Power module packaging structure, controller and electrical equipment

Abstract

The utility model relates to a power module packaging structure, a controller and electrical equipment, the power module packaging structure comprises a substrate and a box dam, and the substrate is provided with a chip and a bonding wire; the box dam is arranged on the periphery of the chip and the bonding wire, and a first encapsulation area is formed in the box dam; the box dam comprises a plurality of box dam single bodies, and the box dam single bodies are arranged in a stacked mode in the height direction of the first potting area. According to the power module packaging structure provided by the invention, the first potting area is formed through the enclosure of the box dam and can be used for potting an insulating material, so that the protection of a chip and a bonding wire in the first potting area is realized, and the effects of electrically isolating and isolating external water vapor are achieved while the fixation of a bonding point is realized; the box dam is formed by stacking the multiple box dam single bodies in the height direction of the first potting area, preparation of the box dam can be achieved through the multi-layer dispensing technology, it is guaranteed that the box dam does not collapse, meanwhile, height guarantee of the first potting area can be achieved, and potting protection of chips and bonding wires in the box dam can be achieved.

Description

Technical Field

[0001] The present application relates to the technical field of power module packaging, and in particular to a power module packaging structure, a controller, and an electrical device. Background Art

[0002] A power module refers to a modular device that connects multiple groups of power chips in series or parallel to form a certain topological relationship. The conventional power module manufacturing process usually uses insulating materials to encapsulate the module, thereby achieving the purpose of internal electrical isolation and isolating the module from external moisture.

[0003] In the prior art, in order to fix the bonding points on the chip, a barrier is used to enclose the potting area so that the insulating material can be solidified inside the potting area and prevent the liquid insulating material from flowing out of the potting area when it is not solidified.

[0004] Since the enclosure is usually formed by dispensing insulating material and then solidifying it, if the enclosure height is high, the amount of glue dispensed is large, and the insulating material is more fluid in the initial stage of dispensing. During the enclosure solidification process, there will be a problem of enclosure collapse, and the preparation of the enclosure of the preset size cannot be achieved. After the enclosure collapses, the enclosure height is greatly reduced, and the insulation material potting height in the potting area cannot be guaranteed, and the chip and bonding wire cannot be fully protected in the height direction. Utility Model Content

[0005] The present application provides a power module packaging structure, a controller and an electrical device to solve the technical problem in the prior art of using a dispensing process to prepare enclosures, in which the enclosures collapse during the curing process due to their high height.

[0006] In a first aspect, the present application provides a power module packaging structure, comprising:

[0007] a substrate on which the chip and bonding wires are arranged;

[0008] The dam is arranged at the periphery of the chip and the bonding wire, and a first encapsulation area is formed inside the dam; the dam includes a plurality of dam units, and the plurality of dam units are stacked along the height direction of the first encapsulation area.

[0009] Optionally, the dam is provided on the substrate, and a side of the dam close to the substrate is sealed to the substrate.

[0010] Optionally, a height of the first encapsulation region is greater than a maximum height of the bonding wire.

[0011] Optionally, a height of the first encapsulation region exceeds more than twice a maximum height of the bonding wire.

[0012] Optionally, there are multiple dams for forming multiple independent first encapsulation regions on the substrate.

[0013] Optionally, the aspect ratio of the first encapsulation region is 1:1-5:1.

[0014] Optionally, the dam sidewall formed by connecting a plurality of dam units has a plurality of recessed portions and a plurality of protruding portions, and the plurality of recessed portions and the plurality of protruding portions are spaced apart from each other along a height direction of the first encapsulation area.

[0015] Optionally, the interior of the first encapsulation area is filled with a first encapsulation layer, and the shrinkage of the first encapsulation layer is smaller than the shrinkage of the dam.

[0016] Optionally, the power module packaging structure further includes a shell, the dam is arranged inside the shell, a second potting area is formed inside the shell, and the first potting area is embedded inside the second potting area.

[0017] Optionally, the interior of the second encapsulation area is filled with a second encapsulation layer, and the shrinkage of the second encapsulation layer is greater than that of the first encapsulation layer.

[0018] Optionally, the material of the second encapsulation layer is the same as that of the dam.

[0019] Optionally, the first potting layer, the second potting layer and the dam are all made of insulating glue.

[0020] In a second aspect, the present application provides a controller, comprising the power module packaging structure provided in the first aspect of the present application.

