CN112397465A - Chip heat radiation structure - Google Patents
Chip heat radiation structure Download PDFInfo
- Publication number
- CN112397465A CN112397465A CN202011516736.6A CN202011516736A CN112397465A CN 112397465 A CN112397465 A CN 112397465A CN 202011516736 A CN202011516736 A CN 202011516736A CN 112397465 A CN112397465 A CN 112397465A
- Authority
- CN
- China
- Prior art keywords
- heat
- chip
- radiating fin
- medium substrate
- heat dissipation
- Prior art date
- Legal status (The legal status 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 status listed.)
- Pending
Links
- 230000005855 radiation Effects 0.000 title claims description 19
- 239000000758 substrate Substances 0.000 claims abstract description 35
- 239000002184 metal Substances 0.000 claims abstract description 28
- 229910052751 metal Inorganic materials 0.000 claims abstract description 28
- 230000017525 heat dissipation Effects 0.000 claims abstract description 21
- 239000003292 glue Substances 0.000 claims abstract description 20
- 229910045601 alloy Inorganic materials 0.000 claims abstract description 13
- 239000000956 alloy Substances 0.000 claims abstract description 13
- 239000007788 liquid Substances 0.000 claims abstract description 13
- 229920001296 polysiloxane Polymers 0.000 claims abstract description 13
- 238000004806 packaging method and process Methods 0.000 claims abstract description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 7
- 229910052802 copper Inorganic materials 0.000 claims description 7
- 239000010949 copper Substances 0.000 claims description 7
- 229910000881 Cu alloy Inorganic materials 0.000 claims description 6
- 239000000853 adhesive Substances 0.000 claims 2
- 230000001070 adhesive effect Effects 0.000 claims 2
- 230000003287 optical effect Effects 0.000 abstract description 16
- 239000004519 grease Substances 0.000 abstract description 10
- 239000010410 layer Substances 0.000 description 19
- 239000000463 material Substances 0.000 description 3
- 238000001816 cooling Methods 0.000 description 2
- 239000002356 single layer Substances 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L23/00—Details of semiconductor or other solid state devices
- H01L23/34—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements
- H01L23/36—Selection of materials, or shaping, to facilitate cooling or heating, e.g. heatsinks
- H01L23/367—Cooling facilitated by shape of device
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L23/00—Details of semiconductor or other solid state devices
- H01L23/34—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements
- H01L23/36—Selection of materials, or shaping, to facilitate cooling or heating, e.g. heatsinks
- H01L23/367—Cooling facilitated by shape of device
- H01L23/3672—Foil-like cooling fins or heat sinks
Abstract
The invention discloses a chip heat dissipation structure, which comprises a heat conduction layer, a heat dissipation sheet and a heat conduction pad, wherein the heat conduction layer is directly contacted with a heat source on a medium substrate in a chip; the heat conduction layer is positioned between the radiating fin and the medium substrate and covers a heat source on the medium substrate; the radiating fin and the medium substrate are fixed through fixing glue; the heat conducting pad covers the front surface of the radiating fin, and the metal shell of the chip is attached to the heat conducting pad for packaging. The invention has the advantages that the heat-conducting silicone grease or liquid alloy is added in the middle of the metal radiating fin close to the heat source, and the fixing glue is added at the four corners of the metal radiating fin, so that the metal radiating fin is directly contacted with the heat source such as an integrated circuit or an optical device, and the thickness of the heat-conducting silicone grease or liquid alloy is greatly reduced. The heat conducting pad is contacted with the metal radiating fin with larger area, and the thermal resistance is in direct proportion to the thickness and in inverse proportion to the area, so that the total thermal resistance is greatly reduced, and the heat conducting pad has higher practical value.
Description
Technical Field
The invention relates to a chip heat radiation structure, and belongs to the field of chip manufacturing.
Background
With the development of communication technology, the speed of optical devices is doubled, and the electric power of the optical transceiver module is also increased more and more. Miniaturization of optical transceiver modules and high power of devices present challenges to thermal management inside the modules.
The original heat dissipation scheme adopts a single-layer heat conduction pad for heat dissipation. The heat conducting pad is directly contacted with the integrated circuit or the optical device, and the other surface of the heat conducting pad is contacted with the metal shell. Due to the structural requirement, the heat conduction pad has to have a certain compression ratio to compensate the tolerance of each part, and the thickness of the heat conduction pad is required, so that the heat conduction pad has to have a certain thickness. However, the thermal resistance of the thermal pad is proportional to the thickness, that is, the greater the thickness of the thermal pad, the greater the thermal resistance of the thermal pad, and the greater the thermal resistance of the thermal pad, so that the purpose of good heat dissipation cannot be achieved by the heat source directly contacting with the thermal pad.
