CN112512218A - Manufacturing method for improving small crimping hole of circuit board - Google Patents
Manufacturing method for improving small crimping hole of circuit board Download PDFInfo
- Publication number
- CN112512218A CN112512218A CN202011292447.2A CN202011292447A CN112512218A CN 112512218 A CN112512218 A CN 112512218A CN 202011292447 A CN202011292447 A CN 202011292447A CN 112512218 A CN112512218 A CN 112512218A
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- plate
- hole
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- holes
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Classifications
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- 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
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- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Printing Elements For Providing Electric Connections Between Printed Circuits (AREA)
Abstract
The invention discloses a manufacturing method for improving the small crimping hole of a circuit board, which comprises the following steps: drilling holes in the production plate, wherein the drilled holes comprise plug holes and crimping holes to be filled with resin; metallizing the plug holes and the compression joint holes by copper deposition and full-plate electroplating; filling resin in the metallized plug holes; removing resin protruding out of the plate surface by adopting a sand belt grinding plate; manufacturing a hole masking pattern on a production plate; the thickness of the copper surface at the non-hole is reduced through etching, and the film is removed; removing a hole ring protruding out of the plate surface at the thinned hole opening by adopting a sand belt grinding plate; then, roughly grinding the plate surface of the production plate twice, wherein the plate grinding directions during the two times of roughly grinding are opposite; and sequentially manufacturing an outer layer circuit, a solder mask layer, silk-screen characters, surface treatment and molding on the production board to obtain the circuit board. The invention can ensure that the burr of the hole ring at the hole opening is cut off and removed by adding the coarse grinding treatment twice after the plate is ground by the abrasive belt for the second time, and the directions of the two plate grinding are opposite, thereby solving the problem of small crimping hole caused by the burr of the hole opening.
Description
Technical Field
The invention relates to the technical field of printed circuit board manufacturing, in particular to a manufacturing method for improving the small crimping hole of a circuit board.
Background
When some circuit boards are subjected to crimping of devices at a client, the problem that crimping holes (generally designed hole diameters of 0.50mm and 0.36mm) in a positioning area are small is caused, so that crimping cannot be performed, when the circuit boards are manufactured, the minimum hole diameters of the crimping holes are required to be 0.45mm and 0.31mm respectively, actual measurement results are 0.42-0.44mm and 0.28mm-0.31mm, and the bad proportion is 100%.
Through slice observation and confirmation, the problem that the aperture of the plated aperture is small due to the very obvious burr of the crimping aperture of the plate is found, the aperture of the middle position of the aperture meets the requirement, and the aperture of the qualified plate is not influenced after the very small burr of the aperture is plated; the reason why the aperture of the 0.36mm and 0.50mm crimping hole is smaller is that the aperture has a serious burr, and the aperture of the aperture is further reduced after electroplating, so that the crimping component can not be crimped.
The circuit board with the resin plug hole is basically manufactured in two modes in the prior art, the first mode is that the resin plug hole and the compression joint hole are drilled separately, so that the copper surface is not required to be thinned too much, but a hole plating process and a secondary drilling process are required to be added, the whole process is complex and tedious, and the production efficiency is influenced; the second is to drill the resin plug hole and the compression joint hole together and reduce the hole plating process, the copper thickness of the surface reaches the design requirement by thinning the copper surface in the later period, the plate grinding process is carried out by abrasive belt after the copper is reduced by the one-time drilling process, the purpose of the process is to remove the hole ring of the PTH hole cover hole protruding out of the surface after the copper is reduced, when the plate is ground, as the abrasive belt is soft, the abrasive belt is slightly deformed along the hole position during the plate grinding process, so that part of the copper can not be cut off and removed to form a flash, and the hole aperture of the hole is too small after the flash is wrapped by subsequent pattern electro-coppering.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a manufacturing method for improving the small crimping hole of a circuit board, which can ensure that the hole ring burr at the hole opening is cut off and removed by adding coarse grinding treatment twice after the plate is ground by a second abrasive belt, and the directions of the two plate grinding are opposite, thereby solving the problem of small crimping hole caused by the hole ring burr.
In order to solve the technical problem, the invention provides a manufacturing method for improving the small crimping hole of a circuit board, which comprises the following steps:
s1, drilling holes in the production board, wherein the drilled through holes comprise plug holes and crimping holes for filling resin;
s2, metallizing the plug holes and the compression joint holes through copper deposition and full-plate electroplating procedures, and plating the hole wall copper thickness of the plug holes to the thickness required by design;
s3, filling resin in the metallized plug holes;
s4, removing resin protruding from the plate surface by using a belt sanding plate;
s5, manufacturing a hole masking pattern on the production board;
s6, thinning the thickness of the copper surface at the non-hole by etching, and retreating the film;
s7, removing a hole ring protruding out of the plate surface at the hole opening after the copper surface is thinned by adopting a sand belt grinding plate;
s8, roughly grinding the plate surface of the production plate twice, wherein the plate grinding directions in the two rough grinding processes are opposite;
and S9, sequentially manufacturing an outer layer circuit, a solder mask layer, silk-screen characters, surface treatment and molding on the production board to obtain the circuit board.