[0021] In a third aspect, the present application provides an electrical device, including the controller provided in the second aspect of the present application.

[0022] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0023] The power module packaging structure provided in the embodiment of the present application has a first potting area formed inside the dam, which can be used to pot the insulating material. After the insulating material is cured, it can protect the chip and bonding wires inside the first potting area, fix the bonding points, and provide electrical isolation inside the module and isolate external moisture. The dam includes multiple dam units, which are stacked along the height direction of the first potting area. When the dam height is constant, the dam can be prepared layer by layer through a multi-layer dispensing process, with each layer forming a dam unit. Due to the low height of the dam units, the collapse of the dam units due to the large amount of glue dispensed during the curing process can be avoided. The upper layer of dam units can be prepared after the lower layer of dam units is nearly cured or completely cured. While ensuring the height of the dam, the collapse of the lower layer of dam units during the dam heightening process can be avoided, thereby ensuring the height of the first potting area and facilitating potting protection of the chip and bonding wires inside the dam. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0025] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0026] One or more embodiments are exemplarily illustrated by pictures in the corresponding drawings. These exemplifications do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements. Unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0027] Figure 1 A top view of the power module packaging structure provided in an embodiment of the present application;

[0028] Figure 2 The embodiment of this application provides Figure 1 Cross-sectional view of AA;

[0029] Figure 3 Provided in the embodiments of this application Figure 2 A magnified view of the details of part B;

[0030] Figure 4 Schematic diagram of dam preparation provided in the embodiment of this application Figure 1 ;

[0031] Figure 5 Schematic diagram of the preparation of the first encapsulation layer provided in the embodiment of the present application Figure 1 ;

[0032] Figure 6 Schematic diagram of the preparation of the second encapsulation layer provided in the embodiment of the present application Figure 1 ;

[0033] Figure 7 Schematic diagram of dam preparation provided in the embodiment of this application Figure 2 ;

[0034] Figure 8 Schematic diagram of the preparation of the first encapsulation layer provided in the embodiment of the present application Figure 2 ;

[0035] Figure 9 Schematic diagram of the preparation of the second encapsulation layer provided in the embodiment of the present application Figure 2 ;

[0036] Figure 10This is a flow chart for preparing the power module packaging structure provided in an embodiment of the present application.

[0037] Description of reference numerals:

[0038] 1. Substrate;

[0039] 2. Chip;

[0040] 3. Bonding wire;

[0041] 4. Dam; 41. First dam unit; 42. Second dam unit; 43. Third dam unit; 44. Concave portion; 45. Protruding portion;

[0042] 5. The first potting layer;

[0043] 6. Shell;

[0044] 7. Second potting layer;

[0045] 8. Glue injection head. DETAILED DESCRIPTION

[0046] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0047] The disclosure below provides many different embodiments or examples for implementing different structures of the present application. In order to simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, these are merely examples and are not intended to limit the present application. In addition, the present application may repeat reference numbers and / or letters in different examples. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed.

[0048] For ease of description, spatially relative terms may be used herein to describe the relative position or movement of one element or feature relative to another element or feature as shown in the figures, such as "inside," "outside," "inside," "outside," "below," "beneath," "above," "above," "front," "back," and the like. Such spatially relative terms are intended to include different orientations of the device in use or operation other than the orientation depicted in the figures. For example, if the device in the figures undergoes a positional flip or a change in posture or a change in motion, then these directional indications will also change accordingly. For example, an element described as "below" or "below" another element or feature will subsequently be oriented as "above" or "above" another element or feature. Thus, the example term "below" can include both above and below orientations. The device may be oriented otherwise (rotated 90 degrees or in other orientations) and the spatially relative descriptors used herein will be interpreted accordingly.

[0049] In order to solve the technical problem of enclosure collapse during the curing process due to the high height of the enclosure when the prior art adopts the dispensing process to prepare the enclosure, the present application provides a power module packaging structure, a controller and an electrical device. The power module packaging structure is enclosed by a dam 4 to form a first potting area. The dam 4 is formed by stacking multiple dam monomers along the height direction of the first potting area. The dam 4 can be prepared by a multi-layer dispensing process. While ensuring the curing effect of each layer of the dam monomer, the height of the first potting area can be guaranteed, which is conducive to the potting protection of the chip 2 and the bonding wire 3 inside the dam 4.

