Method of manufacturing a test socket and test socket

Abstract

The application provides a preparation method of a test seat and the test seat, and relates to the technical field of testing. The method comprises the following steps: firstly, performing first local thinning on the top side surface of the test base to form a base boss; secondly, performing second local thinning on the top side surface of the base boss to form a placing groove; thirdly, placing solder in the placing groove to perform first sintering to form a sintered solder layer; and fourthly, placing heat sink material in the placing groove to perform second sintering to form a heat sink sintered layer. The heat sink material can be silicon carbide and / or diamond. Compared with the prior art, the placing groove formed by the two thinning processes contains the solder, so that the solder can be prevented from flowing out during sintering, and the solder sheet can be limited, so that the stable formation of the sintered solder layer is ensured. The heat sink sintered layer is formed by two sintering processes, so that the combination is better. The silicon carbide and / or diamond is used as the heat sink material, so that the heat dissipation is ensured, the service life and the structural stability are improved, and the process is easy to implement.

Description

Technical Field

[0001] This invention relates to the field of testing technology, and more specifically, to a method for preparing a test socket and a test socket. Background Technology

[0002] Test fixtures, especially aging test fixtures, are crucial devices for testing high-power semiconductor laser devices. Current test fixtures use oxygen-free copper as the heat sink to ensure thermal conductivity, with a gold plating on the surface. However, this material is too soft; even slight contact with foreign objects during testing can damage the heat sink surface, affecting heat dissipation. Furthermore, the gold plating on oxygen-free copper is not durable, requiring replacement approximately every ten days under normal testing. It cannot be reused, and each replacement necessitates a complete change to all testing standards, resulting in high costs. Using other materials as heat sinks presents challenges due to complex manufacturing processes, poor structural stability, and implementation difficulties. Summary of the Invention

[0003] The purpose of this invention is to provide a method for preparing a test holder and a test holder that can improve service life and structural stability by using silicon carbide and / or diamond as heat sink materials through two sintering processes, while ensuring heat dissipation. The process is stable and easy to implement.

[0004] In a first aspect, embodiments of the present invention provide a method for preparing a test holder, the method comprising:

[0005] Provide a test base;

[0006] The top surface of the test base is locally thinned for the first time to form a base boss on the test base;

[0007] The top side surface of the base boss is partially thinned a second time to form a placement groove on the base boss;

[0008] Solder is placed in the placement groove for the first sintering to form a sintered solder layer in the placement groove;

[0009] Heat sink material is placed in the placement groove for a second sintering to form a heat sink sintered layer on the sintered solder layer;

[0010] At least partially thin and remove the base boss remaining around the placement groove;

[0011] The thinned area of ​​the test base surface is gold-plated;

[0012] The heat sink material comprises silicon carbide and / or diamond, and the heat sink sintered layer is configured to place the device to be tested.

[0013] In an optional embodiment, the step of performing a first local thinning of the top side surface of the test base includes:

[0014] The area outside the first preset area on the top side surface of the test base is milled to a first preset depth to form a base boss in the first preset area, wherein the first preset depth is 0.6mm-1mm; and / or, the surface roughness Ra1 of the area outside the first preset area after milling is ≤0.4μm.

[0015] In an optional embodiment, the step of performing a second local thinning of the top side surface of the base boss includes:

[0016] The second preset area on the top side surface of the base boss is milled to a second preset depth to form a placement groove in the second preset area, wherein the second preset depth is 0.2mm-0.4mm; and / or, the surface roughness Ra1 of the second preset area after milling is ≥0.8μm.

[0017] In an optional embodiment, after the step of milling a second preset depth in a second preset area on the top side surface of the base boss, the method further includes:

[0018] The sidewalls of the placement groove are milled so that at least a portion of the cross-section of the placement groove is inverted trapezoidal;

[0019] The angle between the sidewall of the placement groove and the bottom wall of the placement groove after milling is 10°-20°.

[0020] In an optional embodiment, after the step of milling a second preset depth in a second preset area on the top side surface of the base boss, the method further includes:

[0021] The bottom wall of the placement groove is machined to form a plurality of downwardly extending anchoring micropores, wherein the anchoring micropores are configured to fill the sintered solder layer and the heat sink sintered layer;

[0022] The diameter of the anchoring micropores is between 80-120 μm, and the depth is between 180-220 μm.

[0023] In an optional embodiment, the step of placing solder in the placement groove for the first sintering includes:

[0024] Place the test base into the sintering furnace;

[0025] The solder is loaded into the placement groove, wherein the solder is a silver-copper solder with a silver content of 15%-45%;

[0026] The solder is first sintered using a hot pressing sintering process to form a sintered solder layer;

[0027] The thickness of the sintered solder layer is between 4μm and 6μm.

[0028] In an optional embodiment, the process of performing a first sintering of the solder using a hot-pressing sintering process includes:

[0029] The temperature of the sintering furnace is increased to 300°C at a heating rate of 10°C / min.

[0030] The temperature of the sintering furnace is increased to 780°C at a heating rate of 5°C / min.