Disclosure of Invention
The invention provides a chip heat radiation structure aiming at the problem of a heat radiation scheme of single-layer heat conduction pad heat radiation, and the specific technical scheme is as follows:
a chip heat dissipation structure comprises a heat conduction layer, a heat dissipation sheet and a heat conduction pad which are in direct contact with a heat source on a medium substrate in a chip, wherein two surfaces of the heat dissipation sheet are defined as a front surface and a back surface respectively; the heat conduction layer is positioned between the radiating fin and the medium substrate and covers a heat source on the medium substrate; the radiating fin and the medium substrate are fixed through fixing glue; the heat conducting pad covers the front surface of the radiating fin, and the metal shell of the chip is attached to the heat conducting pad for packaging.
According to the technical scheme, the heat conducting layer is added in the middle of the metal radiating fin close to the heat source on the medium substrate in the chip, the fixed glue is reinforced at the edge of the metal radiating fin and directly contacts the heat source such as an integrated circuit or an optical device, and the thickness of the heat conducting layer is greatly reduced. The heat conducting pad is contacted with the metal radiating fin with larger area, and the thermal resistance is in direct proportion to the thickness and in inverse proportion to the area, so that the total thermal resistance is greatly reduced, and the heat conducting pad has higher practical value.
In a further preferred embodiment of the present invention, the heat conducting layer is a heat conducting silicone layer or a liquid alloy layer.
Further preferably, in the technical solution of the present invention, the thickness of the heat conducting layer is less than 0.2 mm.
Preferably, the heat sink is provided with a plurality of round holes filled with fixing glue, and the heat sink is fixed on the surface of the medium substrate through the fixing glue. Because the heat-conducting silicone grease or liquid alloy with good heat conductivity coefficient can not fix the radiating fin, an additional spring or screw is needed to fix the radiating fin, and the spring or screw is difficult to install in the narrow space of the optical module; the heat sink can be conveniently fixed with glue, but the heat conductivity of such glue is poor. Therefore, the four corners of the metal radiating fin are provided with the round holes, and the fixing glue is added in the round holes to be directly contacted with heat sources such as an integrated circuit or an optical device, so that the thickness of the heat conducting layer is greatly reduced.
Preferably, the edge of the back surface of the heat sink is provided with an abdicating notch, the abdicating notch is vertically provided with a plurality of supporting legs, and the tail ends of all the supporting legs are supported on the surface of the medium substrate. The design of the abdicating notch on the back of the radiating fin aims to increase the installation space of the medium substrate.
In a further preferable mode of the technical scheme of the invention, the radiating fin is a rectangular body, two abdicating notches are arranged on the back surface of the radiating fin in parallel, four supporting legs are arranged at the two abdicating notches, and the four supporting legs are arranged at the positions of four corners of the radiating fin of the rectangular body. The supporting legs are arranged to play a role in assisting in fixing the radiating fins.
Further preferably, the tail ends of the supporting legs and the surface of the medium substrate are fixed by dispensing.
In a further preferred embodiment of the present invention, the heat sink and the support legs are made of copper or copper alloy, and the use of copper or copper alloy better refers to the heat conductivity.
According to the technical scheme of the invention, the front surface of the radiating fin is etched with a plurality of radiating fins in parallel. In the case of air cooling, heat can be dissipated through the heat dissipating fins.
Compared with the prior art, the invention has the following beneficial effects:
the chip heat radiation structure adopts two layers of heat radiation, the heat conduction silicone grease or liquid alloy is added between the metal heat radiation fins close to the heat source, and the fixing glue is added at the four corners, so that the metal heat radiation fins are directly contacted with the heat source such as an integrated circuit or an optical device, and the thickness of the heat conduction silicone grease or liquid alloy is greatly reduced. The heat conducting pad is contacted with the metal radiating fin with larger area, and the thermal resistance is in direct proportion to the thickness and in inverse proportion to the area, so that the total thermal resistance is greatly reduced, and the heat conducting pad has higher practical value.
Drawings
Fig. 1 is a perspective view of a chip heat dissipation structure.
Fig. 2 is a front view of the heat dissipation structure of the chip.
Fig. 3 is a first perspective view of the heat sink.
Fig. 4 is a second perspective view of the heat sink.
Fig. 5 is a schematic view of a heat sink mounted on a heat source on a dielectric substrate within a chip.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail with reference to fig. 1-5 and the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.
