CN112399716A - Back drilling method and preparation method of PCB and prepared PCB - Google Patents
Back drilling method and preparation method of PCB and prepared PCB Download PDFInfo
- Publication number
- CN112399716A CN112399716A CN202011116052.7A CN202011116052A CN112399716A CN 112399716 A CN112399716 A CN 112399716A CN 202011116052 A CN202011116052 A CN 202011116052A CN 112399716 A CN112399716 A CN 112399716A
- Authority
- CN
- China
- Prior art keywords
- drilling
- hole
- back drilling
- pcb
- layer
- 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
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
- H05K3/0011—Working of insulating substrates or insulating layers
- H05K3/0044—Mechanical working of the substrate, e.g. drilling or punching
- H05K3/0047—Drilling of holes
-
- 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
- H05K3/0094—Filling or covering plated through-holes or blind plated vias, e.g. for masking or for mechanical reinforcement
-
- 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
- H05K3/40—Forming printed elements for providing electric connections to or between printed circuits
- H05K3/42—Plated through-holes or plated via connections
- H05K3/429—Plated through-holes specially for multilayer circuits, e.g. having connections to inner circuit layers
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Production Of Multi-Layered Print Wiring Board (AREA)
- Perforating, Stamping-Out Or Severing By Means Other Than Cutting (AREA)
Abstract
The invention discloses a PCB back drilling method, a preparation method and the PCB, wherein the back drilling method comprises the steps of firstly drilling the same position twice by using drill pins with different diameters, drilling the position to different heights each time, recording the height of a main shaft, and calculating the thickness from a surface layer to an inner layer to obtain a new back drilling program; and then trying to make a first piece, finding an accurate compensation value through slicing, and calculating the final drilling depth to back drill. The invention also discloses a PCB board, wherein the back drilling holes on a plurality of substrates are connected with the auxiliary holes corresponding to the inner layers, and the auxiliary holes are processed by the back drilling method after being conducted. The PCB and the back drilling method thereof provided by the invention can meet the requirement of smaller Stub length under any depth and any position.
Description
Technical Field
The invention relates to a back drilling method and a preparation method of a PCB (printed circuit board) and the prepared PCB, and belongs to the technical field of PCBs.
Technical Field
Under the background of the rapid development of the communication industry, the requirements of high speed and high frequency of the PCB are higher and higher. The back drilling is used as a key process of the PCB, redundant hole copper above a signal layer in a metalized hole can be removed, and the loss of signals in the transmission process is reduced, so that the accuracy of the back drilling is improved, and the influence of Stub values is reduced, so that the requirements of different PCBs are met, and the back drilling is more important.
The prior art can overcome the influences of plate thickness uniformity and the like, but is limited by a detection mode, only aims at partial areas and partial points, and the stability of stubs at all positions cannot be guaranteed. The requirement that Stub length is small is met for any drilling depth and any position, and the prior art cannot solve the problem.
Disclosure of Invention
The invention provides a back drilling method of a PCB (printed circuit board), aiming at overcoming the defects in the prior art, and the method can meet the requirements of smaller Stub length and tolerance under any depth and any position.
The technical scheme adopted by the invention is as follows: a back drilling method for PCB board includes
A, preparing a substrate required by preparing a PCB (printed Circuit Board), wherein the substrate comprises a plurality of pieces, and inner layer patterns required to be manufactured are arranged on the substrate;
step b, pressing the substrates in the step a into a multilayer board;
c, drilling an auxiliary hole a on the multilayer board, and arranging hole copper electroplating for conduction in the auxiliary hole a;
d, drilling a bottom hole needing back drilling by adopting a back drilling method A;
step e, drilling a back drilling hole with a required aperture at the bottom hole in the step d by adopting a back drilling method B, and then expanding the auxiliary hole a to form an auxiliary hole B, wherein the inner diameter of the auxiliary hole B is larger than that of the auxiliary hole a, and the auxiliary hole a and the auxiliary hole B are coaxial;
and f, plugging the back drilling hole, the bottom hole and the auxiliary hole b by using resin.
