Plugging hole grinding plate process

Abstract

The invention discloses a hole plugging and board grinding process which comprises the following steps: S1, taking a PET (Polyethylene Terephthalate) film, windowing the PET film at a windowing position corresponding to a resin hole in a circuit board, and windowing according to a size which is 4 mil larger than that of a single side of the resin hole; s2, pasting a PET film on the board surface of the circuit board, enabling the window on the PET film to correspond to the resin hole, and then positioning the PET film by using a pin; s3, the resin holes are filled with resin, and the windows in the PET film are filled and leveled up with the resin; s4, the circuit board filled with the resin is baked and kept for a certain time, so that the resin is cured; s5, after the resin is cured, the PET film is torn off, and after the PET film is torn off, the resin at the windowing position of the PET film forms a convex block; and S6, putting the circuit board into a board grinding machine to grind off the resin bumps so as to form a compliant circuit board. The PET film is pasted on the circuit board, and the window is formed in the PET film to correspond to the resin hole in the circuit board, so that the residual amount of resin on the board surface of the circuit board after hole plugging is reduced, and the expansion and shrinkage change of the circuit board in the board grinding process is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of circuit boards, and in particular to a plugging and grinding process. Background Art

[0002] With the development of miniaturization of assembled components, the wiring area of ​​PCB is also decreasing. In order to adapt to this development trend, the designers and manufacturers of PCB are constantly updating the design concepts and process methods.

[0003] The process of resin plugging is also a technical solution invented by people to reduce the design size of circuit boards and to assemble components. Its main purpose is to achieve the effect of plugging holes by filling various types of holes such as mechanical through holes and mechanical blind buried holes on circuit boards with conductive or non-conductive resins. This process is not only conducive to the vacuum reduction of lamination, but also can avoid the surface depression problem caused by insufficient lamination flow glue filling, which is conducive to the production of fine lines and the control of characteristic impedance; in addition, resin plugging can also effectively utilize three-dimensional space, realize arbitrary inter-layer interconnection through hole stacking technology, improve wiring density, and achieve higher density wiring by patch design on the hole.

[0004] At present, the conventional method of resin plugging in the industry is to use a vacuum plugging machine or a scraper to manually scrape the resin into the hole, and after the hole is fully filled, the excess resin on the board surface is recovered, and then the resin is dried and solidified at high temperature, and then the residual resin on the board surface is ground clean by a grinder. This process method causes a large expansion and contraction change to the circuit board, which in turn affects the alignment accuracy of subsequent circuit board drilling, shape processing, graphic exposure and other processes. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a plugging and grinding process, which can reduce the grinding area when grinding the board, and avoid the expansion and contraction of the circuit board during grinding, which affects the quality of the circuit board.

[0006] A plugging and grinding plate process according to an embodiment of the present invention includes:

[0007] S1, take a piece of PET film and make a window on the PET film. The window position corresponds to the resin hole on the circuit board and the window is made according to a size that is 4 mil larger than one side of the resin hole.

[0008] S2, attaching the PET film to the board surface of the circuit board, and making the openings on the PET film correspond to the resin holes, and then positioning the PET film using pins;

[0009] S3, plugging the resin into the resin hole so that the resin fills the window on the PET film;

[0010] S4, baking the circuit board plugged with resin and keeping it for a certain period of time to solidify the resin;

[0011] S5, after the resin is cured, the PET film is torn off, and after the PET film is torn off, the resin at the window opening position of the PET film forms a bulge;

[0012] S6, putting the circuit board into a grinding machine to grind off the resin bumps to form a compliant circuit board.

[0013] A plugging and grinding process according to an embodiment of the present invention has at least the following beneficial effects: the PET film is attached to the circuit board, and windows are opened on the PET film to correspond to the resin holes on the circuit board, so that the non-hole parts of the circuit board will not be adhered by the resin, that is, the residual amount of resin on the board surface of the circuit board after plugging the holes is reduced, and only the local resin protruding from the hole mouth of the resin hole is polished, thereby reducing the expansion and contraction changes in the production process of the printed circuit board, so that the alignment accuracy of the drilling, shape processing, graphic exposure and other processes on the circuit board is higher, thereby ensuring the production quality of the circuit board.

[0014] According to some embodiments of the present invention, in the S3 step, when plugging the holes with resin, the edges of the circuit board are supported so that the middle part of the circuit board with the holes is suspended in the air to maintain the permeability of the resin holes and enable the resin to be poured into the resin holes from the window position when plugging the holes.

[0015] According to some embodiments of the present invention, when plugging the holes, a scraper is used to press back and forth to scrape the resin so that the resin fills the resin holes.

[0016] According to some embodiments of the present invention, in the step S2, adhesive is first applied to the veneer surface of the PET film before the PET film is pasted.

[0017] According to some embodiments of the present invention, in the step S2, the circuit board is pre-punched with positioning holes, the positioning holes are distributed on the four corners of the circuit board, and the PET film should be positioned on the circuit board.

