A method for assembling power module components and a power module

Abstract

The present application proposes an assembly method of a power module component and a power module. The assembly method of the power module component includes: providing a chip, a substrate and a bottom plate, the chip is mounted on the substrate through a first sintering slurry, and the substrate is mounted on the bottom plate through a second sintering slurry to form a preform; at the same time, pressure is applied to the chip and the substrate, and the pressure value of the chip is equal to the first preset sintering pressure value, and the pressure value of the substrate is equal to the second preset sintering pressure value, and the preform is sintered. The assembly method of the power module component in the present application can realize chip connection and substrate connection through one-step sintering, which can improve the qualification rate and processing efficiency of the power module component.

Description

Technical Field

[0001] The present application relates to the technical field of power modules, and in particular to an assembling method of power module components and a power module. Background Art

[0002] With the development of semiconductors, the requirements for the quality, heat dissipation and reliability of power modules are becoming higher and higher. In power modules, chip connection and substrate connection are not only crucial to the thermal performance of the power module, but also affect the overall strength and service life of the power module.

[0003] Some related technologies use soldering technology to achieve chip connection and substrate connection, that is, reflow soldering is used to achieve mutual diffusion between solder alloy and substrate / chip, and molten solder is used to fill the joint gap to form a good interconnection joint. However, the thermal conductivity and electrical conductivity of solder alloys (including tin-lead solder and lead-free solder) in soldering technology cannot meet the heat dissipation requirements of high-power devices, and the reliable operating temperature of solder alloys is generally lower than 250°C, and the high-temperature creep resistance is poor. Creep fatigue is easily generated at high temperatures, resulting in power module failure.

[0004] Some related technologies also use large-area sintering technology to achieve chip connection and substrate connection. Large-area sintering technology often uses a multi-step sintering method. On the one hand, during the production of large-area samples, problems such as uneven printing, sintering warping, sintering defects, and equipment incompatibility will occur, resulting in a low pass rate for the samples. For example, in the actual production process, affected by the heat dissipation base design, substrate design, and process conditions, after the large-area sintering of the substrate is completed, the warping of the entire sample may even be as high as 2mm, which will have a serious adverse effect on the subsequent connection between the chip and the substrate, and will cause chip fragmentation, poor quality of the chip sintering layer, and chip falling off. The yield is very low. On the other hand, the sample needs to go through multiple high temperatures during multi-step sintering, which will cause changes in the internal stress of the sample, thereby posing a risk of increased warping of the sample. On the other hand, the process flow of multi-step sintering is lengthy, resulting in low processing efficiency for the sample. Summary of the invention

[0005] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes an assembly method of power module components and a power module, which can realize chip connection and substrate connection through one-step sintering, and can improve the qualification rate and processing efficiency of power module components.

[0006] The assembly method of the power module components provided in the present application includes: providing a chip, a substrate and a bottom plate, wherein the chip is mounted on the substrate by a first sintering slurry, and the substrate is mounted on the bottom plate by a second sintering slurry to form a preform; and simultaneously applying pressure to the chip and the substrate, and making the pressure value applied to the chip equal to a first preset sintering pressure value, and the pressure value applied to the substrate equal to a second preset sintering pressure value, to sinter the preform.

[0007] The power module component assembly method provided in the present application has at least the following technical effects: the embodiment of the present application applies pressure to the chip and the substrate at the same time and sinters the preform, so that the chip connection and the substrate connection can be achieved through one-step sintering, thereby preventing the components from warping, sintering defects and other problems due to multi-step sintering, and improving the qualification rate and processing efficiency of the power module components.

[0008] According to some embodiments of the present application, a sintering pressure device is provided, wherein the sintering pressure device has a first pressure surface and a second pressure surface, and the sintering pressure device includes a pressure adjustment device, and applying pressure to the chip and the substrate at the same time includes:

[0009] Applying pressure to the chip through the first pressure-applying surface, and applying pressure to the substrate through the second pressure-applying surface;

[0010] The pressure value applied to the chip and the substrate is adjusted by the pressure adjustment device.

