Sintering fixtures

Abstract

This disclosure relates to the field of semiconductor packaging sintering technology, specifically to a sintering fixture, including a base, a lower limiting plate, and an upper limiting plate. The base is capable of placing a power substrate of a power module. The lower limiting plate is pressed onto the base and has a through first limiting hole. The first limiting hole is configured to allow the end of a straight pin terminal to pass through and connect to the power substrate placed in the placement area, and the first limiting hole can restrict the movement of the end of the straight pin terminal in the radial direction of the first limiting hole. The upper limiting plate is pressed onto the top surface of the lower limiting plate and has a through second limiting hole. The second limiting hole allows the front end of the straight pin terminal to pass through and restricts the movement of the front end of the straight pin terminal in the radial direction of the second limiting hole. By providing a lower limiting plate and an upper limiting plate on the top surface of the base, the first limiting hole and the second limiting hole can simultaneously limit the end and front end of the straight pin terminal, improving the problem of poor soldering of the straight pin terminal.

Description

Technical Field

[0001] This disclosure belongs to the field of semiconductor packaging sintering technology, specifically relating to a sintering fixture. Background Technology

[0002] As a core component in power electronic converters, power modules are now widely used in inverters, battery management, electric drive systems, frequency converters and other fields in new energy systems, resulting in a year-on-year increase in demand. Therefore, their production efficiency is particularly important.

[0003] When sintering straight pin terminals for power modules, the commonly used sintering fixture structures cannot ensure that the sintered straight pin terminals are perpendicular. In other words, the straight pin terminals sintered by the current sintering fixtures are all skewed to a certain extent, resulting in a high rate of poor soldering of the straight pin terminals. This also makes it difficult to install the casing in the subsequent assembly process and to test the test process, resulting in a low overall pass rate for the power modules. Utility Model Content

[0004] The purpose of this application is to provide a sintering fixture that can simultaneously limit the end and front end of a straight pin terminal by means of a lower limiting plate and an upper limiting plate, thereby improving the problem of poor soldering of straight pin terminals.

[0005] This disclosure provides a sintering fixture, including:

[0006] A base having a placement area configured to hold a power substrate for a power module; A lower limiting plate is pressed onto the base. The lower limiting plate has a through first limiting hole, which is opposite to the placement area. The first limiting hole is configured to allow the end of the straight pin terminal to pass through and connect to the power substrate placed in the placement area. The first limiting hole is also configured to restrict the movement of the end of the straight pin terminal in the radial direction of the first limiting hole. An upper limiting plate is pressed against the top surface of the lower limiting plate. The upper limiting plate has a through second limiting hole, which is opposite to the first limiting hole. The second limiting hole is configured to allow the front end of the straight needle terminal to pass through and to restrict the movement of the front end of the straight needle terminal in the radial direction of the second limiting hole.

[0007] In one exemplary embodiment of this disclosure, a positioning groove is provided on the top surface of the base, and the positioning groove is configured to limit the displacement of the power substrate on the base; When the lower limiting plate is pressed onto the base, the bottom surface of the lower limiting plate can abut against the top surface of the power substrate placed on the placement area.

[0008] In an exemplary embodiment of this disclosure, the top surface of the base is further provided with at least one communicating groove, the communicating groove being disposed on at least a portion of the side periphery of the positioning groove, and the end of the communicating groove near the positioning groove communicating with the positioning groove.

[0009] In one exemplary embodiment of this disclosure, the end of the connecting groove away from the positioning groove extends through the side of the base.

[0010] In an exemplary embodiment of this disclosure, the bottom surface of the lower limiting plate is provided with an avoidance groove, the orthographic projection of the avoidance groove on the base is located in the positioning groove, and when the lower limiting plate is pressed onto the base, there is a gap between the bottom of the avoidance groove and the top surface of the power substrate located in the positioning groove.

[0011] In one exemplary embodiment of this disclosure, a venting groove is provided on the lower limiting plate, the venting groove is disposed through the lower limiting plate, and the orthographic projection of the venting groove on the base is located in the positioning groove; the venting groove is adjacent to and spaced apart from the first limiting hole.

[0012] In one exemplary embodiment of this disclosure, a first positioning hole is provided on the base; The bottom surface of the lower limiting plate is provided with a first positioning member, which corresponds to the first positioning hole and can be embedded in the first positioning hole.

[0013] In an exemplary embodiment of this disclosure, a second positioning hole is provided on the base, a third positioning hole is provided on the lower limiting plate, and a second positioning member is provided on the bottom surface of the upper limiting plate. The second positioning member corresponds to the second positioning hole and the third positioning hole, and the second positioning member can be embedded in the second positioning hole and the third positioning hole. When the second positioning member is embedded in the second positioning hole and the third positioning hole, the bottom surface of the upper limiting plate and the top surface of the lower limiting plate are spaced apart.