Furthermore, when the back drilling hole is drilled in the step e, the back drilling hole is drilled between the MC layer and the MNC layer from the surface layer.
Further, the back drilling method a comprises: providing a back drilling program, drilling a back drilling bottom hole on the PCB by using a cover plate with a metal single surface; the method comprises the following steps of (1) drilling down the same coordinate position twice, gradually reducing the diameter of a drill point used in each drilling down, enabling the diameter of the drill point at the first time to be larger than that of the drill point at the second time, and collecting the height of a main shaft when the same coordinate position is drilled down to a set position twice; and obtaining the distance D from the surface layer to the MC layer through the height of the main shaft.
Furthermore, the bottom hole is a through hole, the aperture of the back drilling hole is larger than that of the bottom hole, and the back drilling hole is coaxial with the bottom hole.
Further, the back drilling method B includes the steps of:
1) adding half of theoretical distance between the MC layer and the MNC layer to the distance D from the surface layer to the MC layer to obtain the drilling depth D1
2) Obtaining a back drilling program according to the drilling depth D1 and the X, Y coordinates of the back drilling hole;
3) using the back drilling program to try to make a first piece, slicing and cutting each back drilling hole, checking the stub value, comparing the stub value with a standard value, and calculating a difference value R between the stub value and the standard value;
4) calculating the final drilling depth D2 according to the drilling depth D1 and the difference R,
5) and back drilling according to the back drilling program and the depth D2.
Further, the auxiliary hole b is disposed in an area outside the inner layer circuit of the multilayer board.
The invention also provides a preparation method of the pcb, which comprises the steps of
A, preparing a substrate required by preparing a PCB (printed Circuit Board), wherein the substrate comprises a plurality of pieces, and inner layer patterns required to be manufactured are arranged on the substrate;
step b, pressing the substrates in the step a into a multilayer board;
c, drilling an auxiliary hole a on the multilayer board, and arranging hole copper electroplating for conduction in the auxiliary hole a;
d, drilling a bottom hole needing back drilling by adopting a back drilling method A;
step e, drilling a back drilling hole with a required aperture at the bottom hole in the step d by adopting a back drilling method B, and then expanding the auxiliary hole a to form an auxiliary hole B, wherein the inner diameter of the auxiliary hole B is larger than that of the auxiliary hole a, and the auxiliary hole a and the auxiliary hole B are coaxial;
and f, plugging the back drilling hole, the bottom hole and the auxiliary hole b by using resin. The resin block can prevent the conduction of external factors and the surface and prevent the liquid medicine from remaining in the hole.
The invention also provides the PCB prepared according to the preparation method of the PCB.
The beneficial effects produced by the invention comprise: a PCB board and a manufacturing and back drilling method thereof can meet the requirements of Stub length and small tolerance under any depth and any position.
Drawings
FIG. 1 is a schematic cross-sectional view of an auxiliary hole of a PCB board of the present invention;
FIG. 2 is a schematic cross-sectional view of a PCB board back drilling method A and the auxiliary holes after being drilled;
fig. 3 is a schematic diagram of one embodiment of resin plug holes after the PCB back drilling method B of the present invention.
Detailed Description
The present invention is explained in further detail below with reference to the drawings and the specific embodiments, but it should be understood that the scope of the present invention is not limited to the specific embodiments.
The PCB is a multilayer board formed by pressing base boards, holes needing back drilling are designed on the multilayer board, the number of layers of the base boards drilled by different depths of back drilling holes is different, the PCB is divided into a non-drillable layer MNC (most not cut) 2 and a necessary-drillable layer MC (most cut)1 according to functions, and each back drilling hole corresponds to the MNC layer 2 and the necessary-drillable layer MC 1.
