CN111683456A - Method for manufacturing back-drilled printed circuit board - Google Patents
Method for manufacturing back-drilled printed circuit board Download PDFInfo
- Publication number
- CN111683456A CN111683456A CN202010186985.7A CN202010186985A CN111683456A CN 111683456 A CN111683456 A CN 111683456A CN 202010186985 A CN202010186985 A CN 202010186985A CN 111683456 A CN111683456 A CN 111683456A
- Authority
- CN
- China
- Prior art keywords
- hole
- drilling
- circuit board
- drill
- drill bit
- 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.)
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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
- H05K3/22—Secondary treatment of printed circuits
- H05K3/24—Reinforcing the conductive pattern
-
- 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
- H05K3/22—Secondary treatment of printed circuits
- H05K3/28—Applying non-metallic protective coatings
- H05K3/282—Applying non-metallic protective coatings for inhibiting the corrosion of the circuit, e.g. for preserving the solderability
-
- 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
Abstract
The invention belongs to the technical field of circuit board manufacturing, in particular to a method for manufacturing a back-drilled printed circuit board, which comprises the following steps: s1 film preparation; s2 applying; s3 drilling; s4 copper plating and tin plating; s5 back drilling hole solder resist; s6 solder mask of the surface of the circuit board; s7 back drilling. The invention can reduce the reject ratio of the back drilling hole, improve the quality of the manufactured circuit board hole, simultaneously prevent the problem of plating leakage and reduce the rejection rate of the circuit board.
Description
Technical Field
The invention relates to the technical field of circuit board manufacturing, in particular to a method for manufacturing a back-drilled printed circuit board.
Background
With the continuous progress of modern communication technology, PCBs used as communication base stations are continuously developing toward high multi-layer, high thickness and large size. Because the PCBs belong to a multi-layer circuit board with more than or equal to 16 layers, mutual conduction among different layers needs to be realized for high-speed signal transmission, impedance matching and other problems, and the high multi-layer circuit board has higher layers and thicker plate thickness, metalized blind holes cannot be manufactured by a method of laser blind holes and electroplating filling holes, however, with the improvement of the numerical control drilling machine technology, the back drilling process capable of controlling depth can well meet the requirement; backdrilling refers to removing a copper layer on the wall of a hole at one end in a metalized through hole by using a drilling machine, so that one end of the wall of the through hole has no copper and the other end has copper. The existing production process flow for PCBs with back drilled holes is generally as follows: cutting → inner layer pattern → inner layer etching → inner layer AOI → brown oxidation → pressing → outer layer drilling → outer layer copper deposition → whole plate plating → outer layer pattern → pattern plating → drill back drilling → outer layer alkaline time → outer layer AOI → solder resist plug hole → silk screen solder resist → character → surface processing → molding → electric test → FQC → packaging. However, the existing back-drilled printed circuit board is easy to have the phenomena of non-drilling or drilling, and the problem of plating leakage often occurs.
Disclosure of Invention
The invention aims to solve the defects in the prior art and provides a method for manufacturing a back-drilled printed circuit board.
In order to achieve the purpose, the invention adopts the following technical scheme:
a method for manufacturing a back-drilled printed circuit board comprises the following steps:
s1 film preparation: drawing according to the position of the rotary hole of the circuit board and the position of the outer layer circuit, and printing into a hollow adhesive film with the ratio of 1:1, wherein the hollow position is the position of the rotary hole and the position of the outer layer circuit;
s2 application: sticking the hollowed-out adhesive film on the circuit board;
s3 drilling: normally drilling a hole A at the position of the hollow adhesive film needing back drilling by a normal drill bit, wherein the drilling depth is H1, then replacing a small drill bit from the reverse side of the circuit board to drill a hole B, wherein the drilling depth is H2, when the small drill bit is communicated with the normal drill hole A, the hole is stopped to drill, and the diameter of the drill hole at the reverse side is smaller than that of the normal drill hole;
s4 copper plating and tin plating: copper is plated in the drill hole A and the drill hole B and on the exposed outer layer circuit, after the copper is plated to the required copper layer thickness, the tin is plated to the required tin layer thickness; metallizing the hole at the position of the back drilling hole to form a metallized hole;
s5 back-drilling solder resist: filling liquid photosensitive solder resist material in the metallized hole;
s6 circuit board surface solder mask: silk-printing a liquid photosensitive solder resist material on the surface of the circuit board, and then carrying out pre-baking, exposure and development treatment to form a solder resist layer;
s7 back drilling: and (3) drilling at the position of the reverse drilling hole A of the circuit board by using a drilling machine instead of a normal drill bit, drilling off the copper layer on the inner wall of the drilling hole B and the liquid photosensitive solder mask material, rotating the drill bit without resistance after the drill bit is drilled to the position of the drilling hole A, and then stopping drilling to form a back drilling hole with one end provided with the liquid photosensitive solder mask material and the other end without the liquid photosensitive solder mask material.
