A resin plugging method for PCB and PCB

Abstract

The present invention relates to the field of PCB technology, and discloses a PCB resin plugging method and a PCB. The PCB resin plugging method comprises the following steps: providing a PCB with a plated hole to be plugged with resin; applying magnetic inactivation glue on the peripheral area of ​​the plated hole on the PCB board surface and performing a curing treatment; after the magnetic inactivation glue is cured, plugging the plated hole with resin; after the resin is cured, heating the PCB by an alternating magnetic field until the magnetic inactivation glue is melted, and then removing the resin located at the outer end of the hole opening and the peripheral area of ​​the plated hole. The embodiment of the present invention adopts the method of first applying magnetic inactivation glue, then plugging the hole with resin, then melting the magnetic inactivation glue, and finally removing the overflowing resin, so that the resin that should overflow to the PCB board surface due to the resin plugging operation can overflow to the surface of the magnetic inactivation glue, and after the magnetic inactivation glue is melted, the overflowing resin can be separated from the board surface of the PCB, so that the overflowing resin can be easily and completely removed.

Description

Technical Field

[0001] The present invention relates to the technical field of PCBs (Printed Circuit Boards), and in particular to a resin plugging method for a PCB and the PCB. Background Art

[0002] The dense hole locations of current PCBs have large copper plating areas, low current density, and thinner copper thickness than other locations. Therefore, during the resin plugging process, some plugging resin will overflow onto the copper surface around the dense holes. After the board is cured, the copper surface at the dense hole locations is thin. When the ceramic grinding machine is used to grind the board, the resin on the copper surface at the dense hole locations is low due to the low board surface, which affects the subsequent copper plating and etching.

[0003] The current common practice is to manually polish with sandpaper, or to apply dry film before plugging and expose the holes to be plugged, then remove the film after plugging the resin and then remove excess resin with a ceramic grinding plate.

[0004] However, when the dense hole area is large, the exchange between the dry film under the resin and the film stripping solution is often insufficient, resulting in poor film stripping effect. When the concave area is large, the copper surface resin is often not completely removed. Summary of the Invention

[0005] The object of the present invention is to provide a resin plugging method for a PCB and a PCB, so as to overcome the defect in the prior art that it is difficult to completely remove the resin overflowing onto the copper surface when the recessed area is large.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] A method for resin plugging of PCB, comprising the steps of:

[0008] Providing a PCB, wherein the PCB has electroplated holes to be plugged with resin;

[0009] On the surface of the PCB, magnetic deactivation glue is applied to the peripheral area of ​​the electroplated hole and then cured;

[0010] After the magnetic inactivation glue is cured, plugging the electroplated holes with resin;

[0011] After the resin is cured, the PCB is heated by an alternating magnetic field until the magnetically inactivated glue is melted, and then the resin located at the outer end of the hole opening and the peripheral area of ​​the electroplated hole is removed.

[0012] Optionally, in the resin plugging method, the magnetic inactivation glue is applied by screen printing.

[0013] Optionally, the method of applying the magnetic inactivation glue by screen printing includes:

[0014] Providing a screen, and setting blocking points at positions of the screen corresponding to the electroplated holes;

[0015] Aligning the blocking points with the plated holes, placing the screen on the PCB;

[0016] Magnetic inactivation glue is coated on the screen, and the magnetic inactivation glue flows to the board surface of the PCB through the area of ​​the screen where no tapered blocking point is set.

[0017] Optionally, the blocking point is an inverted cone.

[0018] Optionally, after heating the PCB by an alternating magnetic field until the magnetic inactivation glue is melted, and before removing the resin located at the outer end and peripheral area of ​​the hole opening of the electroplated hole, it also includes: removing the magnetic inactivation glue by immersion ultrasonic water washing or high-pressure water washing.

[0019] Optionally, the removing of the resin at the outer end and peripheral area of ​​the hole opening of the electroplating hole includes: using ceramic and non-woven fabric to remove the resin at the outer end and peripheral area of ​​the hole opening of the electroplating hole.

[0020] Optionally, the curing method includes:

[0021] After coating the magnetic inactivation glue, the PCB is first left to stand for a preset time until the magnetic inactivation glue is initially solidified, and then the PCB is placed in an oven and baked until the magnetic inactivation glue is completely solidified.