Example one
According to the preparation method of the PCB, the MC layer 1 of the back drilling hole on the PCB is connected with the auxiliary hole 3, the auxiliary hole is conducted with the MC layer of the back drilling hole after being electroplated, a drilling machine contacts the MC layer to form a conductive loop when drilling down, and the height value of a main shaft when contacting the MC layer can be recorded. And in the drilling through hole stage, calculating the distance D from the surface layer of all the holes to the MC layer by using a back drilling method A, performing normal back drilling by the following process, and calculating the drilling depth by using a back drilling method B to perform back drilling. The term "hole skin" as used herein means the total number of layers Ln in the case of the multilayer sheet, and the drilled surface of the hole skin means the L1 th layer or the Ln th layer.
The method specifically comprises the following steps:
step a: providing a plurality of substrates, and manufacturing inner layer patterns on the substrates;
step b: pressing the plurality of substrates and the outer-layer substrate to obtain a multilayer board;
step c: drilling a hole in the multilayer board, drilling only an auxiliary hole 3, and conducting with the MC layer after hole copper electroplating, as shown in figure 1; after electroplating, the hole wall is provided with a layer of copper, the copper is communicated with the MC layer, and the MC layer is communicated and connected with the surface layer through the hole wall copper. The setting provides assistance for the back drilling method A, the drill point contacts the MC layer when drilling, a loop is formed through the conduction of the auxiliary hole, an electric signal is generated, and the height value of the main shaft when the drill point contacts the MC layer is recorded.
Step d: the multilayer board is drilled with a back-drilled bottom hole 4 by a back-drilling method A, such as a left hole in figure 2; drilling holes other than the bottom hole 4 (the holes other than the bottom hole 4 refer to holes designed on the PCB without back drilling)) by using a common drilling mode;
step e: back drilling the multilayer board again, namely drilling a normal back drilling hole by using a back drilling method B, drilling the auxiliary hole 3, and expanding the auxiliary hole 3 by using a drill needle with the diameter being 4mil larger than the single side of the auxiliary hole 3 to obtain an auxiliary hole 9, such as the right hole in the figure 2; the auxiliary hole 3 is drilled to prevent the auxiliary hole 3 from contacting with a surface conductor to cause short circuit, and the drilled hole becomes a non-conductive hole (called as blind hole);
step f: and (3) plugging the back drilling hole 5, the bottom hole 4 and the auxiliary hole 9 by using resin of the multilayer board as shown in figure 3.
The back drilling method A comprises the steps of using a Schmoll CCD back drilling machine, wherein the back drilling principle is that a drilling needle is contacted with a plate surface to form a conductive loop, so that the designed depth of drilling is drilled, and the function of recording the height value of a main shaft contacted by the drilling needle during conduction is started before operation; the back drilling machine records the height values of the main shafts contacted by the drill point during the conduction in the background, the height values of the main shafts gradually deepened and drilled twice are respectively H0 and H1 (the zero point of a drilling machine is above), and the depth D is calculated according to a calculation formula and is the distance between the outer layer and the MC layer. The calculation formula is D = H1-H0The unit inch. The purpose of drilling twice is as follows: the first purpose is to open a window and obtain the height value of the main shaft of the surface layer, the window is used for preventing the contact with the copper of the surface layer to form a conductive circuit in advance when the second drill is used for contacting the MC layerAnd forming a conductive loop to obtain the height value of the main shaft of the MC layer.
The method comprises the following specific steps: the method comprises the following steps: providing a back drilling program, drilling a back drilling bottom hole 4 on the PCB by using a cover plate with a metal single surface; and (3) drilling the same coordinate position twice, as shown in figure 2, drilling the hole with a large diameter of 7 for the first time, setting the depth to be 8mil, drilling the surface layer 8 only, drilling the hole with a small diameter of 6 for the second time, directly drilling through without setting the depth, collecting the height of a main shaft of the same coordinate position when the hole is drilled to a specified position every time, and marking the height as H0、H1(ii) a Calculating data through a back drilling machine to obtain the distance between the surface layer 8 and the MC layer 1; through the method A, through holes are drilled, and meanwhile, thickness data D from the surface layer 8 to the MC layer 1 are obtained.