[0014] In one exemplary embodiment of this disclosure, the second positioning element includes: The support portion has its top surface connected to the bottom surface of the upper limiting plate, and its cross-section is larger than the cross-section of the third positioning hole; the support portion is configured such that the bottom surface of the upper limiting plate and the top surface of the lower limiting plate are spaced apart. The limiting part has its top surface connected to the bottom surface of the supporting part, and the limiting part can be embedded in the third positioning hole and the second positioning hole.

[0015] In an exemplary embodiment of this disclosure, at least a portion of the side of the upper limiting plate is recessed toward the center of the upper limiting plate to form a notch, the notch is disposed through the upper limiting plate, and the notch is spaced apart from the second limiting hole.

[0016] The technical solutions provided in this disclosure have at least the following advantages: This embodiment of the invention provides a lower limiting plate and an upper limiting plate on the top surface of the base. The first limiting hole on the lower limiting plate and the second limiting hole on the upper limiting plate can simultaneously limit the end and the front end of the straight pin terminal, reducing the problem of the straight pin terminal becoming misaligned during sintering and causing poor soldering. This reduces the rate of poor soldering of the straight pin terminal and reduces the difficulty of subsequent assembly and testing processes, thereby improving the overall pass rate and production efficiency of the power module.

[0017] Other features and advantages of this application will become apparent from the following detailed description, or may be learned in part from practice of this application.

[0018] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0019] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0020] Figure 1 A three-dimensional structural schematic diagram of the sintering fixture in an embodiment of this disclosure is shown.

[0021] Figure 2 An exploded view of the sintering fixture in an embodiment of this disclosure is shown.

[0022] Figure 3 It shows Figure 1 A schematic diagram of the exploded structure of the sintering fixture.

[0023] Figure 4 A schematic diagram of the exploded structure of the sintering fixture in another direction is shown in an embodiment of this disclosure.

[0024] Figure 5 A three-dimensional structural diagram of the base is shown in an embodiment of this disclosure.

[0025] Figure 6A three-dimensional structural diagram of the lower limiting plate in an embodiment of this disclosure is shown.

[0026] Figure 7 A cross-sectional three-dimensional structural schematic diagram of a sintering fixture according to an embodiment of the present disclosure is shown.

[0027] Figure 8 A top view of the sintering fixture in an embodiment of this disclosure is shown.

[0028] Figure 9 This illustration shows another cross-sectional perspective view of the sintering fixture in an embodiment of the present disclosure.

[0029] Explanation of reference numerals in the attached figures: 1. Base; 11. Positioning groove; 12. Connecting groove; 13. First positioning hole; 14. Second positioning hole; 2. Power board; 3. Straight pin terminal; 31. Welding end face; 4. Lower limiting plate; 41. First limiting hole; 42. Clearance groove; 43. Ventilation groove; 44. Third positioning hole; 5. Upper limiting plate; 51. Second limiting hole; 52. Notch; 6. First positioning component; 7. Second positioning component; 71. Limiting part; 72. Support part; X, lateral; Y, longitudinal; Z, vertical. Detailed Implementation

[0030] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make this application more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art.

[0031] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., can be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.

[0032] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments. It should be noted that the technical features involved in the various embodiments described below can be combined with each other as long as they do not conflict with each other. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present application, and should not be construed as limiting the present application.

[0033] like Figures 1 to 4As shown, this disclosure provides a sintering fixture, including: a base 1, a lower limiting plate 4 and an upper limiting plate 5.

[0034] The base 1 has a placement area configured to hold the power substrate 2 of the power module.

[0035] The lower limiting plate 4 is pressed onto the base 1, and the power substrate 2 can be fixed between the lower limiting plate 4 and the base 1. The lower limiting plate 4 has a through first limiting hole 41, which is opposite to the placement area. That is, the orthogonal projection of the first limiting hole 41 on the base 1 is located within the placement area. The first limiting hole 41 is configured to allow the end of the straight pin terminal 3 to pass through, and the end of the straight pin terminal 3 passing through the first limiting hole 41 can connect with the power substrate 2 placed in the placement area. In this embodiment, the first limiting hole 41 can be configured to restrict the radial movement of the end of the straight pin terminal 3 in the first limiting hole 41, thereby improving the problem of the straight pin terminal 3 becoming misaligned on the power substrate 2 due to positional displacement of the end during sintering.

[0036] The upper limiting plate 5 is pressed against the top surface of the lower limiting plate 4, that is, the upper limiting plate 5 is pressed against the side of the lower limiting plate 4 facing away from the base 1. The upper limiting plate 5 has a through second limiting hole 51, which is opposite to the first limiting hole 41. The second limiting hole 51 is configured to allow the front end of the straight pin terminal 3 to pass through and restrict the radial movement of the front end of the straight pin terminal 3 in the second limiting hole 51. This can improve the problem of the straight pin terminal 3 becoming skewed on the power substrate 2 due to the positional displacement of the front end of the straight pin terminal 3 during the sintering process.

[0037] It should be noted that the end and the front end of the straight pin terminal 3 are the two opposite ends of the straight pin terminal 3 in its extension direction.

