Finishing process of needle type heat dissipation substrate and auxiliary needle jig

Abstract

The application discloses a kind of needle type heat dissipation substrate finishing process and auxiliary needle jig, the plate material is finished after being forged and pressed to needle type heat dissipation substrate, and auxiliary needle jig is used to fix plate material in process, jig structure includes base frame, multiple small frames and fastener, can realize accurate positioning of plate material plane in finishing process, and solve the damage problem caused by needle column on heat dissipation substrate in finishing process.The plate material obtained by using the finishing process and auxiliary needle jig of the application has good consistency in structure size and good surface quality, which can realize high-quality batch processing of needle type heat dissipation substrate products, and further improve the overall heat dissipation efficiency and working reliability of downstream power module products.

Description

TECHNICAL FIELD

[0001] The application relates to a precision machining process and an auxiliary needle jig for a power module needle type heat dissipation substrate, and belongs to the field of power semiconductor packaging manufacturing. BACKGROUND

[0002] Power semiconductor modules are widely used in the fields of new energy vehicles, photovoltaic power generation, wind power generation, etc. With the continuous increase of the power density of the modules, the heat management structure is also developing, gradually transitioning from the traditional indirect liquid cooling heat dissipation to direct liquid cooling heat dissipation, and the needle type heat dissipation substrate product emerges as the times require. The needle type heat dissipation substrate product is small in size, directly connected with the power module, and is very suitable for occasions with high heat dissipation demand and harsh application environment conditions. The machining precision and product quality of the needle type heat dissipation substrate have a crucial influence on the heat dissipation efficiency of the power module.

[0003] In the manufacturing process of the needle type heat dissipation substrate, a smooth and flat substrate surface needs to be obtained through precision machining for subsequent welding interconnection with the power module. In the precision machining process, the plate after forging and pressing needs to be fixed on the required plane. In the prior art, part of the needle columns of the needle type heat dissipation substrate are inserted into the reserved holes of the jig for fixation. However, this can easily cause damage and scratches on the surface of the needle columns during the precision machining process, greatly affecting the product quality. Therefore, the application proposes to design a manufacturing process auxiliary needle during forging and pressing, and to fix the plate through the auxiliary needle jig in the precision machining process, so as to realize high-quality machining of the needle type heat dissipation substrate. SUMMARY

[0004] The application aims to improve the machining quality of the needle type heat dissipation substrate. To this end, a precision machining process and an auxiliary needle jig for the needle type heat dissipation substrate are provided. In the precision machining process, the auxiliary needles of the plate after forging and pressing are inserted into the insertion holes in the corresponding positions on the small frames in the jig. Through the clamping action of the fasteners in the horizontal plane and the fixing action of the micro bosses on the insertion hole walls in the vertical plane, the plate is stably fixed in the required plane for subsequent machine tool processes. At the same time, damage or scratches caused by the process on the needle column array on the plate are avoided, the machining precision of the needle type heat dissipation substrate is improved, and the surface quality of the product is improved.

[0005] The auxiliary needle jig comprises a base frame, a plurality of small frames and fasteners, and each small frame is fixed on the base frame through the fasteners.

[0006] Specifically, each small frame is installed on the same horizontal plane and arranged in an array.

[0007] Specifically, the size of the middle groove of the small frame is slightly larger than the size of the outer edge of the pin array on the pin heat dissipation substrate to be processed; the positions of the auxiliary pin insertion holes on the small frame correspond to the auxiliary pins on the pin heat dissipation substrate.

[0008] Specifically, the auxiliary pin insertion holes are symmetrically arranged on both sides of the groove, and the insertion holes in each column are arranged at equal intervals.

[0009] Specifically, the auxiliary pin insertion hole is a cylindrical shape, and a plurality of micro bosses are made outward on the hole wall.

[0010] Specifically, the plurality of micro bosses are staggered on the hole wall.