[0022] A PCB is manufactured according to any one of the above methods for plugging holes with resin.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The embodiment of the present invention adopts a method of first applying magnetic inactivation glue, then plugging the holes with resin, then melting the magnetic inactivation glue, and finally removing the overflow resin. This can cause the resin that should overflow onto the PCB board surface due to the resin plugging operation to overflow onto the surface of the magnetic inactivation glue. After the magnetic inactivation glue is melted, a certain degree of separation can be generated between the overflow resin and the board surface of the PCB, and ultimately the overflow resin can be easily and completely removed. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 This is a flow chart of the resin plugging method for PCB provided in an embodiment of the present invention.

[0027] Figure 2 Schematic diagram of the resin plugging process for a PCB provided in an embodiment of the present invention.

[0028] Illustration: electroplated hole 1, magnetic inactivation glue 2, overflow resin 3, screen 4, stop point 5. DETAILED DESCRIPTION

[0029] In order to make the purpose, features, and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0030] To address the problem of difficulty in cleanly removing overflowed resin in the existing resin plugging process, an embodiment of the present invention uses a magnetically inactivated glue to reduce the difficulty of separating the overflowed resin from the PCB board surface. This not only facilitates the clean removal of the overflowed resin, but also reduces the difficulty and complexity of removing the overflowed resin.

[0031] See also Figure 1 and Figure 2 The embodiment of the present invention provides a method for resin plugging of PCB holes, comprising the steps of:

[0032] Step 101: Provide a PCB, on which a plated hole 1 to be plugged with resin is formed.

[0033] The number and size of the electroplated holes 1 can be set according to actual design requirements and are not specifically limited.

[0034] plating

[0035] Step 102: On the surface of the PCB, magnetic inactivation glue 2 is applied to the peripheral area of ​​the electroplated hole 1 and cured.

[0036] Since the resin usually overflows to the peripheral area of ​​the electroplated hole 1 rather than the entire board surface during the resin plugging operation, in order to reduce costs, the coating area of ​​the magnetic deactivation glue 2 can be limited to the peripheral area of ​​the electroplated hole 1.

[0037] Step 103: After the magnetic inactivation glue 2 is cured, the electroplating holes 1 are plugged with resin.

[0038] After the vias are plugged with resin, the uncured resin, due to its fluid properties, flows from the plated hole 1 to the surrounding area. At this point, because the cured magnetically inactivated glue 2 covers the area surrounding the plated hole 1, excess resin flows onto the surface of the magnetically inactivated glue 2 (for ease of description, this portion of resin is referred to as overflow resin 3 below). In other words, the overflow resin 3 and the magnetically inactivated glue 2 sequentially cover the area surrounding the plated hole 1 on the PCB surface from the outside to the inside.

[0039] Step 104 : After the resin is cured, the PCB is heated by an alternating magnetic field until the magnetically inactivated glue 2 is melted, and then the resin located at the outer end of the hole opening and the peripheral area of ​​the electroplated hole 1 is removed.

[0040] It should be noted that the magnetically inactivated glue 2 can be used with plastics, wood, glass, and metals, and its strength is comparable to current industrial adhesives. Unlike conventional glues, this magnetically inactivated glue 2 contains tiny iron oxide particles. When the magnetically inactivated glue 2 is exposed to a magnetic field oscillating at a certain frequency, the iron oxide particles heat up, causing the magnetically inactivated glue 2 to melt, making it easier to separate the two objects bonded by the magnetically inactivated glue 2.

[0041] The magnetic field itself is relatively weak and safe, and the hands of the person using it will not generate excessive heat. It only needs to be applied to the magnetic inactivation glue 2 for 30 seconds to melt the magnetic inactivation glue 2.

[0042] Therefore, the embodiment of the present invention adopts a method of first applying magnetic inactivation glue 2, then plugging the hole with resin, then melting the magnetic inactivation glue 2, and finally removing the overflow resin 3. The resin that should overflow to the PCB board surface due to the resin plugging operation can overflow to the surface of the magnetic inactivation glue 2. After the magnetic inactivation glue 2 is melted, a certain degree of separation is generated between the overflow resin 3 and the board surface of the PCB, so that the overflow resin 3 can be easily and completely removed.

[0043] The magnetic inactivation glue 2 can be directly applied to the PCB surface manually or by screen printing.

[0044] Specifically, the method of applying the magnetic inactivation glue 2 by screen printing includes:

[0045] Providing a screen 4, and setting blocking points 5 at positions of the screen 4 corresponding to the electroplating holes 1;

[0046] The screen 4 is placed on the PCB surface by aligning the stop points 5 with the electroplated holes 1;

[0047] The magnetically inactivated glue 2 is coated on the screen 4 , and the magnetically inactivated glue 2 flows to the board surface of the PCB through the area of ​​the screen 4 where no conical blocking point 5 is provided.