[0038] This embodiment of the present disclosure provides a lower limiting plate 4 and an upper limiting plate 5 on the top surface of the base 1. The first limiting hole 41 on the lower limiting plate 4 and the second limiting hole 51 on the upper limiting plate 5 can simultaneously limit the end and the front end of the straight pin terminal 3, reducing the problem of the straight pin terminal 3 becoming skewed during the sintering process and causing poor soldering of the straight pin terminal 3. This can reduce the poor soldering rate of the straight pin terminal 3, and reduce the difficulty of subsequent assembly and testing processes, thereby improving the overall pass rate and production efficiency of the power module.

[0039] It should be noted that the first limiting hole 41 on the lower limiting plate 4 and the second limiting hole 51 on the upper limiting plate 5 can at least correspond to the straight pin terminals 3 sintered on the power substrate 2. Specifically, the first limiting hole 41 on the lower limiting plate 4 and the second limiting hole 51 on the upper limiting plate 5 can correspond one-to-one with the straight pin terminals 3 sintered on the power substrate 2, but this is not a limitation. The number of first limiting holes 41 on the lower limiting plate 4 and the number of second limiting holes 51 on the upper limiting plate 5 can also be greater than the number of straight pin terminals 3 sintered on the power substrate 2, thereby enabling the sintering fixture to be adapted to various types of power modules and improving the applicability of the sintering fixture.

[0040] For example, 18 straight pin terminals 3 can be provided on the power board 2 located on the base 1 placement area, 18 first limiting holes 41 corresponding to the straight pin terminals 3 can be provided on the lower limiting plate 4, and 18 second limiting holes 51 corresponding to the straight pin terminals 3 can be provided on the upper limiting plate 5. However, this is not the only possibility; the first limiting holes 41 and the second limiting holes 51 can be specifically set according to the actual situation.

[0041] In this embodiment, the diameter of the first limiting hole 41 can be 1.8 mm and the diameter of the second limiting hole 51 can be 1.4 mm, but is not limited thereto. The values ​​of the diameters of the first limiting hole 41 and the second limiting hole 51 can be set according to the specific dimensions of the end and front end of the straight pin terminal 3.

[0042] like Figure 3 and Figure 5 As shown, in some embodiments, a positioning groove 11 can be formed on the top surface of the base 1. The positioning groove 11 is configured to limit the displacement of the power substrate 2 on the base 1. Specifically, when the lower limiting plate 4 is pressed onto the base 1, the bottom surface of the lower limiting plate 4 can abut against the top surface of the power substrate 2 placed in the placement area. By providing the positioning groove 11 on the base 1, the displacement of the power substrate 2 on the base 1 can be limited, thereby improving the problem of poor soldering of the straight pin terminals 3 caused by positional displacement of the power substrate 2 during the sintering process.

[0043] For example, the positioning groove 11 in this embodiment of the present disclosure can be disposed in the middle of the base 1. Specifically, the orthographic projection of the center of the positioning groove 11 onto the base 1 can coincide with the center of the base 1, so as to facilitate the setting of the positioning groove 11 and the loading and unloading of the power board 2 and the base 1.

[0044] Among them, such as Figure 5 As shown, when the power substrate 2 is rectangular, the base 1 can also be rectangular. The base 1 can extend in the horizontal (X) and vertical (Y) directions. When the power substrate 2 is placed on the base 1, the power substrate 2 can be symmetrical about the center lines of the base 1 in the horizontal (X) and vertical (Y) directions.

[0045] However, it is not limited to this. The positioning groove 11 can also be set at other positions of the base 1 except the middle. The power board 2 and the base 1 can also be other shapes other than rectangles. The specific shape can be determined according to the actual situation.

[0046] In this embodiment, the size of the positioning groove 11 can be adapted to the size of the power substrate 2. Specifically, when the power substrate 2 is placed in the positioning groove 11, the side peripheral surface of the positioning groove 11 can completely fit against the side peripheral surface of the power substrate 2, thereby improving the problem of positional displacement of the power substrate 2 on the base 1 during sintering. However, it is not limited to this; the size of the positioning groove 11 in this embodiment can also be slightly larger than the size of the power substrate 2 to reduce the difficulty of positioning and assembling the power substrate 2 and the positioning groove 11.

[0047] In some embodiments, at least one communicating groove 12 may be provided on the top surface of the base 1. The communicating groove 12 is disposed on at least a portion of the side periphery of the positioning groove 11, and one end of the communicating groove 12 near the positioning groove 11 communicates with the positioning groove 11. When the power substrate 2 is placed in the positioning groove 11, the communicating groove 12 is located on the side periphery of the power substrate 2, and the bottom of the communicating groove 12 is lower than the top surface of the power substrate 2, thereby facilitating personnel to remove and place the power substrate 2 from the base 1 through the communicating groove 12.

[0048] For example, in this embodiment of the present disclosure, two connecting slots 12 can be provided on the base 1. The two connecting slots 12 can be respectively provided on opposite sides of the positioning groove 11 in the horizontal X direction, so as to facilitate personnel to pick up and place the power board 2 from multiple positions. However, it is not limited to this. The number of connecting slots 12 on the base 1 can also be other than two, such as 1, 3, 4, 5, 6, etc., and the position of the connecting slots 12 on the base 1 can also be determined according to the actual situation.

