Right-angle edge gold finger milling method and processing method using multi-blade milling cutter

Abstract

The application discloses a right-angle edge gold finger milling processing method and a processing method adopting a multi-blade milling cutter, and belongs to the technical field of gold finger processing, and comprises the following steps: repairing the edge of the gold finger by adopting a depth control processing method, a tool path of the depth control processing method passes through the connecting part of the gold finger and the lead wire along the edge direction of the gold finger, the removal amount of the tool is controlled to be 5-50 microns per revolution, the processing depth is set to H1-H1+10 microns, and the gold finger structure with a smooth cutting surface is obtained by cutting off or removing the lead wire; the end mill is replaced, the substrate layer in the processing area is milled, and the gold finger plate with the cutting surface perpendicular to the plate surface is obtained. According to the right-angle edge gold finger milling processing method, the lead wire part and the corresponding substrate layer part are removed respectively, the removal amount of the tool is controlled, the probability that the gold finger plate appears burrs in the forming processing is reduced, the forming processing quality of the gold finger plate is improved, manual processing or chamfering processing is not needed, the yield of the forming processing is improved, and the cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of gold finger machining technology, and in particular to a method for milling right-angled gold fingers and a machining method using a multi-bladed milling cutter. Background Technology

[0002] The circuit board for memory processing units needs to have gold fingers manufactured to enable data exchange with the PC system. The manufacturing process and surface quality of the gold fingers are crucial to memory connectivity. The conventional gold finger manufacturing process involves creating leads on a copper-clad laminate, followed by electroplating to deposit a layer of gold on top of the copper layer, forming conductive contacts arranged in a finger-like pattern, i.e., the gold finger board.

[0003] like Figure 1 As shown, some gold fingers need to be shaped and have their leads removed after manufacturing. The existing gold finger board forming process uses a common four- or six-flute milling cutter 300' to simultaneously mill the gold finger 100' and the substrate layer 200', which easily produces burr defects on the cutting surfaces of the gold finger 100' and the substrate layer 200'.

[0004] The cause of the burr defect is that uneven deformation occurs when two dissimilar materials are milled simultaneously: 1. The fiberglass resin substrate layer 200' is prone to breakage and even peeling off entirely, causing the upper gold fingers 100' to lose support; 2. The metal gold fingers 100' are compressed and deformed under the cutting action of the milling cutter 300', making them difficult to cut off, ultimately forming filamentous burrs. The simultaneous milling of these two dissimilar materials results in burr defects on the gold finger plate.

[0005] To eliminate burr defects, the industry typically removes all material in the lead area directly through milling, then manually scrapes off the burrs at the lead with a blade, or chamfers the junction edge between the cutting surface and the top surface of the gold finger to remove burrs.

[0006] However, to ensure the stability of the gold finger connection, the contact area between the gold finger and the connecting device must be preserved as much as possible. This creates a requirement that the cutting surface of the entire gold finger board be perpendicular to the board surface during the forming process. Therefore, chamfering should be avoided as much as possible. Manual processing is extremely inefficient and complicated, and the process is prone to product scrap due to uneven force and operation errors, resulting in low yield and greatly increasing manufacturing costs.

[0007] Therefore, there is an urgent need to provide a milling method for right-angled gold fingers to solve the above problems. Summary of the Invention

[0008] The purpose of this invention is to provide a milling method for right-angled edge gold fingers, which reduces the probability of burrs and flashes appearing in the forming process of the gold finger board by removing the lead wire portion and its corresponding substrate layer portion separately, and by controlling the removal amount of the cutting tool, thereby improving the yield and reducing the cost.

