CN109640547B - Method for improving interlayer alignment precision of multilayer circuit board - Google Patents
Method for improving interlayer alignment precision of multilayer circuit board Download PDFInfo
- Publication number
- CN109640547B CN109640547B CN201811460758.8A CN201811460758A CN109640547B CN 109640547 B CN109640547 B CN 109640547B CN 201811460758 A CN201811460758 A CN 201811460758A CN 109640547 B CN109640547 B CN 109640547B
- Authority
- CN
- China
- Prior art keywords
- layer
- flow
- circuit board
- blocks
- flow blocking
- 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.)
- Active
Links
Images
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K3/00—Apparatus or processes for manufacturing printed circuits
- H05K3/46—Manufacturing multilayer circuits
- H05K3/4611—Manufacturing multilayer circuits by laminating two or more circuit boards
- H05K3/4626—Manufacturing multilayer circuits by laminating two or more circuit boards characterised by the insulating layers or materials
- H05K3/4632—Manufacturing multilayer circuits by laminating two or more circuit boards characterised by the insulating layers or materials laminating thermoplastic or uncured resin sheets comprising printed circuits without added adhesive materials between the sheets
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K3/00—Apparatus or processes for manufacturing printed circuits
- H05K3/46—Manufacturing multilayer circuits
- H05K3/4611—Manufacturing multilayer circuits by laminating two or more circuit boards
- H05K3/4638—Aligning and fixing the circuit boards before lamination; Detecting or measuring the misalignment after lamination; Aligning external circuit patterns or via connections relative to internal circuits
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Production Of Multi-Layered Print Wiring Board (AREA)
Abstract
The invention provides a method for improving interlayer alignment precision of a multilayer circuit board, which is characterized in that the multilayer circuit board comprises a core board layer, wherein a circuit diagram layer region is arranged on the core board layer, a flow blocking region is arranged on one side of the circuit diagram layer region, the flow blocking region comprises flow blocking blocks and a flow channel, and the flow channel is arranged between the flow blocking blocks; the multilayer circuit board realizes interlayer alignment through the flow blocking area so as to improve the interlayer alignment precision. The invention effectively discharges gas generated in the lamination process, and enables resin to uniformly fill gaps among the wires, so that the plate is uniform in thickness, flat in surface, smooth and tidy in plate edges, free from layering and foaming and other defects, and the efficiency can be maximized on the premise of ensuring the interlayer alignment precision and quality of products.
Description
Technical Field
The invention belongs to the technical field of circuit board processing, and particularly relates to a method for improving interlayer alignment precision of a multilayer circuit board.
Background
At present, the scientific technology is leap forward and the competition is increasingly violent, all industries enhance the improvement of the production efficiency and the product quality, and enhance the control of the manufacturing cost and the management of scientific specifications, thereby enhancing the competitiveness of enterprises. The interlayer alignment technology is an unusual and important technology in the manufacturing process of multilayer circuit boards, and has important influence on the stability of product quality, the effectiveness of processing efficiency and the aspect of manufacturing cost.
Nowadays, with the rapid development of the circuit board industry, people make great progress in the circuit board manufacturing process, but it is undeniable that many technical problems still exist and need to be solved, as for the interlayer alignment control technology, because the technical content, the process control and the influence depth are very large, the lamination process is an indispensable important process for printing the multilayer circuit board, no matter how simple or complex the circuit board manufacturing process and technology are, the lamination process is indispensable, and the interlayer alignment technology is an important support for ensuring the product quality of the circuit board. In terms of multilayer circuit boards, the interlayer dislocation phenomenon is a very common circuit board defect, and the defect generally exists in most circuit boards such as high-density multilayer boards, HDI boards, special boards and high-heat dissipation boards, and along with the increase of the number of layers of the circuit boards, the interlayer dislocation phenomenon is increased, the higher the number of layers is, the larger the interlayer dislocation is, and the more serious the dislocation phenomenon is.