[0049] Furthermore, in this embodiment, the end of the connecting groove 12 away from the positioning groove 11 can penetrate through the side of the base 1, allowing personnel to pick up and place the power board 2 from the corresponding side of the base 1 where the connecting groove 12 is provided, further improving the convenience of picking up and placing on the base 1. However, this is not a limitation; the end of the connecting groove 12 away from the positioning groove 11 can also be located between the positioning groove 11 and the side of the base 1, depending on the actual situation.

[0050] like Figure 6 and Figure 7As shown, in some embodiments, a clearance groove 42 can be provided on the bottom surface of the lower limiting plate 4, that is, a clearance groove 42 can be provided on the side of the lower limiting plate 4 near the base 1. When the lower limiting plate 4 is pressed onto the base 1, the bottom surface of the lower limiting plate 4 can abut against the top surface of the power substrate 2, so that the power substrate 2 can be fixed in position under the pressure of the base 1 and the lower limiting plate 4, thereby improving the problem of position displacement of the power substrate 2 during sintering.

[0051] Meanwhile, the bottom of the clearance groove 42 (i.e., the side of the clearance groove 42 away from the base 1) can have a gap with the top surface of the power substrate 2 located in the positioning groove 11, so as to facilitate the flow of gas between the base 1 and the lower limiting plate 4. This improves the problem that due to poor gas flow, the solder paste at the end of the straight pin terminal 3 is exposed to high heat and the contact area between the end of the straight pin terminal 3 and the contact area of ​​the straight pin terminal 3 is exposed to high heat and high air pressure, which squeezes the solder paste and the straight pin terminal 3, causing the solder paste to collapse in all directions and not be able to solidify into a ball, resulting in poor soldering of the straight pin terminal 3. In other words, by making the bottom of the clearance groove 42 and the top surface of the power substrate 2 located in the positioning groove 11, the possibility of cold solder joints of the straight pin terminal 3 can be reduced.

[0052] Furthermore, it should be understood that after the straight pin terminal 3 is sintered, the solder paste changes from a molten state to a solid state during the cooling process. However, when molten, the solder paste is spread out. In this embodiment, by creating a gap between the bottom of the relief groove 42 and the top surface of the power substrate 2 located in the positioning groove 11, the possibility of the solder paste contacting the bottom surface of the lower limiting plate 4 during sintering can be improved. Thus, after the solder paste cools and solidifies, the connection between the lower limiting plate 4 and the power substrate 2 can be improved, reducing the difficulty of separating the power substrate 2 and the lower limiting plate 4 after sintering, thereby reducing the scrap rate of the power module.

[0053] For example, when the power substrate 2 is placed on the base 1, the distance between the bottom of the clearance groove 42 and the top surface of the power substrate 2 in this embodiment of the present disclosure can be in the range of 0.4mm-2mm.

[0054] Specifically, the distance between the bottom of the clearance groove 42 and the top surface of the power substrate 2 can be 0.4mm, 0.6mm, 0.8mm, 1mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm, 2mm, etc., depending on the actual situation.

[0055] In this embodiment, the orthographic projection of the clearance groove 42 on the base 1 can be located within the positioning groove 11, as detailed in the following reference. Figure 7As shown, when the power substrate 2 is placed in the positioning groove 11, the bottom surface of the portion of the lower limiting plate 4 projected onto the base 1 and located in the positioning groove 11 can abut against the top surface of the power substrate 2, thereby pressing the power substrate 2 between the base 1 and the lower limiting plate 4 and achieving the limitation of the power substrate 2.

[0056] like Figure 3 and Figure 6 As shown, in some embodiments, a venting groove 43 may be provided on the lower limiting plate 4. The venting groove 43 extends through the lower limiting plate 4 and is adjacent to and spaced apart from the first limiting hole 41. The orthographic projection of the venting groove 43 on the base 1 is at least partially located within the positioning groove 11. By providing the venting groove 43, this embodiment of the present disclosure can improve the problem of excessive local pressure between the lower limiting plate 4 and the base 1 due to the small gap between them, which causes the solder paste on the end of the straight pin terminal 3 to be squeezed. This can reduce the possibility of cold solder joints on the straight pin terminal 3.

[0057] For example, the orthographic projection of the vent groove 43 on the base 1 can be completely located within the positioning groove 11, thereby improving the smoothness of gas flow between the base 1 and the lower limiting plate 4.

[0058] In some embodiments, a plurality of ventilating grooves 43 arranged at intervals may be provided on the lower limiting plate 4 to increase the area on the lower limiting plate 4 available for gas flow.

[0059] For example, such as Figure 6 As shown, the lower limiting plate 4 can be a rectangular plate extending along the horizontal X and vertical Y sides. Four spaced ventilation slots 43 can be provided on the lower limiting plate 4, and the four ventilation slots 43 can be symmetrically arranged about the centerline of the base 1 in the horizontal X and vertical Y directions. However, this is not limited to this; the number of ventilation slots 43 provided on the lower limiting plate 4 can also be other than four, such as 3, 5, 6, etc. The position of the ventilation slots 43 on the base 1 can also be set according to the actual situation.