[0050] See also Figures 1 to 10 In a first aspect, an embodiment of the present application provides a power module packaging structure, comprising a substrate 1 and a dam 4, wherein a chip 2 and bonding wires 3 are provided on the substrate 1, which can realize electrical connection of various electrical components in the power module, such as Figure 2 and Figure 3 shown.

[0051] The dam 4 is arranged around the chip 2 and the bonding wire 3. A first potting area is formed inside the dam 4, which can be used to pot the insulating material. After the insulating material is cured, the chip 2 and the bonding wire 3 inside the first potting area can be protected. While fixing the bonding point, it can also play the role of electrical isolation inside the module and isolating from external moisture. Figure 2 、 Figure 4 and Figure 5 shown.

[0052] The dam 4 includes a plurality of dam units, which are stacked along the height direction of the first encapsulation area. Figure 2 、 Figure 3 and Figure 4 When the height of the dam 4 is constant, the dam 4 can be fabricated layer by layer through a multi-layer dispensing process, with each layer forming a dam unit. Since the height of the dam unit is relatively low, collapse of the dam unit due to a large amount of dispensing during the curing process can be avoided. The upper dam unit can be fabricated after the lower dam unit is nearly cured or completely cured. This ensures the height of the dam 4 while preventing collapse of the lower dam unit during the heightening process. This ensures the height of the first potting area, facilitating potting protection of the chip 2 and bonding wires 3 within the dam 4.

[0053] It should be noted that the present application utilizes a multi-layer dispensing process to fabricate multiple dam units. By stacking insulating material layer by layer around the chip 2 and bonding point area within the power module to form the dam 4, the difficulty of fabricating the dam 4 is reduced, and the curing effect of the dam 4 is enhanced. The dam 4 completely surrounds the chip area and the bonding point area on the surface of the chip 2. The first potting area formed by the dam 4 has a certain height, which allows for sufficient filling of the insulating material within the first potting area, thereby effectively securing the bonding point between the chip 2 and the bonding wire 3 in situ.

[0054] In some embodiments of this application, please refer to Figure 2 and Figure 3 The dam 4 is arranged on the substrate 1, and the side of the dam 4 close to the substrate 1 is sealed and connected to the substrate 1, which can prevent the insulating material inside the first potting area from seeping out from the connection gap between the dam 4 and the substrate 1 before solidification, causing adverse effects on other areas on the substrate 1.

[0055] It should be noted that the dam 4 of the present application can be prepared directly on the substrate 1, or can be prepared on other clean and flat surfaces (such as glass or a workbench, etc.) and then bonded to the substrate 1, both of which can achieve the purpose of the present application.

[0056] In some preferred embodiments of the present application, the dam 4 is directly prepared on the substrate 1. When the bottom dam monomer is cured, it is directly sealed with the upper surface of the substrate 1. There is no need to perform bonding assembly of the dam 4 and the substrate 1, which can reduce the assembly process of the power module packaging structure and improve the reliability of the sealing connection between the bottom of the dam 4 and the substrate 1.

[0057] In some embodiments of this application, please refer to Figure 2 and Figure 3 The height of the first potting area is greater than the maximum height of the bonding wire 3. When the first potting area is filled with insulating material, the bonding wire 3 can be completely wrapped as a whole, and the bonding point and the bonding wire 3 as a whole can be fixed in situ. The insulating material in the first potting area can protect the bonding wire 3 as a whole, preventing the bonding point and the bonding wire 3 from being bumped and broken due to external factors during use.

[0058] In some preferred embodiments of this application, please refer to Figure 2 and Figure 3 , the height of the first encapsulation area exceeds twice the maximum height of the bonding wire 3, that is, Figure 3 The value of H is preferably more than twice the maximum height of the bonding wire 3. It can not only achieve comprehensive protection for the bonding point and the bonding wire 3, but also ensure that the insulating material in the first potting area forms an isolation protection area with a certain thickness after solidification (the thickness of the isolation protection area is H), which can prevent the bonding wire 3 from extending out of the first potting area, or prevent objects outside the first potting area from penetrating the first potting area and causing damage to the bonding wire 3.

[0059] In the above embodiment, when the area ratio of the first potting area on the substrate 1 is large, the insulating material in the first potting area will have large internal stress due to curing shrinkage, which may easily cause the cured insulating material to warp, crack and delaminate, thereby affecting the reliability and service life of the power module.

