CN101203091A - Circuit board repairing method - Google Patents

Abstract

A printed circuit board repair method includes: a defective daughter board removal step, removing a defective printed circuit board daughter board from a printed circuit board motherboard, and forming a groove at the periphery of the removal area on the motherboard; a normal daughter board repair step, repairing a normal daughter board to the aforementioned motherboard to replace the original defective daughter board, forming a flange corresponding to the groove at the periphery of the normal daughter board; a surface treatment step, treating the defective metal contacts on all daughter boards of the motherboard so that the defective metal contacts on all daughter boards have a uniform appearance surface. The present invention can maintain the precise relative position of the two when repairing the normal daughter board to the motherboard, reduce the slippage of the daughter board on the motherboard, and ensure that the metal contacts on each printed circuit board daughter board have a uniform appearance surface.

Description

Circuit Board Repair Method

technical field

The invention relates to a circuit board repair method

Background technique

For all kinds of electronic devices, whether it is a portable device with a small size or a large computer, the internal circuit board is an indispensable component. With the maturity of the printed circuit board industry, circuit boards manufactured with various technologies have been launched one after another. Although manufacturers strictly control the improvement and control of product yields during the manufacturing process, it is difficult to guarantee that the finished product yields will remain at the same level. 100% perfect condition.

Even with strict control, it is inevitable that defective products will appear in the mass production process. Please refer to Figure 4. When manufacturing printed circuit boards, for small-sized circuit boards, it is planned and designed on a mother board 50 Several regions are formed, and each region is used to form an independent sub-board 51, and its final product is each independent sub-board 51. This method is convenient for the machine to directly process the motherboard 50 and can produce higher number of circuit boards. If there is a defective sub-board 52 in a whole motherboard 50, the traditional method may abandon the entire motherboard 50, and in this way, all the other normal sub-boards 51 will be wasted, which will relatively improve its production for the manufacturer. cost.

With reference to Fig. 5 and Fig. 6, in order to solve the problem of this defective sub-board 52, a repair method is proposed. As far as the mother board 50 , the cross section of the cutting place of the mother board is shown in FIG. 6 , and the connection between the daughter board 51 and the mother board 50 is stepped.

There is following shortcoming in the method for aforementioned repairing circuit board:

1. When the normal sub-board 51 is replenished on the motherboard 50, since the two are combined in a stepped manner, if there is a gap between them, the sub-board 51 will slide horizontally on the motherboard 50, so for Subsequent board work can contribute to alignment errors.

2. Each batch of circuit boards manufactured at different time points may have slightly different appearances, so the sub-board 51 added to the motherboard 50 may be slightly different from the atomic board on the motherboard 50, especially In terms of the appearance of the metal contacts of the two, the metal contacts on the complementary sub-board 51 may have already been polluted or oxidized to present a poor appearance, thus adversely affecting the quality of the overall product.

From the above description, it can be known that the traditional circuit board repair method has the problems of displacement of the replacement sub-board and poor appearance of metal contacts, so the present invention proposes a good solution to these problems.

Contents of the invention

The main technical problem to be solved by the present invention is to overcome the above-mentioned defects in the prior art, and provide a method for repairing a printed circuit board, which can maintain a precise relative position between the normal sub-board and the motherboard when it is replaced. , to reduce the slipping phenomenon of the daughter board on the mother board, and ensure that the metal contacts on the daughter boards of each printed circuit board have a uniform appearance surface.

The technical solution adopted by the present invention to solve its technical problems is:

A method for repairing a printed circuit board, characterized in that it includes: a defective sub-board removal step, removing a defective printed circuit board sub-board from a printed circuit board motherboard, and removing it from the motherboard A groove is formed on the periphery of the removed area; a normal daughter board repairing step is to restore a normal daughter board to the aforementioned mother board to replace the original defective daughter board, and a groove corresponding to the normal daughter board is formed on the periphery of the normal daughter board. flange; a surface treatment step for treating defective metal contacts on all daughter boards of the motherboard so that the defective metal contacts on all daughter boards have a uniform surface appearance.

