Processing method for removing burrs of metalized slot holes of PCB (Printed Circuit Board)

Abstract

The invention relates to the technical field of printed circuit board processing, in particular to a processing method for removing burrs of a metalized slotted hole of a PCB (Printed Circuit Board), which specifically comprises the following steps of: firstly, providing a copper-clad plate and laminating to form a PCB substrate, drilling a required through hole in the PCB substrate, and forming a through hole on the central line of the metalized slotted hole to be processed; the method comprises the following steps: drilling a plurality of pre-drilled holes along a line in advance, milling along a path formed by the pre-drilled holes by using an end mill, communicating adjacent pre-drilled holes to form a complete metalized slotted hole, deburring the PCB, and finally electroplating to form a conductive layer. According to the method, the holes are pre-drilled in the milling groove path, the original continuous groove hole edge is microcosmically divided into a plurality of discontinuous sections, the continuity of burrs is fundamentally cut off, the burrs are prone to falling off in the follow-up deburring procedure, and therefore the burrs are thoroughly eliminated, the size precision of the groove hole is guaranteed, and the milling groove machining efficiency is remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of printed circuit board processing technology, and in particular to a processing method for removing burrs from metallized slots in PCBs. Background Technology

[0002] In PCB manufacturing, metallized slots (i.e., elongated metallized holes) are a common structure used for mounting special components or specific electrical connections. The traditional metallized slot processing flow is typically: lamination - drilling - routing - deburring - electroplating.

[0003] However, the aforementioned traditional methods have obvious technical drawbacks: 1. Burr problem is difficult to eliminate: During the milling process of the slot using a milling cutter, copper foil burrs are easily generated on the edge of the slot, especially at both ends. Subsequent deburring and grinding processes can usually only flatten or grind these burrs, but it is difficult to completely remove them.

[0004] 2. Problems worsen after electroplating: During the electroplating process, the flattened burrs become the base for electroplating, causing a metal layer to be deposited on the burrs as well, thus increasing their size and hardening them. This leads to two serious consequences: first, the enlarged burrs may affect the smooth insertion of components; second, it reduces the effective diameter of the slots, making it impossible to meet the requirements of precision dimensions, resulting in product scrap.

[0005] 3. Processing efficiency needs to be improved: In the traditional direct milling method, the milling cutter needs to mill the entire groove from beginning to end, which results in a long processing path and a lot of time consumption.

[0006] Therefore, there is an urgent need in this field for a new processing method that can fundamentally solve the problem of burrs in metallized slots while improving processing efficiency. Summary of the Invention

[0007] To address the aforementioned technical problems and overcome the shortcomings of existing technologies, this invention provides a method for removing burrs from PCB metallized slots. By pre-drilling holes along the slot path, the originally continuous slot edge is microscopically divided into multiple discontinuous segments, fundamentally severing the continuity of burrs and making them easier to remove in subsequent deburring processes. This completely eliminates burrs, ensures slot dimensional accuracy, and significantly improves slot processing efficiency.

[0008] The PCB metallized slot deburring method provided in this solution includes the following steps: S1: Lamination, providing copper-clad laminate and laminating it to form a PCB substrate; S2: Drilling: Drill the required through holes on the PCB substrate, and pre-drill several holes along the center line of the metallization slot to be processed. All the pre-drilled holes are within the area of ​​the metallization slot to be processed. S3: Milling groove, using a milling cutter to mill along the path formed by the pre-drilled holes, connecting adjacent pre-drilled holes to form a complete metallized groove. S4: Deburring. The PCB board after step S3 is deburred to remove burrs generated during pre-drilling and routing. S5: Electroplating.

[0009] The technical solution further defined in this invention is: Furthermore, the pre-drilled hole described in S2 is a circular hole, and the center of the circular hole is on the center line of the metallization slot hole to be processed.

[0010] Furthermore, the diameter of the pre-drilled hole in S2 is less than or equal to the width of the metallization slot to be processed, and adjacent pre-drilled holes are tangent to each other.

[0011] Furthermore, the outer edge of the pre-drilled hole described in S2 is 1-3 mil away from the edge of the metallized slot to be processed.

[0012] Furthermore, the electroplating specifically includes performing hole metallization treatment on the deburred PCB board to form a conductive layer in the through holes and metallized grooves.

[0013] Furthermore, the diameters of the aforementioned pre-drilled holes are equal.