Further, in step S5, the hole masking pattern is transferred to the production board by a negative process, so that all the holes are completely covered by the protective film, and the copper surface on the production board other than the holes is completely exposed.
Further, in step S6, the remaining thickness of the copper surface after thinning by etching is controlled to 25. + -. 5 μm.
Further, in step S7, the thickness of the copper surface after passing through the belt sander is controlled to 20 + -5 μm.
Further, in step S8, the production board is roughly ground twice using a rough grinding machine.
Further, in step S8, when the production board is roughly ground, the width of the grinding mark is controlled to be 10-16 mm.
Further, in step S8, the production board is first subjected to rough grinding by a rough grinding machine, and after the first rough grinding, the production board is rotated by 180 degrees so that the front and rear directions of the production board are reversed, and then the production board is subjected to rough grinding by a rough grinding machine.
Further, the following steps are included between steps S8 and S9:
and S81, carrying out microetching treatment on the production plate.
Further, in step S81, the microetching amount in the microetching treatment is 2 μm.
Further, in step S1, the production board is a multi-layer board formed by laminating an inner core board and an outer copper foil together by a prepreg.
Compared with the prior art, the invention has the following beneficial effects:
according to the invention, when the production board is drilled, the plug holes and the compression joint holes to be filled with resin are drilled together, and then the plug holes and the compression joint holes are metallized through copper deposition and whole board electroplating procedures, so that the drilling times are reduced, the electroplating process is optimized, the manufacturing period of the circuit board is obviously shortened, and the production efficiency is improved; in order to solve the problem of small compression joint hole, the coarse grinding treatment is added twice after the plate is ground by the abrasive belt for the second time, and the directions of the plate grinding for the two times are opposite, so that the hole opening is cut back and forth, the ring burr at the hole opening is ensured to be completely cut off and removed, and the problem of small compression joint hole caused by the hole opening burr is solved; micro-etching treatment is added after coarse grinding treatment, so that firstly, the flatness of the board surface can be improved, the precision of a post-production line can be improved, secondly, burrs at the hole can be further removed, the burrs at the hole are ensured to be completely removed, and the quality of the crimping hole is further improved; in addition, the micro-etching amount during micro-etching treatment is controlled to be 2 mu m, so that the problems of over-thin surface copper and hole leakage of base materials caused by over-large etching amount are avoided while the hole burrs are effectively etched and removed and the flatness of the plate surface is improved.
Detailed Description
In order to more fully understand the technical contents of the present invention, the technical solutions of the present invention will be further described and illustrated with reference to specific embodiments.
Examples
The manufacturing method of the circuit board shown in this embodiment sequentially includes the following processing steps:
(1) cutting: the core plate is cut according to the size of the jointed board of 520mm multiplied by 620mm, the thickness of the core plate is 0.5mm (excluding the thickness of the outer layer copper), and the thickness of the outer layer copper surface of the core plate is 0.5oz (1oz is approximately equal to 35 mu m).
(2) And inner layer circuit manufacturing (negative film process): transferring the inner layer pattern, coating a photosensitive film by using a vertical coating machine, controlling the film thickness of the photosensitive film to be 8 mu m, completing the exposure of the inner layer circuit by using a 6-8-grid exposure ruler (21-grid exposure ruler) by using a full-automatic exposure machine, and forming the inner layer circuit pattern after development; etching the inner layer, etching the exposed and developed core board to form an inner layer circuit, wherein the line width of the inner layer is measured to be 3 mil; and (4) inner layer AOI, and then, detecting defects of an inner layer circuit, such as open short circuit, circuit notch, circuit pinhole and the like, and performing defect scrapping treatment, wherein a defect-free product is discharged to the next flow.
(3) And pressing: and (3) brown-oxidizing at the speed of brown-oxidizing according to the thickness of the bottom copper, sequentially laminating the core plate, the prepreg and the outer copper foil according to requirements, and then pressing the laminated plate by selecting proper lamination conditions according to the Tg of the plate to form the production plate.
(4) Drilling: according to the existing drilling technique, drilling is performed on the production board according to design requirements, and the drilled holes include a plug hole to be filled with resin and a crimp hole.
(5) And copper deposition: all holes on the production board were metallized, backlight test grade 10, and the thickness of the copper deposit in the holes was 0.5 μm.