As shown in fig. 1 and 2, a chip heat dissipation structure includes a heat conductive layer in direct contact with a heat source 2 on a dielectric substrate 1 within a chip, a heat sink 3, and a heat conductive pad 4. Defining two surfaces of the radiating fin 3 as a front surface and a back surface respectively, wherein the back surface of the radiating fin 3 is attached to the surface of the medium substrate and is positioned at a heat source; the heat conduction layer is positioned between the radiating fin 3 and the medium substrate and covers a heat source on the medium substrate; the radiating fin 3 and the medium substrate are fixed through fixing glue; the heat conducting pad 4 covers the front surface of the radiating fin 3, and the metal shell 5 of the chip is attached to the heat conducting pad 4 for packaging.
According to the technical scheme, the radiating fins 3 are made of copper or copper alloy, and the heat conductivity coefficient of copper is high, so that heat of the heat source 2 is conducted out.
In the present embodiment, the heat source 2 on the dielectric substrate 1 in the chip refers to an integrated circuit or an optical device mounted on the dielectric substrate 1 in the chip, and the integrated circuit or the optical device generates heat during operation, and is therefore referred to as the heat source 2.
In this embodiment, the chip heat dissipation structure design can effectively reduce the technical problem that the thermal resistance is large because of the requirement of the thickness of the heat conduction pad: two sets of contradictions must be resolved to reduce the thermal resistance:
first, there are tolerances on the various parts within the chip, and also some tolerance on the thickness between the integrated circuit or optical device and the metal housing, but the thermal resistance is proportional to the thickness. In order to reduce the thermal resistance, the thinner the thickness of the heat dissipating material is, the better, the zero is preferable. The thickness of the material close to zero cannot compensate the thickness tolerance between the integrated circuit or the optical device and the metal shell, and once the thickness tolerance cannot be compensated, the thermal resistance will rise sharply to damage the device.
The technical scheme of the embodiment provides for solving the first contradiction, and adopts a structure of a metal radiating fin and a heat conducting pad; and a heat conduction layer is added in the middle of the metal radiating fin close to the heat source, and the heat conduction layer is a heat conduction silicone layer or a liquid alloy layer.
Secondly, the heat-conducting silicone grease or liquid alloy with good heat conductivity coefficient cannot fix the metal radiating fin, an additional spring or screw is needed to fix the radiating fin, and the spring or screw is difficult to install in the narrow space of the optical module; the heat sink can be conveniently fixed with glue, but the heat conductivity of such glue is poor.
In order to solve the second contradiction, the present embodiment proposes that the four corners of the metal heat sink are directly contacted with heat sources such as an integrated circuit or an optical device by adding the fixing glue, specifically: a plurality of round holes 34 are formed in the radiating fin 3, fixing glue is filled in the round holes, and the radiating fin 3 is fixed on the surface of the medium substrate through the fixing glue. By the design, the thickness of the heat-conducting silicone grease or the liquid alloy is greatly reduced. The thickness of the heat conducting layer in this embodiment is less than 0.2 mm. Finally, the heat conducting pad is in contact with the front surface of the metal radiating fin with a larger area, the thermal resistance is in direct proportion to the thickness and in inverse proportion to the area, so that the total thermal resistance is greatly reduced, and the heat conducting pad has a larger practical value.
The heat-conducting silicone grease or the liquid alloy mentioned in the technical scheme of the invention are all known heat-conducting layer materials with good heat-conducting systems in the technical field.
Further, in consideration of the arrangement of the heat source 2 on the dielectric substrate 1 in the chip, the metal heat sink 3 is provided with a relief notch 32 at the edge of the back surface of the heat sink 3, a plurality of support legs 31 are vertically provided at the relief notch 32, and the ends of all the support legs 31 are supported on the surface of the dielectric substrate. The end of the support leg 31 is fixed to the surface of the media substrate 1 by dispensing.
As shown in fig. 3 and 4, in the present embodiment, the heat sink 3 is a rectangular body, two abdicating notches 32 are arranged in parallel on the back surface of the heat sink 3, four supporting legs 31 are arranged at the two abdicating notches 32, and the four supporting legs 31 are located at the four corners of the heat sink 3 of the rectangular body. The ends of the four support legs 31 are fixed to the surface of the medium substrate 1 by dispensing.
As shown in fig. 3, 4 and 5, in the present embodiment, four circular holes 34 are always provided at four corners of the heat sink 3, fixing glue is injected into the circular holes 34, and the heat sink 3 is fixed on the dielectric substrate 1 in the chip by the fixing glue.