[0011] According to some embodiments of the present application, the pressure adjustment device includes a pressure block, the pressure block and the chip are staggered, the second pressure surface is arranged on the pressure block, and the sintering pressure device also includes a first sintering pressure head, and applying pressure to the chip through the first pressure surface and applying pressure to the substrate through the second pressure surface includes:

[0012] applying pressure to the chip and the pressure block through the first sintering press head;

[0013] Adjusting the pressure value of the chip and the substrate by the pressure adjustment device includes:

[0014] The pressure difference between the pressure surface of the substrate and the pressure surface of the chip is adjusted by adjusting the height difference between the pressure surface of the pressure block and the pressure surface of the chip.

[0015] According to some embodiments of the present application, the pressure adjustment device includes a spring assembly, the sintering pressure device also includes a second sintering pressure head, the first pressure surface and the second pressure surface are both arranged on the second sintering pressure head, and the spring assembly is arranged above the first pressure surface and the second pressure surface, and applying pressure to the chip through the first pressure surface and applying pressure to the substrate through the second pressure surface includes:

[0016] Applying pressure to the spring assembly, and applying pressure to the chip and the substrate through the second sintering press head;

[0017] Adjusting the pressure value of the chip and the substrate by the pressure adjustment device includes:

[0018] The pressure value applied by the second sintering press head to the chip and the substrate is adjusted by adjusting the stiffness coefficient of the spring assembly.

[0019] According to some embodiments of the present application, the height difference between the pressure surface of the chip and the pressure surface of the substrate is less than 2 mm, and the pressure difference between the pressure surface of the chip and the pressure surface of the substrate is less than 10 MPa.

[0020] According to some embodiments of the present application, the area of ​​the pressure-bearing surface of the substrate is A, and the pressure-bearing area of ​​the substrate is greater than 0.9A.

[0021] According to some embodiments of the present application, the first sintering slurry is a silver paste or a copper paste, and the second sintering slurry is a silver paste or a copper paste.

[0022] According to some embodiments of the present application, the chip is mounted on the substrate through a first sintering slurry, including: printing the first sintering slurry in a first preset area on the substrate, the single-side size of the first preset area is at least 0.1 mm larger than the single-side size of the chip, the ratio of the printing thickness of the first sintering slurry to the sintering thickness is B, and the printing thickness of the first sintering slurry is 30Bμm-60Bμm; baking the first sintering slurry, and mounting the chip on the first sintering slurry, the thrust of the chip on the first sintering slurry is greater than 6kPa.

[0023] According to some embodiments of the present application, the substrate is mounted on the base plate through the second sintering slurry, including: printing the second sintering slurry in a second preset area on the base plate, the single side size of the second preset area is at least 0.1 mm larger than the single side size of the substrate, the ratio of the printing thickness of the second sintering slurry to the sintering thickness is C, and the printing thickness of the second sintering slurry is 120Cμm-150Cμm; baking the second sintering slurry, and mounting the substrate on the second sintering slurry, and the position of the substrate relative to the base plate is less than 0.15mm.

[0024] According to the power module provided in the present application, the power module includes power module components manufactured by the above-mentioned power module component assembly method.

[0025] The power module provided in the present application has the corresponding beneficial effects provided by the assembly method of the power module components of the present application, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0027] Figure 1 is a flow chart of a method for assembling a power module component according to an embodiment of the present application;

[0028] Figure 2 It is a schematic diagram of the structure in which the chip is mounted on the substrate through the first sintering slurry and the substrate is mounted on the bottom plate through the second sintering slurry in the embodiment of the present application;

[0029] Figure 3 is a schematic diagram of the structure when pressure is applied to the preform by the sintering pressure head in the embodiment of the present application;

[0030] Figure 4 It is a schematic structural diagram of a sintered pressure head when a spring is provided in an embodiment of the present application;

[0031] Figure 5 It is a structural schematic diagram of the embodiment of the present application when pressure is applied to the preform by a sintering pressure head provided with a spring.

