Power module packaging method and power module
By using large-size carrier plates and small-size metal base plate array mounting in the power module package, array packaging small units are formed, which solves the problems of low packaging efficiency and CTE mismatch, and achieves efficient and reliable power module manufacturing.
Patent Information
- Application Number
- CN202510877050.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-26
- Publication Date
- 2025-08-08
AI Technical Summary
In the existing power module packaging process, the frame size limits the number of integrated power modules and has low packaging efficiency; large-sized substrates aggravate the CTE mismatch between the substrate, EMC and metal base plate, affecting the reliability of the module.
Large-size carrier plates and multiple small-size metal base plates are arranged in array, and the substrate corresponds one by one to the metal base plate to form an array packaging unit. The independent power module is formed by wrapping and cutting through a plastic seal to localize CTE differences to avoid overall stress accumulation.
Break through the frame size limitations, realize batch packaging, improve packaging efficiency, and alleviate the problem of CTE mismatch, and enhance the reliability and heat dissipation performance of power modules.
Smart Images
Figure CN120453178A_ABST
Abstract
Description
Technical Field
[0001] The embodiments of the present disclosure belong to the field of semiconductor packaging technology, and particularly relate to a power module packaging method and a power module. Background Art
[0002] A power module is a module that integrates power devices according to a certain functional combination. Compared with discrete devices, its structure shortens the current loop and reduces conduction loss.
[0003] like Figure 1 and Figure 2 As shown, the specific packaging process of the existing power module is as follows: several substrates 1 are fixed on the frame 3 through pins 2, the power device 4 is fixed to the surface of the substrate 1 by welding, and signal transmission is achieved through wire bonding 5 and pins 6. After the EMC 7 protection device is formed, the pins 2 are cut off to separate the frame 3 and the substrate 1 to complete the module packaging, and finally the substrate 1 is welded to the metal base plate to achieve heat dissipation.
[0004] The existing power module packaging process has the following problems:
[0005] 1) Due to the limitation of frame size, the number of power modules that can be integrated on the frame is limited, and the packaging efficiency is low;
[0006] 2) The large-size substrate exacerbates the CTE mismatch problem between the substrate, EMC and metal base plate, affecting module reliability.
[0007] In view of the above problems, it is necessary to propose a power module packaging method and a power module that are reasonably designed and effectively solve the above problems. Summary of the Invention
[0008] The embodiments of the present disclosure aim to solve at least one of the technical problems existing in the prior art and provide a power module packaging method and a power module.
[0009] One aspect of an embodiment of the present disclosure provides a power module packaging method.
[0010] The law includes:
[0011] Providing a carrier board and a plurality of metal base plates, and attaching the plurality of metal base plates to the first surface of the carrier board;
[0012] Mounting a plurality of substrates on the corresponding metal base plates;
[0013] Mounting a plurality of chips on the corresponding substrates;
[0014] Fixing first ends of a plurality of external terminals to the corresponding substrates and electrically connecting them to the chip;
[0015] A plastic package body is formed on the first surface of the carrier board to wrap the metal bottom plate, the substrate and the chip, wherein the second end of the external terminal passes through the plastic package body;
[0016] The carrier board is removed and cut into individual power modules.
[0017] Optionally, before attaching the plurality of metal base plates to the first surface of the carrier plate, the method further includes:
[0018] A plurality of blind holes are formed on the second surface of the carrier board.
[0019] Optionally, the plurality of blind holes are evenly distributed on the second surface of the carrier board.
[0020] Optionally, the plurality of blind holes are evenly distributed in an edge area of the second surface of the carrier board.
[0021] Optionally, the step of attaching the plurality of metal base plates to the first surface of the carrier plate comprises:
[0022] forming a temporary bonding adhesive layer on the first surface of the carrier;
[0023] A plurality of the metal base plates are mounted on the temporary bonding adhesive layer in an array.
[0024] Optionally, removing the carrier board includes:
[0025] decomposing the temporary bonding adhesive layer to peel off the carrier;
[0026] The residual temporary bonding adhesive layer is cleaned and removed.
[0027] Optionally, mounting the plurality of substrates on the corresponding metal base plates includes:
[0028] The plurality of substrates are soldered to the corresponding metal base plates through solder.
[0029] Optionally, fixing the first ends of the plurality of external terminals to the corresponding substrate and electrically connecting them to the chip includes:
[0030] Mounting the first ends of the plurality of external terminals on the pads of the substrate by reflow soldering, or fixing the first ends of the plurality of external terminals on the pin holders of the substrate by mechanical pressing;
[0031] The external terminals are electrically connected to the chip through bonding wires.
[0032] Optionally, the carrier plate is made of stainless steel, or a material that matches the CTE of the metal base plate;
[0033] The metal bottom plate is made of copper or aluminum.