[0011] The finishing process of the pin heat dissipation substrate of the application comprises the following steps:

[0012] Step 1: forging the plate, the shape of the forged plate includes a bottom plate, a pin array and an auxiliary pin; the auxiliary pin is made on the bottom plate and is symmetrically distributed around the pin array region on the same side as the pin array;

[0013] Step 2: place the forged plate with the pin array on one side downward in the small frame of the auxiliary pin jig, and insert each auxiliary pin into the corresponding auxiliary pin insertion hole on the auxiliary pin jig;

[0014] Step 3: adjust the fastener to fix the small frame and the base together, and the fastener clamps the small frame and the base in the horizontal direction;

[0015] Step 4: operate the machine tool according to the preset program, remove the reinforcing ribs on the forged plate, mill the welding bumps at the preset position, and drill the mounting holes on the edge of the plate.

[0016] The application has the following advantages:

[0017] The application makes process auxiliary pins outside the pin array region of the pin heat dissipation substrate, and through the auxiliary pin jig, the forged plate is fixed on the required plane in the finishing process, which improves the processing precision and solves the problem of pin damage, thereby improving the product quality of the pin heat dissipation substrate.

[0018] 2, In addition to fixing the small frame and the base in the horizontal plane by the fastener, micro bosses are made on the wall of the auxiliary pin insertion hole, which can fix the position of the plate in the vertical direction, and realize the processing precision and stability in the finishing process. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a cross-sectional structure schematic diagram of the pin heat dissipation substrate product to be made by the application.

[0020] Figure 2This is a schematic diagram of the planar structure of a pin-type heat sink substrate product.

[0021] Figure 3 This is a three-dimensional structural diagram of the fixture used in the prior art.

[0022] Figure 4 yes Figure 3 A magnified view of a small frame on the fixture.

[0023] Figure 5 This is a schematic diagram of the planar structure of the forged sheet metal in an embodiment of the present invention.

[0024] Figure 6 This is a three-dimensional structural diagram of the auxiliary needle fixture in an embodiment of the present invention.

[0025] Figure 7 yes Figure 6 A magnified view of a small frame in the auxiliary needle device.

[0026] Figure 8 This is a cross-sectional structural diagram of the base frame in an auxiliary needle fixture.

[0027] Figure 9 This is a cross-sectional schematic diagram of the auxiliary needle insertion hole of the auxiliary needle fixture in an embodiment of the present invention. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0029] This invention relates to the fabrication of a pin-type heat sink substrate in the thermal management structure of a power module. The product structure of this pin-type heat sink substrate 10 is as follows: Figure 1 , 2 As shown, it includes two parts: a base plate 101 and a pin array 102. Figure 2 In the middle, the base plate 101 has three sets of welding bumps 103, four in each set, and multiple mounting holes 104 for reliable connection with the power module during subsequent assembly. To manufacture this pin-type heat sink substrate, the mold must first be designed according to the product structure, the metal substrate is forged, and then precision-machined, including removing reinforcing ribs, and making welding bumps 103 and mounting holes 104.

[0030] In existing technologies, the obtained forged sheet metal is typically fixed in a manner such as... Figure 3 The fixture 20 shown in Figure 4 includes a base frame 41, a plurality of small frames 42 and fasteners 43, with the small frames 42 fixed to the base frame 41 by the fasteners 43.

[0031] Each small frame 42 includes multiple product pin holes 221, grooves 422, borders 423, and multiple positioning protrusions 424, such as Figure 4The part of the needle column 102 on the plate after forging is inserted into the product needle insertion hole 221 reserved on the small frame border 423 of the jig 20, so as to fix the plate in the subsequent finishing process. By using this fixing method, the needle column 102 is usually pressed or scratched in the finishing process due to the force of the machine tool and the jig fastener 43 on the needle column 102, which affects the surface quality of the product.

[0032] The present application proposes a method for finishing the needle type heat dissipation substrate by using an auxiliary needle jig 40. First, the shape of the forging die needs to be changed, so that the forging die is made on the same side of the needle column array 102 on the plate 30, and a plurality of process auxiliary needles 301 are made around the needle column array 102. The position and number of the auxiliary needles 301 are adjusted according to the size of the heat dissipation substrate. Figure 5 In the embodiment shown, six auxiliary needles 301 are made, which are symmetrically distributed on both sides of the needle column array 102 region, and three auxiliary needles 301 on each side are arranged at equal intervals along the X direction. Good position accuracy can improve the stress balance of the plate 30 during rough milling. In the finishing process, the side of the needle column array 102 of the plate 30 after forging is installed downward on the auxiliary needle jig 40. The structure of the auxiliary needle jig 40 of the present application is shown in Figures 6-8 The auxiliary needle jig 40 includes a base frame 41, an array of small frames 42, and a fastener 43. Each small frame 42 is the same size and is fixed to the base frame 41 by the fastener 43, and all small frames 42 are installed on the same horizontal plane.