[0032] Reference numerals:

[0033] Chip 100 ; substrate 200 ; bottom plate 300 ; first sintering slurry 410 , second sintering slurry 420 ; first sintering press head 511 , second sintering press head 512 , pressure block 521 , spring assembly 522 , first pressure surface 530 , second pressure surface 540 . DETAILED DESCRIPTION

[0034] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0035] In the description of the present application, reference is made to “some embodiments”, which describe a subset of all possible embodiments, but it can be understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0036] In the description of this application, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, and "above", "below", "within", etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0037] In the description of the present application, it should be understood that descriptions involving orientation, such as “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0038] In the description of this application, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meaning of the above terms in this application based on the specific content of the technical solution.

[0039] The embodiment of the present application provides an assembly method of power module components, which can achieve chip connection and substrate connection through one-step sintering, thereby improving the qualification rate and processing efficiency of the power module components.

[0040] For example, Figure 1 A flow chart of some embodiments of the method for assembling power module components provided in the present application is shown. The method for assembling power module components may include the following steps.

[0041] Step S100: See Figure 2, a chip 100, a substrate 200 and a base plate 300 are provided, the chip 100 is mounted on the substrate 200 through a first sintering paste 410, and the substrate 200 is mounted on the base plate 300 through a second sintering paste 420 to form a preform.

[0042] Optionally, in some embodiments, “mounting the chip 100 on the substrate 200 via the first sintering slurry 410 ” in step S100 may include the following steps.

[0043] Step S111: Print the first sintering paste 410 in the first preset area on the substrate 200, the single side size of the first preset area is at least 0.1 mm larger than the single side size of the chip 100, the ratio of the printing thickness of the first sintering paste 410 to the sintering thickness is B, and the printing thickness of the first sintering paste 410 is 30Bμm-60Bμm.

[0044] Exemplarily, the first preset area and the chip 100 are both rectangular, so the length of the first preset area is at least 0.1 mm longer than the length of the chip 100, and the width of the first preset area is at least 0.1 mm larger than the width of the chip 100. Of course, the first preset area and the chip 100 can also be other shapes, which are not specifically limited here. It can be understood that the single-side size of the first preset area is at least 0.1 mm larger than the single-side size of the chip 100, which is conducive to the mounting of the chip 100 and can improve the fault tolerance when mounting the chip 100.

[0045] It should be noted that the ratio of the printing thickness to the sintering thickness of the first sintering slurry 410 is B, the printing thickness of the first sintering slurry 410 is 30Bμm-60Bμm, and the thickness of the first sintering layer formed after sintering the first sintering slurry 410 is 30μm-60μm.

[0046] Step S112: Bake the first sintering slurry 410 and mount the chip 100 on the first sintering slurry 410. The thrust of the chip 100 on the first sintering slurry 410 is greater than 6 kPa, which can prevent the chip 100 from shifting or falling off on the first sintering slurry 410 before sintering, thereby ensuring the stability of the chip 100 mounting.

[0047] Optionally, one or more chips 100 may be mounted on the substrate 200 through the first sintering paste 410, and the number of the first preset regions may be equal to the number of the chips 100, and the first preset regions correspond to the chips 100 one by one. Figure 2 , four chips 100 are mounted on the substrate 200 through the first sintering paste 410, and the four chips 100 are arranged at intervals.

[0048] Optionally, in some embodiments, the step of “mounting the substrate 200 on the bottom plate 300 via the second sintering slurry 420 ” in step S100 may include the following steps.

[0049] Step S121: Print the second sintering slurry 420 in the second preset area on the base plate 300, the single side dimension of the second preset area is at least 0.1 mm larger than the single side dimension of the substrate 200, the ratio of the printing thickness of the second sintering slurry 420 to the sintering thickness is C, and the printing thickness of the second sintering slurry 420 is 120Cμm-150Cμm.

