PCB large-diameter non-through hole drilling method
By making concentric copper pads on the PCB board and adding a transition layer, and drilling pre-drilled holes before drilling, the problem of hole damage and whitening in large diameter insurgent holes is solved, improving the drilling quality and reducing the defective part rate.
Patent Information
- Application Number
- CN202510343376.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-21
- Publication Date
- 2025-08-05
AI Technical Summary
In PCB process design, the holes are likely to become white or damaged when drilling large diameter incomplete holes, resulting in an increase in defective parts. The existing technology is difficult to effectively solve, resulting in an increase in labor and material costs.
Made a copper pad concentric with the infiltration area and add a transition layer thereon, using the transition layer to make up for the height difference, avoiding the drilling needle from directly contacting the substrate, and drilling multiple small-sized pre-drilled holes before drilling to remove chips, providing support and reducing pulling force during drilling.
It effectively avoids hole damage and whitening problems during drilling, reduces defective parts, reduces repair costs, and improves product quality stability.
Smart Images
Figure CN120434896A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a method for drilling large-diameter blind holes in a PCB board, and belongs to the technical field of printed circuit board processing. Background Art
[0002] During PCB design, customers often design large-diameter blind holes (≥3.6mm in diameter) on the PCB substrate to serve as fixed locations for electronic components. However, due to the large diameter of these blind holes, the hole openings can easily turn white or break due to a lack of support points during drilling. Defective products will need to be repaired later, and some products may even be too severely damaged to be repaired and become unqualified, requiring significant investment in manpower and material resources. Currently, existing technologies do not have a good method to improve the whitening of the large-diameter blind hole openings, resulting in significant fluctuations in product quality. Summary of the Invention
[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for drilling large-diameter blind holes in PCB boards, which can avoid whitening and hole damage when drilling large-diameter blind holes, and solve the current problem of defective parts being easily generated when drilling large-diameter blind holes.
[0004] In order to solve the above technical problems, the present invention is implemented by adopting the following technical solutions: The present invention provides a method for drilling large-diameter blind holes in a PCB board, comprising: In a predetermined area of a non-through hole to be drilled on the substrate, a copper pad concentric with the non-through hole is produced; Adding a transition layer on the copper pad to make the center of the blind hole flat, wherein the transition layer is concentric with the copper pad and the covering area does not exceed the area to be drilled of the blind hole; The center of the transition layer is used as the drilling center to drill a non-through hole.
[0005] Furthermore, after adding the transition layer, it is necessary to drill a plurality of pre-drilled holes with a size smaller than the size of the blind hole in the area to be drilled.
[0006] Furthermore, the pre-drilled hole has a diameter of 1.0-2.0 mm.
[0007] Furthermore, the position of the pre-drilled hole needs to avoid the center of the drilled hole.
[0008] Furthermore, the copper pad is a circular copper pad, and the copper pad is smaller than the area to be drilled by the non-through hole by X on one side, and the value range of X is 8-16 mil.
[0009] Furthermore, the step of adding a transition layer on the copper pad to smooth the center of the blind hole includes: completely covering the surface of the copper pad with the transition layer so that the copper pad does not form a height difference with the solder resist oil layer on the substrate.
[0010] Furthermore, the transition layer is larger than the copper pad on one side by Y, and the value of Y ranges from 4 to 8 mil.
[0011] Furthermore, the transition layer includes solder resist ink.
[0012] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention first makes a copper pad concentric with the blind hole in the area where the blind hole is to be drilled, thereby increasing the bonding force between the drill bit and the substrate surface while avoiding direct contact between the drill bit and the substrate surface. In addition, a transition layer is added to the surface of the copper pad. The transition layer makes up for the height difference between the copper pad and the substrate surface, provides support, and avoids the drill bit from moving downward smoothly due to the unevenness of the substrate surface, preventing the drill bit from damaging the substrate surface, and solving the current problem of defective parts easily appearing when drilling large-diameter blind holes.
[0013] 2. After adding the transition layer, the present invention also drills multiple pre-drilled holes with a size smaller than the size of the blind hole in the area to be drilled. The multiple small-sized pre-drilled holes are used to remove chips in advance, thereby avoiding drilling too many chips at one time when drilling a large-diameter blind hole, thereby avoiding excessive force on the hole mouth, causing pulling, and ultimately leading to damage to the hole mouth. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 This is a flow chart of a method for drilling large-diameter blind holes in a PCB board provided by an embodiment of the present invention; Figure 2 This is a schematic diagram of a drilling structure for a large-diameter blind hole on a PCB board provided in Example 1 of the present invention; Figure 3 This is a schematic diagram of a drilling structure for a large-diameter blind hole on a PCB board provided in Example 2 of the present invention.