[0034] Another aspect of the embodiments of the present disclosure provides a power module, which is packaged using the power module packaging method described above.
[0035] The power module packaging method and power module of the embodiments of the present disclosure, in which a large-sized carrier and multiple small-sized metal base plates are provided, the multiple small-sized metal base plates are mounted on the first surface of the carrier, and multiple substrates are sequentially mounted on the corresponding metal base plates, the substrates and the metal base plates form multiple array-type packaging small units, breaking through the frame size limitations in the prior art, realizing batch packaging, and greatly improving packaging efficiency; the substrates and the metal base plates are distributed in array-type small units, localizing the CTE differences between the substrates, the plastic package body and the metal base plate, avoiding overall stress accumulation, alleviating CTE mismatch, and improving the reliability of the power module. BRIEF DESCRIPTION OF THE DRAWINGS
[0036] Figure 1 and Figure 2 A schematic diagram of a power module packaging process in the prior art;
[0037] Figure 3 Schematic diagram of a power module packaging method according to an embodiment of the present disclosure;
[0038] Figures 4 to 15 Schematic diagram of a packaging process of a power module packaging method in an embodiment of the present disclosure. DETAILED DESCRIPTION
[0039] In order to enable those skilled in the art to better understand the technical solutions of the embodiments of the present disclosure, the embodiments of the present disclosure are further described in detail below with reference to the accompanying drawings and specific implementation methods.
[0040] like Figure 3 As shown, one aspect of an embodiment of the present disclosure provides a power module packaging method S100, and the method S100 may specifically include:
[0041] S110 , providing a carrier board and a plurality of metal base plates, and attaching the plurality of metal base plates to the first surface of the carrier board.
[0042] like Figure 4 As shown, a carrier board 100 and a plurality of metal base plates 102 are provided. The metal base plates 102 can be made of copper or aluminum to provide heat dissipation and structural support. Of course, the metal base plates 102 can be made of other metal materials with heat dissipation functions, and this embodiment does not specifically limit this.
[0043] In this embodiment, the carrier 100 has a first surface and a second surface along its thickness, wherein both the first surface and the second surface of the carrier 100 are smooth surfaces. The carrier 100 can be made of stainless steel, or a material that matches the CTE of the metal base plate 102 to reduce thermal stress.
[0044] The step of attaching the plurality of metal base plates 102 to the first surface of the carrier 100 may specifically include:
[0045] First, if Figure 4 As shown, a temporary bonding adhesive layer 101 is formed on the upper surface of the carrier 100. Specifically, the temporary bonding adhesive layer 101 can be disposed on the carrier 100 by spin coating, lamination, etc. The temporary bonding adhesive layer 101 has laser responsiveness.
[0046] Secondly, if Figure 4 and Figure 7 As shown, the plurality of metal base plates 102 are mounted on the temporary bonding adhesive layer 101 in an array, and then the plurality of metal base plates 102 are fixed to the carrier 100 in an array.
[0047] like Figure 5 and Figure 6 As shown, in another embodiment, before attaching the plurality of metal base plates 102 to the first surface of the carrier 100 , the method S100 may further include: forming a plurality of blind holes 100 a on the second surface of the carrier 100 .
[0048] Specifically, a plurality of arc-shaped blind holes 100 a may be formed on the lower surface of the carrier 100 by machining (such as stamping), laser etching, or the like.
[0049] like Figure 5 As shown, in one embodiment, a plurality of blind holes 100a can be evenly distributed on the second surface of the carrier 100. Figure 6 As shown, in another embodiment, the plurality of blind holes 100 a may also be evenly distributed in the edge region of the second surface of the carrier 100 .
[0050] It should be noted that the number and distribution positions of the blind holes 100 a are not specifically limited in this embodiment and can be limited according to actual needs.
[0051] like Figure 5 and Figure 6 As shown, after forming a plurality of blind holes 100a on the second surface of the carrier 100, a plurality of metal base plates 102 are mounted on the first surface of the carrier 100. The mounting process of the plurality of metal base plates 102 can refer to the above description.
[0052] In this embodiment, by forming multiple blind holes on the second surface of the carrier, when the plastic package is formed on the first surface of the carrier, the shrinkage stress of the plastic package during curing can be absorbed and dispersed, thereby preventing the edge of the plastic package from warping up and balancing the stress distribution on the upper and lower surfaces of the carrier.
[0053] S120, mounting a plurality of substrates on the corresponding metal base plates.
[0054] like Figure 8 As shown, multiple substrates 104 are mounted on the corresponding metal base plates 102, that is, the substrates 104 are arranged in a one-to-one correspondence with the metal base plates 102. The specific process of step S120 can be: multiple substrates 104 are soldered to the corresponding metal base plates 102 using solder 103.
[0055] like Figure 8 and Figure 9 As shown, in this embodiment, the substrate 104 can be a DBC (copper-clad ceramic substrate), an AMB (active metal brazing substrate), etc., wherein the substrate 104 includes an insulating layer 1041 and a metal layer 1042. The metal layer 1042 is respectively provided on the upper and lower surfaces of the insulating layer 1041. It should be noted that this embodiment does not specifically limit the type of substrate 104, and can be selected according to actual needs.
[0056] In this embodiment, the small-sized substrate and metal base plate are divided into multiple small units and distributed in a matrix on a large-area carrier board, realizing batch packaging and greatly improving packaging efficiency; the substrate and the metal base plate form multiple array-type small units, which can reduce the interface stress concentration problem caused by material CTE mismatch and improve the reliability of the power module; in addition, the substrate and the metal base plate correspond one-to-one, enhancing the heat dissipation and mechanical support of the substrate.
[0057] S130, mounting a plurality of chips on the corresponding substrates.
[0058] like Figure 9 As shown, multiple chips 110 are mounted on the corresponding substrate 104 through solder / silver paste 105, and electrical connections between the chips 110 and the substrate 104 are achieved through bonding wires 111, and electrical connections between the chips 110 are achieved through bonding wires 111.
[0059] S140 , fixing first ends of a plurality of external terminals to the corresponding substrates and electrically connecting them to the chip.
[0060] like Figure 10As shown, in one embodiment, the first ends of the plurality of external terminals 112 can be mounted on the pads of the substrate 104 by reflow soldering, and then the external terminals 112 can be electrically connected to the chip 110 via bonding wires 111 to lead out the signals of the chip 110. In this embodiment, the external terminals 112 can be pins.
[0061] like Figure 10 As shown, in another embodiment, the first ends of the plurality of external terminals 112 can be fixed to the pin holders of the substrate 104 by mechanical pressing, and then the external terminals 112 can be electrically connected to the chip 110 through bonding wires 111 to lead out the signals of the chip 110.
[0062] It should be noted that the embodiment does not specifically limit the manner in which the external terminal 112 is fixed to the substrate 104 and can be selected according to actual needs.
[0063] S150 , forming a plastic package body on the first surface of the carrier board to wrap the metal base plate, the substrate, and the chip, wherein the second end of the external terminal passes through the plastic package body.
[0064] like Figure 11 As shown, a plastic package 113 is formed on the upper surface of the carrier 100 using a process such as injection molding to encapsulate the metal base plate 102, the substrate 104, and the chip 110. The second ends of the external terminals 112 extend through the top of the plastic package 113 to lead signals from the chip 110 through the external terminals 112. The plastic package 113 protects the metal base plate 102, the substrate 104, and the chip 110.
[0065] like Figure 12 As shown, when multiple blind holes 100a can be evenly distributed on the second surface of the carrier 100, the multiple blind holes 100a can absorb and disperse the shrinkage stress of the plastic package 113 during curing, prevent the edge of the plastic package 113 from warping up, and balance the stress distribution on the upper and lower surfaces of the carrier 100.
[0066] Similarly, if Figure 13 As shown, when multiple blind holes 100a are evenly distributed in the edge area of the second surface of the carrier 100, the multiple blind holes 100a can also absorb and disperse the shrinkage stress of the plastic package 113 during solidification, prevent the edge of the plastic package 113 from warping up, and balance the stress distribution on the upper and lower surfaces of the carrier 100.
[0067] S160 , removing the carrier board and cutting it to form a plurality of separate power modules.
[0068] Among them, Figure 14 As shown, the specific process of removing the carrier board 100 may be as follows:
[0069] First, the temporary bonding layer 101 is decomposed to separate the carrier 100. Specifically, since the carrier 100 is made of metal and opaque, a laser can be used to scan the interface of the temporary bonding layer 101 to decompose the temporary bonding layer 101 and then peel off the carrier 100.
[0070] Then, the remaining temporary bonding adhesive layer 101 is cleaned and removed.
[0071] In this embodiment, the peeled carrier plate can be recycled, saving costs.
[0072] like Figure 14 and Figure 15 As shown, after removing the carrier board 100, the plastic package 113 between two adjacent metal base plates 102 is cut to obtain Figure 15 Multiple individual power modules 200 are shown. In power modules 200, substrates 104 correspond one-to-one with metal base plates 102, enhancing heat dissipation and mechanical support for substrates 104. Each substrate 104 is attached to its corresponding metal base plate 102. The small size of substrates 104 and metal base plates 102 form a small package unit, which can reduce interfacial stress concentration caused by material CTE mismatch and enhance the reliability of power module 200.
[0073] The power module packaging method of the embodiment of the present disclosure provides a large-sized carrier and multiple small-sized metal base plates, mounts the multiple small-sized metal base plates on the first surface of the carrier, and sequentially mounts multiple substrates on the corresponding metal base plates. The substrates and the metal base plates form multiple array-type packaging small units, breaking through the frame size limitations in the prior art, realizing batch packaging, and greatly improving packaging efficiency; the substrates and the metal base plates are distributed in an array-type small unit, localizing the CTE difference between the substrate, the plastic package body and the metal base plate, avoiding overall stress accumulation, alleviating CTE mismatch, and improving the reliability of the power module.
[0074] like Figure 15 As shown, another aspect of the present disclosure provides a power module 200, which is packaged using the power module packaging method S100 described above. The specific steps of the power module packaging method S100 have been described in detail above and will not be repeated here.
[0075] like Figure 15As shown, the power module 200 includes multiple metal base plates 102, multiple substrates 104, multiple chips 110, multiple external terminals 112, and a plastic package 113. Each substrate 104 is disposed on its corresponding metal base plate 102. The chip 110 is disposed on its corresponding substrate 104. The first end of the external terminal 112 is disposed on the substrate 104 and is electrically connected to the chip 110 via a bonding wire 111. The plastic package 113 encapsulates the substrate 104, the metal base plate 102, and the chip 110, wherein the external terminal 112 extends from the top of the plastic package 113 to lead out the signal of the chip 110.
[0076] In the power module of the disclosed embodiment, each substrate is arranged on a corresponding metal base plate to form a plurality of array-type small units, which can reduce the problem of interface stress concentration caused by material CTE mismatch and improve the reliability of the power module; in addition, the substrate corresponds one-to-one with the metal base plate, thereby enhancing the heat dissipation and mechanical support of the substrate.
[0077] It is understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the embodiments of the present disclosure, but the embodiments of the present disclosure are not limited thereto. Those skilled in the art may make various modifications and improvements without departing from the spirit and essence of the embodiments of the present disclosure, and such modifications and improvements are also considered to be within the scope of protection of the embodiments of the present disclosure.
Claims
1. A power module packaging method, characterized in that: The method comprises: Providing a carrier board and a plurality of metal base plates, and attaching the plurality of metal base plates to the first surface of the carrier board; Mounting a plurality of substrates on the corresponding metal base plates; Mounting a plurality of chips on the corresponding substrates; Fixing first ends of a plurality of external terminals to the corresponding substrates and electrically connecting them to the chip; A plastic package body is formed on the first surface of the carrier board to wrap the metal bottom plate, the substrate and the chip, wherein the second end of the external terminal passes through the plastic package body; The carrier board is removed and cut into individual power modules.
2. The power module packaging method according to claim 1, wherein: Before attaching the plurality of metal base plates to the first surface of the carrier, the method further includes: A plurality of blind holes are formed on the second surface of the carrier board.
3. The power module packaging method according to claim 2, wherein: A plurality of the blind holes are evenly distributed on the second surface of the carrier board.
4. The power module packaging method according to claim 2, wherein: The plurality of blind holes are evenly distributed in the edge area of the second surface of the carrier board.
5. The power module packaging method according to any one of claims 1 to 4, characterized in that: The step of attaching the plurality of metal base plates to the first surface of the carrier plate comprises: forming a temporary bonding adhesive layer on the first surface of the carrier; A plurality of the metal base plates are mounted on the temporary bonding adhesive layer in an array.
6. The power module packaging method according to claim 5, characterized in that: The removing of the carrier board comprises: decomposing the temporary bonding adhesive layer to peel off the carrier; The residual temporary bonding adhesive layer is cleaned and removed.
7. The power module packaging method according to any one of claims 1 to 4, characterized in that: The step of attaching the plurality of substrates to the corresponding metal base plates includes: The plurality of substrates are soldered to the corresponding metal base plates through solder.
8. The power module packaging method according to any one of claims 1 to 4, characterized in that: The method of fixing the first ends of the plurality of external terminals to the corresponding substrate and electrically connecting the first ends to the chip includes: Mounting the first ends of the plurality of external terminals on the pads of the substrate by reflow soldering, or fixing the first ends of the plurality of external terminals on the pin holders of the substrate by mechanical pressing; The external terminals are electrically connected to the chip through bonding wires.
9. The power module packaging method according to any one of claims 1 to 4, characterized in that: The carrier plate is made of stainless steel, or a material having a CTE matching that of the metal base plate; The metal bottom plate is made of copper or aluminum.
10. A power module, characterized in that: The power module is packaged and formed by the power module packaging method according to any one of claims 1 to 9.