[0050] Exemplarily, the second preset area and the substrate 200 are both rectangular, then the length of the second preset area is at least 0.1 mm longer than the length of the substrate 200, and the width of the second preset area is at least 0.1 mm larger than the width of the substrate 200. Optionally, the length of the second preset area can be 0.3 mm longer than the length of the substrate 200, and the width of the second preset area can be 0.3 mm larger than the width of the substrate 200. Of course, the second preset area and the substrate 200 can also be other shapes, which are not specifically limited here. It can be understood that the unilateral dimension of the second preset area is at least 0.1 mm larger than the unilateral dimension of the substrate 200, which is conducive to the mounting of the substrate 200 and can improve the fault tolerance when mounting the substrate 200.

[0051] Alternatively, the second sintering slurry 420 may be printed using a doctor blade having a thickness greater than 0.1 mm, or using a doctor blade reinforced by a doctor blade holder.

[0052] It should be noted that when the printing area is less than 10mm*10mm, using a scraper with a thickness greater than 0.1mm can prevent the scraper from deforming due to being too thin. As the printing area increases, the scraper thickness needs to be appropriately increased to prevent the scraper from deforming severely during printing, resulting in a depression in the center of the printing area. Alternatively, the scraper can be supported by a scraper holder to control the deformation of the scraper and avoid deformation. A scraper reinforced by a scraper holder is more suitable for use when the printing area is greater than 10*10mm.

[0053] It should be noted that the ratio of the printing thickness to the sintering thickness of the second sintering slurry 420 is C, the printing thickness of the second sintering slurry 420 is 120Cμm-150Cμm, and the thickness of the second sintering layer formed after the second sintering slurry 420 is sintered is 120μm-150μm.

[0054] Step S122: bake the second sintering slurry 420, and mount the substrate 200 on the second sintering slurry 420, and the position accuracy of the substrate 200 relative to the base plate 300 is less than 0.15 mm.

[0055] Optionally, in some embodiments, the substrate 200 with the chip 100 mounted thereon is mounted on the second sintering slurry 420 of the bottom plate 300 by a mounting device.

[0056] Optionally, in some embodiments, the first sintering slurry 410 is a silver paste or a copper paste, and the second sintering slurry 420 is a silver paste or a copper paste.

[0057] Exemplarily, the first sintering slurry 410 and the second sintering slurry 420 both use copper paste, then the first preset area on the substrate 200 and the second preset area on the base plate 300 do not need to be surface coated, but plasma or other reduction treatment is required before printing the sintering slurry to ensure that the oxidation of the copper surface meets the requirements.

[0058] In another exemplary embodiment, the first sintering slurry 410 and the second sintering slurry 420 are both made of silver paste, and the first preset area on the substrate 200 and the second preset area on the bottom plate 300 need to be silver plated. Optionally, the thickness of the silver plated layer may be 0.1 μm-1.0 μm.

[0059] Silver and copper have good thermal conductivity, electrical conductivity and high melting point, and will not have fatigue failure problems associated with solder. Therefore, using silver paste or copper paste as sintering paste can improve the reliability of the connection between the chip 100 and the substrate 200.

[0060] Step S200: Apply pressure to the chip 100 and the substrate 200 at the same time, and make the pressure value of the chip 100 equal to the first preset sintering pressure value, and the pressure value of the substrate 200 equal to the second preset sintering pressure value, and sinter the preform. Optionally, the roughness (arithmetic mean deviation of the profile) Ra of the sintered surface can be 0.2μm-0.8μm.

[0061] Optionally, in some embodiments, a sintering pressure device is provided, wherein the sintering pressure device has a first pressure surface 530 and a second pressure surface 540 , and the sintering pressure device includes a pressure adjustment device 520 .