In the embodiment, the diameter difference of the first drill point and the second drill point is unilateral < =6mil, and the depth of the large-diameter drill point is 8mil, so that the situation that the subsequent normal back drill can drill the orifice of the electroplated copper is ensured. The large diameter uses the drill point with short edge length to ensure that the hole site precision meets the requirement.
Back drilling method B: a Schmoll CCD back drilling machine is used, and the back drilling principle is that a conductive loop is formed by a drill point contacting a board surface, so that the designed depth of drilling is achieved, and the function of recording the height value of a main shaft contacted by the drill point during the conduction is not required to be started before operation.
The method comprises the following specific steps:
step two: adding half of the theoretical distance between the MC and MNC layers to the data D obtained in the step one to obtain the drilling depth D1
Step three: and associating the data D1 with X and Y coordinates of a normal back drilling hole and the type of a cutter, splitting the coordinates with the depth difference according to the cutter number after software processing, increasing the cutter number again, accurately finishing the partitioning process, and finally outputting a new back drilling program.
Step four: a new back drill program is used to try the first sheet, slice each back drilled hole, look up the stub value, compare it with the standard value (i.e., the center value of the stub specification), and calculate the difference R.
Step five: the depth D1+/-R of each backdrilled hole, the final drill-down depth D2,
step six: the back drilling is performed by using a new back drilling program and the depth D2, and a drill point with the diameter 4mil larger than the single side of the auxiliary hole 3 is used to drill the auxiliary hole 3 through the program.
In the embodiment, the back drilling programs are partitioned according to the depth difference value of 1mil, the types of the cutters reach the limit of the drilling machine, and 2 or more programs need to be output, so that each back drilling hole can meet the requirement of extremely small Stub length.
In the embodiment, only the auxiliary hole 3 is drilled in the step c, only the auxiliary hole 3 is electroplated in the first hole copper electroplating, and the position of the auxiliary hole 3 needs to avoid an inner layer circuit;
in this embodiment, back drilling is performed on both the front and back surfaces, and the method a is performed from the front surface and the back surface twice, otherwise the accurate drilling depth cannot be calculated.
In this embodiment, after the back drilling is completed in step d, a hole is additionally drilled in the auxiliary hole during ordinary drilling, and the hole diameter is 4 mils larger than the single side of the auxiliary hole, so that smooth resin plugging of the auxiliary hole is ensured.
And e, the back drilling coordinates in the step e and the step c are consistent with the drilling sequence of each hole, the one-to-one correspondence between the coordinates and the depth is ensured, and the accuracy of the depth is ensured. If the total number of bottom holes needing back drilling on one side is N, the sequence and the position are from left to right when the back drilling method A is used for drilling, the corresponding hole ID from top to bottom is 1, 2, 3 … N, after the down drilling depth of each hole is obtained, the sequence and the position of the drilling are also 1, 2, 3 … N when the back drilling method B is used for drilling, and the depth can be in one-to-one correspondence.
In the step d, the sequence of back drilling before auxiliary hole drilling cannot be disordered, otherwise, the drilling depth cannot be calculated.
And c, operating the step c, the step d and the step e in sequence, otherwise, the drilling depth cannot be calculated.
Example two
A back drilling method of a PCB comprises steps c to e in the first embodiment.
EXAMPLE III
A PCB board is processed by the preparation method.
In the description of the present application, it is to be understood that the terms "central," "longitudinal," "lateral," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in the orientations and positional relationships indicated in the drawings for the convenience of description and simplicity of description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus are not to be considered limiting of the claimed invention.
The above description is only a preferred embodiment of the present invention, and the present invention is not limited to the content of the embodiment. It will be apparent to those skilled in the art that various changes and modifications can be made within the technical scope of the present invention, and any changes and modifications made are within the protective scope of the present invention.