[0060] In order to solve the above problems, in some embodiments of the present application, please refer to Figure 7 Multiple dams 4 are provided to form multiple independent first potting regions on the substrate 1. Each first potting region can provide potting protection for the chip 2 and bonding wires 3 within it. Using multiple dams 4 divides the interior of the power module into several smaller potting areas (i.e., multiple first potting areas). Each potting area is then potted with insulating material in separate areas. This reduces internal curing shrinkage stress and prevents warping, cracking, and delamination of the insulating material in the first potting areas after curing.

[0061] In the above embodiment, the shape of the dam 4 can be circular, elliptical or polygonal, etc., which can achieve the purpose of this application. In order to reduce the difficulty of path planning when preparing the dam unit by the dispensing process, the shape of the dam 4 is preferably rectangular.

[0062] In some embodiments of this application, please refer to Figure 4 and Figure 7 The aspect ratio of the first potting area is 1:1-5:1. Since the aspect ratio of the first potting area is highly correlated with the warping and delamination of the power module, the present application limits the aspect ratio of the first potting area to 1:1-5:1. This can avoid an excessively large difference between the long side and the wide side of the dam 4, and prevent the first potting area from shrinking much more in the length direction than in the width direction, thereby reducing the possibility of warping and delamination of the power module.

[0063] In some embodiments of this application, please refer to Figure 3The side wall of the dam formed by connecting multiple dam monomers has multiple recessed portions 44 and multiple protruding portions 45. The multiple recessed portions 44 and the multiple protruding portions 45 are arranged at intervals along the height direction of the first potting area, which can make the side wall of the dam uneven, forming a rough connection surface, thereby improving the connection reliability between the dam 4 and the insulating material in the first potting area, and avoiding separation between the insulating material inside the first potting area and the dam 4.

[0064] As a specific embodiment of the present application, the dam 4 includes a first dam monomer 41, a second dam monomer 42 and a third dam monomer 43 arranged in sequence from top to bottom along the height direction of the first potting area. After the dam monomer is cured, its cross-section is long and narrow, a protrusion 45 is formed in the middle of the dam monomer, and a recessed portion 44 is formed at the connection between two adjacent dam monomers, so that both sides of the dam 4 have an uneven structure, such as Figure 4 shown.

[0065] In some embodiments of this application, please refer to Figure 2 and Figure 3 The first potting area is filled with a first potting layer 5. The first potting layer 5 is an insulating layer formed after the insulating material potted in the first potting area is cured. It can be used to wrap the chip 2 and the bonding wire 3 to achieve in-situ fixation of the bonding wire 3 and achieve electrical isolation of the first potting area and isolation from external water vapor. Figure 2 、 Figure 3 、 Figure 5 and Figure 8 shown.

[0066] The shrinkage of the first potting layer 5 is smaller than that of the dam 4, which can reduce the shrinkage degree of the first potting layer 5 after curing, thereby reducing the internal stress generated on the chip 2 and the bonding wire 3. The shrinkage of the dam 4 is greater than that of the first potting layer 5, and can act as a stress matching medium with a large deformation ability at the periphery of the first potting layer 5, which can effectively reduce the curing shrinkage stress of the first potting layer 5 inside the first potting area and play a stress buffering role at the periphery of the first potting area.

[0067] In some embodiments of this application, please refer to Figures 1 to 9 The power module package structure also includes a housing 6, with a dam 4 disposed within the housing 6. A second potting region is formed within the housing 6 for potting all substrate 1 areas within the housing 6, thereby forming a complete power module package structure. The first potting region is embedded within the second potting region, and the insulating material potted in the second potting region provides dual protection for critical areas of the power module (such as the chip 2 and bonding wires 3).

[0068] It should be noted that the housing 6 can be a fully enclosed box structure, or a ring frame extending along the periphery of the substrate 1, and the ring frame and the substrate 1 are sealed. Figures 4 to 9 As shown, the purpose of this application can be achieved and is not limited here.

[0069] In some embodiments of this application, please refer to Figure 1 、 Figure 2 、 Figure 6 and Figure 9 The interior of the second potting area is filled with a second potting layer 7. The second potting layer 7 is an insulating layer formed after the insulating material potted inside the second potting area is cured. It can be used to wrap the first potting area and fully fill the non-chip area on the substrate 1 inside the shell 6 to avoid the existence of a potting gap inside the power module packaging module.