[0062] Optionally, in some embodiments, “applying pressure to the chip 100 and the substrate 200 simultaneously” in step S200 includes:

[0063] Step S210: applying pressure to the chip 100 through the first pressure surface 530 , and applying pressure to the substrate 200 through the second pressure surface 540 ;

[0064] Step S220 : adjusting the pressure value exerted on the chip 100 and the substrate 200 by the pressure adjusting device 520 .

[0065] It should be noted that the first preset sintering pressure value can be a specific value or a numerical range; the second preset sintering pressure value can be a specific value or a numerical range. Optionally, the first preset sintering pressure value is equivalent to the sintering pressure of the first sintering slurry 410, and the second preset sintering pressure value is equivalent to the sintering pressure of the second sintering slurry 420, so as to ensure that the first sintering slurry 410 and the second sintering slurry 420 can be sintered.

[0066] Optionally, in some embodiments, the pressure adjustment device includes a pressure block 521, the pressure block 521 is staggered with the chip 100, and the second pressure surface is arranged on the pressure block 521 (see Figure 3 , the second pressure surface is the bottom surface of the pressure block 521), and the sintering pressure device also includes a first sintering pressure head 511.

[0067] Optionally, in some embodiments, the above step S210 includes:

[0068] Step S211 a : applying pressure to the chip 100 and the pressure block 521 through the first sintering press 511 .

[0069] Optionally, in some embodiments, the above step S220 includes:

[0070] Step S221 a : adjusting the pressure difference between the pressure surface of the substrate 200 and the pressure surface of the chip 100 by adjusting the height difference between the pressure surface of the pressure block 521 and the pressure surface of the chip 100 .

[0071] It is understandable that the height difference between the pressure surface of the pressure block 521 and the pressure surface of the chip 100 can be set according to the pressure requirement, and no specific limitation is made here.

[0072] For example, if the first preset sintering pressure value is equal to the second preset sintering pressure value (i.e., the sintering pressure of the first sintering slurry 410 is equal to the sintering pressure of the second sintering slurry 420), then the pressure surface of the pressure block 521 can be flush with the pressure surface of the chip 100, so that the pressure value received by the substrate 200 is equal to the pressure value received by the chip 100. For another example, if the first preset sintering pressure value is less than the second preset sintering pressure value (i.e., the sintering pressure of the first sintering slurry 410 is less than the sintering pressure of the second sintering slurry 420), then the pressure surface of the pressure block 521 can be higher than the pressure surface of the chip 100, so that the pressure value received by the chip 100 is less than the pressure value received by the substrate 200.

[0073] Optionally, the height difference between the pressure surface of the chip 100 and the pressure surface of the substrate 200 is less than 0.5 mm, and the pressure difference between the pressure surface of the chip 100 and the pressure surface of the substrate 200 is less than 5 MPa. This can avoid damage to the product due to excessive height difference and / or pressure difference.

[0074] Optionally, the pressure surface of the first sintering press head 511 (i.e., the bottom surface of the first sintering press head 511) is a plane, and the pressure surface of the first sintering press head 511 directly contacts the chip 100 and applies pressure to the chip 100. The first sintering press head 511 applies pressure to the substrate 200 through the pressure block 521, and the pressure block 521 can transfer the pressure of the first sintering press head 511 to the substrate 200. Optionally, the pressure surface of the chip 100 is the top surface of the chip 100, and the pressure surface of the substrate 200 is the top surface of the substrate 200.

[0075] Exemplarily, the first sintering press head 511 is in the shape of a cuboid. When in use, the pressure block 521 can be placed on the preform first, and the second pressure surface 540 can be made close to the substrate 200, and then the first sintering press head 511 can be placed on the top surface of the pressure block 521 and the chip 100 to apply pressure.