[0060] like Figures 3 to 6 As shown, in some embodiments, a first positioning hole 13 can be provided on the base 1, and a first positioning member 6 can be provided on the bottom surface of the lower limiting plate 4. The first positioning member 6 corresponds to the first positioning hole 13 and can be embedded in the first positioning hole 13. When the lower limiting plate 4 is pressed onto the base 1, the positioning of the lower limiting plate 4 on the base 1 can be achieved through the first positioning member 6 and the first positioning hole 13, thereby reducing the problem of the end of the straight pin terminal 3 becoming skewed due to the positional shift of the lower limiting plate 4 relative to the base 1 during the sintering process.

[0061] Multiple first positioning elements 6 can be provided on the lower limiting plate 4. At this time, the first positioning hole 13 on the base 1 can correspond one-to-one with the first positioning element 6.

[0062] For example, such as Figure 6 As shown, a first positioning element 6 can be provided at both ends of the longitudinal Y direction of the lower limiting plate 4, and the two first positioning elements 6 on the lower limiting plate 4 can be symmetrical about the center line of the lower limiting plate 4 in the longitudinal Y direction to strengthen the limiting of the lower limiting plate 4. However, it is not limited to this. The number of first positioning elements 6 on the lower limiting plate 4 can also be 3, 4, 5, etc., and the position of the first positioning elements 6 on the lower limiting plate 4 can be set according to the actual situation.

[0063] In this embodiment, the first positioning member 6 can be a cylindrical structure, the axial direction of the first positioning member 6 can extend vertically in the Z direction, the circular surface at the top of the first positioning member 6 is connected to the bottom surface of the lower limiting plate 4, and the first positioning hole 13 can be set as a circular hole accordingly. Compared with other prismatic or irregular structures, the cylindrical second positioning member 7 can reduce the difficulty of alignment between the lower limiting plate 4 and the base 1, and can reduce the degree of wear between the first positioning member 6 and the base 1 during the alignment process.

[0064] Furthermore, the diameter of the first positioning member 6 can be slightly smaller than the diameter of the first positioning hole 13. For example, the diameter of the first positioning member 6 can be 0.2 mm smaller than the diameter of the first positioning hole 13 to reduce the difficulty of alignment between the lower limiting plate 4 and the base 1.

[0065] However, it is not limited to this. The first positioning member 6 in the embodiments of this disclosure can also be a structure other than a cylindrical structure, and the size between the first positioning hole 13 and the first positioning member 6 can also be determined according to the actual situation.

[0066] In this embodiment of the disclosure, the first positioning hole 13 can penetrate the base 1, but is not limited thereto; the radial length of the first positioning hole 13 can also be less than the thickness of the base 1. For example... Figure 7 As shown, when the lower limiting plate 4 is pressed onto the base 1, the bottom surface of the first positioning member 6 away from the lower limiting plate 4 can be no lower than the bottom surface of the base 1 away from the lower limiting plate 4.

[0067] In some embodiments, a second positioning hole 14 may be provided on the base 1, a third positioning hole 44 may be provided on the lower limiting plate 4, and a second positioning member 7 may be provided on the bottom surface of the upper limiting plate 5. The second positioning member 7 corresponds to the second positioning hole 14 and the third positioning hole 44, and the second positioning member 7 can be embedded in the second positioning hole 14 and the third positioning hole 44. When the upper limiting plate 5 is pressed onto the lower limiting plate 4 and the base 1, the positioning of the upper limiting plate 5 on the lower limiting plate 4 and the base 1 can be achieved through the second positioning member 7, the second positioning hole 14, and the third positioning hole 44. This can reduce the problem of the front end of the straight pin terminal 3 becoming skewed due to the positional shift of the upper limiting plate 5 relative to the lower limiting plate 4 during the sintering process.

[0068] In this embodiment, multiple second positioning elements 7 can be provided on the upper limiting plate 5. At this time, the second positioning hole 14 on the base 1 and the third positioning hole 44 on the lower limiting plate 4 can correspond one-to-one with the second positioning elements 7.

[0069] For example, two second positioning members 7 can be provided at both ends of the upper limiting plate 5 in the longitudinal Y direction. The two second positioning members 7 can be symmetrical about the center lines of the upper limiting plate 5 in the longitudinal Y direction and the transverse X direction to strengthen the limiting of the upper limiting plate 5. However, it is not limited to this. The number of second positioning members 7 on the upper limiting plate 5 can also be 5, 6, 7, etc., and the position of the second positioning members 7 on the upper limiting plate 5 can be set according to the actual situation.