[0070] The shrinkage of the second potting layer 7 is greater than that of the first potting layer 5 , so that the second potting layer 7 and the dam 4 can work together to achieve a good stress buffering effect on the first potting layer 5 .

[0071] In the above embodiment, the material of the second potting layer 7 can be the same as or different from the material of the dam 4. As long as the shrinkage of the second potting layer 7 is greater than that of the first potting layer 5, stress buffering, insulation, dustproof and waterproof functions can be achieved.

[0072] In some preferred embodiments of the present application, the second potting layer 7 is made of the same material as the dam 4. After thermal curing, the second potting layer 7 fuses with the dam 4, giving them identical material properties. This creates an insulating and waterproof barrier within the entire power module, thereby improving the reliability of the power module. Furthermore, the soft medium formed by the dam 4 and the second potting layer 7, made of the same material, effectively reduces the curing shrinkage stress of the first potting layer 5 within the power module, acting as a stress buffer. This provides excellent insulation, dustproofing, and waterproofing, while also extending the service life of the power module.

[0073] In the above embodiment, the dam 4 is made of a paste-like fluid (before curing) that is easily extrudable, has a viscosity requirement of 450 Pa.s (at a shear rate of 1 1 / s), and, after curing, forms an organic material with a Shore A hardness of 30-60 and a tensile strength of 4-6 MPa. Specifically, the dam 4, first potting layer 5, and second potting layer 7 can be made of materials such as epoxy resin, silicone gel, organosilicon, and polyurethane, all of which are capable of potting the power module.

[0074] In some embodiments of the present application, the first potting layer 5, the second potting layer 7 and the dam 4 are all made of insulating glue, which can be formed by curing insulating materials such as epoxy resin, silicone gel, silicone, polyurethane, etc. Since the insulating glue has excellent insulation properties, it can effectively isolate different circuit parts in the power module, prevent current leakage and short circuit, and help improve the electrical performance of the power module to ensure its stable and reliable operation.

[0075] In some preferred embodiments of the present application, the first potting layer 5 is made of epoxy resin, which has excellent mechanical strength, electrical insulation, and corrosion resistance. While epoxy resin shrinks somewhat during the curing process, its shrinkage is relatively low compared to other thermosetting materials, thus preventing significant positional movement of the bonding wires 3 and bonding points. When the first potting region is cured by epoxy resin to form the first potting layer 5, the epoxy resin encapsulates the chip 2 and bonding wires 3 and cures. Due to its low shrinkage, the first potting layer 5 can be prevented from shrinking excessively, potentially causing the bonding points to fall off.

[0076] The second potting layer 7 and the dam 4 are both made of silicone gel, which has good insulation properties, moisture resistance and chemical corrosion resistance. At the same time, silicone gel also has a certain softness and elasticity, which can buffer external impact and vibration. It can provide good wrapping and support for the cured epoxy resin in the first potting layer 5, and effectively reduce the curing shrinkage stress of the epoxy resin inside the module, thereby playing a stress buffering role.

[0077] It should be noted that the existing technology usually uses full silicone gel potting or full epoxy resin potting to pot the power module. When the full silicone gel potting process is used, the following defects will occur: 1) The service temperature of silicone gel is not enough to meet the service conditions of high junction temperature devices (such as SiC MOSFET, silicon carbide metal-oxide-semiconductor field-effect transistors). During long-term high junction temperature operation, the chip area will have problems such as blistering and aging; 2) Silicone gel has a high water absorption rate and insufficient ability to isolate water vapor in a high humidity environment; 3) Silicone gel is soft in nature and will deform when touched by fingers. It can only enhance insulation and dust and splash protection inside the power module, but cannot have an in-situ fixing effect on the bonding points in the chip area. During the second-level power cycle test, the bonding points are easily degraded and fall off due to uninterrupted hot and cold cycles.

[0078] However, when full epoxy resin potting is used, the following defects will occur: 1) The cross-linking between epoxy resin monomers will cause its volume to shrink, resulting in greater internal stress; 2) When the length and width of the epoxy resin potting area are relatively large, the degree of shrinkage in the length direction is much greater than that in the width direction, which can easily lead to delamination between the epoxy resin and the internal components of the module; 3) Epoxy resin is relatively brittle and is easily affected by internal stress and external impact, which can cause cracking and delamination of the internal epoxy resin.

