrate 100;

the PCB substrate 100 comprises a preset through hole matched with the MEMS base 400, and the MEMS base 400 penetrates through the PCB substrate 100 through the preset through hole;

the MEMS pressure sensing chip 300 is disposed on the MEMS base 400, and is disposed on the same side of the PCB substrate 100 as the ASIC;

the MEMS base 400 includes a contact through hole through which a fluid to be measured presses the MEMS pressure-sensitive chip 300;

the MEMS mount 400 is a corrosion resistant mount.

As a preferred embodiment, the MEMS base 400 is fixed to the PCB substrate 100 by bonding, which is simple and efficient, and further, the MEMS base 400 may include an epitaxial structure cooperating with the PCB substrate 100 to facilitate adhesion therebetween. Of course, the MEMS base 400 and the PCB substrate 100 may be fixedly connected by other methods, such as welding or locking, and the like, and may be selected according to actual situations.

Of course, the upper surface of the MEMS base 400 (i.e. the surface on which the MEMS pressure-sensing chip 300 is disposed) does not have to be flush with the surface of the PCB substrate 100, and may be slightly higher or lower than the surface of the PCB substrate 100 on the premise of ensuring the connection between the MEMS pressure-sensing chip 300 and external signals, as shown in fig. 1, the upper surface of the MEMS base 400 is slightly higher than the upper surface of the PCB substrate 100.

In addition, the opening of the contact through hole, which is far away from the MEMS pressure sensing chip 300, is a gradually converging opening, and specifically, one or more steps, i.e., a step-shaped convergence, may be disposed at the opening of the contact through hole, which is far away from the MEMS pressure sensing chip 300, or a chamfer may be directly disposed, i.e., the opening is set to be funnel-shaped, which may refer to fig. 3, i.e., funnel-shaped convergence in fig. 3.

The MEMS base 400 may be any one of a ceramic base, a metal base, and an LCP base, and of course, a base made of another material may be selected according to the actual use and the properties of the fluid to be measured.

Further, the pressure sensor package module further includes a test pad 600; the test pad 600 is disposed on the back surface of the PCB substrate 100. Referring to fig. 4, fig. 4 is a schematic diagram of a back side structure of the present embodiment, the test pad 600 is used for detecting whether the mounted MEMS pressure sensing chip 300 and the ASIC chip 200 can work normally, and performing subsequent packaging processing or connecting with an external component after the test is completed can timely find a problem, thereby avoiding that a previous packaging procedure is found to be faulty after a subsequent process is completed, which leads to capacity waste, which is equivalent to improving a yield of a finished product and reducing a cost.

As a specific embodiment, the ASIC chip 200 and other components may be attached to the PCB substrate 100 by SMT (surface mount technology), and the MEMS pressure sensing chip 300 is attached to the MEMS base 400 by die bonding glue.

The pressure sensor packaging module provided by the invention comprises a PCB substrate 100, an ASIC chip 200, an MEMS pressure sensing chip 300 and an MEMS base 400; the ASIC chip 200 is fixedly connected to the PCB substrate 100; the PCB substrate 100 comprises a preset through hole matched with the MEMS base 400, and the MEMS base 400 penetrates through the PCB substrate 100 through the preset through hole; the MEMS pressure sensing chip 300 is disposed on the MEMS base 400, and is disposed on the same side of the PCB substrate 100 as the ASIC; the MEMS base 400 includes a contact through hole through which a fluid to be measured presses the MEMS pressure-sensitive chip 300; the MEMS mount 400 is a corrosion resistant mount. In the invention, the PCB substrate 100 is perforated, and the MEMS base 400 is embedded on the PCB substrate 100 through the preset through hole, so that double-sided reflow soldering in the prior art is avoided, the manufacturing process of a packaging piece is greatly simplified, the production efficiency is improved, meanwhile, as the MEMS base 400 only exists at the preset through hole, expensive corrosion-resistant materials are prevented from being paved on the whole surface, the consumption of the corrosion-resistant materials is reduced, and the cost is further saved, in addition, the fluid to be detected can only contact the MEMS pressure sensing chip 300 through the contact through hole, so that the contact between the fluid to be detected and the MEMS pressure sensing chip 300 is more controllable, and the protection effect on the MEMS pressure sensing chip 300 is improved.

On the basis of the first embodiment, the protection measures for the MEMS pressure-sensitive chip 300 are further improved, and a second embodiment is obtained, where an exploded view of the structure is shown in fig. 2 and includes a PCB substrate 100, an ASIC chip 200, a MEMS pressure-sensitive chip 300, and a MEMS base 400;

the ASIC chip 200 is fixedly connected to the PCB substrate 100;

the MEMS base 400 is a corrosion resistant base;

the pressure sensor packaging module further comprises a protection frame 500 arranged on the same side as the MEMS pressure sensing chip 300;

the protection frame 500, the PCB substrate 100 and the MEMS base 400 enclose a protection cavity, and the MEMS pressure-sensitive chip 300 is disposed at the bottom of the protection cavity.

In this embodiment, the protection frame 500 is added to the package, and the protection frame 500 surrounds the MEMS pressure sensing chip 300 in the center, so as to avoid the MEMS pressure sensing chip 300 from being misaligned due to external impact or scratch of foreign matter or contact with the MEMS pressure sensing chip 300, and even further cause device damage, in other words, this embodiment further improves the measurement accuracy and the working stability of the pressure sensor package module.

As a preferred embodiment, the pressure sensor package module further includes a front potting adhesive layer 310; the front side glue-sealing layer is arranged in the protection cavity and covers the front side of the MEMS pressure sensing chip 300 to isolate the front side of the MEMS pressure sensing chip 300 from being in direct contact with an external fluid atmosphere, so that the protection effect is further improved.