[0009] To achieve the above objectives, the following technical solution is provided:

[0010] Milling method for right-angled edge gold fingers

[0011] The gold finger board to be processed is milled. The gold finger board includes a substrate layer and a metal layer with a thickness of H1. The metal layer includes a plurality of gold fingers and leads connected to each gold finger. The area where the leads need to be removed is the processing area. The process includes the following steps:

[0012] S1: The edge of the gold finger is repaired by the depth control machining method. The tool path of the depth control machining method passes through the connection between the gold finger and the lead wire along the edge of the gold finger. The removal amount of the tool is controlled to be 5-50μm / r, and the machining depth is set to H1~H1+10μm, so as to cut off or remove the lead wire and obtain a gold finger structure with a flat cutting surface.

[0013] S2: Replace the end mill and mill the substrate layer in the machining area to obtain a gold finger plate with the cutting surface perpendicular to the plate surface.

[0014] Preferably, in step S1, the diameter of the tool used in the depth control machining method is greater than or equal to the width of the machining area, and the lead wire is removed in one pass.

[0015] Preferably, in step S2, the transverse cutting depth of the end mill is less than or equal to the width of the machining area, and the width of the substrate layer finally removed is equal to the width of the machining area.

[0016] Preferably, in step S1, the cutting tools used in the controlled depth machining method are flat end mills, micro-end mills, multi-end mills, or flat end mills.

[0017] Preferably, the grinding head has a particle size of 200-800#.

[0018] When the end mill in step S2 is a left-hand end mill, the tool path is from left to right; when the end mill in step S2 is a right-hand end mill, the tool path is from right to left.

[0019] Preferably, the cutting tools used in the controlled deep machining method in step S1 and / or the end mills in step S2 are made of diamond, cemented carbide or ceramic.

[0020] The present invention also aims to provide a method for milling right-angled gold fingers using a multi-blade milling cutter. By separately removing the lead portion and its corresponding substrate layer portion, and controlling the removal amount of the cutter, the probability of burrs and flash appearing on the gold finger board during forming is reduced, thereby increasing the yield and reducing costs.

[0021] To achieve the above objectives, the following technical solution is provided:

[0022] A method for machining right-angled edge gold fingers using a multi-blade milling cutter.

[0023] A milling process is performed on a gold finger board to be processed. The gold finger board includes a substrate layer and a metal layer with a thickness of H1. The metal layer includes a plurality of gold fingers and leads connected to each gold finger. The area where the leads are located and need to be removed is the processing area. The process is characterized by the following steps:

[0024] S1: The edge of the gold finger is repaired by the controlled depth machining method. The controlled depth machining method uses a multi-flute end mill with more than 10 flutes. Its tool path passes through the connection between the gold finger and the lead wire along the edge of the gold finger. The removal amount of the tool is controlled to be 5-50μm / r, and the machining depth is set to H1-10μm~H1, so as to cut off or remove the lead wire and obtain a gold finger structure with a flat cutting surface.

[0025] S2: Replace the end mill and mill the substrate layer in the machining area to obtain a gold finger plate with the cutting surface perpendicular to the plate surface.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] The milling method for right-angle edge gold fingers and the processing method using a multi-blade milling cutter provided by this invention reduce the probability of burrs and flash during the forming process of the gold finger board by removing the lead wire portion and its corresponding substrate layer portion separately and controlling the removal amount of the cutter. This improves the quality of the gold finger board forming process, eliminates the need for manual processing or chamfering, increases the yield of the forming process, and reduces costs. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram illustrating the processing of gold fingers using existing technology;

[0030] Figure 2This is a top view of the gold fingers before processing in an embodiment of the present invention;

[0031] Figure 3 This is a front view of the gold finger before processing in an embodiment of the present invention;

[0032] Figure 4 This is a side view of the processing area of ​​the gold finger before processing in an embodiment of the present invention;

[0033] Figure 5 This is a schematic diagram of a depth-controlled machining tool performing depth-controlled machining on the machining area of ​​the gold finger in an embodiment of the present invention;

[0034] Figure 6 This is a side view of the processing area of ​​the gold finger during the initial processing in an embodiment of the present invention;

[0035] Figure 7 This is a schematic diagram of an end mill milling the remaining substrate layer in the machining area in an embodiment of the present invention;

[0036] Figure 8 This is a side view of the processing area of ​​the secondary gold finger in an embodiment of the present invention.