[0033] As shown in Figure 7 The middle of the small frame 42 is a groove 422 for accommodating the needle column array of the heat dissipation substrate, and the periphery of the small frame 42 is a border 423. The border 423 and the groove 422 are provided with auxiliary needle insertion holes 421, and the border 423 is provided with a plurality of positioning convex points 424.

[0034] Figure 6 The four small frames 42 on the auxiliary needle jig 40 are arranged in two rows and two columns in the horizontal plane. The size of the groove 422 on the small frame 42 is slightly larger than the outer edge size of the needle column array 102 of the needle type heat dissipation substrate; six auxiliary needle insertion holes 421 are made on the border 423 of each small frame 42, and the positions are consistent with Figure 5 The auxiliary needles 301 on the plate 30 after forging correspond to the auxiliary needles 301 shown in the embodiment. There are two columns of auxiliary needle insertion holes 421 symmetrically arranged on both sides of the long side of the groove 422, and three auxiliary needle insertion holes 421 are arranged at equal intervals in each column. There are also ten positioning convex points 424 on the border 423 of each small frame 42, which are symmetrically distributed on both sides of the groove 422 along the long side direction, and there are six positioning convex points 424 symmetrically distributed on both sides of the groove 422 along the short side direction.

[0035] The upper surface of the base frame 41 of the auxiliary needle jig 40 is machined with 2n grooves 411 in the X direction, for mounting n rows of small frames 42, in the embodiment n equals 2, as shown in the figure, the width of the groove 411 is equal to the sum of the width a of the part of the small frame border 423 clamped into the groove 411 and the width b of the part of the fastener 43 clamped into the groove 411. The small frame 42 is clamped and mounted on the base frame 41 by the fasteners 43 on both sides. Figure 8

[0036] As shown in the figure, the auxiliary needle insertion hole 421 on the small frame 42 is cylindrical, in the embodiment, 4 micro bosses 44 are made on the wall of the cylindrical hole in the outward direction of the hole, and the micro bosses 44 are staggered. Figure 9

[0037] The present application proposes a kind of fine processing technology of needle type heat dissipation substrate, the overall process of embodiment is as follows:

[0038] Step 1: forging and pressing plate material to obtain Figure 5 As shown in the figure, the plate material 30 with needle column array 102 and auxiliary needle 301. Auxiliary needle 301 is made on the bottom plate 101, on the same side with needle column array 102, symmetrically distributed around the needle column array 102 area.

[0039] Step 2: place Figure 5 As shown in the figure, the side of the needle column array 102 of the forged plate material 30 downward, is placed in Figure 7 As shown in the figure, small frame 42, insert each auxiliary needle 301 into corresponding position auxiliary needle insertion hole 421, while making positioning boss 424 and frame part of plate material 30 good contact, make plate material 30 positioning in processing plane.

[0040] Step 3: adjust fastener 43, fix small frame 42 and base frame 41 together, through the fastener 43 clamped in the groove 411 of base frame 41, top small frame 42 in horizontal direction, all small frame 42 is installed in the same horizontal plane.

[0041] In actual processing, under the combined action of machine tool cutter moving along preset trajectory and fastener 43, plate material 30 may be displaced in vertical direction, resulting in error of processing size, size consistency between same parts is not good. As shown in the figure, 4 micro bosses 44 are made outward on the wall of auxiliary needle insertion hole 421 on small frame 42 in the embodiment of the present application, staggered. In this way, when fastener 43 clamps small frame 42 and base frame 41 together, auxiliary needle 301 will be deformed slightly at the position of micro boss 44 due to the pressure in horizontal direction, which can solve the problem of plate material 30 moving in vertical direction. Figure 9

[0042] ​​​Step 4: operate the machine tool according to the preset program, remove the reinforcing ribs on the forged plate 30, mill the welding bumps 103 at the preset positions, and then drill the mounting holes 104 on the edge of the plate 30.