(6) And electroplating the whole plate: according to the prior art and according to the design requirement, the production board is subjected to full-board electroplating, the board surface and the copper layer in the hole are thickened, and the thickness of the copper layer in the hole wall of the plug hole reaches the design requirement.
(7) And resin filling: and filling resin in the metallized plug holes.
(8) The first abrasive belt grinding plate: and removing the resin protruding out of the plate surface in the plug hole by using a belt sanding plate.
(9) And masking the hole pattern: and transferring the hole masking pattern, coating a photosensitive film by using a vertical coating machine, controlling the film thickness of the photosensitive film to be 8 mu m, completing hole masking pattern exposure by using a 6-8-grid exposure ruler (21-grid exposure ruler) by using a full-automatic exposure machine, and forming a hole masking pattern on the production plate after development, so that all the drill holes are completely covered by the protective film, and the copper surfaces of the non-hole positions on the production plate are completely exposed.
(10) Masking holes to reduce copper: then reducing the thickness of the copper surface at the non-hole by acid etching, and controlling the thickness of the copper after the etching reduction to be 25 +/-5 mu m; by reducing the thickness of the copper surface, the etching difficulty caused by too thick copper surface in the process of manufacturing the outer layer circuit is reduced, the later-stage manufacture of the outer layer circuit is facilitated, and then the protective film is removed; wherein, before reducing copper, the thickness of the copper on the full measuring surface of the 8-10pnl production board is measured by extraction, and the copper reduction amount is controlled strictly according to the requirement of the copper thickness.
(11) And a second abrasive belt grinding plate: and (3) removing surface copper (namely a hole ring) protruding from the plate surface at the orifice after the copper surface is thinned by adopting abrasive belt grinding, and controlling the residual thickness of the copper surface after the plate is ground by the abrasive belt to be 20 +/-5 mu m.
(12) Coarse grinding, namely performing coarse grinding twice on the production plate by using a coarse grinding machine, wherein the directions of the grinding plates during the two times of coarse grinding are opposite, and the width of a grinding mark is controlled to be 10-16mm during the coarse grinding of the production plate, so that the surface of the production plate forms uniform roughness; specifically, make the production board pass once rough grinding machine earlier and carry out the corase grind to it and handle, rotate 180 degrees to the production board after the first corase grind, pass once again after making the front and back direction of production board change rough grinding machine and carry out the corase grind to it to the mill board opposite direction of production board when making twice corase grind.
(13) And micro-etching: carrying out microetching treatment on the production plate, wherein the microetching amount during the microetching treatment is 2 mu m; wherein, before the micro-etching treatment, the core plate is required to be used for testing, and after the micro-etching quantity is confirmed to be OK, the micro-etching can be carried out on the production plate in batch.
(14) And manufacturing an outer layer circuit: adopting a full-automatic exposure machine and a positive film circuit film, completing outer layer circuit exposure by using 6-8 exposure rulers (21 exposure rulers), and forming an outer layer circuit graph on a production board through development; electroplating an outer layer pattern, and then respectively plating copper and tin on the production plate, wherein the copper plating is carried out for 60min at the current density of 1.8ASD, the tin plating is carried out for 10min at the current density of 1.2ASD, and the tin thickness is 3-5 mu m; then sequentially removing the film, etching and removing tin, and etching an outer layer circuit on the production board; the outer layer AOI is used for detecting the defects of open short circuit, circuit gaps, circuit pinholes and the like of the outer layer circuit and repairing or scrapping defective products; the outer layer pattern is measured in a front extraction mode by 8-10pnl production boards, the thickness of outer layer surface copper is measured completely, graph current parameters are given according to the copper thickness range, graph current is obtained in batches after the graph current needs to be subjected to FA first board confirmation and the surface copper is OK, and the hole copper is plated as thin as possible under the condition that the surface copper requirement is met.
(15) Solder resist and silk screen printing of characters: after the solder resist ink is printed on the surface of the production board in a silk-screen manner, the solder resist ink is cured into a solder resist layer through pre-curing, exposure, development and thermocuring treatment in sequence; specifically, TOP surface solder resist ink is printed by a white screen, and the TOP surface characters are added with UL marks, so that a protective layer which prevents bridging between circuits during welding and provides a permanent electrical environment and chemical corrosion resistance is coated on the circuits and the base materials which do not need to be welded, and the effect of beautifying the appearance is achieved.
(16) Surface treatment (nickel-gold deposition): the copper surface of the welding pad at the solder stop windowing position is communicated with a chemical principle, a nickel layer and a gold layer with certain required thickness are uniformly deposited, and the thickness of the nickel layer is as follows: 3-5 μm; the thickness of the gold layer is as follows: 0.05-0.1 μm.
(17) And electrical test: testing the electrical conduction performance of the finished board, wherein the board use testing method comprises the following steps: and (5) flying probe testing.