Disclosure of Invention
In view of this, the present invention provides a method for improving the interlayer alignment precision of a multilayer circuit board, which effectively discharges gas generated in the lamination process, enables resin to uniformly fill the gaps between the wires, enables the thickness of the board to be uniform, the board surface to be flat, the board edges to be smooth and tidy, and avoids the defects of layering and bubbling in the board, and can maximize the efficiency on the premise of ensuring the interlayer alignment precision and quality of the product.
The technical scheme of the invention is as follows: the method for improving the interlayer alignment precision of the multilayer circuit board is characterized in that the multilayer circuit board comprises a core board layer, a circuit diagram layer region is arranged on the core board layer, a flow blocking region is arranged on one side of the circuit diagram layer region, the flow blocking region comprises flow blocking blocks and flow channels, and the flow channels are arranged between the flow blocking blocks; the multilayer circuit board realizes interlayer alignment through the flow blocking area so as to improve the interlayer alignment precision.
Furthermore, the horizontal section of the flow blocking block is a regular quadrangle with chamfers, and the flow channel formed between the flow blocking blocks can be smoother by arranging the flow blocking blocks in the shape of the layer, and meanwhile, the flow blocking blocks between the adjacent plate layers are easier to be matched and fixed.
Furthermore, the flow blocking blocks are symmetrically arranged in the flow blocking area, flow channels are formed among the flow blocking blocks, and the flow channels are filled with resin so as to realize the fixed connection of the adjacent core board layers.
Furthermore, the choke block comprises an outer layer, a protective layer and a hollow layer, and a matching block is arranged inside the hollow layer.
Furthermore, the matching block occupies 1/3-1/2 of the area of the hollow layer, so that the matching block and the hollow structure of the hollow layer are easier to match.
Furthermore, the coordination block is arranged on one side of the hollow layer.
Furthermore, the outer layer is a polyphenylene sulfide plastic layer, and a flow channel formed by the polyphenylene sulfide plastic layer can be formed between adjacent flow blocking blocks through the polyphenylene sulfide plastic layer, so that the resin can smoothly flow downwards along the flow channel, and the effect of filling the flow channel is realized.
Furthermore, the protective layer is a silica gel layer, the smoothness of the interior of the hollow layer in matching between the coordination blocks of the adjacent core plate layers can be improved through the arrangement of the silica gel layer, and meanwhile, the hollow layer is formed by the internal space formed by enclosing the silica gel layer.
Further, the coordination blocks of the adjacent core plate layers can be matched and connected with the other side of the hollow layer. According to the invention, one side of the hollow layer is the coordination block, the other side of the hollow layer is a hollow structure formed by enclosing of the silica gel layer, the alignment connection can be realized through the matching of adjacent core plate layers, specifically, the coordination block is matched with the hollow structure of the hollow layer, and meanwhile, the fixed connection of the adjacent core plate layers is realized through the filling of resin in the flow channel.
In the prior art, for a multilayer board (such as more than or equal to 10 layers) with high density, micro holes, high layers and thin plates, a designer usually separates a power supply layer, a ground layer and a signal layer to independently occupy one or more layers, because the areas of various functional conductors in the inner layer are not equal, and the conductor parts of each layer are distributed unevenly, a local area with high conductor density and another area with sparse conductor density is formed, even a local large-area copper foil area is left on the electricity and ground layer, and the thickness of the copper foil area is very thin (such as 0.10 mm), the dimensional change of each layer is inconsistent and the local dimensional change of each layer is different, the X-direction and Y-direction expansion difference and the like are caused, and the reasons can cause interlaminar dislocation.