Further, the inner wall of the protection frame body 500 includes an anti-creeping groove, when the front potting adhesive layer 310 is arranged, the liquid potting adhesive can climb up along the side wall of the protection frame body 500 due to large surface tension, so that the potting effect is influenced, the climbing-out glue can damage other structures on the PCB substrate 100, and the anti-creeping groove can effectively prevent the glue from climbing up to protect other original devices and improve the yield of final finished products. The anti-creeping grooves may be equal-height grooves formed in the side walls of the protective frame 500, or may be stepped grooves, specifically refer to fig. 3 or fig. 6, and fig. 3 is a sectional view of the assembled structure corresponding to fig. 2; fig. 6 is a cross-sectional view of the protection frame 500 corresponding to fig. 3, and the stepped groove is provided to prevent the glue from climbing upwards.

The structural schematic diagram of the pressure sensor package module after the glue layer is arranged is shown in fig. 5.

Of course, the pressure sensor package module may further include a back potting adhesive layer 320; the back potting adhesive layer 320 is disposed at the bottom of the contact through hole and covers the back of the MEMS pressure-sensitive chip 300. The back potting adhesive layer 320 functions similar to the front potting adhesive layer 310 described above, and is used to isolate the fluid to be tested from directly contacting the MEMS pressure-sensitive chip 300, so as to avoid corrosion of the chip by the fluid to be tested, which is specifically referred to above.

Of course, it is obvious that the back-side potting adhesive layer 320 should be a flexible adhesive layer for transmitting pressure, and a rigid adhesive layer cannot transmit pressure, which is not valuable to the present invention.

Further, the front encapsulation adhesive layer 310 and the back encapsulation adhesive layer 320 are adhesive layers that are easy to seal and are not corroded by the fluid to be tested, such as any one of a silica gel layer, a fluorosilicone layer, or a polyurethane layer.

As a specific embodiment, the protective frame 500 has a size ranging from 0.8 mm to 1.2 mm, inclusive, such as any of 0.80 mm, 1.00 mm, or 1.20 mm. It should be noted that if the size of the protection frame 500 is too small, it is not beneficial to the automatic pickup of the production line during the assembly process, but if the size is too large, it will result in the waste of space on the PCB and the increase of the volume of the package, and through a lot of theoretical calculation and practical inspection, the protection frame 500 in the above size range can satisfy the automatic pickup condition on the premise of miniaturization.

On the basis of the second embodiment, in order to facilitate assembly, the MEMS base 400 is further modified to obtain a third embodiment, and the structural schematic diagram thereof can refer to fig. 2 and 3, and includes a PCB substrate 100, an ASIC chip 200, a MEMS pressure-sensitive chip 300, and a MEMS base 400;

the ASIC chip 200 is fixedly connected to the PCB substrate 100;

the MEMS base 400 is a corrosion resistant base;

the protection frame 500, the PCB substrate 100 and the MEMS base 400 enclose a protection cavity, and the MEMS pressure-sensitive chip 300 is disposed at the bottom of the protection cavity;

the MEMS mount 400 includes a stepped extension 410;

the stepped extension 410 is attached to the rear surface of the PCB substrate 100.

In the present embodiment, as mentioned above, the MEMS base 400 is further improved, and the step-shaped extension portion 410 is added, and specifically, refer to fig. 2 to fig. 4, where fig. 3 shows the step-shaped extension portion 410 by a dashed frame, and the step-shaped extension portion 410 increases the bonding area between the MEMS base 400 and the PCB substrate 100, so that the bonding between the MEMS base 400 and the PCB substrate 100 is easier and firmer, and the step-shaped extension portion 410 protrudes from the PCB substrate 100, which further facilitates the subsequent assembly. Of course, besides the step-shaped extension portion 410, extension portions with other shapes may be also involved according to actual needs to increase the contact area between the MEMS base 400 and the PCB substrate 100, so as to facilitate the fixed connection therebetween.

The embodiments are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same or similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.

It is to be noted that, in the present specification, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The pressure sensor package module provided by the invention is described in detail above. The principles and embodiments of the present invention are explained herein using specific examples, which are presented only to assist in understanding the method and its core concepts. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.

Claims

1. A pressure sensor packaging module is characterized by comprising a PCB substrate, an ASIC chip, an MEMS pressure sensing chip and an MEMS base;

the ASIC chip is fixedly connected to the PCB substrate;

the MEMS base is a corrosion-resistant base.

2. The pressure sensor package module of claim 1 further comprising a protective frame disposed on a same side as the MEMS pressure sensing die;

3. The pressure sensor package module of claim 2, wherein the pressure sensor package module further comprises a front potting layer;

4. The pressure sensor package module of claim 3, wherein the inner wall of the protective frame includes an anti-creep groove.

5. The pressure sensor package module of any of claims 1-4, further comprising a backside potting layer;

6. The pressure sensor package module of claim 1, wherein the MEMS mount comprises a stepped extension;

7. The pressure sensor package module of claim 1 wherein said MEMS mount is adhesively secured to said PCB substrate.

8. The pressure sensor package module of claim 1, wherein the opening of the contact via away from the MEMS pressure sensitive die is a tapered opening.

9. The pressure sensor package module of claim 1 wherein the MEMS mount is any one of a ceramic mount, a metal mount, or an LCP mount.

10. The pressure sensor package module of claim 1, wherein said pressure sensor package module further comprises a test pad;

the test pad is arranged on the back surface of the PCB substrate.