(18) And forming: according to the prior art and according to the design requirement, routing the shape, and obtaining the circuit board with the external tolerance of +/-0.05 mm.
(19) FQC: according to the customer acceptance standard and the inspection standard of my department, the appearance of the circuit board is inspected, if a defect exists, the circuit board is repaired in time, and the excellent quality control is guaranteed to be provided for the customer.
(20) FQA: and (5) measuring whether the appearance, the hole copper thickness, the dielectric layer thickness, the green oil thickness, the inner layer copper thickness and the like of the circuit board meet the requirements of customers or not again.
(21) And packaging: and hermetically packaging the circuit boards according to the packaging mode and the packaging quantity required by customers, putting a drying agent and a humidity card, and then delivering.
The technical solutions provided by the embodiments of the present invention are described in detail above, and the principles and embodiments of the present invention are explained herein by using specific examples, and the descriptions of the embodiments are only used to help understanding the principles of the embodiments of the present invention; meanwhile, for a person skilled in the art, according to the embodiments of the present invention, there may be variations in the specific implementation manners and application ranges, and in summary, the content of the present description should not be construed as a limitation to the present invention.
Claims (10)
1. A manufacturing method for improving the small crimping hole of a circuit board is characterized by comprising the following steps:
s1, drilling holes in the production plate, wherein the drilled holes comprise plug holes and crimping holes for filling resin;
s2, metallizing the plug holes and the compression joint holes through copper deposition and full-plate electroplating procedures, and plating the hole wall copper thickness of the plug holes to the thickness required by design;
s3, filling resin in the metallized plug holes;
s4, removing resin protruding from the plate surface by using a belt sanding plate;
s5, manufacturing a hole masking pattern on the production board;
s6, thinning the thickness of the copper surface at the non-hole by etching, and retreating the film;
s7, removing a hole ring protruding out of the plate surface at the hole opening after the copper surface is thinned by adopting a sand belt grinding plate;
s8, roughly grinding the plate surface of the production plate twice, wherein the plate grinding directions in the two rough grinding processes are opposite;
and S9, sequentially manufacturing an outer layer circuit, a solder mask layer, silk-screen characters, surface treatment and molding on the production board to obtain the circuit board.
2. The method as claimed in claim 1, wherein in step S5, the hole masking pattern is transferred to the production board by negative film process, so that all the holes are completely covered by the protective film and the copper surfaces on the production board other than the holes are completely exposed.
3. The manufacturing method for improving the small pressure contact hole of the circuit board according to claim 1, wherein in step S6, the residual thickness of the copper surface after the thinning by etching is controlled to be 25 ± 5 μm.
4. The manufacturing method for improving the small press contact hole of the circuit board according to claim 1, wherein in step S7, the thickness of the copper surface after passing through the belt sander is controlled to 20 ± 5 μm.
5. The manufacturing method for improving the small press contact hole of the circuit board according to claim 1, wherein in step S8, the production board is roughly ground twice by using a rough grinding machine.
6. The manufacturing method for improving the small press contact hole of the circuit board according to claim 5, wherein in step S8, the width of the grinding mark is controlled to be 10-16mm when the production board is roughly ground.
7. The manufacturing method of claim 6, wherein in step S8, the production board is roughly ground by a rough grinding machine, and after the first rough grinding, the production board is rotated 180 degrees, and after the front and back directions of the production board are changed, the production board is roughly ground by a rough grinding machine.
8. The manufacturing method for improving the small pressure contact hole of the circuit board as claimed in claim 1, wherein the steps between S8 and S9 further comprise the following steps:
and S81, carrying out microetching treatment on the production plate.
9. The manufacturing method of claim 8, wherein in step S81, the microetching amount in the microetching treatment is 2 μm.
10. The manufacturing method of improving the small press connection hole of the circuit board according to claim 1, wherein in step S1, the production board is a multi-layer board formed by laminating an inner core board and an outer copper foil together with a prepreg.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011292447.2A CN112512218A (en) | 2020-11-18 | 2020-11-18 | Manufacturing method for improving small crimping hole of circuit board |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011292447.2A CN112512218A (en) | 2020-11-18 | 2020-11-18 | Manufacturing method for improving small crimping hole of circuit board |
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| Publication Number | Publication Date |
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| CN112512218A true CN112512218A (en) | 2021-03-16 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011292447.2A Pending CN112512218A (en) | 2020-11-18 | 2020-11-18 | Manufacturing method for improving small crimping hole of circuit board |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN114599162A (en) * | 2022-03-25 | 2022-06-07 | 景旺电子科技(龙川)有限公司 | Circuit board burr processing method and circuit board |
| WO2023184727A1 (en) * | 2022-03-31 | 2023-10-05 | 生益电子股份有限公司 | Pcb grinding method, pcb regrinding device, and pcb |
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Application publication date: 20210316 |
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