In the invention, the rigidity of the sheet substrate is improved, the uniform escape of gas between layers and the uniform flow of resin during lamination are adopted to fill the flow channel, so that the uniformity of the size change of the substrate during lamination is improved, a reasonable flow blocking area is designed on each layer, the overflowing speed and uniformity of the resin during lamination are controlled by the flow blocking blocks in the flow blocking areas, the cleanness and tidiness of the laminated plate are ensured, the filling of the plate is full, the influence of impurities generated by excessive flow glue on the product quality is avoided, and the uniform plate thickness and the phenomena of layering and foaming are also ensured.
The invention effectively discharges gas generated in the lamination process, and enables resin to uniformly fill gaps among the wires, so that the plate is uniform in thickness, flat in surface, smooth and tidy in plate edges, free from layering and foaming and other defects, and the efficiency can be maximized on the premise of ensuring the interlayer alignment precision and quality of products.
Drawings
FIG. 1 is a schematic view of the processing structure of the present invention;
FIG. 2 is a schematic view of the flow blocking block according to the present invention.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.
Example 1
A method for improving the interlayer alignment precision of a multilayer circuit board is characterized in that the multilayer circuit board comprises a core board layer 10, a circuit diagram layer region 1 is arranged on the core board layer, a choke region 2 is arranged on one side of the circuit diagram layer region, the choke region comprises choke blocks 21 and a flow channel 22, and the flow channel is arranged between the choke blocks; the multilayer circuit board realizes interlayer alignment through the flow blocking area so as to improve the interlayer alignment precision.
Furthermore, the horizontal section of the flow blocking block is a regular quadrangle with chamfers, and the flow channel formed between the flow blocking blocks can be smoother by arranging the flow blocking blocks in the shape of the layer, and meanwhile, the flow blocking blocks between the adjacent plate layers are easier to be matched and fixed.
Furthermore, the flow blocking blocks are symmetrically arranged in the flow blocking area, flow channels are formed among the flow blocking blocks, and the flow channels are filled with resin so as to realize the fixed connection of the adjacent core board layers.
Further, the choke block comprises an outer layer 211, a protective layer 212 and a hollow layer 213, and a matching block 214 is arranged inside the hollow layer.
Furthermore, the matching block occupies 1/3 of the area of the hollow layer, so that the matching block and the hollow structure of the hollow layer are easier to match.
Furthermore, the coordination block is arranged on one side of the hollow layer.
Furthermore, the outer layer is a polyphenylene sulfide plastic layer, and a flow channel formed by the polyphenylene sulfide plastic layer can be formed between the adjacent flow blocking blocks through the polyphenylene sulfide plastic layer, so that the resin can smoothly flow down along the flow channel, and the effect of filling the flow channel is realized.
Furthermore, the protective layer is a silica gel layer, the smoothness of the interior of the hollow layer in matching between the coordination blocks of the adjacent core plate layers can be improved through the arrangement of the silica gel layer, and meanwhile, the hollow layer is formed by the internal space formed by enclosing the silica gel layer.
Further, the coordination blocks of the adjacent core plate layers can be matched and connected with the other side of the hollow layer. According to the invention, one side of the hollow layer is provided with the coordination block, the other side of the hollow layer is provided with the hollow structure formed by enclosing the silica gel layer, the alignment connection can be realized through the matching of the adjacent core plate layers, specifically, the coordination block is matched with the hollow structure of the hollow layer, and meanwhile, the fixed connection of the adjacent core plate layers is realized through the filling of resin in the flow channel.
In the prior art, for a multilayer board (such as more than or equal to 10 layers) with high density, micro holes, high layers and thin plates, a designer usually separates a power supply layer, a ground layer and a signal layer to independently occupy one or more layers, because the areas of various functional conductors in the inner layer are not equal, and the conductor parts of each layer are distributed unevenly, a local area with high conductor density and another area with sparse conductor density is formed, even a local large-area copper foil area is left on the electricity and ground layer, and the thickness of the copper foil area is very thin (such as 0.10 mm), the dimensional change of each layer is inconsistent and the local dimensional change of each layer is different, the X-direction and Y-direction expansion difference and the like are caused, and the reasons can cause interlaminar dislocation.