[0070] In this embodiment, the second positioning member 7 can be a cylindrical structure, and the axial direction of the second positioning member 7 can extend vertically along Z. The circular surface at the top of the second positioning member 7 is connected to the bottom surface of the upper limiting plate 5. The second positioning hole 14 can be set as a circular hole accordingly. Compared with other prismatic or irregular structures, the cylindrical second positioning member 7 can reduce the difficulty of alignment between the upper limiting plate 5, the lower limiting plate 4, and the base 1, and can reduce the degree of wear between the second positioning member 7 and the lower limiting plate 4 and the base 1 during the alignment process.

[0071] The diameter of the second positioning member 7 can be slightly smaller than the diameters of the second positioning hole 14 and the third positioning hole 44. For example, when the diameters of the second positioning hole 14 and the third positioning hole 44 are equal, the diameter of the second positioning member 7 can be 0.2 mm smaller than the diameter of the second positioning hole 14 to reduce the difficulty of alignment between the upper limiting plate 5, the lower limiting plate 4, and the base 1.

[0072] However, it is not limited to this. The second positioning member 7 in the embodiments of this disclosure can also be a structure other than a cylindrical structure. The size of the second positioning hole 14 and the second positioning member 7 and the third positioning hole 44 can also be determined according to the actual situation.

[0073] In this embodiment, the third positioning hole 44 penetrates the lower limiting plate 4. The second positioning hole 14 may penetrate the base 1, but is not limited thereto; the radial length of the second positioning hole 14 may also be less than the thickness of the base 1. When the upper limiting plate 5 is pressed onto the base 1, the bottom surface of the second positioning member 7 away from the upper limiting plate 5 may not be lower than the bottom surface of the base 1 away from the upper limiting plate 5.

[0074] It should be noted that the sintering fixture can simultaneously provide a first positioning element 6 on the lower limiting plate 4 and a second positioning element 7 on the upper limiting plate 5 to enhance the stability of the overall structure of the sintering fixture. This can reduce the problem of the lower limiting plate 4 and the upper limiting plate 5 shifting relative to the base 1 during the sintering process, which would cause the straight pin terminal 3 to become skewed, thereby improving the sintering yield of the power module.

[0075] For example, in the longitudinal direction Y, a first positioning element 6 can be respectively provided at each of the opposite ends of the bottom surface of the lower limiting plate 4, and two second positioning elements 7 can be respectively provided at each of the opposite ends of the bottom surface of the upper limiting plate 5. The first positioning element 6 can be symmetrical about the centerline of the lower limiting plate 4 in the longitudinal direction Y, and the second positioning element 7 can be symmetrical about the centerlines of the upper limiting plate 5 in both the longitudinal direction Y and the transverse direction X. At one end of the longitudinal direction Y, the first positioning element 6 can be located between the two second positioning elements 7, thereby facilitating personnel to observe the sintering status of the straight pin terminal 3 through the sintering fixture on the opposite sides in the transverse direction X.

[0076] In some embodiments, when the second positioning member 7 is embedded in the second positioning hole 14 and the third positioning hole 44, the bottom surface of the upper limiting plate 5 can be spaced apart from the top surface of the lower limiting plate 4, which facilitates the flow of gas in the sintering fixture, improves the problem of poor soldering of the straight pin terminal 3 caused by the increase of gas pressure inside the sintering fixture, and improves the sintering efficiency and yield of the power module.

[0077] For example, when a ventilation groove 43 is provided on the lower limiting plate 4, the gas between the base 1 and the lower limiting plate 4 can flow through the ventilation groove 43 to the space between the lower limiting plate 4 and the upper limiting plate 5, and then flow through the gap between the lower limiting plate 4 and the upper limiting plate 5 to the outside of the sintering fixture, thereby achieving heat dissipation.

[0078] like Figure 2As shown, in some embodiments, the second positioning member 7 may include a support portion 72 and a limiting portion 71. The top surface of the support portion 72 is connected to the bottom surface of the upper limiting plate 5, and the cross-section of the support portion 72 is larger than the cross-section of the third positioning hole 44. That is, in this embodiment of the present disclosure, the second positioning member 7 may be a stepped shaft type. The support portion 72 is configured such that the bottom surface of the upper limiting plate 5 and the top surface of the lower limiting plate 4 are spaced apart. The top surface of the limiting portion 71 is connected to the bottom surface of the support portion 72, and the limiting portion 71 can be embedded in the third positioning hole 44 and the second positioning hole 14.

[0079] For example, both the support portion 72 and the limiting portion 71 can be cylindrical structures extending vertically in the Z direction. The diameter of the second positioning hole 14 can be equal to the diameter of the third positioning hole 44, and the diameter of the limiting portion 71 can be 0.2 mm smaller than the diameter of the second positioning hole 14 to reduce the difficulty of alignment between the second positioning member 7 and the third positioning hole 44 and the second positioning hole 14. The diameter of the support portion 72 can be 3 mm larger than the diameter of the third positioning hole 44, allowing the support portion 72 to be supported between the upper limiting plate 5 and the lower limiting plate 4, and the support portion 72 to create a gap between the bottom surface of the upper limiting plate 5 and the top surface of the lower limiting plate 4.

[0080] In this embodiment of the disclosure, the height of the support portion 72 in the vertical Z direction can be in the range of 3mm-4.5mm.