[0076] Optionally, the pressure adjustment device may further include a buffer layer, wherein a first buffer layer is disposed between the first sintered pressure head 511 and the pressure surface of the chip 100, and a second buffer layer is disposed between the first sintered pressure head 511 and the pressure surface of the pressure block 521, and the height of the first buffer layer may be equal to the height of the second buffer layer. The buffer layer may or may not rebound when the pressure is released. The buffer layer that can rebound may be reused, for example, the buffer layer may be a spring; the buffer layer that cannot rebound is a disposable buffer layer, for example, the buffer layer may be a graphite sheet. It can be understood that the buffer layer is compressed when subjected to pressure, and the amount of compression is different, and the pressure transmitted downward is also different. By adjusting the height difference between the pressure surface of the pressure block 521 and the pressure surface of the chip 100 to adjust the pressure difference between the pressure surface of the substrate 200 and the pressure surface of the chip 100, the first buffer layer and the second buffer layer undergo different degrees of deformation due to the height difference, so that the pressures transmitted downward to the chip 100 and the pressure block 521 are different, and the pressure difference between the pressure surface of the substrate 200 and the pressure surface of the chip 100 can be adjusted.

[0077] Optionally, in some embodiments, the pressure adjustment device includes a spring assembly 522, the sintering pressure device also includes a second sintering head 512, the first pressure surface 530 and the second pressure surface 540 are both arranged on the second sintering head 512, and the spring assembly 522 is arranged above the first pressure surface 530 and the second pressure surface 540.

[0078] Optionally, in some embodiments, the above step S210 includes:

[0079] Step S211 b : applying pressure to the spring assembly 522 , and applying pressure to the chip 100 and the substrate 200 via the second sintering press head 512 .

[0080] Optionally, in some embodiments, the above step S220 includes:

[0081] Step S221 b: adjusting the stiffness coefficient of the spring assembly 522 to adjust the pressure value applied by the second sintering press head 512 to the chip 100 and the substrate 200 .

[0082] It is understandable that the second pressure surface 540 protrudes from the first pressure surface 530 in the vertical direction, so that the first pressure surface 530 can be in close contact with the top surface of the chip 100 and the second pressure surface 540 can be in close contact with the top surface of the substrate 200 .

[0083] Optionally, the spring assembly 522 includes one or more springs. Optionally, the spring may be one or more of a spiral spring, a volute spring, a leaf spring, a disc spring, an annular spring, and a special-shaped spring, which are not specifically limited here and can be selected according to actual needs. The number of springs in each spring assembly 522 can also be set according to actual needs and is not specifically limited here.

[0084] Optionally, the spring constant of the spring assembly 522 may be adjusted by adjusting at least one of the number, overlap, and size of the springs.

[0085] It is understood that according to Hooke's law, the spring applied pressure F=kx, where k is the spring constant and x is the spring compression / extension. Changing the number, overlapping method or size of the springs (which may be the wire diameter of the springs) will change the spring constant of the spring assembly 522, thereby applying different pressures under the same deformation. For example, two strings of springs in parallel are k=k1+k2, thereby increasing the applied pressure.

[0086] Exemplarily, a first spring component is disposed above the first pressure surface 530, and a second spring component is disposed above the second pressure surface 540. For example, if the first preset sintering pressure value is equal to the second preset sintering pressure value, then the stiffness coefficient of the first spring component is equal to the stiffness coefficient of the second spring component, so that the pressure value received by the substrate 200 is equal to the pressure value received by the chip 100. For another example, if the first preset sintering pressure value is less than the second preset sintering pressure value, then the stiffness coefficient of the first spring component is less than the stiffness coefficient of the second spring component, so that the pressure value received by the chip 100 is less than the pressure value received by the substrate 200.

[0087] Optionally, when the second sintering press head 512 is used to apply pressure, the height difference between the pressure surface of the chip 100 and the pressure surface of the substrate 200 is less than 2 mm, and the pressure difference between the pressure surface of the chip 100 and the pressure surface of the substrate 200 is less than 10 MPa. This can avoid damage to the product due to excessive height difference and / or pressure difference. It is understandable that in this case, "the height difference between the pressure surface of the chip 100 and the pressure surface of the substrate 200 is less than 2 mm" can be equivalent to "the height difference between the first pressure surface 530 and the second pressure surface 540 of the sintering press head is less than 2 mm".