[0048] Compared with the manual coating method, the screen printing method not only has the advantage of high work efficiency, but also can achieve a uniform coating effect, laying a good foundation for the subsequent removal of overflow resin 3 operation.

[0049] To improve convenience, the stop points 5 applied to the screen 4 can be designed as inverted cones that match the corresponding electroplated holes 1. In this way, both the selective coating purpose and the precise positioning of the screen 4 and the electroplated holes 1 are achieved.

[0050] In the above-mentioned PCB resin plugging method, after heating the PCB by an alternating magnetic field until the magnetic inactivation glue 2 is melted, and before removing the resin located at the outer end and peripheral area of ​​the hole opening of the electroplated hole 1, it can also include: removing the magnetic inactivation glue 2 by immersion ultrasonic water washing or high-pressure water washing.

[0051] Since the magnetically inactivated glue 2 in a molten state is fluid and can be easily caused to flow out by washing with water, the embodiment of the present invention removes the magnetically inactivated glue 2 before removing the overflowing resin 3, so that a gap is formed between the resin overflowing to the peripheral area of ​​the electroplating hole 1 and the board surface of the PCB. In other words, the resin overflowing to the peripheral area of ​​the electroplating hole 1 is separated from the board surface of the PCB, which is more conducive to the execution of the removal operation of the overflowing resin 3.

[0052] Optionally, in the operation of removing the resin located at the outer end and peripheral area of ​​the hole opening of the electroplated hole 1 , ceramic and non-woven fabric may be used to remove the resin.

[0053] In addition, the curing method of the magnetic inactivation glue 2 includes: after applying the magnetic inactivation glue 2, first leaving the PCB to stand for a preset time until the magnetic inactivation glue 2 is initially cured, and then placing the PCB in an oven and baking until the magnetic inactivation glue 2 is completely cured.

[0054] In summary, the embodiment of the present invention achieves simple, efficient and clean removal of overflow resin 3 through the application of magnetically inactivated glue 2, and is particularly suitable for PCBs with dense holes.

[0055] An embodiment of the present invention further provides a PCB manufactured according to the above-mentioned PCB resin plugging method. Due to the use of the resin plugging method based on magnetically inactivated glue 2, overflow resin 3 can be easily and completely removed, thus having higher product quality.

[0056] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some of the technical features thereof can be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A resin plugging method for PCB, characterized in that: Including steps: Providing a PCB, wherein the PCB has electroplated holes to be plugged with resin; On the surface of the PCB, magnetic deactivation glue is applied to the peripheral area of ​​the electroplated hole and then cured; After the magnetic inactivation glue is cured, the electroplated holes are plugged with resin, and the resin overflows to the surface of the cured magnetic inactivation glue; After the resin is cured, the PCB is heated by an alternating magnetic field until the magnetically inactivated glue is melted, and then the resin located at the outer end of the hole opening and the peripheral area of ​​the electroplated hole is removed.

2. The resin plugging method for PCB according to claim 1, characterized in that: In the resin plugging method, the magnetic inactivation glue is coated by screen printing.

3. The resin plugging method for PCB according to claim 2, characterized in that: The method of applying the magnetic inactivation glue by screen printing comprises: Providing a screen, and setting blocking points at positions of the screen corresponding to the electroplated holes; The screen is placed on the PCB surface by aligning the blocking points with the electroplated holes; Magnetic inactivation glue is coated on the screen, and the magnetic inactivation glue flows to the board surface of the PCB through the area of ​​the screen where no tapered blocking point is set.

4. The resin plugging method for PCB according to claim 3, characterized in that: The blocking point is an inverted cone.

5. The resin plugging method for PCB according to claim 1, characterized in that: After the PCB is heated by the alternating magnetic field until the magnetic inactivation glue is melted, and before the resin at the outer end and peripheral area of ​​the hole opening of the electroplated hole is removed, the method further includes: removing the magnetic inactivation glue by immersion ultrasonic water washing or high-pressure water washing.

6. The resin plugging method for PCB according to claim 1, characterized in that: The method of removing the resin at the outer end and peripheral area of ​​the hole opening of the electroplating hole comprises: using ceramic and non-woven fabric to remove the resin at the outer end and peripheral area of ​​the hole opening of the electroplating hole.

7. The resin plugging method for PCB according to claim 1, characterized in that: The curing method comprises: After coating the magnetic inactivation glue, the PCB is first left to stand for a preset time until the magnetic inactivation glue is initially solidified, and then the PCB is placed in an oven and baked until the magnetic inactivation glue is completely solidified.

8. A PCB, characterized in that: The PCB is manufactured according to the resin plugging method for PCB according to any one of claims 1 to 7.

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