Claims (7)
1. A preparation method of a PCB provided with a back drilling hole is characterized by comprising the following steps: comprises that
A, preparing a substrate required by preparing a PCB (printed Circuit Board), wherein the substrate comprises a plurality of pieces, and inner layer patterns required to be manufactured are arranged on the substrate;
step b, pressing the substrates in the step a into a multilayer board;
c, drilling an auxiliary hole a on the multilayer board, and arranging hole copper electroplating for conduction in the auxiliary hole a;
d, drilling a bottom hole needing back drilling by adopting a back drilling method A;
step e, drilling a back drilling hole with a required aperture at the bottom hole in the step d by adopting a back drilling method B, and then expanding the auxiliary hole a to form an auxiliary hole B, wherein the inner diameter of the auxiliary hole B is larger than that of the auxiliary hole a, and the auxiliary hole a and the auxiliary hole B are coaxial;
and f, plugging the back drilling hole, the bottom hole and the auxiliary hole b by using resin.
2. The method for manufacturing a PCB panel according to claim 1, wherein: and e, drilling a back drilling hole from the surface layer to the position between the MC layer and the MNC layer when drilling the back drilling hole.
3. The method for manufacturing a PCB panel according to claim 1, wherein: the back drilling method A comprises the following steps: providing a back drilling program, drilling a back drilling bottom hole on the PCB by using a cover plate with a metal single surface; the method comprises the following steps of (1) drilling down the same coordinate position twice, gradually reducing the diameter of a drill point used in each drilling down, and collecting the height of a main shaft when the same coordinate position is drilled down to a set position twice; and obtaining the distance D from the surface layer to the MC layer through the height of the main shaft.
4. The method for manufacturing a PCB panel according to claim 1, wherein: the bottom hole is a through hole, the aperture of the back drilling hole is larger than that of the bottom hole, and the back drilling hole is coaxial with the bottom hole.
5. The method for manufacturing a PCB panel according to claim 3, wherein: the back drilling method B comprises the following steps:
1) adding half of the theoretical distance between the MC layer and the MNC layer to the distance D from the surface layer to the MC layer to obtain the drilling depth D1;
2) obtaining a back drilling program according to the drilling depth D1 and the X, Y coordinates of the back drilling hole;
3) using the back drilling program to try to make a first piece, slicing and cutting each back drilling hole, checking the stub value, comparing the stub value with a standard value, and calculating a difference value R between the stub value and the standard value;
4) calculating the final drilling depth D2 according to the drilling depth D1 and the difference R,
5) and back drilling according to the back drilling program and the depth D2.
6. The method for manufacturing a PCB panel according to claim 1, wherein: the auxiliary hole b is arranged in the area outside the inner layer circuit of the multilayer board.
7. A PCB board prepared according to the method for preparing a PCB board of any one of claims 1 to 6.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011116052.7A CN112399716A (en) | 2020-10-19 | 2020-10-19 | Back drilling method and preparation method of PCB and prepared PCB |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011116052.7A CN112399716A (en) | 2020-10-19 | 2020-10-19 | Back drilling method and preparation method of PCB and prepared PCB |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112399716A true CN112399716A (en) | 2021-02-23 |
Family
ID=74596910
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011116052.7A Pending CN112399716A (en) | 2020-10-19 | 2020-10-19 | Back drilling method and preparation method of PCB and prepared PCB |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112399716A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114190011A (en) * | 2021-11-11 | 2022-03-15 | 江苏普诺威电子股份有限公司 | High-heat-dissipation PCB and manufacturing process thereof |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005116945A (en) * | 2003-10-10 | 2005-04-28 | Nec Corp | Multilayer printed-circuit board, and stub countersunk machine and method therefor |