[0031] The sintering furnace is held at 780℃ for 10-40 minutes.

[0032] The temperature of the sintering furnace is reduced to 200°C at a cooling rate of 5°C / min.

[0033] The temperature of the sintering furnace was naturally cooled to room temperature.

[0034] In an optional embodiment, the step of placing heat sink material in the placement groove for a second sintering includes:

[0035] The heat sink material is filled into the placement groove, wherein the heat sink material comprises a mixture of silicon carbide powder and silver powder;

[0036] The heat sink material is scraped and pre-pressed to form an initial blank;

[0037] The graphite block is pressed and placed on the initial blank;

[0038] The heat sink material is sintered a second time to form a heat sink sintered layer.

[0039] In an optional embodiment, the step of performing a second sintering on the heat sink material includes:

[0040] The temperature of the sintering furnace is increased to 300°C at a heating rate of 10°C / min.

[0041] The temperature of the sintering furnace is increased to 850°C at a heating rate of 5°C / min.

[0042] The sintering furnace is held at 850℃ for 20-50 minutes.

[0043] The temperature of the sintering furnace is reduced to 200°C at a cooling rate of 5°C / min.

[0044] The temperature of the sintering furnace was naturally cooled to room temperature.

[0045] In an optional embodiment, the heat sink sintered layer includes a dense layer and a porous layer, the porous layer being located on the dense layer, and the step of performing a second sintering on the heat sink material includes:

[0046] The initial blank is sintered a second time by controlling the temperature gradient along the vertical direction to form a dense layer and a porous layer, wherein the porosity of the dense layer is <2% and the porosity of the porous layer is between 10% and 15%.

[0047] In an optional embodiment, the step of performing a second sintering by controlling the temperature gradient along the vertical direction of the placement groove includes:

[0048] The temperature of the sintering furnace is increased to 300°C at a heating rate of 10°C / min.

[0049] The temperature of the bottom of the initial billet is raised to 850°C, and the temperature of the top of the initial billet is raised to 600°C;

[0050] The bottom of the initial blank is kept at 850℃ for 20-50 minutes, and the top of the initial blank is kept at 600℃ for 20-50 minutes.

[0051] The temperature of the sintering furnace was lowered to 200°C;

[0052] The temperature of the sintering furnace was naturally cooled to room temperature.

[0053] Secondly, embodiments of the present invention provide a test holder, which is prepared using the aforementioned test holder preparation method, the test holder comprising:

[0054] A test base, on which a base boss is formed;

[0055] A sintered solder layer and a heat sink sintered layer are sequentially disposed on the substrate boss. The heat sink sintered layer is sintered and fixed on the substrate boss by the sintered solder layer. The heat sink sintered layer contains silicon carbide and / or diamond. The heat sink sintered layer is configured to place the device to be tested.

[0056] In an optional embodiment, the test base is further provided with a slide rail placement groove and a slide rail slidably disposed on the slide rail placement groove. The slide rail placement groove is spaced apart from the heat sink sintered layer, wherein the slide rail is configured to drive the device to move.

[0057] In an optional embodiment, the test base is further provided with a cooling channel, the side wall of the test base is provided with a first cooling hole, and the base protrusion is further provided with a second cooling hole extending to the top of the heat sink sintered layer. The first cooling hole and the second cooling hole are both connected to the cooling channel, wherein the first cooling hole is configured to input cooling liquid and the second cooling hole is configured to output cooling liquid.

[0058] In an optional embodiment, a placement groove is formed on the substrate boss, the cross-section of the placement groove is an inverted trapezoid, the sintered solder layer and the heat sink sintered layer fill the placement groove, and the protrusion height of the substrate boss relative to the test base is less than the protrusion height of the heat sink sintered layer relative to the test base.

[0059] In an optional embodiment, anchoring micropores are also formed on the substrate boss, and both the sintered solder layer and the heat sink sintered layer fill the anchoring micropores.

[0060] In an optional embodiment, the heat sink sintered layer includes a dense layer and a porous layer, the dense layer being formed on the sintered solder layer, the porous layer being formed on the dense layer, wherein the porosity of the dense layer is <2%, and the porosity of the porous layer is between 10% and 15%; and / or, the thickness H1 of the dense layer is 1 to 3 times the thickness H2 of the porous layer.

[0061] The beneficial effects of the embodiments of the present invention include:

[0062] The method for preparing a test base provided in this invention first involves providing a test base. Then, a first local thinning is performed on the top surface of the test base to form a base boss. Next, a second local thinning is performed on the top surface of the base boss to form a placement groove. Solder is then placed in the placement groove and subjected to a first sintering process to form a sintered solder layer. Heat sink material is then placed in the placement groove and subjected to a second sintering process to form a heat sink sintered layer. Finally, at least a portion of the base boss located around the placement groove is removed. The heat sink material can be silicon carbide and / or diamond. The heat sink sintered layer can accommodate the device to be tested. Compared to existing technologies, this invention first forms the placement groove through two thinning processes. By accommodating the solder in the placement groove, solder leakage during the first and second sintering processes can be prevented. It also limits the placement of the solder sheet, ensuring the stable formation of the solder sintered layer. Simultaneously, the heat sink sintered layer is formed through two sintering processes, which can replace the conventional solution of gold plating on oxygen-free copper surfaces. Using silicon carbide and / or diamond as heat sink materials, it can improve service life and structural stability while ensuring heat dissipation. Moreover, the process has good stability and is easy to implement. Attached Figure Description