In this embodiment, the heat sink 3 is made of copper or copper alloy, and the support legs 31 are made of copper or copper alloy.
As shown in fig. 3 and 4, a plurality of heat dissipating fins 33 are etched in parallel on the front surface of the heat sink 3, and in the case of air cooling, heat can be dissipated through the heat dissipating fins 33.
The chip heat radiation structure provided by the embodiment adopts two layers of heat radiation, the heat conduction silicone grease or liquid alloy is added in the middle of the metal heat radiation sheet close to the heat source, and the four corners of the metal heat radiation sheet are added with the fixing glue, so that the metal heat radiation sheet is directly contacted with the heat sources such as an integrated circuit or an optical device, and the thickness of the heat conduction silicone grease or liquid alloy is greatly reduced. The heat conducting pad is contacted with the metal radiating fin with larger area, and the thermal resistance is in direct proportion to the thickness and in inverse proportion to the area, so that the total thermal resistance is greatly reduced, and the heat conducting pad has higher practical value.
It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (9)
1. A chip heat radiation structure is characterized by comprising a heat conduction layer, a heat radiation fin (3) and a heat conduction pad (4), wherein the heat conduction layer is directly contacted with a heat source on a medium substrate in a chip, two surfaces of the heat radiation fin (3) are defined as a front surface and a back surface respectively, and the back surface of the heat radiation fin (3) is attached to the surface of the medium substrate and is positioned at the heat source; the heat conduction layer is positioned between the radiating fins (3) and the medium substrate and covers a heat source on the medium substrate; the radiating fin (3) is fixed with the medium substrate through fixing glue; the heat conducting pad (4) covers the front surface of the radiating fin (3), and the metal shell (5) of the chip is attached to the heat conducting pad (4) for packaging.
2. The chip heat dissipation structure of claim 1, wherein the heat conductive layer is a heat conductive silicone layer or a liquid alloy layer.
3. The chip heat dissipation structure of claim 2, wherein the thickness of the heat conductive layer is less than 0.2 mm.
4. The chip heat dissipation structure according to claim 1, wherein the heat sink (3) has a plurality of circular holes, the circular holes are filled with a fixing adhesive, and the heat sink (3) is fixed on the surface of the dielectric substrate by the fixing adhesive.
5. The chip heat dissipation structure according to claim 1 or 4, wherein the edge of the back surface of the heat sink (3) is provided with an abdication notch (32), a plurality of support legs (31) are vertically arranged at the abdication notch (32), and the ends of all the support legs (31) are supported on the surface of the dielectric substrate.
6. The chip heat dissipation structure according to claim 5, wherein the heat sink (3) is a rectangular body, two abdicating notches (32) are arranged on the back surface of the heat sink (3) in parallel, four support legs (31) are arranged at the two abdicating notches (32), and the four support legs (31) are arranged at the four corners of the rectangular body of the heat sink (3).
7. The heat sink structure of claim 5, wherein the ends of the support legs (31) are fixed to the surface of the dielectric substrate by dispensing.
8. The chip heat dissipation structure according to claim 5, wherein the heat sink (3) and the support legs (31) are made of copper or a copper alloy.
9. The chip heat dissipation structure according to claim 1, wherein a plurality of heat dissipation fins (33) are etched in parallel on the front surface of the heat dissipation plate (3).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011516736.6A CN112397465A (en) | 2020-12-21 | 2020-12-21 | Chip heat radiation structure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011516736.6A CN112397465A (en) | 2020-12-21 | 2020-12-21 | Chip heat radiation structure |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112397465A true CN112397465A (en) | 2021-02-23 |
Family
ID=74625327
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011516736.6A Pending CN112397465A (en) | 2020-12-21 | 2020-12-21 | Chip heat radiation structure |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112397465A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113484471A (en) * | 2021-07-05 | 2021-10-08 | 郑州水伟环境科技有限公司 | Air exhaust chamber structure of micro thermal power pump of gas sensor |