[0037] Figure label:

[0038] 100', Metal layer; 200', Substrate layer; 300', Milling cutter;

[0039] 1. Gold fingers; 2. Depth control machining tools; 3. End mills;

[0040] 11. Metal layer; 111. Lead wire; 12. Substrate layer; 13. Processing area. Detailed Implementation

[0041] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0042] like Figure 2-8 As shown, in one embodiment of the present invention, a method for milling right-angled edge gold fingers is provided for milling a gold finger plate to be processed. To facilitate the calibration of the corresponding positions of the machining operations on the gold finger plate, this embodiment first provides an overview of the structure of the gold finger plate, clearly defining the machining area 13 and the reserved area:

[0043] The gold finger board comprises a substrate layer 12 and a metal layer 11, with the metal layer 11 formed on the substrate layer 12 to create a stable connection. The metal layer 11 includes three gold fingers 1 distributed on the top surface of the substrate layer 12 and three leads 111 integrally connected to each of the three gold fingers 1. Both the leads 111 themselves and the substrate layer 12 within the area containing the three leads 111 are to be removed; therefore, this area is designated as the processing area 13. Furthermore, for ease of description of the processing depth range later, the thickness of the metal layer 11 is defined as H1.

[0044] In this embodiment, a method for milling a right-angled edge gold finger includes the following steps.

[0045] S1: The edge of the gold finger 1 is repaired by the depth control machining method. The tool path of the depth control machining method passes through the connection between the gold finger 1 and the lead wire 111 along the edge of the gold finger 1. The removal amount of the tool is controlled to be 5-50μm / r, and the machining depth is set to H1~H1+10μm, so as to cut off or remove the lead wire 111 and obtain a gold finger structure with a flat cutting surface.

[0046] S2: Replace the end mill 3 and mill the substrate layer 12 in the machining area 13 to obtain a gold finger plate with the cutting surface perpendicular to the plate surface.

[0047] In step S1, in order to achieve precise separation between the gold finger 1 and the lead wire 111, when setting the tool path for depth control machining, the edge of the gold finger 1 is used as the tool path reference, so that the tool path of the depth control machining method passes through the connection between the lead wire 111 and the gold finger 1 along the edge direction of the gold finger 1, while approaching but not contacting the gold finger 1.

[0048] When the tool diameter is not limited in depth-controlled machining:

[0049] If the diameter of the tool used in the controlled depth machining method is smaller than the length of the lead wire 111, the lead wire 111 is cut off, resulting in a complete gold finger, while a residual portion of the lead wire 111 remains in the machining area 13 awaiting removal in a secondary machining process. If the diameter of the tool used in the controlled depth machining method is larger than the length of the lead wire 111, the lead wire 111 is directly removed, resulting in a complete gold finger.

[0050] In step S1, to further optimize the cross-sectional integrity of the connection between the gold finger 1 and the lead wire 111, the cutting stability is improved and the probability of burrs is reduced by controlling the tool removal rate. In this embodiment, the milling efficiency and the finished gold finger are described when the tool removal rate is 5μm / r, 30μm / r, and 60μm / r, respectively:

[0051] When the tool removal rate is 5 μm / r: due to the low removal rate, the depth of cut changes little, the processing time is prolonged, and the tool accumulates heat during prolonged high-speed rotation, which can severely lead to deformation or damage of the gold finger 1 or the substrate layer 12 at high temperatures. Furthermore, inefficient cutting also significantly impacts production efficiency, consumes a large amount of energy, and increases production costs. Therefore, after extensive experimental verification, it was found that a removal rate of 5 μm / r is the minimum limit for this method; processing below this parameter cannot achieve the goals of improving the cutting quality of the gold finger 1 and saving costs.