[0081] For example, the height of the support part 72 in the vertical Z direction can be 3mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm, 4mm, 4.1mm, 4.2mm, 4.3mm, 4.4mm, 4.5mm, etc., which can be determined according to the height of the straight pin terminal 3.

[0082] In this embodiment of the present disclosure, when the upper limiting plate 5 is pressed onto the top surface of the lower limiting plate 4, the front end of the straight needle terminal 3 passes through the upper limiting plate 5 via the second limiting hole 51, and the front end of the straight needle terminal 3 protrudes upward from the top surface of the upper limiting plate 5.

[0083] For example, when the upper limiting plate 5 is pressed onto the top surface of the lower limiting plate 4, the height by which the front end of the straight pin terminal 3 protrudes upward from the top surface of the upper limiting plate 5 can be no less than 1mm, in order to ensure the limiting effect of the upper limiting plate 5 on the front end of the straight pin terminal 3. For details, please refer to... Figure 1 and Figure 7 As shown.

[0084] like Figure 1 and Figure 8As shown, in some embodiments, at least a portion of the side of the upper limiting plate 5 may be recessed toward the center of the upper limiting plate 5 to form a notch 52. The notch 52 is disposed through the upper limiting plate 5, and the notch 52 is spaced apart from the second limiting hole 51.

[0085] In this embodiment, by forming a notch 52 on the side of the upper limiting plate 5, the flow path of gas on the sintering fixture can be shortened, thereby improving the heat dissipation rate of the sintering fixture and improving the problem of poor welding of the straight pin terminal 3 caused by poor gas flow in the sintering fixture.

[0086] For example, in this embodiment of the present disclosure, the upper limiting plate 5 may be a rectangular plate extending along the horizontal X and the vertical Y. The two opposite sides of the upper limiting plate 5 in the horizontal X and the two opposite sides in the vertical Y may each form a notch 52. The notch 52 may be located in the middle of the corresponding side, and the four notches 52 may be symmetrical about the center line of the upper limiting plate 5 in the horizontal X and the vertical Y.

[0087] When a through-ventilation groove 43 is provided on the lower limiting plate 4, the gas between the base 1 and the lower limiting plate 4 can flow through the ventilation groove 43 to the space between the lower limiting plate 4 and the upper limiting plate 5. Since the upper limiting plate 5 is provided with a notch 52, the distance that the gas between the lower limiting plate 4 and the upper limiting plate 5 flows to the outside of the sintering fixture is shortened, which can accelerate heat dissipation and improve the problem of poor welding of the straight pin terminal 3 caused by poor gas flow in the sintering fixture.

[0088] The power module in this embodiment may be a baseless power module, but it is not limited thereto. The sintering fixture in this embodiment may also be applicable to other power modules besides baseless power modules.

[0089] The workflow of the sintering fixture in this embodiment can be as follows: First, the power substrate 2, with the chip soldered and solder paste applied, is placed in the positioning groove 11 of the base 1. Then, the lower limiting plate 4 is installed on the base 1 through the first positioning member 6 and the first positioning hole 13. At this time, the bottom surface of the lower limiting plate 4 can abut against the top surface of the power substrate 2 to limit the position of the power substrate 2. Next, multiple straight pin terminals 3 are pressed... Figure 9The straight pin terminal 3 is inserted into the corresponding second limiting hole 51 of the upper limiting plate 5 in the indicated direction. The front end of the straight pin terminal 3 may include a welding end face 31 that is welded to the power substrate 2. The size of the welding end face 31 is larger than the size of the second limiting hole 51. Therefore, the size of the front end of the straight pin terminal 3 is larger than the size of the second limiting hole 51 of the upper limiting plate 5. When the front end of the straight pin terminal 3 penetrates the top surface of the upper limiting plate 5 from the bottom surface of the upper limiting plate 5, the end of the straight pin terminal 3 will be limited by the bottom surface of the upper limiting plate 5. Subsequently, the entire assembly of the base 1, power substrate 2, and lower limiting plate 4 is placed opposite the upper limiting plate 5 with the straight pin terminal 3 inserted. When the second positioning member 7 on the upper limiting plate 5 is embedded in the third positioning hole 44 and the second positioning hole 14, the end of the straight pin terminal 3 can be embedded in the first limiting hole 41 and abut against the top surface of the power substrate 2.

[0090] It should be noted that when the assembled base 1, power board 2, and lower limiting plate 4 are aligned with the upper limiting plate 5 to which the straight pin terminal 3 is inserted, the assembled base 1, power board 2, and lower limiting plate 4, along with the upper limiting plate 5 to which the straight pin terminal 3 is inserted, can be aligned according to... Figure 9 The orientation is as shown, that is, the lower limiting plate 4 is placed horizontally below the base 1, and the upper limiting plate 5 is placed horizontally below the lower limiting plate 4. When the limiting part 71 in the second positioning member 7 is fully inserted into the third positioning hole 44 and the second positioning hole 14, Figure 9 The sintering fixture is rotated 180° so that the upper limiting plate 5, the lower limiting plate 4, and the base 1 in the sintering fixture are arranged from top to bottom in the vertical Z direction. At this time, the straight pin terminal 3 on the upper limiting plate 5 can fall into the corresponding first limiting hole 41 under the action of gravity, and the welding end face 31 of the end of the straight pin terminal 3 can contact the solder paste on the power substrate 2.