Preferably, the thickness of the liquid photosensitive solder resist material after prebaking in the step S6 is 30 to 40 micrometers.
Preferably, the aperture of the back drilled hole is 5mm, the aperture of the normal drilled hole A is 5mm, and the aperture of the drilled hole B is less than 5 mm.
Preferably, the drill bit in the step S3 is provided with a heat conducting coating, the heat conducting coating is a high temperature resistant heat conducting coating, the high temperature resistant heat conducting coating is a viscous suspension fluid composed of refractory powder, transition group element oxide, zirconia and silicate refractory material, solid solution and suspending agent are formed by high temperature doping, and the viscous suspension fluid is sprayed on the surface of the heat conductor to form a coating with a thickness of 0.3-0.5 mm.
Compared with the prior art, the invention has the beneficial effects that:
1. the problem that the precision of the existing mechanical depth control drilling technology of the circuit board is insufficient is solved, the high-precision depth control manufacturing of the back drilling hole is realized, the phenomenon that the back drilling hole is not drilled through or drilled is avoided, the reject ratio of the back drilling hole is reduced, and the quality of a hole of the manufactured circuit board is improved;
2. the back drilling is carried out after the solder mask is manufactured on the circuit board, so that the problem that the solder mask of a back drilling hole is not full can be solved, the solder mask can be prevented from polluting the solder mask surface, the appearance of the circuit board is prevented from being influenced, or the problem of plating leakage during subsequent surface treatment is avoided, and the rejection rate of products can be reduced;
the invention can reduce the reject ratio of the back drilling hole, improve the quality of the manufactured circuit board hole, simultaneously prevent the problem of plating leakage and reduce the rejection rate of the circuit board.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments.
Example one
A method for manufacturing a back-drilled printed circuit board comprises the following steps:
s1 film preparation: drawing according to the position of the rotary hole of the circuit board and the position of the outer layer circuit, and printing into a hollow adhesive film with the ratio of 1:1, wherein the hollow position is the position of the rotary hole and the position of the outer layer circuit;
s2 application: sticking the hollowed-out adhesive film on the circuit board;
s3 drilling: normally drilling a hole A at the position of the hollow adhesive film needing back drilling by a normal drill bit, wherein the drilling depth is H1, then replacing a small drill bit from the reverse side of the circuit board to drill a hole B, wherein the drilling depth is H2, when the small drill bit is communicated with the normal drill hole A, the hole is stopped to drill, and the diameter of the drill hole at the reverse side is smaller than that of the normal drill hole;
s4 copper plating and tin plating: copper is plated in the drill hole A and the drill hole B and on the exposed outer layer circuit, after the copper is plated to the required copper layer thickness, the tin is plated to the required tin layer thickness; metallizing the hole at the position of the back drilling hole to form a metallized hole;
s5 back-drilling solder resist: filling solder resist ink in the metalized hole;
s6 circuit board surface solder mask: silk-printing a liquid photosensitive solder resist material on the surface of the circuit board, and then carrying out pre-baking, exposure and development treatment to form a solder resist layer;
s7 back drilling: and (3) drilling at the position of the reverse drilling hole A of the circuit board by using a drilling machine instead of a normal drill bit, drilling off the copper layer on the inner wall of the drilling hole B and the liquid photosensitive solder mask material, rotating the drill bit without resistance after the drill bit moves to the position of the drilling hole A, and then stopping drilling to form a back drilling hole with the liquid photosensitive solder mask material at one end and the liquid-free solder mask ink at the other end.
In the present invention, the thickness of the liquid solder resist ink pre-baked in step S6 is 30 to 40 μm.
In the invention, the aperture of the back drilling hole is 5mm, the aperture of the normal drilling hole A is 5mm, and the aperture of the drilling hole B is less than 5 mm.
In the invention, the drill bit in the step S3 is provided with a heat conducting coating, the heat conducting coating is a high temperature resistant heat conducting coating, the high temperature resistant heat conducting coating is a sticky suspension fluid composed of refractory powder, transition group element oxide, zirconia and silicate refractory material, solid solution and suspending agent are formed by high temperature doping, and the sticky suspension fluid is sprayed on the surface of the heat conductor to form a coating with the thickness of 0.3-0.5 mm.