[0063] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0064] Figure 1 A flowchart illustrating the steps of a method for preparing a test holder according to an embodiment of the present invention;

[0065] Figure 2 This is a schematic diagram of the structure corresponding to step S1 in the preparation method of the test seat provided in the embodiment of the present invention;

[0066] Figure 3 This is a schematic diagram of the structure corresponding to step S2 in the preparation method of the test seat provided in the embodiment of the present invention;

[0067] Figure 4 This is a schematic diagram of the structure corresponding to step S3 in the preparation method of the test seat provided in the embodiment of the present invention;

[0068] Figure 5 This is a schematic diagram of the structure corresponding to step S4 in the preparation method of the test seat provided in the embodiment of the present invention;

[0069] Figure 6 This is a schematic diagram of the structure corresponding to step S5 in the preparation method of the test seat provided in the embodiment of the present invention;

[0070] Figure 7 This is a schematic diagram of the structure corresponding to step S6 in the preparation method of the test seat provided in the embodiment of the present invention;

[0071] Figure 8 A schematic diagram of the structure corresponding to steps S2 and S5 of the second process in the preparation method of the test seat provided in the embodiment of the present invention;

[0072] Figure 9 A schematic diagram of the structure corresponding to steps S2 and S5 of the third process in the preparation method of the test seat provided in the embodiment of the present invention;

[0073] Figure 10 This is a schematic diagram of the structure of the test stand provided in an embodiment of the present invention.

[0074] Icons: 100-Test base; 110-Test base; 111-First cooling hole; 113-Second cooling hole; 115-Slide rail placement groove; 120-Base boss; 130-Placement groove; 131-Anchoring micropore; 140-Sintered solder layer; 150-Heat sink sintered layer; 151-Dense layer; 153-Porous layer. Detailed Implementation

[0075] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0076] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0077] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0078] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed, they are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0079] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0080] As disclosed in the background section, existing test fixtures typically use oxygen-free copper as the heat sink to ensure thermal conductivity, with a gold-plated surface. However, while this type of heat sink meets the thermal conductivity requirements, the overall material is too soft and easily damaged by foreign objects during testing, affecting heat dissipation. Furthermore, the gold-plated material on the oxygen-free copper surface is not durable, requiring replacement after only ten days of normal testing. It cannot be reused, and each replacement necessitates a complete change to all testing standards, resulting in high costs.

[0081] Furthermore, existing technologies have also explored solutions that utilize other high thermal conductivity non-metallic materials as heat sinks. However, using non-metallic materials as heat sinks presents challenges such as high manufacturing difficulty, poor integration with the test base body, poor structural stability, and difficulty in implementation.

[0082] To address the aforementioned problems, this invention provides a novel method for preparing a test holder and a test holder. It should be noted that, unless otherwise specified, the features in the embodiments of this invention can be combined with each other.

[0083] This invention provides a method for preparing a test socket. The method involves a two-stage sintering process, using silicon carbide or diamond as the heat sink material. This ensures heat dissipation while improving service life and structural stability. Furthermore, the heat sink exhibits good bonding properties, process stability, and ease of implementation.

[0084] See Figure 1 The method for preparing a test socket 100 provided in this embodiment of the invention includes the following steps:

[0085] S1: Provides test base 110.

[0086] See Figure 2 Specifically, a test base 110 is provided, which is made of oxygen-free copper and has been pre-plated with gold to form a gold layer on its surface. This test base 110 can be used for aging tests of semiconductor lasers, as well as for other tests of other devices.

[0087] S2: Perform a first local thinning on the top surface of the test base 110 to form a base boss 120 on the test base 110.

[0088] See Figure 3 Specifically, a milling process can be used to mill the area outside the first preset area on the top side surface of the test base 110 to a first preset depth, so as to form a base boss 120 in the first preset area. The first preset depth is 0.6mm-1mm, for example, the first preset depth is any value of 0.6mm, 0.8mm or 1mm or any point value between two of them.

[0089] In actual fabrication, a first preset area can be pre-defined, which can be the edge of the center of the top surface of the test base 110. The area outside the first preset area is then machined for the first time, milling the top surface of the test base 110 to create a recess while retaining the first preset area, thus forming a raised base boss 120. The height of the base boss 120 can be 0.8 mm. Furthermore, the surface roughness of the milled test base 110 is less than or equal to 0.4 μm, which is relatively smooth, providing a foundation for subsequent gold plating or transition layers.