In the invention, the rigidity of the sheet substrate is improved, and the uniform escape of gas among layers and the uniform flow of resin during lamination are adopted to fill a flow channel, so that the uniformity of the size change of the substrate during lamination is improved, a reasonable flow blocking area is designed on each layer, and the overflowing speed and uniformity of the resin during lamination are controlled by the flow blocking blocks in the flow blocking areas, so that the cleanness and tidiness of a laminated plate are ensured, the filling of the plate is full, the influence of impurities generated by excessive flow glue on the product quality is avoided, and the plate thickness is ensured to be uniform, and the phenomena of layering and foaming are avoided.
The invention effectively discharges gas generated in the lamination process, and enables resin to uniformly fill gaps among the wires, so that the plate is uniform in thickness, flat in surface, smooth and tidy in plate edges, free from layering and foaming and other defects, and the efficiency can be maximized on the premise of ensuring the interlayer alignment precision and quality of products.
Example 2
A method for improving the interlayer alignment precision of a multilayer circuit board is characterized in that the multilayer circuit board comprises a core board layer 10, a circuit diagram layer region 1 is arranged on the core board layer, a choke region 2 is arranged on one side of the circuit diagram layer region, the choke region comprises choke blocks 21 and a flow channel 22, and the flow channel is arranged between the choke blocks; the multilayer circuit board realizes interlayer alignment through the choke zone so as to improve the interlayer alignment precision.
Furthermore, the horizontal section of the flow blocking block is a regular quadrangle with a chamfer, the flow channel formed between the flow blocking blocks can be more unobstructed by arranging the flow blocking blocks in the shape of the layer, and meanwhile, the flow blocking blocks between adjacent plate layers are more easily matched and fixed.
Furthermore, the flow blocking blocks are symmetrically arranged in the flow blocking area, flow channels are formed among the flow blocking blocks, and the flow channels are filled with resin so as to realize the fixed connection of the adjacent core board layers.
Further, the choke block comprises an outer layer 211, a protective layer 212 and a hollow layer 213, and a matching block 214 is arranged inside the hollow layer.
Further, the matching block occupies 1/2 of the area of the hollow layer, so that the matching block is more easily matched with the hollow structure of the hollow layer.
Furthermore, the coordination block is arranged on one side of the hollow layer.
Furthermore, the outer layer is a polyphenylene sulfide plastic layer, and a flow channel formed by the polyphenylene sulfide plastic layer can be formed between the adjacent flow blocking blocks through the polyphenylene sulfide plastic layer, so that the resin can smoothly flow down along the flow channel, and the effect of filling the flow channel is realized.
Furthermore, the protective layer is a silica gel layer, and through the arrangement of the silica gel layer, the smoothness of the interior of the hollow layer during matching between the coordination blocks of the adjacent core plate layers can be improved, and meanwhile, the hollow layer is formed by enclosing the inner space formed by the silica gel layer.
Further, the coordination blocks of the adjacent core plate layers can be matched and connected with the other side of the hollow layer. According to the invention, one side of the hollow layer is the coordination block, the other side of the hollow layer is a hollow structure formed by enclosing of the silica gel layer, the alignment connection can be realized through the matching of adjacent core plate layers, specifically, the coordination block is matched with the hollow structure of the hollow layer, and meanwhile, the fixed connection of the adjacent core plate layers is realized through the filling of resin in the flow channel.
Example 3
A method for improving the interlayer alignment precision of a multilayer circuit board is characterized in that the multilayer circuit board comprises a core board layer 10, a circuit diagram layer region 1 is arranged on the core board layer, a choke region 2 is arranged on one side of the circuit diagram layer region, the choke region comprises choke blocks 21 and a runner 22, and the runner is arranged between the choke blocks; the multilayer circuit board realizes interlayer alignment through the choke zone so as to improve the interlayer alignment precision.