[0079] In this application, encapsulation is performed by combining epoxy resin and silicone gel. The encapsulation area and aspect ratio of the epoxy resin are first defined by the silicone gel dam 4. The epoxy resin of the first encapsulation layer 5 has a high hardness and strength after curing (strength > 80MPa, elasticity 10-20GPa, flexural modulus 15-20GPa), which can play an in-situ fixing role for the bonding points on the surface of the chip 2, and can reduce fatigue cracks caused by the continuous hot and cold of the bonding points on the surface of the chip 2 during the second-level power cycle. In addition, since the epoxy resin is in direct contact with the chip 2, the epoxy resin in the first encapsulation layer 5 is required to have an insulation breakdown strength greater than 15kV / mm, a Tg (glass transition temperature) greater than 180°C, a water absorption rate of less than 0.3% after boiling for 1 hour, and a peel strength greater than 10MPa between Cu and epoxy resin at 175°C, so that the epoxy resin has certain insulation, high temperature resistance, waterproofness and strong adhesion properties.

[0080] The silicone gel dam 4 is required to have a hardness of 25-55 Shore A and a tensile strength of 4-6 MPa. This defines a specific filling range for the epoxy resin (i.e., the first potting area) and limits the aspect ratio of the epoxy resin-filled area, thereby reducing warping, delamination, and cracking after the epoxy resin cures. The silicone gel in the second potting layer 7 provides excellent insulation and stress buffering for the non-chip area within the power module, preventing cracking and delamination of the epoxy resin when subjected to internal stress and / or external impact. Its insulation breakdown strength is required to be greater than 15 kV / mm, and after curing, it forms an organic insulating layer with a hardness of 5-15 Shore A.

[0081] See also Figures 1 to 10 In a second aspect, embodiments of the present application provide a controller including the power module packaging structure described in the aforementioned embodiments. Because the power module packaging structure in the controller has excellent insulation, dustproof, and waterproof properties, as well as a very long cycle life, it can be widely used in industries such as home appliances, automobiles, power generation, and intelligent manufacturing, achieving efficient power electronic information conversion and control.

[0082] See also Figures 1 to 10 In a third aspect, an embodiment of the present application provides an electrical device, including the controller in the above embodiment, which can realize efficient, reliable and flexible control of the electrical device.

[0083] Specifically, the electrical equipment may be household appliances such as refrigerators, air conditioners, and televisions, or industrial equipment such as steam generators and cooling towers.

[0084] See also Figures 1 to 10 In some embodiments of the present application, the production process of the power module packaging structure is as follows:

[0085] Step 1: Assemble and solder the power module so that the chip 2 and bonding wires 3 are stably placed on the substrate 1;

[0086] Step 2: Prepare the dam 4 on the substrate 1 by the glue injection head 8, and construct the dam 4 by a multi-layer glue dispensing process. Multiple dam monomers are prepared from bottom to top in sequence to form one or more first encapsulation areas on the substrate 1, such as Figure 4 and Figure 7 As shown;

[0087] Step 3: After the dam 4 is thermally cured, local epoxy resin filling is achieved through the injection head 8, and the epoxy resin is injected into one or more first potting areas, such as Figure 5 and Figure 8 The epoxy resin is then cured through secondary thermal curing to form effective electrical protection for the chip area and bonding area.

[0088] Step 4: Perform overall silicone gel encapsulation inside the shell 6, and further fill silicone gel above and around the encapsulated area (i.e., the first encapsulation area). After three thermal curing steps, the second encapsulation layer 7 inside the shell 6 is integrated with the silicone gel dam 4 to form an insulating and waterproof barrier inside the entire power module, thereby achieving the purpose of improving the reliability of the power module.

[0089] It should be noted that compared with the traditional full silicone gel potting method or full epoxy resin potting method, this application Figure 10 The production method shown uses a combination of epoxy resin and silicone gel for potting. Leveraging the high elasticity of silicone gel, the power module's interior is divided into multiple small areas, which can then be potted with epoxy resin, effectively protecting the chip 2. Silicone gel dams 4 act as an isolation barrier around the epoxy resin, dividing the originally high-aspect-ratio potting area into multiple zones, thereby reducing internal stress.