In the aforementioned method for repairing printed circuit boards, the step of removing defective daughter boards includes: detecting whether each daughter board on the motherboard is a defective product, performing appearance and electrical function checks, and noting the defective daughter boards according to A picture file is generated; the cutting coordinates of the defective daughter board are determined according to the target points on the mother board and the daughter board; and the defective daughter board is cut off from the mother board according to the cutting coordinates.

The above-mentioned printed circuit board repair method, wherein the normal sub-board repairing step includes: applying adhesive to the bonding area between the daughter board and the motherboard; checking whether the accuracy of the relative position of the daughter board and the motherboard meets the requirements, and if so, Then fit it.

The above-mentioned printed circuit board repairing method, wherein the surface treatment step includes: removing the unevenly colored metal contacts on the sub-board as the area to be processed; forming a protective film on the motherboard to expose only the aforementioned area to be processed; Rework the metal contacts on the area; remove the protective film.

In the aforementioned method for repairing the printed circuit board, the unevenly colored metal contacts on the sub-board are removed by means of etching, laser processing, micro-abrasive belts or grinding wheels.

In the aforementioned method for repairing a printed circuit board, the protective film is a dry film made of a polymer material.

In the aforementioned method for repairing a printed circuit board, the defective daughter board is cut off from the mother board by means of laser, stamping or micro-saw machining.

The aforementioned printed circuit board repair method, wherein the groove in the cutting area on the motherboard is a vertical groove, and the outer edge of the vertical groove is to form an upward convex stop edge; the peripheral edge of the supplementary daughter board is corresponding to the motherboard The vertical groove and the stop edge form a complementary structure.

The beneficial effect of the present invention is that when the normal sub-board is replaced on the motherboard, the two can maintain a precise relative position, reduce the slipping phenomenon of the sub-board on the motherboard, and ensure that the sub-boards of each printed circuit board Metal contacts have a uniform appearance surface.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

FIG. 1 is a schematic plan view of a printed circuit board motherboard of the present invention.

Fig. 2 is a cross-sectional view of an embodiment of the present invention.

Fig. 3 is a cross-sectional view of another embodiment of the present invention.

Fig. 4 is a schematic diagram of cutting a conventional repaired printed circuit board.

Fig. 5 is a perspective schematic diagram of a cutting gap of a conventional repaired printed circuit board.

Fig. 6 is a sectional view of a conventional repaired circuit board.

Explanation of symbols in the figure:

10 motherboard 11 motherboard target

12 engagement groove 13 stop edge

20 sub-board 20a defective sub-board

20b back to sub-board 21 sub-board target

22 Flange 23 Groove

50 motherboards

51 daughter boards

52 defective daughter boards

Detailed ways

Please refer to FIG. 1. First, a printed circuit board (PCB) motherboard 10 is inspected. Several independent sub-boards 20 are formed on the motherboard 10. The appearance inspection can be judged by visual inspection or by equipment, and the circuit The characteristic inspection can be carried out by means of a testing machine. After the inspection is completed, the defective area or sub-board 20 is marked, and a corresponding drawing file (CAD) is made, which is used for cutting equipment to remove the defective sub-board 20a For counterpoint with the whole.

Specifically, several motherboard targets 11 for rough alignment are firstly formed on the motherboard 10 , and daughterboard targets 21 for fine alignment are also formed on each daughterboard 20 . Then the motherboard 10 is transported to a laser cutting equipment, and the image recognition device CCD on the laser cutting equipment is used to calculate the expansion and contraction ratio of the overall motherboard 10 according to the motherboard target point 21, and then the laser cutting beam pair is used to judge it as a defect. The coordinate position of the plate 20a is cut. As shown in FIG. 2 , engaging grooves 12 are formed on the periphery of the cutting area on the motherboard 10 . When the thickness of the circuit board is greater than 0.8mm, a combination of micro-saw mechanical cutting, stamping and laser can be used to increase the processing speed.

In order to correspond to the joint groove 12 on the motherboard 10, the peripheral edge of the supplementary daughter board 20b as a replacement for the defective daughter board 20a is also processed to form a flange 22, and the joint surface of the joint groove 12 and the flange 22 is coated and bonded agent for bonding.