[0018] According to some embodiments of the present invention, in the step S4, curing the resin is performed by baking the circuit board, and the circuit board is baked in an oven, and a predetermined air pressure is given in the oven.

[0019] According to some embodiments of the present invention, in the step S4, the resin may be cured by UV light curing, and the circuit board may be placed under a UV lamp for irradiation.

[0020] According to some embodiments of the present invention, in the step S1, in the step S5, before tearing off the PET film, the PET film is blown with hot air to soften the PET film.

[0021] According to some embodiments of the present invention, in the step S6, cooling liquid is added when grinding the plate to remove the heat of the grinding plate.

[0022] According to some embodiments of the present invention, the circuit board is inspected after grinding, and the accumulated debris and dust on the surface of the circuit board are cleaned.

[0023] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0025] Figure 1 This is a schematic diagram of a circuit board after affixing a PET film according to an embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of a circuit board after being coated with resin according to an embodiment of the present invention;

[0027] Figure 3 Schematic diagram of the circuit board after the PET film is torn off according to the embodiment of the present invention

[0028] Figure 4 The figure is a schematic diagram of a circuit board after grinding according to an embodiment of the present invention.

[0029] Circuit board 100, resin hole 110;

[0030] PET film 200 and window opening position 210 . DETAILED DESCRIPTION

[0031] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0032] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0033] In the description of the present invention, "several" means one or more, "more" means two or more, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0034] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0035] Reference Figures 1 to 4 , a plugging and grinding plate process, comprising:

[0036] S1, take a PET film 200, and make a window on the PET film 200, wherein the window position 210 corresponds to the resin hole 110 on the circuit board 100, and the window is made according to a size that is 4 mil larger than one side of the resin hole 110;

[0037] S2, attaching a PET film 200 to the board surface of the circuit board 100, and making the openings on the PET film 200 correspond to the resin holes 110, and then positioning the PET film 200 using pins;

[0038] S3, plugging the resin into the resin hole 110, so that the resin fills the window on the PET film 200;

[0039] S4, baking the circuit board 100 plugged with resin and keeping it for a certain time to solidify the resin;

[0040] S5, after the resin is cured, the PET film 200 is torn off. After the PET film 200 is torn off, the resin at the window opening position 210 of the PET film 200 forms a convex block;

[0041] S6, placing the circuit board 100 into a grinding machine to grind off the resin bumps to form a compliant circuit board 100.

[0042] A PET film 200 is attached to the circuit board, and a window is opened on the PET film 200 to correspond to the resin hole 110 on the circuit board 100, so that the non-hole part of the circuit board 100 will not be attached by the resin, that is, the residual amount of resin on the board surface of the circuit board 100 after plugging the hole is reduced, and only the local resin protruding from the hole mouth of the resin hole 110 is polished, thereby reducing the expansion and contraction changes in the production process of the printed circuit board 100, so that the alignment accuracy of the drilling, shape processing, pattern exposure and other processes on the circuit board 100 is higher, thereby ensuring the production quality of the circuit board.

[0043] It should be noted that the size of the window of the PET film 200 has a critical impact on this process. If the window is too small, the quality of the plugging will be affected. This is because if the window is too small, the surface tension and viscous resistance of the resin will hinder the resin from entering the resin hole 110. If the window is too large, the effect of local resin residue cannot be achieved for dense holes; that is, when the resin holes 110 are too dense, the window will be too large and at least one hole will be accommodated in the window. Sometimes, two resin holes are in one window. This will also cause some positions that do not need to be filled with resin to be filled with resin, thus losing the effect to be expressed by the present invention.

[0044] In addition, the type of PET film 200 generally uses a medium viscosity film. If it is too sticky, there will be glue residue on the board surface after the film is torn off. If the viscosity is not enough, the film will fall off during the resin curing process, affecting the quality of the plugging hole.

[0045] In addition, the window opening method and parameter requirements of the PET film 200 are as follows:

[0046] The high temperature generated by the laser will melt the dense PET film 200, causing the dense holes to stick together. At the same time, there will be melted glue on the surface of the film, which will affect the quality of the plugging holes. Therefore, the PET film 200 is generally opened by mechanical drilling.

[0047] In some embodiments, in step S3, when plugging the hole with resin, the edge of the circuit board 100 is supported so that the middle part of the circuit board 100 with the hole is suspended in the air to maintain the permeability of the resin hole 110, so that the resin can be poured into the resin hole 110 from the window position 210 when plugging the hole. It should be noted that supporting the edge of the circuit board 100 actually allows the circuit board 100 to be suspended in the air. When supporting, a hollow bracket or a track plate can be used for support. Two track plates are provided, and the middle part of the circuit board 100 with the hole is suspended between the two track plates.

[0048] It should be noted that when plugging the hole, a scraper is used to press and scrape the resin back and forth so that the resin fills the resin hole 110. Scraping the resin back and forth can repeatedly put pressure on the resin, and after the resin enters the resin hole 110, scraping it again can allow the resin to fill the resin hole 110 again. In this way, repeated scraping allows the resin to fill the resin hole 110 and achieve the effect of plugging the hole.