| US20080087461A1 (en) * | 2006-10-16 | 2008-04-17 | Dell Products L.P. | Combination Impedance/Back Drill Coupon |
| CN101342604A (en) * | 2008-08-08 | 2009-01-14 | 东莞生益电子有限公司 | Hole drilling method with single-side brass plate as back drill cover plate |
| CN102883522A (en) * | 2012-09-28 | 2013-01-16 | 华为机器有限公司 | Printed circuit board, method and device for drilling printed circuit board |
| CN103433969A (en) * | 2013-08-28 | 2013-12-11 | 华为技术有限公司 | Drilling method and device of a printed circuit board |
| CN110475432A (en) * | 2019-08-08 | 2019-11-19 | 沪士电子股份有限公司 | A kind of pcb board and its manufacture and back drilling method |
-
2020
- 2020-10-19 CN CN202011116052.7A patent/CN112399716A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005116945A (en) * | 2003-10-10 | 2005-04-28 | Nec Corp | Multilayer printed-circuit board, and stub countersunk machine and method therefor |
| US20080087461A1 (en) * | 2006-10-16 | 2008-04-17 | Dell Products L.P. | Combination Impedance/Back Drill Coupon |
| CN101342604A (en) * | 2008-08-08 | 2009-01-14 | 东莞生益电子有限公司 | Hole drilling method with single-side brass plate as back drill cover plate |
| CN102883522A (en) * | 2012-09-28 | 2013-01-16 | 华为机器有限公司 | Printed circuit board, method and device for drilling printed circuit board |
| CN103433969A (en) * | 2013-08-28 | 2013-12-11 | 华为技术有限公司 | Drilling method and device of a printed circuit board |
| CN110475432A (en) * | 2019-08-08 | 2019-11-19 | 沪士电子股份有限公司 | A kind of pcb board and its manufacture and back drilling method |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114190011A (en) * | 2021-11-11 | 2022-03-15 | 江苏普诺威电子股份有限公司 | High-heat-dissipation PCB and manufacturing process thereof |
| CN114190011B (en) * | 2021-11-11 | 2024-02-23 | 江苏普诺威电子股份有限公司 | High-heat-dissipation PCB and manufacturing process thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103433969B (en) | The boring method of printed circuit board (PCB) and device | |
| CN106961798B (en) | A kind of deep method of PCB aperture processing control | |
| CN110475432B (en) | PCB and manufacturing and back drilling method thereof | |
| CN108391378B (en) | The production method of minute grooves on a kind of improvement wiring board | |
| CN108696997B (en) | Manufacturing method of semi-hole circuit board | |
| CN109168265A (en) | A kind of high-frequency microwave plate high density interconnection board manufacturing method | |
| CN109714907A (en) | A kind of production method of the multi-layer PCB for 5G communication | |
| CN104427762A (en) | Buried resistance printed board and manufacturing method thereof | |
| CN112399716A (en) | Back drilling method and preparation method of PCB and prepared PCB | |
| CN105682363A (en) | Fabrication method of PCB with metalized plate edges | |
| CN108617097B (en) | Manufacturing method of printed circuit board and printed circuit board | |
| CN113133226B (en) | Circuit board high-precision back drilling method and circuit board | |
| CN110740591B (en) | Blind hole processing method of multilayer printed board | |
| CN114828424A (en) | Method for improving alignment of back drilling hole | |
| CN114938570A (en) | High-precision PCB processing method | |
| CN115103513A (en) | PCB (printed circuit board) with high-depth-aperture-ratio metal blind hole plug-in hole and manufacturing process thereof | |
| JP2005268318A (en) | Method for manufacturing multilayer printed wiring board | |
| TWI786910B (en) | Circuit board and back-drilling method | |
| CN105682365A (en) | Method of manufacturing semi-metallized platform on PCB | |
| CN112911791B (en) | Printed circuit board for detecting deviation of drilling hole | |
| CN113597117B (en) | Ultra-deep PTH blind hole manufacturing method for large-size plate double areas | |
| CN112867266B (en) | PCB grooving process method | |
| CN117939808A (en) | Processing method of intensive back drilling and PCB | |
| KR20150059358A (en) | method for manufacturing a printed circuit board | |
| JPH01133392A (en) | Manufacture of printed wiring 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 | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20210223 |