When carrying out the lamination operation, the image recognition device CCD is used to confirm whether the overall position accuracy meets the requirements according to the motherboard target point 11 and the daughter board target point 21. If the requirements are met, the lamination operation is carried out, otherwise, then It is automatically corrected by the operator or the machine, and after the correction is completed, the image recognition device CCD confirms that there is no error before laminating. Since the bonding between the complementary sub-board 20b and the motherboard 10 is that the flange 22 is placed in the groove 12 correspondingly, the slipping phenomenon between the two can be reduced, so that the overall position accuracy can be effectively improved.

Please refer to FIG. 3, another embodiment of the present invention is to form a vertical groove 12 at the periphery of the cutting area on the motherboard 10, and extend a vertically convex stop edge 13 on the outer edge of the groove 12, so that The peripheral edge of the patch board 20b is formed with a corresponding complementary structure, and the complementary structure also includes a vertical groove 23 and a flange 22 extending on the outer edge of the groove 23 .

When the filling operation is completed, another surface treatment procedure is carried out. If the metal joints on the sub-boards 20, 20b have different colors, use etching, laser processing, micro-abrasive belts, grinding wheels, etc. to remove the uneven color of the metal joints. After cleaning, the part of the non-metal contact area is covered with a protective film made of polymer materials such as dry film, and only the metal contact area to be repaired is exposed. Then re-make the metal contact in the cleaned area, and peel off the protective film after the metal contact is made, so that the finished product with uniform color is completed.

To sum up, the present invention can not only repair the defective area on a printed circuit board motherboard, but also maintain a good alignment effect during the repairing process to obtain better positional accuracy, and a surface treatment process can Ensures a uniform color appearance in the final product.

Claims (8)

1. A method for repairing a printed circuit board, characterized in that it comprises: A defective daughter board removal step is to determine that a defective printed circuit board daughter board is removed from a printed circuit board motherboard, and a groove is formed on the periphery of the removal area on the motherboard; A normal sub-board repair step, a normal daughter board is repaired to the aforementioned mother board to replace the original defective daughter board, and a flange corresponding to the groove is formed on the periphery of the normal daughter board; A surface treatment step, processing the defective metal contacts on all the sub-boards of the motherboard, so that the defective metal contacts on all the sub-boards have a uniform surface appearance. 2. The method for repairing a printed circuit board according to claim 1, wherein the defective sub-board removal step includes: Detect whether each sub-board on the motherboard is a defective product, check the appearance and electrical function, mark the defective sub-board and generate a picture file accordingly; Determine the cutting coordinates of the defective daughter board according to the target points on the mother board and the daughter board; Cut off the defective daughter board from the mother board according to the cutting coordinates. 3. The method for repairing a printed circuit board according to claim 1 or 2, wherein said normal sub-board replenishment step includes: Apply adhesive to the bonding area between the daughter board and the motherboard; Check whether the accuracy of the relative position of the sub-board and the motherboard meets the requirements, and if so, fit them together. 4. The method for repairing a printed circuit board according to claim 3, wherein said surface treatment step comprises: Remove the metal contacts with uneven color on the sub-board as the area to be processed; Forming a protective film on the motherboard, only exposing the aforementioned area to be processed; Re-make metal contacts on the area to be processed; Remove the protective film. 5. The method for repairing a printed circuit board according to claim 4, wherein the unevenly colored metal contacts on the sub-board are removed by means of etching, laser processing, micro-abrasive belts or grinding wheels. 6. The method for repairing a printed circuit board according to claim 4, wherein the protective film is a dry film made of a polymer material. 7. The method for repairing a printed circuit board according to claim 4, wherein the defective daughter board is cut off from the mother board by laser, stamping or micro-saw machining. 8. The method for repairing a printed circuit board according to claim 4, wherein the groove in the cutting area on the motherboard is a vertical groove, and the outer edge of the vertical groove forms an upper convex stop edge; The peripheral edge of the supplementary sub-board is a complementary structure formed by the vertical groove corresponding to the main board and the stop edge.

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