[0090] It should be noted that for the first machining operation, a PCD end mill can be used to ensure a smooth milled surface without noticeable tool marks. The tool diameter can be between D3 and D5, the cutting speed between 10,000 RPM and 18,000 RPM, the feed rate between 400 and 1,000 mmPM, and the depth of cut between 0.01 mm and 0.04 mm, resulting in a surface free of tool marks. Furthermore, a full-surface cutting fluid should be used to cool the tool and prevent tool wear.

[0091] S3: Perform a second local thinning on the top side surface of the base boss 120 to form a placement groove 130 on the base boss 120.

[0092] See Figure 4 Specifically, a milling process can be used again to mill the second preset area on the top side surface of the base boss 120 to a second preset depth, thereby forming a placement groove 130 in the second preset area. The second preset depth is 0.2mm-0.4mm, for example, any value among 0.2mm, 0.3mm, or 0.4mm, or a point value between any two. The size of the second preset area is smaller than the size of the first preset area, and the second preset area is located in the middle region of the base boss 120, thereby forming a device placement area.

[0093] In actual fabrication, a second preset region can be pre-defined, which may be the central position of the base boss 120. A second machining process is performed on the second preset region to mill the surface of the base boss 120, creating a recess. This mills out a second region within the raised first preset region, forming a placement groove 130 with a depth of 0.3 mm. Furthermore, the surface roughness of the milled second region is greater than or equal to 0.8 μm, which enhances subsequent solder wettability and mechanical interlocking.

[0094] It should be noted that during the second machining step, a PCD end mill can be used to ensure a smooth milled surface without noticeable tool marks. The tool diameter can be between D1 and D3, the cutting speed between 12000 RPM and 18000 RPM, the feed rate between 400 and 1000 mmPM, and the depth of cut between 0.01 mm and 0.04 mm, resulting in a surface free of tool marks. Furthermore, a full-surface cutting fluid should be used to cool the tool and prevent tool wear.

[0095] It should also be noted that the depth of the placement groove 130 can be set according to the thickness of the subsequent heat-sintered layer 150. The placement groove 130 is formed by further thinning a specific second preset area within the first preset area, and the placement groove 130 does not penetrate the base boss 120.

[0096] See Figure 8 In some embodiments, after forming the placement groove 130, the bonding strength of the subsequent heat-sink sintered layer 150 can be improved by optimizing the structure of the placement groove 130. Specifically, the sidewalls of the placement groove 130 can be milled to make at least a portion of the cross-section of the placement groove 130 in an inverted trapezoidal shape, thereby preventing axial delamination of the subsequently formed heat-sink sintered layer 150. The angle of inclination of the sidewalls of the milled placement groove 130 relative to the bottom wall of the placement groove 130 is 10°-20°, for example, the angle of inclination of the sidewalls of the placement groove 130 relative to the bottom wall of the placement groove 130 is any value among 10°, 15°, and 20°, or a value between any two of these values.

[0097] See Figure 9 In some embodiments, after forming the placement groove 130, laser processing can be performed on the bottom wall of the placement groove 130 to form a plurality of downwardly extending anchoring microholes 131, wherein the anchoring microholes 131 are configured to fill the sintered solder layer 140 and the heat sink sintered layer 150; wherein the aperture of the anchoring microholes 131 is between 80-120 μm, for example, any point value or any two points of aperture among 80 μm, 100 μm, and 120 μm. Simultaneously, the depth of the anchoring microholes 131 is between 180-220 μm, for example, any point value or any two points of depth among 180 μm, 200 μm, and 220 μm. By designing the anchoring microholes 131, an anchoring effect can be formed during the subsequent formation of the heat sink sintered layer 150, further enhancing the bonding force between the heat sink sintered layer 150 and the substrate boss 120. Meanwhile, the design of the inverted trapezoidal placement groove 130, combined with the anchoring micropores 131, can more effectively improve the bonding force and structural stability of the heat sink sintering layer 150.

[0098] S3: Placing solder in placement groove 130 for the first sintering to form sintered solder layer 140 in placement groove 130.

[0099] Please continue reading Figure 5 Specifically, during the first sintering, the test base 110 is first placed in the sintering furnace, and then the solder is loaded into the placement groove 130; the solder is then sintered for the first time using a hot-pressing sintering process to form a sintered solder layer 140. The sintering furnace can be a vacuum reflow furnace or an argon reflow furnace with an oxygen content of less than 10 ppm. The solder is a silver-copper solder with a silver content of 15%-45%, and a 0.005mm standard silver-copper solder part can be used for the first sintering. The thickness of the sintered solder layer 140 is between 4μm and 6μm. Here, "silver-copper solder with a silver content of 15%-45%" refers to the mass fraction of silver.

[0100] Furthermore, in the process of first sintering the solder using hot pressing sintering, the temperature of the sintering furnace can be first increased to 300℃ at a heating rate of 10℃ / min to effectively remove organic matter; then the temperature of the sintering furnace can be increased to 780℃ at a heating rate of 5℃ / min to allow silver and copper to achieve eutectic melting; the sintering furnace can then be held at 780℃ for 10-40 minutes to ensure that the liquid solder fills the micropores of the anchoring micropores 131, forming a dense sintered solder layer 140 (approximately 0.005mm thick) that is tightly bonded to oxygen-free copper; then the temperature of the sintering furnace can be decreased to 200℃ at a cooling rate of 5℃ / min; finally, the temperature of the sintering furnace can be allowed to cool naturally to room temperature.

[0101] It should be noted that the presence of the placement groove 130, which accommodates the silver-copper solder, prevents the molten solder from flowing out of its placement area during sintering, thus avoiding voids in the sintered solder layer 140 and ensuring the subsequent welding effect of the sintered solder layer 140. Simultaneously, the placement groove 130 also limits the placement of standard silver-copper solder pieces, ensuring more accurate placement.

[0102] S4: Heat sink material is placed in placement groove 130 for a second sintering to form heat sink sintering layer 150 on sintered solder layer 140.

[0103] Please continue reading Figure 6Specifically, during the second sintering, heat sink material can first be filled into the placement groove 130. The heat sink material includes materials such as silicon carbide and / or diamond that meet the requirements for hardness and thermal conductivity. Preferably, the heat sink material can be a mixture of silicon carbide powder and silver powder. Then, the heat sink material is leveled and pre-pressed (10-20 MPa) to form an initial blank. Next, a graphite block is pressed onto the initial blank. Finally, the heat sink material undergoes a second sintering to form a heat sink sintered layer 150, which is configured to hold the device to be tested. The silicon carbide powder can be hexagonal or rhombic (α-SiC), with a particle size of 1-3 μm and a purity ≥99.9%. Simultaneously, when leveling the heat sink material, it can be leveled slightly above the edge of the placement groove 130 to allow for sintering shrinkage.

[0104] Furthermore, during the second sintering of the heat sink material, the temperature of the sintering furnace can be first increased to 300°C at a heating rate of 10°C / min to effectively remove organic matter; then the temperature of the sintering furnace can be increased to 850°C at a heating rate of 5°C / min to achieve the Ag-SiC eutectic reaction; the sintering furnace can then be held at 850°C for 20-50 minutes, preferably 30 minutes; then the temperature of the sintering furnace can be decreased to 200°C at a cooling rate of 5°C / min; finally, the temperature of the sintering furnace can be naturally cooled to room temperature.

[0105] It should be noted that a dense heat sink sintered layer 150 can be formed through the second sintering. This heat sink sintered layer 150 is a silicon carbide layer with a thickness adapted to the placement groove 130 and a porosity of less than 3%. Placing a graphite block on the silicon carbide powder for lamination before sintering can reduce the porosity of the sintered silicon carbide layer. Furthermore, the sidewalls of the silicon carbide layer can be fitted into the sidewalls of the placement groove 130. The inverted trapezoidal structure of the placement groove 130 effectively prevents axial delamination of the silicon carbide layer, improving adhesion. Anchoring micropores 131 can be embedded at the bottom of the silicon carbide layer, forming a micropillar structure to better achieve the anchoring effect and enhance the adhesion between the heat sink sintered layer 150 and the substrate protrusion 120.

[0106] See Figure 9In some embodiments, during the sintering process to form the heat sink sintered layer 150, a second sintering can be performed by controlling the temperature gradient along the vertical direction of the initial blank to form a dense layer 151 and a porous layer 153, wherein the porosity of the dense layer 151 is <2%, and the porosity of the porous layer 153 is between 10% and 15%. Specifically, the formed heat sink sintered layer 150 includes a dense layer 151 and a porous layer 153, wherein the porous layer 153 is located on top of the dense layer 151. The layered design of the heat sink sintered layer 150 can effectively alleviate the thermal stress at the contact surface between the silicon carbide layer and the device, while the placement groove 130 and anchoring micropores 131 with their inverted trapezoidal design can alleviate surface thermal stress while ensuring bonding strength, resulting in better performance.

[0107] Furthermore, when performing the second sintering by controlling the temperature gradient along the vertical direction of the placement groove 130, the temperature of the sintering furnace can first be raised to 300°C at a heating rate of 10°C / min; then, the temperature of the bottom of the initial blank can be raised to 850°C and the temperature of the top of the initial blank can be raised to 600°C by temperature gradient control, which can be achieved through the thermal field control function of the heater, which will not be elaborated here; then, the bottom of the initial blank is held at 850°C for 20-50 minutes and the top of the initial blank is held at 600°C for 20-50 minutes, thereby forming a dense layer 151 and a porous layer 153 respectively; then, the temperature of the sintering furnace is lowered to 200°C; finally, the temperature of the sintering furnace is allowed to cool naturally to room temperature.

[0108] It should be noted that the second sintering is performed by controlling the temperature gradient to control the morphology of the silicon carbide surface and alleviate the thermal stress at the contact surface between the silicon carbide layer and the device. Specifically, the temperature gradient causes the bottom of the silicon carbide layer to become dense, forming a dense layer 151, while the top of the silicon carbide layer becomes porous, forming a porous layer 153, effectively relieving thermal stress. The thickness H1 of the dense layer 151 is 1-3 times the thickness H2 of the porous layer 153.

[0109] S6: At least partially thin out and remove the remaining base boss 120 around the placement groove 130.

[0110] See Figure 7 Specifically, in some embodiments, when the sidewalls of the placement groove 130 are not structurally optimized, the cross-sectional shape of the placement groove 130 can also be rectangular. In this case, the raised copper material in the first preset area can be completely thinned and removed, that is, the base bosses 120 remaining around the placement groove 130 can be completely removed. CNC processes, such as machining, milling, and machine milling, can be used to remove the portion in the first preset area where the silicon carbide layer has not been formed. The removal can include two thinning removals: first, the base bosses 120 near the edge of the placement groove 130 are removed, and then the base bosses 120 near the edge of the test base 110 are removed.

[0111] In some embodiments, the remaining base bosses 120 around the placement groove 130 may be partially removed, thereby retaining part of the placement groove 130 to ensure that the silicon carbide layer can be firmly fitted into the placement groove 130.

[0112] S7: Gold plating is applied to the thinned area of ​​the test base 110.

[0113] Specifically, all areas except the second preset area can be gold-plated to achieve replating and ensure that the test base 110 is covered by a gold plating layer.

[0114] See also Figure 10 It should be noted that a cooling channel is pre-prepared within the test base 110. A first cooling hole 111 is formed on the side wall of the test base 110, and a second cooling hole 113 is formed on the base boss 120. Both the first cooling hole 111 and the second cooling hole 113 are connected to the cooling channel. The first cooling hole 111 is configured to input cooling liquid, and the second cooling hole 113 is configured to output cooling liquid. After the silicon carbide layer is prepared, holes can be drilled in the silicon carbide layer, for example, by punching holes with a 0.2mm drill bit, to discharge the solder and connect it to the second cooling hole 113, thereby allowing the second cooling hole 113 to penetrate to the surface of the silicon carbide layer.

[0115] Please continue reading Figure 10 This invention also provides a test socket 100, which is prepared using the aforementioned test socket preparation method. The test socket 100 includes a test base 110, a sintered solder layer 140, and a heat sink sintered layer 150. A base boss 120 is formed on the test base 110. The sintered solder layer 140 and the heat sink sintered layer 150 are sequentially disposed on the base boss 120. The heat sink sintered layer 150 is sintered and fixed on the base boss 120 by the sintered solder layer 140. The heat sink sintered layer 150 contains silicon carbide and / or diamond. The heat sink sintered layer 150 is configured to place the device to be tested.

[0116] In some embodiments, the test base 110 is further provided with a slide rail placement groove 115 and a slide rail slidably disposed on the slide rail placement groove 115. The slide rail placement groove 115 is spaced apart from the heat sink sintered layer 150, wherein the slide rail is configured to move during driving. Specifically, the slide rail may be provided with grippers, and the device may be a high-power semiconductor laser single-tube chip, the package of which may be COS (Chip on Sub-mount), C-mount, F-mount, etc. The chip is transferred from the tray to the heat sink sintered layer 150 by the test nozzle and the position is corrected by the grippers, and finally fixed by the probe pressing down.

[0117] In some embodiments, the test base 110 is further provided with a cooling channel, and the sidewall of the test base 110 is provided with a first cooling hole 111. The substrate boss 120 is also provided with a second cooling hole 113 extending to the top of the heat sink sintered layer 150. Both the first cooling hole 111 and the second cooling hole 113 are connected to the cooling channel, wherein the first cooling hole 111 is configured to input cooling liquid, and the second cooling hole 113 is configured to output cooling liquid. Specifically, after the silicon carbide layer is prepared, a hole can be drilled in the silicon carbide layer, for example, by punching a hole with a 0.2mm drill bit, to discharge the solder and connect it to the second cooling hole 113, so that the second cooling hole 113 extends to the surface of the silicon carbide layer.

[0118] Please see Figure 8 and Figure 9 In some embodiments, a placement groove 130 is formed on the base boss 120. The cross-section of the placement groove 130 is an inverted trapezoid. The sintered solder layer 140 and the heat sink sintered layer 150 are filled in the placement groove 130, and the protrusion height of the base boss 120 relative to the test base 110 is less than the protrusion height of the heat sink sintered layer 150 relative to the test base 110. Specifically, the placement groove 130 is designed with an inverted trapezoidal shape, and the inclination angle of the sidewall of the placement groove 130 relative to the bottom wall of the placement groove 130 is 10°-20°. This can effectively prevent the heat sink sintered layer 150 from axially delaminating, ensuring that the heat sink sintered layer 150 can be firmly embedded in the placement groove 130, and improving the bonding force between the heat sink sintered layer 150 and the base boss 120.

[0119] In some embodiments, anchoring microholes 131 are also formed on the substrate boss 120, and both the sintered solder layer 140 and the heat sink sintered layer 150 fill the anchoring microholes 131. Specifically, the diameter of the anchoring microholes 131 is between 80-120 μm and the depth is between 180-220 μm. The heat sink sintered layer 150 can extend into the anchoring microholes 131 to form an anchoring effect, further enhancing the bonding force between the heat sink sintered layer 150 and the substrate boss 120.

[0120] In some embodiments, the heat sink sintered layer 150 includes a dense layer 151 and a porous layer 153. The dense layer 151 is formed on the sintered solder layer 140, and the porous layer 153 is formed on the dense layer 151. The porosity of the dense layer 151 is <2%, and the porosity of the porous layer 153 is between 10% and 15%. Furthermore, the thickness H1 of the dense layer 151 is 1-3 times the thickness H2 of the porous layer 153. A second sintering is performed by controlling the temperature gradient to control the morphology of the silicon carbide surface, thereby alleviating the thermal stress at the contact surface between the silicon carbide layer and the device. Specifically, the temperature gradient causes the bottom of the silicon carbide layer to become dense, forming the dense layer 151, while the top of the silicon carbide layer becomes porous, forming the porous layer 153, effectively alleviating thermal stress.

[0121] In summary, the method for preparing the test socket and the test socket 100 provided in this embodiment of the invention first provides a conventional test base 110. Then, a first local thinning is performed on the top surface of the test base 110 to form a base boss 120 on the test base 110. Next, a second local thinning is performed on the top surface of the base boss 120 to form a placement groove 130 on the base boss 120. Solder is then placed in the placement groove 130 and subjected to a first sintering to form a sintered solder layer 140. Then, heat sink material is placed in the placement groove 130 and subjected to a second sintering to form a heat sink sintered layer 150. Finally, at least a portion of the base boss 120 located around the placement groove 130 is removed. The heat sink material can be silicon carbide powder and / or diamond powder, and the heat sink sintered layer 150 is capable of holding the device to be tested. Compared to existing technologies, this invention first forms a placement groove 130 through a two-stage thinning process. The placement groove 130 accommodates the solder, preventing solder leakage during the first and second sintering processes. It also limits the placement of the solder sheet, ensuring stable formation of the solder sintered layer. Simultaneously, the two sintering processes form a heat sink sintered layer 150, which can replace the conventional oxygen-free copper surface gold plating solution. Using silicon carbide and / or diamond as the heat sink material ensures heat dissipation while improving service life and structural stability. Furthermore, the process exhibits good stability and is easy to implement.

[0122] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing a test holder, characterized in that, The method includes: Provide test base (110); The top surface of the test base (110) is thinned locally for the first time to form a base boss (120) on the test base (110). The top side surface of the base boss (120) is thinned a second time to form a placement groove (130) on the base boss (120). The sidewall of the placement groove (130) is milled so that at least a portion of the cross-section of the placement groove (130) is an inverted trapezoid, wherein the angle of inclination of the sidewall of the placement groove (130) after milling is 10°-20° relative to the bottom wall of the placement groove (130). Solder is placed in the placement groove (130) for a first sintering to form a sintered solder layer (140) in the placement groove (130). Heat sink material is placed in the placement groove (130) for a second sintering to form a heat sink sintering layer (150) on the sintered solder layer (140). A second cooling hole (113) is formed by drilling holes in the heat sink sintering layer (150), and the second cooling hole (113) extends to the surface of the heat sink sintering layer (150). At least partially thin out and remove the base boss (120) remaining around the placement groove (130). The thinned area of ​​the test base (110) is plated with gold; The heat sink material comprises silicon carbide and / or diamond, and the heat sink sintered layer (150) is configured to place the device to be tested.

2. The method for preparing the test holder according to claim 1, characterized in that, The step of performing a first local thinning of the top surface of the test base (110) includes: The area outside the first preset area on the top side surface of the test base (110) is milled to a first preset depth to form a base boss (120) in the first preset area. The first preset depth is 0.6mm-1mm; and / or the surface roughness Ra1 of the area outside the first preset area after milling is ≤0.4μm.

3. The method for preparing the test holder according to claim 1, characterized in that, The step of performing a second local thinning of the top side surface of the base boss (120) includes: A second preset depth is milled on the second preset area of ​​the top side surface of the base boss (120) to form a placement groove (130) in the second preset area. The second preset depth is 0.2mm-0.4mm; and / or the surface roughness Ra1 of the second preset area after milling is ≥0.8μm.

4. The method for preparing the test holder according to claim 1, characterized in that, After the step of milling a second preset depth in the second preset area of ​​the top side surface of the base boss (120), the method further includes: The bottom wall of the placement groove (130) is processed to form a plurality of downwardly extending anchoring microholes (131), wherein the anchoring microholes (131) are configured to fill the sintered solder layer (140) and the heat sink sintered layer (150). The diameter of the anchoring micropore (131) is between 80-120 μm and the depth is between 180-220 μm.

5. The method for preparing the test holder according to any one of claims 1-4, characterized in that, The step of placing solder in the placement groove (130) for the first sintering includes: The test base (110) is placed in the sintering furnace; The solder is loaded into the placement groove (130), wherein the solder is a silver-copper solder with a silver content of 15%-45%; The solder is first sintered using a hot pressing sintering process to form a sintered solder layer (140). The thickness of the sintered solder layer (140) is between 4μm and 6μm.

6. The method for preparing the test holder according to claim 5, characterized in that, The process of performing the first sintering of the solder using hot pressing sintering includes: The temperature of the sintering furnace is increased to 300°C at a heating rate of 10°C / min. The temperature of the sintering furnace is increased to 780°C at a heating rate of 5°C / min. The sintering furnace is held at 780℃ for 10-40 minutes. The temperature of the sintering furnace is reduced to 200°C at a cooling rate of 5°C / min. The temperature of the sintering furnace was naturally cooled to room temperature.

7. The method for preparing the test socket according to claim 1, characterized in that, The step of placing heat sink material in the placement groove (130) for a second sintering includes: The heat sink material is filled into the placement groove (130), wherein the heat sink material comprises a mixture of silicon carbide powder and silver powder; The heat sink material is scraped and pre-pressed to form an initial blank; The graphite block is pressed and placed on the initial blank; The heat sink material is sintered a second time to form a heat sink sintered layer (150).

8. The method for preparing the test socket according to claim 7, characterized in that, The step of performing a second sintering on the heat sink material includes: The temperature of the sintering furnace is increased to 300℃ at a heating rate of 10℃ / min. The temperature of the sintering furnace is increased to 850°C at a heating rate of 5°C / min. The sintering furnace is held at 850℃ for 20-50 minutes. The temperature of the sintering furnace is reduced to 200°C at a cooling rate of 5°C / min. The temperature of the sintering furnace was naturally cooled to room temperature.

9. The method for preparing the test holder according to claim 7, characterized in that, The heat sink sintered layer (150) includes a dense layer (151) and a porous layer (153), wherein the porous layer (153) is located on the dense layer (151). The step of performing a second sintering on the heat sink material includes: A second sintering is performed by controlling the temperature gradient along the vertical direction of the initial blank to form a dense layer (151) and a porous layer (153), wherein the porosity of the dense layer (151) is <2% and the porosity of the porous layer (153) is between 10% and 15%.

10. The method for preparing the test holder according to claim 9, characterized in that, The step of performing a second sintering by controlling the temperature gradient along the vertical direction of the placement groove (130) includes: The temperature of the sintering furnace is increased to 300℃ at a heating rate of 10℃ / min. The temperature of the bottom of the initial billet is raised to 850°C, and the temperature of the top of the initial billet is raised to 600°C; The bottom of the initial blank is kept at 850℃ for 20-50 minutes, and the top of the initial blank is kept at 600℃ for 20-50 minutes. The temperature of the sintering furnace was lowered to 200°C; The temperature of the sintering furnace was naturally cooled to room temperature.

11. A test socket, manufactured using the method for preparing a test socket as described in any one of claims 1-10, characterized in that, The test socket includes: Test base (110), on which a base boss (120) is formed. A sintered solder layer (140) and a heat sink sintered layer (150) are sequentially disposed on the substrate boss (120). The heat sink sintered layer (150) is sintered and fixed on the substrate boss (120) by the sintered solder layer (140). The heat sink sintered layer (150) contains silicon carbide and / or diamond. The heat sink sintered layer (150) is configured to place the device to be tested.

12. The test fixture according to claim 11, characterized in that, The test base (110) is also provided with a slide rail placement groove (115) and a slide rail slidably disposed on the slide rail placement groove (115). The slide rail placement groove (115) is spaced apart from the heat sink sintered layer (150). The slide rail is configured to drive the device to move.

13. The test fixture according to claim 11, characterized in that, The test base (110) is also provided with a cooling channel. The side wall of the test base (110) is provided with a first cooling hole (111). The base boss (120) is also provided with a second cooling hole (113) that extends to the top of the heat sink sintered layer (150). The first cooling hole (111) and the second cooling hole (113) are both connected to the cooling channel. The first cooling hole (111) is configured to input cooling liquid, and the second cooling hole (113) is configured to output cooling liquid.

14. The test fixture according to claim 11, characterized in that, A placement groove (130) is formed on the base boss (120). The cross-section of the placement groove (130) is an inverted trapezoid. The sintered solder layer (140) and the heat sink sintered layer (150) are filled in the placement groove (130). The protrusion height of the base boss (120) relative to the test base (110) is less than the protrusion height of the heat sink sintered layer (150) relative to the test base (110).

15. The test fixture according to claim 11 or 14, characterized in that, Anchoring microholes (131) are also formed on the substrate boss (120), and the sintered solder layer (140) and the heat sink sintered layer (150) are both filled into the anchoring microholes (131).

16. The test fixture according to claim 11 or 14, characterized in that, The heat sink sintered layer (150) includes a dense layer (151) and a porous layer (153), wherein the dense layer (151) is formed on the sintered solder layer (140), and the porous layer (153) is formed on the dense layer (151), wherein the porosity of the dense layer (151) is <2%, and the porosity of the porous layer (153) is between 10% and 15%; and / or, the thickness H1 of the dense layer (151) is 1 to 3 times the thickness H2 of the porous layer (153).

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