| EP4357826A1 (en) * | 2022-10-19 | 2024-04-24 | Adtran Networks SE | Electronic module, especially optical transceiver module |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH10189841A (en) * | 1996-12-25 | 1998-07-21 | Nec Shizuoka Ltd | Heat sink |
| CN2632849Y (en) * | 2003-06-09 | 2004-08-11 | 旭扬热导股份有限公司 | Chip structure with fortified colloid hole solt |
| US20050068739A1 (en) * | 2003-09-26 | 2005-03-31 | Arvelo Amilcar R. | Method and structure for cooling a dual chip module with one high power chip |
| JP2005217003A (en) * | 2004-01-28 | 2005-08-11 | Kyocera Corp | Package for storing semiconductor element |
| CN201590413U (en) * | 2009-12-07 | 2010-09-22 | 中兴通讯股份有限公司 | Radiating structure of flip chip |
| CN205716741U (en) * | 2016-06-20 | 2016-11-23 | 创维液晶器件(深圳)有限公司 | Spacing pad and side incident type display device |
| CN107946263A (en) * | 2017-11-22 | 2018-04-20 | 华进半导体封装先导技术研发中心有限公司 | A kind of high efficiency and heat radiation encapsulating structure and its manufacture method based on graphene thermal boundary layer |
| WO2018223934A1 (en) * | 2017-06-05 | 2018-12-13 | 深圳市鸿富诚屏蔽材料有限公司 | Heat sink and manufacturing method therefor |
| WO2023071671A1 (en) * | 2021-10-26 | 2023-05-04 | 北京比特大陆科技有限公司 | Chip module and circuit board |
-
2020
- 2020-12-21 CN CN202011516736.6A patent/CN112397465A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH10189841A (en) * | 1996-12-25 | 1998-07-21 | Nec Shizuoka Ltd | Heat sink |
| CN2632849Y (en) * | 2003-06-09 | 2004-08-11 | 旭扬热导股份有限公司 | Chip structure with fortified colloid hole solt |
| US20050068739A1 (en) * | 2003-09-26 | 2005-03-31 | Arvelo Amilcar R. | Method and structure for cooling a dual chip module with one high power chip |
| JP2005217003A (en) * | 2004-01-28 | 2005-08-11 | Kyocera Corp | Package for storing semiconductor element |
| CN201590413U (en) * | 2009-12-07 | 2010-09-22 | 中兴通讯股份有限公司 | Radiating structure of flip chip |
| CN205716741U (en) * | 2016-06-20 | 2016-11-23 | 创维液晶器件(深圳)有限公司 | Spacing pad and side incident type display device |
| WO2018223934A1 (en) * | 2017-06-05 | 2018-12-13 | 深圳市鸿富诚屏蔽材料有限公司 | Heat sink and manufacturing method therefor |
| CN107946263A (en) * | 2017-11-22 | 2018-04-20 | 华进半导体封装先导技术研发中心有限公司 | A kind of high efficiency and heat radiation encapsulating structure and its manufacture method based on graphene thermal boundary layer |
| WO2023071671A1 (en) * | 2021-10-26 | 2023-05-04 | 北京比特大陆科技有限公司 | Chip module and circuit board |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113484471A (en) * | 2021-07-05 | 2021-10-08 | 郑州水伟环境科技有限公司 | Air exhaust chamber structure of micro thermal power pump of gas sensor |
| EP4357826A1 (en) * | 2022-10-19 | 2024-04-24 | Adtran Networks SE | Electronic module, especially optical transceiver module |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP1528850B1 (en) | Power electronic system with passive cooling | |
| CN213583120U (en) | Memory radiator | |
| TWI731622B (en) | Automotive electronic device | |
| CN112397465A (en) | Chip heat radiation structure | |
| CN114764269B (en) | Computing system and computing device | |
| TW201204227A (en) | Heat dissipation apparatus | |
| CN113115569B (en) | Display panel, display device and buffering heat radiation structure | |
| CN110060966B (en) | Optical module | |
| CN210130059U (en) | Heat dissipation device and electronic equipment | |
| CN209845602U (en) | Elastic heat conducting structure | |
| TWI607675B (en) | Dc/dc power module and dc/dc power system assembly | |
| CN211403361U (en) | Radiator, circuit board assembly and computing device | |
| CN214504355U (en) | Integrated heat dissipation device and Mini intelligent box | |
| US20050199377A1 (en) | Heat dissipation module with heat pipes | |
| CN110764598A (en) | Radiator, circuit board assembly and computing device | |
| CN210244274U (en) | Heat sink device | |
| CN219437446U (en) | Circuit board assembly | |
| CN219435299U (en) | Heat dissipation structure | |
| CN220674182U (en) | Power conversion module and energy storage equipment | |
| CN215647962U (en) | Mobile phone heat dissipation mainboard based on copper material | |
| CN214477407U (en) | Memory with ceramic radiating fin | |
| CN216852902U (en) | Natural convection type radiator for radiating heat of multiple heat sources | |
| CN220753407U (en) | Power tube assembly and PCB assembly | |
| CN215301268U (en) | GPU board card structure | |
| CN218920813U (en) | Heat abstractor for be used for circuit board electrical component |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |