Plastic package mold and plastic package method for improving warping of single-sided water-cooled power module

Abstract

The plastic package mold comprises an upper mold and a lower mold which are arranged in a mold closing mode, at least one upper mold cavity is formed in the lower surface of the upper mold, a lower mold cavity corresponding to the upper mold cavity is formed in the upper surface of the lower mold, an arc-shaped structure opposite to the warping direction of a product is formed in the top of the upper mold cavity, and the arc-shaped structure is arranged in the middle of the upper mold cavity. A cavity insert opposite to the warping direction of a product is arranged in the lower mold cavity; a plurality of core-pulling needles for pressing a product are arranged in the upper mold cavity; compared with the prior art, the arc-shaped structure opposite to the warping direction of the product is arranged at the top of the upper die cavity, and the cavity insert with the reverse convex surface is arranged in the lower die cavity, so that a reverse deformation quantity is preset for the product in a plastic package forming stage; the combined design can accurately counteract mismatching of thermal expansion coefficients of the metal bottom plate and the epoxy molding compound and a smiling face type warping trend inevitably generated by curing shrinkage of the epoxy molding compound, so that the flatness of a final product is remarkably improved from the source.

Description

Technical Field

[0001] This invention relates to the field of power semiconductor module packaging technology, specifically to a molding die and molding method for improving warpage of a single-sided water-cooled power module. Background Technology

[0002] Single-sided water-cooled power modules (such as IGBT modules and SiC modules) are widely used in new energy vehicles, industrial control, and new energy power generation due to their excellent heat dissipation performance. These modules typically adopt a "sandwich" structure: the bottom layer is a base plate made of metal materials such as copper or aluminum, the middle layer contains electronic components such as chips, substrates, and bonding wires, and the top layer is protected by epoxy molding compound.

[0003] Because of the significant differences in the coefficient of thermal expansion and curing shrinkage behavior between metal base plates (such as copper, CTE about 17ppm / °C) and epoxy molding compounds (EMC, CTE about 8-20ppm / °C, but with a large curing shrinkage rate), this asymmetric structure generates huge internal stress during the cooling process after molding, causing the entire module to bulge towards one side of the molded surface, forming the so-called "smiley face" warping.

[0004] Module warping can affect the assembly between the module and the heat sink, leading to poor contact, reduced heat dissipation efficiency, and even failure due to thermal cycling fatigue. It can also cause internal structures such as chips and bonding wires to be subjected to additional mechanical stress, affecting their reliability and lifespan. Modules with excessive warping cannot meet the assembly requirements of automated production lines, reducing production yield.

[0005] Chinese Patent Application No. 202211321262.9 discloses a method for fabricating a ceramic copper-clad laminate and a power module. The disclosed method describes a ceramic copper-clad laminate comprising a ceramic layer and a first copper-clad layer and a second copper-clad layer disposed on opposite sides of the ceramic layer. The ceramic copper-clad laminate also includes a protective frame connected to and surrounding the edge of the first copper-clad layer, with the surface of the first copper-clad layer facing away from the ceramic layer exposed through the protective frame. Chinese Patent Application No. 201910571566.2 discloses a mold and method for improving the warpage of ultra-thin molded products. The disclosed mold and method include the following steps: Step 1, designing the upper mold of the encapsulation mold as a grooved structure on all four sides; Step 2, installing the grooved upper mold of the encapsulation mold on the mold position of the encapsulation machine; Step 3, after the substrate is encapsulated, a reinforced stepped encapsulation is formed around the entire substrate encapsulation; Step 4, designing a pressure plate with an irregular structure according to the stepped encapsulation; Step 5, overlapping multiple warped substrates in the same direction; Step 6, pressing the irregularly shaped pressure plate into the middle of the encapsulation; Step 7, applying pressure through the irregularly shaped pressure plate during post-curing, concentrating the force in the middle of the encapsulation, causing the substrate and the encapsulation to deform in opposite directions.

[0006] In existing technologies, single-sided water-cooled power modules, due to their "sandwich" asymmetrical structure (significant differences in the coefficients of thermal expansion and shrinkage behavior between the metal base plate and the upper epoxy molding compound), generate significant internal stress during the cooling process after molding. This causes the entire module to bulge towards the molded surface, forming a "smiley face" warping. This warping severely affects the fit between the module and the heat sink, heat dissipation efficiency, internal structural reliability, and production yield. Existing solutions either focus on changing materials and local structures or rely on external pressure correction during the post-curing stage. Both suffer from complex processes, low efficiency, or insufficient compensation accuracy. There is a lack of an effective means to proactively, directly, and precisely compensate for and suppress warping in this specific direction during the molding process through mold design. Summary of the Invention

[0007] The present invention aims to overcome the defects in the prior art and provide a molding die and molding method for improving warpage of single-sided water-cooled power modules by actively pre-deforming the product during the molding process, suppressing the generation of "smiley face" warpage from the root, thereby simplifying the process, improving product flatness and production yield.

[0008] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: a molding die for improving the warpage of a single-sided water-cooled power module, comprising an upper die and a lower die with the upper die closed, wherein the lower surface of the upper die has at least one upper cavity, and the upper surface of the lower die has a lower cavity corresponding to the upper cavity, wherein the top of the upper cavity forms an arc-shaped structure opposite to the warpage direction of the product, the arc-shaped structure being recessed by 150 micrometers, and the lower cavity having a cavity insert opposite to the warpage direction of the product, the cavity insert being protruding by 250 micrometers; wherein the upper cavity has a plurality of core-pulling pins for pressing the product, the core-pulling pins being located above the product and capable of moving vertically, and having a reset component to automatically reset after pressing.

[0009] As a preferred embodiment of the present invention, the arc-shaped structure is an arc surface disposed on the top of the upper mold cavity, and the arc surface is recessed inward.

[0010] As a preferred embodiment of the present invention, the top of the cavity insert is formed with a convex surface opposite to the warping direction of the product, and the convex surface protrudes outward.

[0011] In a preferred embodiment of the present invention, the convex surface is disposed in the middle of the cavity insert, and the product is placed on the convex surface.

[0012] As a preferred embodiment of the present invention, the upper mold is provided with an inner cavity, and a needle plate is provided in the inner cavity. A plurality of core-pulling needles are fixedly arranged on the lower surface of the needle plate. A plurality of needle holes communicating with the inner cavity are provided at the top of the upper mold cavity, and the core-pulling needles are pushed out from the needle holes.

[0013] As a preferred embodiment of the present invention, the upper surface of the needle plate is provided with a pressure block, and the top surface of the upper mold is provided with a through hole that cooperates with the pressure block, and the pressure block passes through the through hole.

[0014] In a preferred embodiment of the present invention, the reset member is a plurality of springs disposed on the needle plate, and the plurality of springs abut against the cavity wall of the inner cavity.

[0015] As a preferred embodiment of the present invention, the lower surface of the upper mold is provided with a plurality of positioning holes, and the upper surface of the lower mold is provided with positioning blocks corresponding one-to-one with the plurality of positioning holes.

[0016] A molding process for improving warpage in single-sided water-cooled power modules includes the following steps:

[0017] Step 1: Assemble the product components, including the substrate, AMB substrate, and chip, and place them in the lower mold cavity;

[0018] Step 2: Close the mold and activate the core-pulling pin to press the AMB liner tightly, making it completely fit with the cavity insert;

[0019] Step 3: Injection molding of the epoxy molding compound;

[0020] Step 4: After injection molding, maintain the mold temperature for curing to allow the epoxy molding compound to fully cross-link and cure.

[0021] Step 5: Open the mold and remove the plastic-encapsulated power module;

[0022] Step 6: Perform post-curing to obtain a product with improved warpage.

[0023] As a preferred embodiment of the present invention, the injection temperature in step three is controlled at 175±5℃, and the molding compound temperature is controlled at 200±5℃.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] 1. By setting an arc-shaped structure at the top of the upper mold cavity that is opposite to the warping direction of the product, and setting a cavity insert with a reverse convex surface in the lower mold cavity, a reverse deformation is preset for the product during the molding stage. This combination design can accurately offset the "smiley face" warping trend that is inevitably caused by the mismatch of the thermal expansion coefficients of the metal base plate and the epoxy molding compound, as well as the curing shrinkage of the epoxy molding compound, thereby significantly improving the flatness of the final product from the root.

[0026] 2. By setting several core-pulling pins, the product (such as the AMB liner) can be directly pressed before or during mold closing, so that it is firmly pressed and completely attached to the reverse convex surface of the lower mold cavity insert. This feature ensures that the key components of the product are fixed in the mold cavity, preventing them from shifting or floating during injection molding. This ensures that the preset reverse deformation amount can be applied to the entire product accurately and consistently, avoiding the failure or deviation of the compensation effect, improving the stability of the process and the consistency of the product. It ensures that the preset reverse deformation amount can be accurately transmitted to the product, avoiding the failure or deviation of compensation due to the non-attachment of components, and improving the stability and repeatability of the warp improvement effect.

[0027] 3. The upper and lower molds are precisely aligned through the cooperation of positioning holes and positioning blocks, ensuring that the reverse arc structure of the upper mold cavity and the reverse convex surface of the insert in the lower mold cavity can accurately correspond, further ensuring the precise implementation of the warp compensation structure and improving the overall precision and product consistency of the molding process.

[0028] 4. This invention integrates the warpage correction step into the molding process, eliminating the need for complex post-curing pressure fixtures or additional correction procedures. After injection molding and in-mold curing, the product warpage is fundamentally improved, and only conventional post-curing is required. This simplifies the production process, improves production efficiency, and is more suitable for automated mass production. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of the mold of the present invention;

[0030] Figure 2 This is a schematic diagram of the structure of the mold of the present invention;

[0031] Figure 3 This is a cross-sectional view of the upper and lower molds of the present invention being joined together;

[0032] Figure 4 This is a sectional view of the upper mold;

[0033] Reference numerals: Upper mold 1, upper mold cavity 101, arc structure 1011, pin hole 1012, positioning hole 102, inner cavity 103, pin plate 104, pressure block 1041, spring 1042, through hole 105, lower mold 2, lower mold cavity 201, positioning block 202, cavity insert 3, convex surface 301, core-pulling pin 4, product 5, reset component 6. Detailed Implementation

[0034] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0035] like Figures 1-4As shown, a molding die for improving the warpage of a single-sided water-cooled power module includes an upper die 1 and a lower die 2 configured for mold assembly. The lower surface of the upper die 1 has at least one upper mold cavity 101, and the upper surface of the lower die 2 has a lower mold cavity 201 corresponding to the upper mold cavity 101. The top of the upper mold cavity 101 forms an arc-shaped structure 1011 opposite to the warpage direction of the product 5, with the arc-shaped structure 1011 being recessed by 150 micrometers. The lower mold cavity 201 has a cavity insert 3 opposite to the warpage direction of the product 5, with the cavity insert 3 being protruded by 250 micrometers. The upper mold cavity 101 has a plurality of core-pulling pins 4 for pressing the product 5. The core-pulling pins 4 are located above the product 5 and can move in a vertical direction, and are provided with a reset member 6 so that they automatically reset after being pressed.

[0036] This invention creatively proposes a combined solution of "upper mold cavity 101 top reverse arc structure 1011" and "lower mold cavity 201 reverse cavity insert 3". By proactively pre-setting a deformation opposite to the natural warping direction (smiley face) for the product during the molding stage, it directly and precisely offsets the internal stress caused by the mismatch of the material's thermal expansion coefficient and the shrinkage of the epoxy molding compound, effectively suppressing warping from the source and significantly improving the flatness and quality consistency of the product.

[0037] Furthermore, the molding die includes an upper die 1 and a lower die 2. The lower surface of the upper die 1 is provided with a plurality of positioning holes 102, and the upper surface of the lower die 2 is provided with positioning blocks 202 corresponding one-to-one with the plurality of positioning holes 102.

[0038] Specifically, the lower surface of the upper mold 1 is provided with a positioning hole 102, and the upper surface of the lower mold 2 is provided with a corresponding positioning block 202, which is used for precise positioning during mold closing to ensure that the upper and lower mold cavities are aligned.

[0039] The lower surface of the upper mold 1 has one or more upper mold cavities 101, and the top of the cavity is machined to form an inwardly recessed arc-shaped structure 1011, specifically an arc surface with an arc height of 150 micrometers. The curvature of the arc surface is precisely designed according to the warp of the target product, and its concave direction is opposite to the "smiley face" shaped warp (concave in the middle and raised at both ends) produced by the natural cooling of product 5 (power module), that is, a deformation space is preset to make the middle of the product bulge upward.

[0040] The upper surface of the lower mold 2 has a lower mold cavity 201 corresponding to the upper mold cavity 101. A cavity insert 3 is installed inside the lower mold cavity 201. The top of the cavity insert 3 has a convex surface 301 that is opposite to the warping direction of the product 5, and the convex surface 301 protrudes outward. The convex surface 301 is located in the middle of the cavity insert 3, and the product 5 is placed on the convex surface 301.

[0041] Specifically, the top of the cavity insert 3 is machined with an outwardly protruding convex surface 301, which is preferably located in the middle and has an arc height of 250 micrometers. The metal base plate or AMB liner of the product 5 will be placed on this convex surface 301. The design of this convex surface 301 is also opposite to the natural warping direction of the product, used to support from the bottom and give the product an initial upward pre-arch. The arc structure 1011 is an arc surface set on the top of the upper mold cavity 101, which is recessed inward. The recessed arc surface of the upper mold cavity 101 and the convex surface 301 of the cavity insert 3 together form a complete "reverse pre-deformation" cavity.

[0042] The upper mold 1 has an inner cavity 103, and a needle plate 104 is provided in the inner cavity 103. Several core-pulling needles 4 are fixedly arranged on the lower surface of the needle plate 104. The top of the upper mold cavity 101 has several needle holes 1012 that communicate with the inner cavity 103, and the core-pulling needles 4 are ejected from the needle holes 1012. A pressure block 1041 is provided on the upper surface of the needle plate 104, and a through hole 105 that mates with the pressure block 1041 is provided on the top surface of the upper mold 1, and the pressure block 1041 passes through the through hole 105. The reset member 6 consists of several springs 1042 provided on the needle plate 104, and the several springs 1042 abut against the cavity wall of the inner cavity 103.

[0043] Specifically, to achieve the clamping and fixing of the product, the upper mold 1 has an inner cavity 103, in which a vertically movable needle plate 104 is installed. The upper ends of multiple core-pulling needles 4 are fixed to the lower surface of the needle plate 104. The top of the upper mold cavity 101 has multiple needle holes 1012 communicating with the inner cavity 103, and the lower ends of the core-pulling needles 4 can extend through the needle holes 1012. A pressure block 1041 is fixed on the upper surface of the needle plate 104, which protrudes from the through hole 105 on the top surface of the upper mold 1 for connecting an external driving device (such as a hydraulic cylinder). Multiple return springs 1042 are also installed on the needle plate 104, with the upper ends of the springs 1042 abutting against the top wall of the inner cavity 103, providing an upward return force for the needle plate 104.

[0044] A molding process for improving warpage in single-sided water-cooled power modules includes the following steps:

[0045] Step 1: Assemble the components of product 5, including the substrate, AMB substrate, and chip, and place them in the lower mold cavity 201;

[0046] The power module semi-finished product (including substrate, AMB substrate, and chip assembly) that has completed the chip mounting, bonding and other preliminary processes is placed on the cavity insert 3 of the lower mold cavity 201, so that the bottom surface of the AMB substrate makes initial contact with the convex surface 301.

[0047] Step 2: Close the mold and activate the core-pulling pin 4 to press the AMB liner tightly so that it fits completely with the cavity insert 3;

[0048] The upper mold 1 and lower mold 2 are driven to close. An external drive device drives the pin plate 104 downward through the pressure block 1041, overcoming the elastic force of the spring 1042, so that all the core-pulling pins 4 are pushed downward synchronously. The ends of the core-pulling pins 4 press against the upper surface of the AMB liner plate of the product (or a specific pressure point), firmly pressing it against the convex surface 301 of the cavity insert 3 below, ensuring that the two are completely fitted. At this time, the product has been pre-bent into a shape opposite to the final warp.

[0049] Step 3: Inject the epoxy molding compound, with the injection temperature controlled at 175±5℃ and the molding compound temperature controlled at 200±5℃.

[0050] After mold closing, preheated epoxy molding compound (200±5℃) is injected into a closed cavity consisting of upper and lower mold cavities and the product through an injection system. The injection temperature of the mold is controlled at 175±5℃.

[0051] Step 4: After injection molding, maintain the mold temperature for curing to allow the epoxy molding compound to fully cross-link and cure.

[0052] After injection molding, maintain the mold temperature to allow the epoxy molding compound to fully cross-link and cure within the cavity. During this process, the epoxy molding compound shrinks, but because the product has been forcibly pre-bent into a reverse shape by the mold, the stress generated by the shrinkage will partially offset the pre-bending stress. The ultimate goal is to make the product tend to be straight after demolding.

[0053] Step 5: Open the mold and remove the plastic-encapsulated power module;

[0054] After curing, the external driving force is released, and the needle plate 104, under the action of the return spring 1042, drives the core-pulling needle 4 to retract to the top of the upper mold cavity 101. Then the mold is opened, and the plastic-encapsulated power module product 5 is taken out.

[0055] Step 6: Perform post-curing to obtain product 5 with improved warpage.

[0056] Product 5 is then placed in an oven for standard post-curing. Since the main warpage compensation has been completed within the mold, the final warpage of the product after post-curing will be significantly improved, meeting design requirements.

[0057] This invention achieves active warpage compensation during molding through innovative mold structure design and matching process, effectively solving the "smiley face" warpage problem of single-sided water-cooled power modules, and improving product reliability, production efficiency and yield.

[0058] The arc-shaped structure 1011 is specifically an arc surface with an arc height of 150 micrometers, meaning it is concave upwards by 150 micrometers. The arc height of the convex surface 301 of the cavity insert 3 is 250 micrometers, meaning it convex upwards by 250 micrometers. Due to the difference in the coefficient of thermal expansion (CTE) of the materials, the CTE of the metal base plate (such as copper) is approximately 17 ppm / ℃, while the CTE of the epoxy molding compound is approximately 8–20. The temperature is ppm / ℃, and the curing shrinkage rate is large. Therefore, the warping direction caused by the shrinkage of epoxy molding compound is mainly upward convex (smiley face shape). In addition, the uneven stress distribution caused by the asymmetrical structure means that the lower surface (metal base plate) of product 5 has high rigidity and small shrinkage, while the upper surface (epoxy molding compound) has large shrinkage and stress concentration. Therefore, a larger reverse pre-deformation (250 micrometers) needs to be applied at the bottom to balance the shrinkage stress of the upper layer. Secondly, the upper and lower arc synergistic mechanism, the 150-micrometer concavity of the arc structure 1011 restricts the upward convexity of the epoxy molding compound, and the 250-micrometer protrusion of the cavity insert 3 forces the metal base plate to pre-arch upward. The two form a "clamping reverse pre-bending" to jointly counteract the natural warping trend.

[0059] The arc-shaped structure 1011 and the cavity insert 3 work together to force the product 5 to be pre-bent into a reverse arch shape between the upper mold cavity 101 and the lower mold cavity 201. After curing and shrinkage, the pre-bending stress and shrinkage stress are partially offset, and the net warpage is reduced by about 200 micrometers. As shown in the table below, the improved mold design has an improvement of about 200 micrometers in product warpage.

[0060] Cavity insert type Material Brands Material Model Mold temperature (°C) Post-curing temperature (°C) Product warpage (µm) before sealing Post-curing product warpage (µm) flat Sumitomo EME-G720ECType A 175±5 200±5 315 260 curved surface Sumitomo EME-G720ECType A 175±5 200±5 135 50

[0061] This invention employs an asymmetrical arc-shaped structure design for the upper and lower mold cavities. The upper mold cavity 101 has a 150-micron concavity, while the cavity insert 3 of the lower mold 201 has a 250-micron protrusion, forming a synergistic reverse pre-bending mechanism. This design is based on the asymmetrical material structure and thermal shrinkage characteristics of a single-sided water-cooled power module. The larger pre-arching amount (250 microns) in the lower part offsets the CTE mismatch stress between the metal base plate and the epoxy molding compound, while the smaller pre-concavity amount (150 microns) in the upper part restricts the EMC shrinkage direction, together achieving a warpage improvement of approximately 200 microns. This ratio (approximately 3:5) was determined through experimental optimization and can effectively match the shrinkage-stress balance point of a typical power module.

[0062] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. 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 invention; therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0063] Although this document frequently uses reference numerals from the figures, such as upper mold 1, upper mold cavity 101, arc-shaped structure 1011, pin hole 1012, positioning hole 102, inner cavity 103, pin plate 104, pressure block 1041, spring 1042, through hole 105, lower mold 2, lower mold cavity 201, positioning block 202, cavity insert 3, convex surface 301, core-pulling pin 4, product 5, and reset component 6, the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of the invention; interpreting them as any additional limitation would contradict the spirit of the invention.

Claims

1. A molding die for improving warpage of a single-sided water-cooled power module, comprising an upper die (1) and a lower die (2) configured for mold assembly, wherein the lower surface of the upper die (1) is provided with at least one upper mold cavity (101), and the upper surface of the lower die (2) is provided with a lower mold cavity (201) corresponding to the upper mold cavity (101), characterized in that, The top of the upper mold cavity (101) forms an arc-shaped structure (1011) opposite to the warping direction of the product (5), the arc-shaped structure (1011) is recessed by 150 micrometers, and the lower mold cavity (201) is provided with a cavity insert (3) opposite to the warping direction of the product (5), the cavity insert (3) is raised by 250 micrometers; the upper mold cavity (101) is provided with a plurality of core-pulling pins (4) for pressing the product (5), the core-pulling pins (4) are located above the product (5), and the core-pulling pins (4) can move in the vertical direction, and are provided with a reset member (6) to automatically reset after pressing.

2. A molding die for improving warpage of a single-sided water-cooled power module according to claim 1, characterized in that, The arc-shaped structure (1011) is an arc surface set on the top of the upper mold cavity (101), and the arc surface is recessed inward.

3. A molding die for improving warpage of a single-sided water-cooled power module according to claim 1, characterized in that, The top of the cavity insert (3) has a convex surface (301) that is opposite to the warping direction of the product (5), and the convex surface (301) protrudes outward.

4. A molding die for improving warpage of a single-sided water-cooled power module according to claim 3, characterized in that, The convex surface (301) is located in the middle of the cavity insert (3), and the product (5) is placed on the convex surface (301).

5. A molding die for improving warpage of a single-sided water-cooled power module according to claim 1, characterized in that, The upper mold (1) has an inner cavity (103), and a needle plate (104) is provided in the inner cavity (103). A number of core-pulling needles (4) are fixedly set on the lower surface of the needle plate (104). The top of the upper mold cavity (101) has a number of needle holes (1012) that communicate with the inner cavity (103). The core-pulling needles (4) are pushed out from the needle holes (1012).

6. A molding die for improving warpage of a single-sided water-cooled power module according to claim 5, characterized in that, The needle plate (104) has a pressure block (1041) on its upper surface, and the upper mold (1) has a through hole (105) on its top surface that cooperates with the pressure block (1041). The pressure block (1041) passes through the through hole (105).

7. A molding die for improving warpage of a single-sided water-cooled power module according to claim 5, characterized in that, The reset component (6) consists of several springs (1042) disposed on the needle plate (104), and the several springs (1042) abut against the cavity wall of the inner cavity (103).

8. A molding die for improving warpage of a single-sided water-cooled power module according to claim 1, characterized in that, The lower surface of the upper mold (1) is provided with a plurality of positioning holes (102), and the upper surface of the lower mold (2) is provided with positioning blocks (202) corresponding one-to-one with the plurality of positioning holes (102).

9. A molding method for improving warpage of a single-sided water-cooled power module, characterized in that, A molding die for improving warpage of a single-sided water-cooled power module as described in any one of claims 1-8, comprising the following steps: Step 1: Assemble the components of product (5), including substrate, AMB substrate and chip, and place them in the lower mold cavity (201); Step 2: Close the mold and start the core-pulling pin (4) to press the AMB liner tightly so that it fits completely with the cavity insert (3); Step 3: Injection molding of the epoxy molding compound; Step 4: After injection molding, maintain the mold temperature for curing to allow the epoxy molding compound to fully cross-link and cure. Step 5: Open the mold and remove the plastic-encapsulated power module; Step 6: Perform post-curing to obtain a product with improved warpage (5).

10. A molding method for improving warpage of a single-sided water-cooled power module according to claim 9, characterized in that, In step three, the injection temperature is controlled at 175±5℃, and the molding compound temperature is controlled at 200±5℃.

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