[0043] The finishing process of the pin type heat dissipation substrate provided by the application increases the auxiliary needle 301 outside the original heat dissipation substrate structure 10, fixes the forged plate 30 on the auxiliary needle jig 40 through the locking action of the auxiliary needle jig 40 in the horizontal plane and the vertical plane, and then stably completes the finishing process. The application can realize the accurate positioning of the plate plane in the finishing process, solve the damage problem of the pin column on the heat dissipation substrate caused by the finishing process, improve the surface quality of the product, avoid damage to the pin column 102 in the machining process, obtain good consistency of the structure size of each part of the plate, realize high-quality batch manufacturing of the pin type heat dissipation substrate, and improve the overall heat dissipation efficiency and working reliability of the downstream power module product.

[0044] The application described herein is merely the preferred embodiment of the application and is not intended to limit the application. Any modification, equivalent replacement and improvement made within the spirit and principle of the application shall be included in the protection scope of the application.

Claims

1. An auxiliary needle fixture for a needle-type heat dissipation substrate, comprising a base frame (41), a plurality of small frames (42), and fasteners (43), wherein each small frame (42) is fixed to the base frame (41) by the fasteners (43); characterized in that, The small frame (42) has a groove (422) in the middle for accommodating the pin array of the heat dissipation substrate, and a frame (423) around the small frame (42). An auxiliary pin insertion hole (421) is provided at the junction of the frame (423) and the groove (422). Multiple positioning protrusions (424) are provided on the frame (423).

2. The auxiliary needle fixture for the needle-type heat dissipation substrate according to claim 1, characterized in that, Each small frame (42) is installed on the same horizontal plane and arranged in an array.

3. The auxiliary needle fixture for the needle-type heat dissipation substrate according to claim 1, characterized in that, The size of the groove (422) in the middle of the small frame (42) is slightly larger than the size of the outer edge of the pin array on the pin heat sink substrate to be processed; the position of the auxiliary pin insertion hole (421) on the small frame (42) corresponds to the auxiliary pin on the pin heat sink substrate.

4. The auxiliary needle fixture for the needle-type heat dissipation substrate according to claim 1, characterized in that, The auxiliary pin holes (421) are symmetrically arranged on both sides of the groove, with each row of holes arranged at equal intervals.

5. The auxiliary needle fixture for the needle-type heat dissipation substrate according to claim 1, characterized in that, The auxiliary pin insertion hole (421) is cylindrical, and multiple micro-protrusions (44) are made outward on its hole wall.

6. The auxiliary needle fixture for the needle-type heat dissipation substrate according to claim 5, characterized in that, The multiple micro-protrusions (44) are arranged alternately on the hole wall.

7. A precision machining process for a pin-type heat sink substrate, characterized in that, Includes the following steps: Step 1: Forging the sheet metal, the forged sheet metal includes a base plate, a needle column array and auxiliary needles; the auxiliary needles are made on the base plate, on the same side as the needle column array, and symmetrically distributed around the needle column array area; Step 2: Place the forged sheet metal pin array side down in the small frame of the auxiliary pin fixture, and insert each auxiliary pin into the corresponding auxiliary pin insertion hole on the auxiliary pin fixture; the auxiliary pin fixture includes a base frame, multiple small frames and fasteners, and each small frame is fixed to the base frame by fasteners; the center of each small frame is a groove for accommodating the pin array of the heat dissipation substrate, and the surrounding area of ​​each small frame is a frame, with auxiliary pin insertion holes provided at the junction of the frame and the groove, and multiple positioning protrusions provided on the frame; Step 3: Adjust the fasteners to fix the small frame to the base frame together. The fasteners should clamp the small frame to the base frame in the horizontal direction. Step 4: Operate the machine tool according to the preset program, remove the reinforcing ribs on the forged plate, mill welding protrusions at the preset positions, and drill mounting holes on the edge of the plate.

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