[0052] When the tool removal rate is 30 μm / r: This removal rate is moderate, and the cut material will not generate excessive resistance to the tool, allowing for smooth tool operation. This ensures that the flatness of the cut surface of the gold finger 1 meets the processing requirements. Furthermore, the suitable removal rate shortens the processing time and avoids heat accumulation during prolonged processing. This combination of processing efficiency and quality significantly improves the quality of the finished product and reduces the likelihood of burrs and flash.

[0053] When the material removal rate is 60 μm / r: due to the excessive material removal per revolution, the cut material generates significant resistance to the tool, which in turn counteracts the tool's rotational driving force, producing strong vibrations. This causes the tool's central axis to wobble, resulting in serrated chips, severely affecting the quality of the cutting surface of the gold finger 1 and failing to resolve the burr problem. Extensive experimental verification revealed that a material removal rate of 50 μm / r is the maximum limit for this method; further increasing the removal rate may even lead to tool breakage.

[0054] Based on the above embodiments, in this embodiment, the removal amount of the cutting tool is controlled between 5-50 μm / r, which can significantly reduce burrs and improve the quality of gold finger plate forming. No further manual processing or chamfering is required, thus improving the yield of the forming process.

[0055] It is worth mentioning that in this embodiment, the thickness of the metal layer 11 is H1, which is also the thickness of the gold finger 1 and the lead wire 111. This is because the substrate layer 12 lies below the metal layer 11, and the substrate layer 12 within the processing area 13 will be removed in subsequent steps. Therefore, an error margin can be allowed when setting the processing depth, ensuring that even at its shallowest depth, the thickness H1 of the lead wire 111 is reached, completely severing or removing it. This prevents the lead wire 111 from becoming entangled with the gold finger 1, and avoids the remaining connection tearing the cutting surface of the gold finger 1 during the subsequent removal of the substrate layer 12 within the processing area 13. However, if the cutting depth of the substrate layer 12 is too large during the controlled-depth machining process, it will also cause the substrate layer 12 to break. Experiments have shown that keeping the cutting depth of the substrate layer 12 below 10 μm during the controlled-depth machining process will not cause it to break. Therefore, the processing depth of this controlled-depth machining method is set to H1 to H1+10 μm.

[0056] After completing step S1 to cut or remove the lead wire 111, the cutting tool is replaced with an end mill 3, which then enters the machining area 13 to mill the remaining substrate layer 12. During the process, the end mill 3 does not contact the gold finger 1, thus ensuring that the cutting surface of the gold finger plate obtained after the forming process is perpendicular to its plate surface, i.e., a right-angled edge gold finger plate. Furthermore, there is no need for manual deburring or chamfering.

[0057] Furthermore, in another embodiment, to improve processing efficiency, the tool diameter of the depth-controlled machining method can be adjusted in step S1 of the above embodiment, so that the tool diameter of the depth-controlled machining method is greater than or equal to the width of the machining area 13, so that the entire machining area 13 can be cut in one horizontal feed. Under the control of the removal amount and machining depth in the above embodiment, the lead wire 111 can be completely removed. This greatly shortens the processing cycle and improves the production line efficiency.

[0058] Furthermore, in another embodiment, since the positions of the gold fingers 1 and the leads 111 on the gold finger plate are determined according to product requirements, and the machining method of the end mill 3 needs to start from the edge, the end mill 3 completes the milling process by making a transverse cutting depth from one side of the machining area 13 toward the gold fingers 1. The transverse cutting depth is a single milling parameter of the end mill 3. To avoid excessive damage to the gold fingers 1 due to excessive transverse cutting depth, the transverse cutting depth of the end mill 3 needs to be controlled to be less than or equal to the width of the machining area 13. Regardless of how the transverse cutting depth parameter of the end mill 3 is set, the end mill 3 will eventually complete the milling process within the entire width of the machining area 13, completely removing all the material within the machining area 13.