[0088] Optionally, in some embodiments, the area of ​​the pressure-bearing surface of the substrate 200 is A, and the pressure-bearing area of ​​the substrate 200 is greater than 0.9 A. It can be understood that the pressure-bearing surface of the substrate 200 refers to the surface of the substrate 200 where the pressure is applied.

[0089] For example, see Figure 2 , the pressure surface of the substrate 200 is the top surface of the substrate 200, that is, the area of ​​the top surface of the substrate 200 is A. The sum of the contact areas between the substrate 200 and each pressure block 521 is A1, and the sum of the contact areas between the substrate 200 and each first sintering slurry 410 is A2. When the sintering pressure device applies pressure to each chip 100, each chip 100 will also generate pressure on the substrate 200 through the first sintering slurry 410. Therefore, the pressure area of ​​the substrate 200 is the sum of A1 and A2, that is, A1+A2>0.9A. Since there are generally grooves on the substrate 200, the pressure area of ​​the substrate 200 is generally smaller than the area of ​​the pressure surface of the substrate 200, that is, A1+A2<A. The pressure area of ​​the substrate 200 greater than 0.9A can make the pressure of the substrate 200 more uniform, which is conducive to sintering connection.

[0090] It should be noted that when the sintering pressure device applies pressure to each chip 100, each chip 100 will also exert pressure on the substrate 200 through the first sintering slurry 410. Therefore, in order to avoid affecting the sintering of the second sintering slurry 420 and causing product damage, the first sintering slurry 410 can be made of a sintering material whose sintering pressure is less than or equal to the sintering pressure of the second sintering slurry 420.

[0091] It is understandable that the first sintering press head 511 or the second sintering press head 512 can be selected to apply pressure according to actual needs, and the structure of the pressure adjustment device can also be selected according to actual needs, and no specific limitation is made here.

[0092] The embodiment of the present application applies pressure to the chip and the substrate at the same time and sinters the preform, so that the chip connection and the substrate connection can be achieved through one-step sintering, and problems such as warping and sintering defects of the components caused by multi-step sintering can be prevented, thereby improving the qualification rate and processing efficiency of the power module components.

[0093] Optionally, in some embodiments, after the preform is sintered, the density of the first sintered layer (sintered by the first sintering slurry 410) and the second sintered layer (sintered by the second sintering slurry 420) can be tested by an ultrasonic scanner; the internal defects of the first sintered layer and the second sintered layer can be analyzed by auxiliary slicing; the slices can be subjected to scanning electron microscopy analysis after ion grinding to determine the porosity of the first sintered layer and the second sintered layer; the connection strength of the chip 100 and the substrate 200 can be analyzed by thrust testing; and the reliability of the first sintered layer and the second sintered layer can be analyzed by tests such as thermal shock testing and power cycling.

[0094] An embodiment of the present application further provides a power module, including power module components manufactured by the above-mentioned power module component assembly method.

[0095] It can be understood that the power module in the embodiment of the present application has the beneficial effects provided by the above-mentioned method for assembling power module components, which will not be described in detail here.

[0096] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0097] In some selectable embodiments, the function / operation mentioned in the block diagram may not occur in the order mentioned in the operation diagram. For example, depending on the function / operation involved, the two boxes shown in succession can actually be executed substantially simultaneously or the boxes can sometimes be executed in reverse order. In addition, the embodiment presented and described in the flow chart of the application is provided by way of example, for the purpose of providing a more comprehensive understanding of technology. The disclosed method is not limited to the operation and logic flow presented herein. Selectable embodiments are expected, wherein the order of various operations is changed and the sub-operation of a part described as a larger operation is performed independently.