[0090] When substrate 1 has multiple first potting regions, the high elasticity of the silicone gel in second potting layer 7 and dam 4 acts as a stress-matching medium between the epoxy resins in each region, thereby reducing the risk of internal cracking in the epoxy resin. The silicone gel in second potting layer 7 acts as the outermost insulating medium, providing isolation and insulation for the power module's bonding wires 3. Furthermore, the silicone gel in second potting layer 7 can fully penetrate into other gaps within the power module (i.e., within housing 6), thereby completely isolating the module from moisture.

[0091] In addition to combining the material performance advantages of epoxy resin and silicone gel, the above-mentioned potting method can also greatly reduce the use of epoxy resin in the potting process. Since the raw material cost of epoxy resin is usually higher than the material cost of silicone gel, this application limits the epoxy resin potting area through the dam 4, which can save materials and reduce costs, and is conducive to the large-scale production of power module packaging structures.

[0092] It should be understood that the terms used herein are for the purpose of describing specific example embodiments only and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "said" as used herein may also be meant to include plural forms. The terms "comprise", "include", "contain" and "have" are inclusive and therefore specify the presence of stated features, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, steps, operations, elements, parts, and / or combinations thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring them to be performed in the specific order described or illustrated, unless the order of execution is clearly indicated. It should also be understood that additional or alternative steps may be used.

[0093] Although the terms first, second, third, etc. can be used in the text to describe multiple elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can only be used to distinguish an element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates otherwise, terms such as "first", "second" and other numerical terms do not imply order or sequence when used in the text. Therefore, the first element, component, region, layer or section discussed below can be referred to as the second element, component, region, layer or section without departing from the teaching of the example embodiments.

[0094] The foregoing is merely a list of specific embodiments of the present application, intended to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the broadest scope consistent with the principles and novel features of the present application.

Claims

1. A power module packaging structure, characterized in that: include: A substrate (1), wherein a chip (2) and bonding wires (3) are provided on the substrate (1); A dam (4), the dam (4) being arranged on the periphery of the chip (2) and the bonding wire (3), a first encapsulation area being formed inside the dam (4); the dam (4) comprising a plurality of dam units, the plurality of dam units being stacked and arranged along the height direction of the first encapsulation area.

2. The power module packaging structure according to claim 1, characterized in that: The dam (4) is arranged on the substrate (1), and the side of the dam (4) close to the substrate (1) is sealed and connected to the substrate (1).

3. The power module packaging structure according to claim 1, wherein: The height of the first encapsulation area is greater than the maximum height of the bonding wire (3).

4. The power module packaging structure according to claim 3, characterized in that: The height of the first encapsulation area exceeds more than twice the maximum height of the bonding wire (3).

5. The power module packaging structure according to claim 1, wherein: There are multiple dams (4) for forming multiple mutually independent first encapsulation areas on the substrate (1).

6. The power module packaging structure according to claim 1, wherein: The aspect ratio of the first encapsulation region is 1:1-5:

1.

7. The power module packaging structure according to claim 1, wherein: The dam sidewall formed by connecting a plurality of the dam monomers has a plurality of recessed portions (44) and a plurality of protruding portions (45), and the plurality of recessed portions (44) and the plurality of protruding portions (45) are spaced apart along the height direction of the first encapsulation area.

8. The power module packaging structure according to any one of claims 1 to 7, characterized in that: The interior of the first encapsulation area is filled with a first encapsulation layer (5), and the shrinkage of the first encapsulation layer (5) is smaller than the shrinkage of the dam (4).

9. The power module packaging structure according to claim 8, characterized in that: It also includes an outer shell (6), the dam (4) is arranged inside the outer shell (6), a second potting area is formed inside the outer shell (6), and the first potting area is embedded inside the second potting area.

10. The power module packaging structure according to claim 9, characterized in that: The interior of the second encapsulation area is filled with a second encapsulation layer (7), and the shrinkage of the second encapsulation layer (7) is greater than the shrinkage of the first encapsulation layer (5).

11. The power module packaging structure according to claim 10, characterized in that: The material of the second encapsulation layer (7) is the same as that of the dam (4).

12. The power module packaging structure according to claim 10, wherein: The first potting layer (5), the second potting layer (7) and the dam (4) are all made of insulating glue.

13. A controller, characterized in that: The invention comprises a power module packaging structure according to any one of claims 1 to 12.

14. An electrical device, characterized in that: Comprising the controller of claim 13.

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