[0059] It is worth mentioning that when the diameter of the tool used in the depth-controlled machining method in the first embodiment is smaller than the length of the lead wire 111, and it can only cut off the lead wire 111 but cannot remove the residue of the lead wire 111, the end mill 3 can remove the residue of the lead wire 111 by milling the entire machining area 13. Since the residue of the lead wire 111 has been separated from the gold finger 1, using the end mill 3 to mill the residue of the lead wire 111 and the substrate layer 12 in the machining area 13 at the same time will no longer affect the quality of the cutting surface of the gold finger 1.

[0060] Since existing machining methods mostly use ordinary end mills, to further improve the flatness of the cutting surface of the gold finger 1, in another embodiment, in step S1, the depth-controlled machining method uses flat-end mills, micro-end mills, multi-flute end mills, or flat-end grinding heads. Different tools have different characteristics and can be selected according to the product batch size, delivery time, and quality requirements.

[0061] Flat end mills offer a balance between material removal and stability, resulting in optimal efficiency.

[0062] Micro-cut end mills have a large number of cutting edges and provide smooth machining, but they remove less material. They are of higher quality than flat end mills, but less efficient.

[0063] Multi-flute end mills have fewer cutting edges than micro-flute end mills, and their stability is slightly less than that of micro-flute end mills, but their removal capacity is between that of flat end mills and micro-flute end mills.

[0064] Flat-bottomed grinding heads have the smallest removal capacity and the highest stability, but also the lowest efficiency, making them suitable for producing high-quality products.

[0065] Furthermore, in the embodiments based on the tool types used in the aforementioned depth-controlled machining method, although the flat-bottom grinding head has the smallest removal volume and lowest efficiency, its quality is relatively higher. To balance production efficiency and quality, in another embodiment, if a flat-bottom grinding head is used in the depth-controlled machining method in step S1, a flat-bottom grinding head with a grit size of 200-800# can be selected according to the product quality requirements. A higher grit number on the flat-bottom grinding head results in finer grinding but lower yield. A lower grit number results in coarser grinding but higher yield. However, the initial purpose of using a flat-bottom grinding head is to prioritize product quality control. Therefore, the roughness effect produced by reducing the grit number is limited to reducing the quality from semi-finished to rough-finished. In the gold finger plate forming process using a flat-bottom grinding head of any grit number, the cutting surface quality of the gold finger 1 always remains above the quality standard of reducing burrs.

[0066] In another embodiment, the cutting tools used in the controlled deep machining method in step S1 and / or the end mill 3 in step S2 are both made of diamond, cemented carbide, or ceramic. Cutting tools made of any of these materials have higher hardness than ordinary stainless steel or high-speed steel tools. Higher hardness results in a sharper edge, smoother material cutting during milling, less pressure on the material, a smoother cutting surface for the gold fingers 1, and less burrs caused by pressure or coiling effects due to uneven cutting. Furthermore, the high hardness of these tools makes them less prone to wear and extends their service life, saving on tool replacement costs.

[0067] In another embodiment, when the end mill 3 in step S2 is a left-hand end mill, the tool path is from left to right. When the end mill 3 is a right-hand end mill, the tool path is from right to left. The milling efficiency is improved by coordinating the tool path with the tool rotation direction.

[0068] In another embodiment, the present invention also provides a method for milling right-angled edge gold fingers using a multi-flute end mill. The steps are the same as those in the aforementioned embodiment, but this embodiment uses a multi-flute end mill and adjusts the cutting depth. Details are as follows:

[0069] In step S1, the cutting tool used in the depth-controlled machining method is a multi-flute end mill with more than 10 flutes, a total length of 38-40 mm, and a cutting edge length of 1-3 mm. Compared to the four- or six-flute end mills used in existing machining methods, this multi-flute end mill, with more than 10 flutes, increases the contact area with the gold finger 1 being cut, while reducing the width of the cutting groove. This results in finer and smaller milling chips, effectively reducing the resistance caused by the cut material. Consequently, the multi-flute end mill experiences less resistance, improves its stability during cutting, ensures a smooth and flat cutting surface for the gold finger 1, and reduces the likelihood of burrs or flash.