Example two
A method for manufacturing a back-drilled printed circuit board comprises the following steps:
s1 film preparation: drawing according to the position of the rotary hole of the circuit board and the position of the outer layer circuit, and printing into a hollow adhesive film with the ratio of 1:1, wherein the hollow position is the position of the rotary hole and the position of the outer layer circuit;
s2 application: sticking the hollowed-out adhesive film on the circuit board;
s3 drilling: normally drilling a hole A at the position of the hollow adhesive film needing back drilling by a normal drill bit, wherein the drilling depth is H1, then replacing a small drill bit from the reverse side of the circuit board to drill a hole B, wherein the drilling depth is H2, when the small drill bit is communicated with the normal drill hole A, the hole is stopped to drill, and the diameter of the drill hole at the reverse side is smaller than that of the normal drill hole;
s4 copper plating and tin plating: copper is plated in the drill hole A and the drill hole B and on the exposed outer layer circuit, after the copper is plated to the required copper layer thickness, the tin is plated to the required tin layer thickness; metallizing the hole at the position of the back drilling hole to form a metallized hole;
s5 back-drilling solder resist: filling liquid photosensitive solder resist material in the metallized hole;
s6 circuit board surface solder mask: silk-printing a liquid photosensitive solder resist material on the surface of the circuit board, and then carrying out pre-baking, exposure and development treatment to form a solder resist layer;
s7 back drilling: and (3) drilling at the position of the reverse drilling hole A of the circuit board by using a drilling machine instead of a normal drill bit, drilling off the copper layer on the inner wall of the drilling hole B and the liquid photosensitive solder mask material, rotating the drill bit without resistance after the drill bit is drilled to the position of the drilling hole A, and then stopping drilling to form a back drilling hole with one end provided with the liquid photosensitive solder mask material and the other end without the liquid photosensitive solder mask material.
In the invention, the thickness of the liquid photosensitive solder mask material pre-baked in the step S6 is 30 to 40 microns.
In the invention, the aperture of the back drilling hole is 5mm, the aperture of the normal drilling hole A is 5mm, and the aperture of the drilling hole B is less than 5 mm.
In the invention, the drill bit in the step S3 is provided with a heat conducting coating, the heat conducting coating is a high temperature resistant heat conducting coating, the high temperature resistant heat conducting coating is a sticky suspension fluid composed of refractory powder, transition group element oxide, zirconia and silicate refractory material, solid solution and suspending agent are formed by high temperature doping, and the sticky suspension fluid is sprayed on the surface of the heat conductor to form a coating with the thickness of 0.3-0.5 mm.
In the invention, film preparation: drawing according to the position of the rotary hole of the circuit board and the position of the outer layer circuit, and printing into a hollow adhesive film with the ratio of 1:1, wherein the hollow position is the position of the rotary hole and the position of the outer layer circuit; pasting: sticking the hollowed-out adhesive film on the circuit board; drilling: normally drilling a hole A at the position of the hollow adhesive film needing back drilling by a normal drill bit, wherein the drilling depth is H1, then replacing a small drill bit from the reverse side of the circuit board to drill a hole B, wherein the drilling depth is H2, when the small drill bit is communicated with the normal drill hole A, the hole is stopped to drill, and the diameter of the drill hole at the reverse side is smaller than that of the normal drill hole; copper plating and tin plating: copper is plated in the drill hole A and the drill hole B and on the exposed outer layer circuit, after the copper is plated to the required copper layer thickness, the tin is plated to the required tin layer thickness; metallizing the hole at the position of the back drilling hole to form a metallized hole; back drilling and resistance welding: filling liquid photosensitive solder resist material in the metallized hole; solder-resisting the surface of the circuit board: silk-printing a liquid photosensitive solder resist material on the surface of the circuit board, and then carrying out pre-baking, exposure and development treatment to form a solder resist layer; drilling a back drilling hole: and (3) drilling at the position of the reverse drilling hole A of the circuit board by using a drilling machine instead of a normal drill bit, drilling off the copper layer on the inner wall of the drilling hole B and the liquid photosensitive solder mask material, rotating the drill bit without resistance after the drill bit is drilled to the position of the drilling hole A, and then stopping drilling to form a back drilling hole with one end provided with the liquid photosensitive solder mask material and the other end without the liquid photosensitive solder mask material.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.