[0091] Next, each straight pin terminal 3 can be gently pressed to make the straight pin terminal 3 make closer contact with the solder paste. After that, the sintering fixture carrying the power substrate 2 and the straight pin terminals 3 can be placed into the soldering furnace and soldered according to the predetermined process. After the soldering is completed, the sintering fixture can be disassembled from the sintering fixture in the following order: first separate the upper limiting plate 5, then separate the lower limiting plate 4, and finally separate the base 1.

[0092] In the description of this specification, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," or "third" may explicitly or implicitly include one or more of that feature. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0093] Furthermore, it should be noted that terms such as "upper," "lower," "left," and "right" are used only for distinction and convenience of description, and do not impose any positional limitations on the embodiments of the present invention. For example, "upper" in practice can refer to "lower," "left," or "right." In this disclosure, unless otherwise explicitly specified and limited, terms such as "assembly" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this disclosure can be understood according to the specific circumstances.

[0094] In the description of this specification, references to terms such as "some embodiments," "exemplarily," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. The illustrative expressions of the above terms in this specification do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0095] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application. Therefore, any changes or modifications made in accordance with the claims and description of this application should fall within the scope of this patent application.

Claims

1. A sintering fixture, characterized in that, include: A base having a placement area configured to hold a power substrate for a power module; A lower limiting plate is pressed onto the base. The lower limiting plate has a through first limiting hole, which is opposite to the placement area. The first limiting hole is configured to allow the end of the straight pin terminal to pass through and connect to the power substrate placed in the placement area. The first limiting hole is also configured to restrict the movement of the end of the straight pin terminal in the radial direction of the first limiting hole. An upper limiting plate is pressed against the top surface of the lower limiting plate. The upper limiting plate has a through second limiting hole, which is opposite to the first limiting hole. The second limiting hole is configured to allow the front end of the straight needle terminal to pass through and to restrict the movement of the front end of the straight needle terminal in the radial direction of the second limiting hole.

2. The sintering fixture according to claim 1, characterized in that, The top surface of the base is provided with a positioning groove, which is configured to limit the displacement of the power board on the base. When the lower limiting plate is pressed onto the base, the bottom surface of the lower limiting plate can abut against the top surface of the power substrate placed on the placement area.

3. The sintering fixture according to claim 2, characterized in that, The top surface of the base is also provided with at least one connecting groove, which is disposed on at least a portion of the side periphery of the positioning groove, and the end of the connecting groove near the positioning groove is connected to the positioning groove.

4. The sintering fixture according to claim 3, characterized in that, The end of the connecting groove away from the positioning groove extends through the side of the base.

5. The sintering fixture according to claim 2, characterized in that, The bottom surface of the lower limiting plate is provided with an avoidance groove. The orthographic projection of the avoidance groove on the base is located in the positioning groove. When the lower limiting plate is pressed onto the base, there is a gap between the bottom of the avoidance groove and the top surface of the power substrate located in the positioning groove.

6. The sintering fixture according to claim 2, characterized in that, A ventilation groove is provided on the lower limiting plate, the ventilation groove passes through the lower limiting plate, and the orthogonal projection of the ventilation groove on the base is located in the positioning groove; the ventilation groove is adjacent to and spaced apart from the first limiting hole.

7. The sintering fixture according to claim 1, characterized in that, The base is provided with a first positioning hole; The bottom surface of the lower limiting plate is provided with a first positioning member, which corresponds to the first positioning hole and can be embedded in the first positioning hole.

8. The sintering fixture according to claim 1, characterized in that, The base is provided with a second positioning hole, the lower limiting plate is provided with a third positioning hole, and the bottom surface of the upper limiting plate is provided with a second positioning member. The second positioning member corresponds to the second positioning hole and the third positioning hole, and the second positioning member can be embedded in the second positioning hole and the third positioning hole. When the second positioning member is embedded in the second positioning hole and the third positioning hole, the bottom surface of the upper limiting plate and the top surface of the lower limiting plate are spaced apart.

9. The sintering fixture according to claim 8, characterized in that, The second positioning element includes: The support portion has its top surface connected to the bottom surface of the upper limiting plate, and its cross-section is larger than the cross-section of the third positioning hole; the support portion is configured such that the bottom surface of the upper limiting plate and the top surface of the lower limiting plate are spaced apart. The limiting part has its top surface connected to the bottom surface of the supporting part, and the limiting part can be embedded in the third positioning hole and the second positioning hole.

10. The sintering fixture according to claim 5, characterized in that, At least a portion of the side of the upper limiting plate is recessed towards the center of the upper limiting plate to form a notch, the notch is disposed through the upper limiting plate, and the notch is spaced apart from the second limiting hole.

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