[0015] In the figure: 1. Blind hole; 2. Copper pad; 3. Transition layer; 4. Pre-drilled hole. DETAILED DESCRIPTION
[0016] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Example 1
[0017] like Figure 1 As shown, a method for drilling a large-diameter blind hole 1 on a PCB board includes: In the area of the blind hole 1 to be drilled that is predetermined on the substrate, a copper pad 2 is made that is concentric with the blind hole 1; Figure 2As shown, the copper pad 2 is circular and is smaller than the area to be drilled of the blind hole 1 by X on one side, with the value of X ranging from 8 to 16 mils. By first making the copper pad 2 concentric with the blind hole 1 in the area to be drilled, the surface bonding force between the drill bit and the substrate is increased while avoiding direct contact between the drill bit and the substrate surface in the longitudinal direction. Add a transition layer 3 on the copper pad 2 to level the center of the blind hole 1, wherein the transition layer 3 is concentric with the copper pad 2 and the coverage area does not exceed the area to be drilled of the blind hole 1. Specifically: The transition layer 3 is completely covered on the surface of the copper pad 2 so that the copper pad 2 does not form a height difference with the solder mask oil layer on the substrate. The transition layer 3 is larger than the copper pad 2 on one side by Y, and the value of Y ranges from 4 to 8 mils. The transition layer 3 makes up for the height difference between the copper pad 2 and the substrate surface, while providing support and preventing the drill from moving down smoothly due to the uneven substrate surface, thereby causing damage to the substrate surface; In this embodiment, the transition layer 3 is a solder resist ink layer; A non-through hole 1 is drilled with the center of the transition layer 3 as the drilling center. Example 2
[0018] like Figure 1 As shown, a method for drilling a large-diameter blind hole 1 on a PCB board includes: In the area of the blind hole 1 to be drilled that is predetermined on the substrate, a copper pad 2 is made that is concentric with the blind hole 1; Figure 3 As shown, the copper pad 2 is circular and is smaller than the area to be drilled of the blind hole 1 by X on one side, with the value of X ranging from 8 to 16 mils. By first making the copper pad 2 concentric with the blind hole 1 in the area to be drilled, the surface bonding force between the drill bit and the substrate is increased while avoiding direct contact between the drill bit and the substrate surface in the longitudinal direction. Add a transition layer 3 on the copper pad 2 to level the center of the blind hole 1, wherein the transition layer 3 is concentric with the copper pad 2 and the coverage area does not exceed the area to be drilled of the blind hole 1. Specifically: The transition layer 3 is completely covered on the surface of the copper pad 2 so that the copper pad 2 does not form a height difference with the solder mask oil layer on the substrate. The transition layer 3 is larger than the copper pad 2 on one side by Y, and the value of Y ranges from 4 to 8 mils. The transition layer 3 makes up for the height difference between the copper pad 2 and the substrate surface, while providing support and preventing the drill from moving down smoothly due to the uneven substrate surface, thereby causing damage to the substrate surface; In this embodiment, the transition layer 3 is a solder resist ink layer; After adding the transition layer 3, it is necessary to drill multiple pre-drilled holes 4 with a size smaller than the size of the blind hole 1 in the area to be drilled. The location of the pre-drilled holes 4 should avoid the center of the drilling hole. The use of multiple small-sized pre-drilled holes 4 can remove chips in advance to avoid drilling too many chips at a time when drilling a large-diameter blind hole 1, thereby avoiding excessive force on the hole mouth and causing pulling. In this embodiment, the diameter of the pre-drilled hole 4 is 1.0-2.0 mm, the number of the pre-drilled holes 4 is four, and the four pre-drilled holes 4 are evenly arranged in the area to be drilled of the blind hole 1; The center of the transition layer 3 is used as the drilling center to drill a blind hole 1. Since the copper pad 2, transition layer 3 and pre-drilled hole 4 in the method proposed in this embodiment are all drilled in the waste area of the blind hole 1 to change the shape of the outer copper surface and solder mask of the board, they will be removed by the drill needle during the drilling process. The board shape remains consistent with the customer's design, so it will not affect the customer's final PCB functionality.
[0019] In the description of the present invention, it should be understood that the terms "center," "longitudinal," "upper," and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They do not indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, in the description of the present invention, unless otherwise specified, "plurality" means two or more.
[0020] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.
Claims
1. A method for drilling large-diameter blind holes in a PCB board, characterized in that: include: In a predetermined area of a non-through hole to be drilled on the substrate, a copper pad concentric with the non-through hole is produced; Adding a transition layer on the copper pad to make the center of the blind hole flat, wherein the transition layer is concentric with the copper pad and the covering area does not exceed the area to be drilled of the blind hole; The center of the transition layer is used as the drilling center to drill a non-through hole.
2. The method for drilling large-diameter blind holes in a PCB according to claim 1, wherein: After adding the transition layer, it is necessary to drill a plurality of pre-drilled holes with a size smaller than the size of the blind hole in the area to be drilled.
3. The method for drilling large-diameter blind holes in a PCB board according to claim 2, characterized in that: The pre-drilled hole diameter is 1.0-2.0 mm.
4. The method for drilling large-diameter blind holes in a PCB board according to claim 2, wherein: The position of the pre-drilled hole needs to avoid the center of the drill hole.
5. The method for drilling large-diameter blind holes in a PCB according to claim 1, wherein: The copper pad is a circular copper pad, and the copper pad is smaller than the area to be drilled by the non-through hole by X on one side, and the value range of X is 8-16 mil.
6. The method for drilling large-diameter blind holes in a PCB board according to claim 1, wherein: The step of adding a transition layer to the copper pad to make the center of the blind hole flat includes: completely covering the surface of the copper pad with the transition layer so that the copper pad does not form a height difference with the solder resist oil layer on the substrate.
7. The method for drilling large-diameter blind holes in a PCB board according to claim 6, characterized in that: The transition layer is larger than one side of the copper pad by a value Y, and the value of Y ranges from 4 to 8 mils.
8. The method for drilling large-diameter blind holes in a PCB according to claim 6, wherein: The transition layer includes solder resist ink.