[0070] Due to the inherent cutting performance of the multi-flute end mill, it exhibits excellent cutting performance on the metal material of the gold finger 1, but it is not suitable for cutting two materials simultaneously. Therefore, when using this multi-flute end mill with more than 10 flutes as the depth-controlled machining tool 2 in step S1, the machining depth needs to be adjusted to H1-10μm~H1. The retained lead wire 111 portion is clearly visible when the end mill 3 mills the machining area 13 in step S2. The connection portion between the lead wire 111 and the gold finger 1 has a maximum thickness of no more than 10μm, and will not have a significant impact on the milled surface of the gold finger 1 during the milling process of the end mill 3, which is negligible as it would affect the flatness of the milled surface.

[0071] This invention is not limited to the above-described embodiments. If any modifications or variations to this invention do not depart from the spirit and scope of this invention, and if such modifications and variations fall within the scope of the claims and equivalent technologies of this invention, then this invention also intends to include such modifications and variations.

Claims

1. A method for milling right-angled edge gold fingers, comprising milling a gold finger board to be processed, the gold finger board comprising a substrate layer and a metal layer with a thickness of H1; the metal layer comprising a plurality of gold fingers and leads connected to each gold finger, wherein the area where the leads are located and to be removed is the processing area; characterized in that, Includes the following steps: S1: The edge of the gold finger is repaired by the depth control machining method. The tool path of the depth control machining method passes through the connection between the gold finger and the lead wire along the edge of the gold finger. The removal amount of the tool is controlled to be 5-50μm / r, and the machining depth is set to H1~H1+10μm, so as to cut off or remove the lead wire and obtain a gold finger structure with a flat cutting surface. S2: Replace the end mill and mill the substrate layer in the machining area to obtain a gold finger plate with the cutting surface perpendicular to the plate surface.

2. The milling method for right-angled edge gold fingers according to claim 1, characterized in that, In step S1, the diameter of the tool used in the depth control machining method is greater than or equal to the width of the machining area, and the lead wire is removed in one pass.

3. The milling method for right-angled edge gold fingers according to claim 1, characterized in that, In step S2, the transverse cutting depth of the end mill is less than or equal to the width of the machining area, and the width of the substrate layer finally removed is equal to the width of the machining area.

4. The milling method for right-angled edge gold fingers according to claim 1, characterized in that, In step S1, the cutting tools used in the controlled depth machining method are flat end mills, micro-end mills, multi-end mills, or flat end mills.

5. The milling method for right-angled edge gold fingers according to claim 4, characterized in that, The grinding head has a particle size of 200-800#.

6. The milling method for right-angled edge gold fingers according to claim 1, characterized in that, When the end mill in step S2 is a left-hand end mill, the tool path is from left to right; when the end mill in step S2 is a right-hand end mill, the tool path is from right to left.

7. The milling method for right-angled edge gold fingers according to claim 1, characterized in that, The cutting tools used in the controlled deep machining method in step S1 and / or the end mills in step S2 are made of diamond, cemented carbide or ceramic.

8. A method for milling right-angled edge gold fingers using a multi-blade milling cutter, characterized in that, A milling process is performed on a gold finger board to be processed. The gold finger board includes a substrate layer and a metal layer with a thickness of H1. The metal layer includes a plurality of gold fingers and leads connected to each gold finger. The area where the leads are located and need to be removed is the processing area. The process is characterized by the following steps: S1: The edge of the gold finger is repaired by the controlled depth machining method. The controlled depth machining method uses a multi-flute end mill with more than 10 flutes. Its tool path passes through the connection between the gold finger and the lead wire along the edge of the gold finger. The removal amount of the tool is controlled to be 5-50μm / r, and the machining depth is set to H1-10μm~H1, so as to cut off or remove the lead wire and obtain a gold finger structure with a flat cutting surface. S2: Replace the end mill and mill the substrate layer in the machining area to obtain a gold finger plate with the cutting surface perpendicular to the plate surface.

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