[0049] It should be understood that in step S2, before attaching the PET film 200, adhesive is first applied to the veneer of the PET film 200. The adhesive is applied when the PET film is not sticky enough. It is necessary to use an appropriate adhesive or other fixing method to fix the PET film 200 on the circuit board. Other fixing methods, such as rivets or limit columns, fix the PET film by physical connection. The purpose of this step is to prevent the PET film 200 from shifting or falling off during use, thereby ensuring the reliability and stability of the electronic product. The process of opening the window involves punching holes or cutting out a specified area on the PET film 200, so that the window on the PET film 200 can be accurately aligned with the resin hole 110 on the circuit board 100. When opening the window, it is necessary to operate according to the specific position and size of the resin hole 110 on the circuit board 100.

[0050] In some embodiments, in step S2, the circuit board 100 is pre-punched with positioning holes, and the positioning holes are distributed on the four corners of the circuit board 100. The PET film 200 should be positioned on the circuit board. It is understandable that the PET film 200 also needs to be positioned after being pasted.

[0051] It should be noted that in step S4 , the resin is cured by baking the circuit board 100 . The baking of the circuit board 100 is carried out in an oven. A predetermined air pressure is applied in the oven. It is understandable that the air pressure in the oven is used to allow the resin to enter the resin holes 110 .

[0052] In some embodiments, in step S4, the resin can also be cured by UV light curing, and the circuit board 100 is placed under a UV lamp for irradiation. It should be understood that during the light curing process, both surfaces of the circuit board 100 are irradiated.

[0053] It should be emphasized that in step S1, before the PET film 200 is torn off in step S5, the PET film 200 is blown with hot air to soften the PET film 200. It should be noted that the PET film 200 is prevented from being stuck with resin.

[0054] In some embodiments, in step S6, coolant is added when grinding the plate to remove the heat from the grinding plate.

[0055] In some embodiments, after grinding, the circuit board 100 is inspected, and the accumulated debris and dust on the surface of the circuit board 100 are cleaned.

[0056] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A plugging and grinding plate process, characterized in that: include: S1, taking a PET film (200), and opening a window in the PET film (200), wherein the window opening position (210) corresponds to the resin hole (110) on the circuit board (100), and the window is opened in a size that is 4 mil larger than the single side of the resin hole (110); S2, attaching the PET film (200) to the board surface of the circuit board (100), making the opening on the PET film (200) correspond to the resin hole (110), and then positioning the PET film (200) using a pin; S3, inserting resin into the resin hole (110) so that the resin fills the opening on the PET film (200); S4, baking the circuit board (100) plugged with the resin and keeping it for a certain period of time to solidify the resin; S5, after the resin is solidified, the PET film (200) is torn off, and after the PET film (200) is torn off, the resin at the window opening position (210) of the PET film (200) forms a convex block; S6, placing the circuit board (100) into a grinding machine to grind off the resin bumps to form a compliant circuit board (100).

2. A plugging and grinding plate process according to claim 1, characterized in that: In the step S3, when the resin is plugged into the hole, the edge of the circuit board (100) is supported so that the middle part of the circuit board (100) with the hole is suspended in the air, so as to maintain the permeability of the resin hole (110) and enable the resin to be poured into the resin hole (110) from the window position (210) when plugging the hole.

3. A plugging and grinding plate process according to claim 1, characterized in that: When plugging the hole, use a scraper to press back and forth to scrape the resin so that the resin fills the resin hole (110).

4. A plugging and grinding plate process according to claim 1, characterized in that: In the step S2, before attaching the PET film (200), adhesive is first applied to the veneer surface of the PET film (200).

5. The plugging and grinding process according to claim 1, characterized in that: In the step S2, the circuit board (100) is pre-punched with positioning holes, the positioning holes are distributed at the four corners of the circuit board (100), and the PET film (200) should be positioned on the circuit board.

6. A plugging and grinding plate process according to claim 1, characterized in that: In the step S4, the resin is cured by baking the circuit board (100), and the baking of the circuit board (100) is carried out in an oven, and a predetermined air pressure is applied in the oven.

7. The plugging and grinding process according to claim 1, characterized in that: In the step S4, the resin may also be cured by UV light curing, and the circuit board (100) is placed under a UV lamp for irradiation.

8. The plugging and grinding process according to claim 1, characterized in that: In the step S1, in the step S5, before tearing off the PET film (200), the PET film (200) is blown with hot air to soften the PET film (200).

9. The plugging and grinding process according to claim 1, characterized in that: In the step S6, cooling liquid is added when the grinding plate is being ground so that the heat of the grinding plate can be taken away.

10. The plugging and grinding process according to claim 1, characterized in that: After grinding, the circuit board (100) is inspected, and the accumulated chips and dust on the surface of the circuit board (100) are cleaned.

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