Claims (4)
1. A method for manufacturing a back-drilled printed circuit board is characterized by comprising the following steps:
s1 film preparation: drawing according to the position of the rotary hole of the circuit board and the position of the outer layer circuit, and printing into a hollow adhesive film with the ratio of 1:1, wherein the hollow position is the position of the rotary hole and the position of the outer layer circuit;
s2 application: sticking the hollowed-out adhesive film on the circuit board;
s3 drilling: normally drilling a hole A at the position of the hollow adhesive film needing back drilling by a normal drill bit, wherein the drilling depth is H1, then replacing a small drill bit from the reverse side of the circuit board to drill a hole B, wherein the drilling depth is H2, when the small drill bit is communicated with the normal drill hole A, the hole is stopped to drill, and the diameter of the drill hole at the reverse side is smaller than that of the normal drill hole;
s4 copper plating and tin plating: copper is plated in the drill hole A and the drill hole B and on the exposed outer layer circuit, after the copper is plated to the required copper layer thickness, the tin is plated to the required tin layer thickness; metallizing the hole at the position of the back drilling hole to form a metallized hole;
s5 back-drilling solder resist: filling liquid photosensitive solder resist material in the metallized hole;
s6 circuit board surface solder mask: silk-printing a liquid photosensitive solder resist material on the surface of the circuit board, and then carrying out pre-baking, exposure and development treatment to form a solder resist layer;
s7 back drilling: and (3) drilling at the position of the reverse drilling hole A of the circuit board by using a drilling machine instead of a normal drill bit, drilling off the copper layer on the inner wall of the drilling hole B and the liquid photosensitive solder mask material, rotating the drill bit without resistance after the drill bit is drilled to the position of the drilling hole A, and then stopping drilling to form a back drilling hole with one end provided with the liquid photosensitive solder mask material and the other end without the liquid photosensitive solder mask material.
2. The method of claim 1, wherein the thickness of the liquid photosensitive solder resist material pre-baked in step S6 is 30-40 μm.
3. The method of claim 1, wherein the diameter of the back-drilled hole is 5mm, the diameter of the normal drilled hole A is 5mm, and the diameter of the drilled hole B is less than 5 mm.
4. The method according to claim 1, wherein the drill bit in step S3 is provided with a heat conductive coating, the heat conductive coating is a high temperature resistant heat conductive coating, the high temperature resistant heat conductive coating is a viscous suspension fluid composed of refractory powder, transition group element oxide, zirconia, silicate refractory material, high temperature doping to form solid solution, suspending agent, etc., and the viscous suspension fluid is sprayed on the surface of the heat conductor to form a coating of 0.3-0.5 mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010186985.7A CN111683456A (en) | 2020-03-17 | 2020-03-17 | Method for manufacturing back-drilled printed circuit board |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010186985.7A CN111683456A (en) | 2020-03-17 | 2020-03-17 | Method for manufacturing back-drilled printed circuit board |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111683456A true CN111683456A (en) | 2020-09-18 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010186985.7A Pending CN111683456A (en) | 2020-03-17 | 2020-03-17 | Method for manufacturing back-drilled printed circuit board |
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| Country | Link |
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| CN (1) | CN111683456A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114481239A (en) * | 2022-04-06 | 2022-05-13 | 新恒汇电子股份有限公司 | Flexible lead frame preparation process capable of avoiding electroplating of blind holes |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05175651A (en) * | 1991-12-26 | 1993-07-13 | Oki Electric Ind Co Ltd | Manufacture of printed wiring board |
| CN203900569U (en) * | 2014-06-18 | 2014-10-29 | 昆山立特纳米电子科技有限公司 | Nano diamond film PCB micro drill |
| CN105578801A (en) * | 2015-12-15 | 2016-05-11 | 深圳崇达多层线路板有限公司 | Manufacturing method of back-drilling hole of solder resist ink half-plug hole |
| CN109348621A (en) * | 2018-09-12 | 2019-02-15 | 生益电子股份有限公司 | A kind of PCB production method and PCB |
-
2020
- 2020-03-17 CN CN202010186985.7A patent/CN111683456A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05175651A (en) * | 1991-12-26 | 1993-07-13 | Oki Electric Ind Co Ltd | Manufacture of printed wiring board |
| CN203900569U (en) * | 2014-06-18 | 2014-10-29 | 昆山立特纳米电子科技有限公司 | Nano diamond film PCB micro drill |
| CN105578801A (en) * | 2015-12-15 | 2016-05-11 | 深圳崇达多层线路板有限公司 | Manufacturing method of back-drilling hole of solder resist ink half-plug hole |
| CN109348621A (en) * | 2018-09-12 | 2019-02-15 | 生益电子股份有限公司 | A kind of PCB production method and PCB |
Non-Patent Citations (1)
| Title |
|---|
| 曹志超: "《乡镇企业机电实用技术手册 上册》", 31 December 1997 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114481239A (en) * | 2022-04-06 | 2022-05-13 | 新恒汇电子股份有限公司 | Flexible lead frame preparation process capable of avoiding electroplating of blind holes |
| CN114481239B (en) * | 2022-04-06 | 2022-06-24 | 新恒汇电子股份有限公司 | Flexible lead frame preparation process capable of avoiding electroplating of blind holes |
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Application publication date: 20200918 |