[0098] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A method for assembling a power module component, characterized in that: include: Providing a chip, a substrate and a bottom plate, wherein the chip is mounted on the substrate through a first sintering slurry, and the substrate is mounted on the bottom plate through a second sintering slurry to form a preform; Applying pressure to the chip and the substrate at the same time, so that the pressure value applied to the chip is equal to a first preset sintering pressure value, and the pressure value applied to the substrate is equal to a second preset sintering pressure value, to sinter the preform; A sintering pressure device is provided, wherein the sintering pressure device has a first pressure surface and a second pressure surface, and the sintering pressure device includes a pressure adjustment device, and applying pressure to the chip and the substrate at the same time includes: Applying pressure to the chip through the first pressure-applying surface, and applying pressure to the substrate through the second pressure-applying surface; adjusting the pressure value exerted on the chip and the substrate by the pressure adjusting device; The pressure adjustment device includes a spring assembly, the sintering pressure device also includes a second sintering pressure head, the first pressure surface and the second pressure surface are both arranged on the second sintering pressure head, and the spring assembly is arranged above the first pressure surface and the second pressure surface, and the chip is pressed by the first pressure surface, and the substrate is pressed by the second pressure surface. Applying pressure to the spring assembly, and applying pressure to the chip and the substrate through the second sintering press head; Adjusting the pressure value of the chip and the substrate by the pressure adjustment device includes: The pressure value applied by the second sintering press head to the chip and the substrate is adjusted by adjusting the stiffness coefficient of the spring assembly.

2. The method for assembling a power module component according to claim 1, characterized in that: The pressure adjustment device includes a pressure block, the pressure block and the chip are staggered, the second pressure surface is arranged on the pressure block, and the sintering pressure device also includes a first sintering pressure head, and the chip is pressed by the first pressure surface, and the substrate is pressed by the second pressure surface. applying pressure to the chip and the pressure block through the first sintering press head; Adjusting the pressure value of the chip and the substrate by the pressure adjustment device includes: The pressure difference between the pressure surface of the substrate and the pressure surface of the chip is adjusted by adjusting the height difference between the pressure surface of the pressure block and the pressure surface of the chip.

3. The method for assembling a power module component according to claim 1, characterized in that: The height difference between the pressure-bearing surface of the chip and the pressure-bearing surface of the substrate is less than 2 mm, and the pressure difference between the pressure-bearing surface of the chip and the pressure-bearing surface of the substrate is less than 10 MPa.

4. The method for assembling a power module component according to any one of claims 1 to 3, characterized in that: The area of ​​the pressure-bearing surface of the substrate is A, and the pressure-bearing area of ​​the substrate is greater than 0.9A.

5. The method for assembling a power module component according to claim 1, characterized in that: The first sintering slurry is silver paste or copper paste, and the second sintering slurry is silver paste or copper paste.

6. The method for assembling a power module component according to claim 1, characterized in that: The chip is mounted on the substrate by means of a first sintering slurry, comprising: Printing a first sintering paste in a first preset area on the substrate, wherein the single side size of the first preset area is at least 0.1 mm larger than the single side size of the chip, the ratio of the printing thickness of the first sintering paste to the sintering thickness is B, and the printing thickness of the first sintering paste is 30 B μm-60 B μm; The first sintering slurry is baked, and the chip is mounted on the first sintering slurry, wherein the pushing force of the chip on the first sintering slurry is greater than 6 kPa.

7. The method for assembling a power module component according to claim 1, characterized in that: The substrate is mounted on the bottom plate through the second sintering slurry, comprising: Printing a second sintering slurry on a second preset area on the bottom plate, wherein the single side dimension of the second preset area is at least 0.1 mm larger than the single side dimension of the substrate, the ratio of the printing thickness of the second sintering slurry to the sintering thickness is C, and the printing thickness of the second sintering slurry is 120 C μm-150 C μm; The second sintering slurry is baked, and the substrate is mounted on the second sintering slurry, wherein the position accuracy of the substrate relative to the base plate is less than 0.15 mm.

8. A power module, characterized in that: The invention comprises a power module component manufactured by the power module component assembling method according to any one of claims 1 to 7.

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