Furthermore, the horizontal section of the flow blocking block is a regular quadrangle with a chamfer, the flow channel formed between the flow blocking blocks can be more unobstructed by arranging the flow blocking blocks in the shape of the layer, and meanwhile, the flow blocking blocks between adjacent plate layers are more easily matched and fixed.
Furthermore, the flow blocking blocks are symmetrically arranged in the flow blocking area, flow channels are formed among the flow blocking blocks, and the flow channels are filled with resin so as to realize the fixed connection of the adjacent core plate layers.
Further, the choke block comprises an outer layer 211, a protective layer 212 and a hollow layer 213, and a matching block 214 is arranged inside the hollow layer.
Further, the matching block occupies 2/5 of the area of the hollow layer, so that the matching block is more easily matched with the hollow structure of the hollow layer.
Furthermore, the coordination block is arranged on one side of the hollow layer.
Furthermore, the outer layer is a polyphenylene sulfide plastic layer, and a flow channel formed by the polyphenylene sulfide plastic layer can be formed between adjacent flow blocking blocks through the polyphenylene sulfide plastic layer, so that the resin can smoothly flow downwards along the flow channel, and the effect of filling the flow channel is realized.
Furthermore, the protective layer is a silica gel layer, the smoothness of the interior of the hollow layer in matching between the coordination blocks of the adjacent core plate layers can be improved through the arrangement of the silica gel layer, and meanwhile, the hollow layer is formed by the internal space formed by enclosing the silica gel layer.
Further, the coordination blocks of the adjacent core plate layers can be matched and connected with the other side of the hollow layer. According to the invention, one side of the hollow layer is the coordination block, the other side of the hollow layer is a hollow structure formed by enclosing of the silica gel layer, the alignment connection can be realized through the matching of adjacent core plate layers, specifically, the coordination block is matched with the hollow structure of the hollow layer, and meanwhile, the fixed connection of the adjacent core plate layers is realized through the filling of resin in the flow channel.
It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
Furthermore, it should be understood that although the present specification describes embodiments, not every embodiment includes only a single embodiment, and such description is for clarity purposes only, and it is to be understood that all embodiments may be combined as appropriate by one of ordinary skill in the art to form other embodiments as will be apparent to those of skill in the art from the description herein. It should be noted that the technical features not described in detail in the present invention can be implemented by any prior art in the field.
Claims (9)
1. The method for improving the interlayer alignment precision of the multilayer circuit board is characterized in that the multilayer circuit board comprises a core board layer, a circuit diagram layer region is arranged on the core board layer, a choke region is arranged on one side of the circuit diagram layer region, the choke region comprises choke blocks and runners, and the runners are arranged between the choke blocks; the multilayer circuit board realizes interlayer alignment through the flow resisting area so as to improve the interlayer alignment precision;
the choke block comprises an outer layer, a protective layer and a hollow layer, and a matching block is arranged in the hollow layer.
2. The method as claimed in claim 1, wherein the horizontal cross-section of the flow-blocking block is a regular quadrilateral with a chamfer.
3. The method as claimed in claim 1, wherein the flow-blocking blocks are symmetrically arranged in the flow-blocking area, and a flow channel is formed between the flow-blocking blocks.
4. The method of claim 1, wherein the alignment block occupies 1/3 to 1/2 of the area of the hollow layer.
5. The method of claim 1, wherein the alignment block is disposed on one side of the hollow layer.
6. The method of claim 1, wherein the outer layer is a polyphenylene sulfide layer.
7. The method of claim 1, wherein the protective layer is a silicone layer.
8. The method of claim 5, wherein the coordination blocks of adjacent core layers are connected to the other side of the hollow layer.