[0014] The beneficial effects of this invention are: (1) The PCB metallization slot deburring method of the present invention pre-drills holes on the slot path to divide the originally continuous slot edge into multiple discontinuous segments on a microscopic scale. During the slotting process, the burrs generated are local and discontinuous, and their adhesion is greatly weakened. In subsequent deburring processes (such as grinding, plasma cleaning, etc.), these discontinuous burrs are easily ground off or washed away completely, rather than simply flattened, thereby eliminating the burr hazard before electroplating, ensuring the accuracy and consistency of the slot size after electroplating, and meeting the high-precision customer requirements; (2) Since the pre-drilled hole has removed most of the material from the center line of the slot, the milling cutter mainly plays the role of "connection" and "refinement" in the subsequent milling process, which greatly reduces the amount of material to be milled and the processing path. Practical verification has shown that the processing time of the milling process can be reduced by more than 50% compared with the traditional method, effectively improving production efficiency and reducing production costs; (3) The present invention significantly reduces the cutting resistance and load during the routing process, thereby reducing the wear of the routing tool, extending the service life of the routing tool, and further reducing the processing cost. The method is simple and easy to implement, requires no special equipment, and can be easily implemented on the basis of existing PCB production lines, and has high promotional value. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the PCB metallization slot hole processing in a specific embodiment of the present invention; Figure 2 This is a schematic diagram illustrating the burrs produced after grooving using traditional methods. Figure 3 This is a schematic diagram of the burr morphology after the groove in the processing method of the present invention; In the diagram: 100, PCB substrate; 110, metallization slot to be processed; 120, center line; 130, pre-drilled hole. Detailed Implementation

[0016] This invention provides a method for deburring PCB metallized slots, specifically including the following steps: S1: Lamination, providing copper-clad laminate and laminating it to form PCB substrate 100.

[0017] S2: Drilling. Drill the required through holes on the PCB substrate 100. Along the center line 120 of the metallized slot 110 to be processed, pre-drill a row of holes 130. All pre-drilled holes 130 are within the area of ​​the metallized slot 110 to be processed. The diameter of each pre-drilled hole 130 is less than or equal to the width of the final metallized slot 110 to be processed, and adjacent pre-drilled holes 130 are tangent to each other. Figure 1 As shown.

[0018] S3: Milling groove, using a milling cutter to mill along the path formed by the pre-drilled holes 130, connecting adjacent pre-drilled holes 130 to form a complete metallized groove.

[0019] S4: Deburring. The PCB board after step S3 is deburred to remove burrs generated during the pre-drilling of holes 130 and the routing of grooves.

[0020] S5: Electroplating, which is a process of metallizing holes in the deburred PCB board to form a conductive layer in the through holes and metallized slots.

[0021] like Figure 2The diagram illustrates the burr formation after slotting using traditional methods. This application pre-drills holes along the slotting path, microscopically dividing the originally continuous slot edges into multiple discontinuous segments. During slotting, the resulting burrs are localized and discontinuous, with significantly weakened adhesion. In subsequent deburring processes (such as grinding, plasma cleaning, etc.), these discontinuous burrs are easily and completely ground off or washed away, rather than merely flattened. See [reference needed]. Figure 3 .

[0022] Meanwhile, since the pre-drilled hole 130 has already removed most of the material from the center line 120 of the slot, the milling cutter mainly plays a "connecting" and "refining" role in the subsequent milling process, significantly reducing the amount of material to be milled and the machining path. Practical experience has shown that using this method can save more than 50% of the machining time for the milling process compared to traditional methods, effectively improving production efficiency and reducing production costs.

[0023] In addition to the embodiments described above, the present invention may have other implementations. All technical solutions formed by equivalent substitution or equivalent transformation fall within the protection scope claimed by the present invention.

Claims

1. A method for deburring PCB metallized slots, characterized in that, Includes the following steps: S1: Lamination, providing copper-clad laminate and laminating it to form a PCB substrate; S2: Drilling: Drill the required through holes on the PCB substrate, and pre-drill several holes along the center line of the metallization slot to be processed. All the pre-drilled holes are within the area of ​​the metallization slot to be processed. S3: Milling groove, using a milling cutter to mill along the path formed by the pre-drilled holes, connecting adjacent pre-drilled holes to form a complete metallized groove. S4: Deburring. The PCB board after step S3 is deburred to remove burrs generated during pre-drilling and routing. S5: Electroplating.

2. The processing method according to claim 1, characterized in that, The pre-drilled hole described in S2 is a circular hole, and the center of the circular hole is on the center line of the metallization slot hole to be processed.

3. The processing method according to claim 2, characterized in that, The diameter of the pre-drilled hole in S2 is less than or equal to the width of the metallization slot to be processed, and adjacent pre-drilled holes are tangent to each other.

4. The processing method according to claim 3, characterized in that, The outer edge of the pre-drilled hole described in S2 is 1-3 mil away from the edge of the metallized slot to be processed.

5. The processing method according to claim 1, characterized in that, The electroplating specifically includes metallizing the holes in the deburred PCB board to form a conductive layer in the through holes and metallized slots.

6. The processing method according to claim 1, characterized in that, The diameters of the pre-drilled holes are equal.

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