9. The method of claim 1, wherein the flow channel is filled with resin.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811460758.8A CN109640547B (en) | 2018-12-01 | 2018-12-01 | Method for improving interlayer alignment precision of multilayer circuit board |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811460758.8A CN109640547B (en) | 2018-12-01 | 2018-12-01 | Method for improving interlayer alignment precision of multilayer circuit board |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109640547A CN109640547A (en) | 2019-04-16 |
| CN109640547B true CN109640547B (en) | 2022-11-22 |
Family
ID=66070378
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811460758.8A Active CN109640547B (en) | 2018-12-01 | 2018-12-01 | Method for improving interlayer alignment precision of multilayer circuit board |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109640547B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112485969A (en) * | 2020-11-25 | 2021-03-12 | 广东世运电路科技股份有限公司 | Film and film processing technology |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102458033A (en) * | 2010-10-18 | 2012-05-16 | 上海嘉捷通电路科技有限公司 | Inner-layer plate side structure of thick-copper printed circuit board |
| CN202425188U (en) * | 2011-11-15 | 2012-09-05 | 胜宏科技（惠州）股份有限公司 | PCB with rhombic meshy gummosis slots |
| CN204131859U (en) * | 2014-09-09 | 2015-01-28 | 广州杰赛科技股份有限公司 | A kind of choker bar of multi-layer PCB board |
| CN205160902U (en) * | 2015-11-16 | 2016-04-13 | 磊鑫达电子(深圳)有限公司 | PCB technology limit gummosis structure |
| CN106255326B (en) * | 2016-08-26 | 2019-12-03 | 奥士康精密电路（惠州）有限公司 | A kind of multilayer impedance circuit board producing method improving edges of boards impedance strip |
-
2018
- 2018-12-01 CN CN201811460758.8A patent/CN109640547B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN109640547A (en) | 2019-04-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103209550B (en) | A kind of pressing laminate structure of multilayer printed board and the control method of pressing thickness | |
| CN102224771A (en) | Printed wiring board and method for manufacturing same | |
| JP2014127701A (en) | Wiring board and method of manufacturing the same | |
| MX2011013097A (en) | Circuit board and manufacturing method thereof. | |
| WO2022179163A1 (en) | Printed circuit board and manufacturing method therefor, and display device | |
| CN103153005A (en) | Multilayer printed board lamination method | |
| CN109640547B (en) | Method for improving interlayer alignment precision of multilayer circuit board | |
| CN102905464A (en) | Wiring board and method for manufacturing the same | |
| CN103108485A (en) | Multi-layer printed circuit board and manufacturing method thereof | |
| CN110213910A (en) | A kind of production method of 5G high frequency mixed pressure stepped circuit board | |
| WO2015196673A1 (en) | Pcb board and electronic apparatus | |
| CN106163081A (en) | The manufacture method of a kind of PCB and PCB | |
| US8921705B2 (en) | Wiring board and fabrication method therefor | |
| CN105101625A (en) | Uniform board edge gumming structure for PCB (Printed Circuit Board) inner-layer boards | |
| CN104735900A (en) | Circuit board with side face metal structure and manufacturing method thereof | |
| CN110392484A (en) | Circuit board drilling method and device | |
| CN102365006B (en) | Processing method of multi-layer circuit board | |
| CN201797646U (en) | Printed circuit board (PCB) structure capable for improving difference of dimensional stability of multilayer board | |
| CN107484342A (en) | A kind of ceramic PCB support plates preparation method of the materials of FR 4 | |
| CN105128454B (en) | A kind of double-side aluminum copper-clad plate of LED lamp | |
| CN210202171U (en) | Multilayer PCB structure with uniform plate thickness | |
| CN208227429U (en) | It is a kind of can electromagnetism interference circuit board | |
| TWI386135B (en) | Method for manufacturing multilayer printed circuit board and base for manufacturing the multilayer printed circuit board | |
| CN211792239U (en) | High-frequency blind hole printed board | |
| CN204887688U (en) | Microcellular structure of multilayer HDI circuit board |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |