A lead frame-less embedded IPM packaging structure

Abstract

The present invention discloses an embedded IPM package structure without a lead frame, comprising an IPM package structure body, the IPM package structure body mainly comprising an insulating ceramic substrate and a chip module arranged on the edge ceramic substrate, and a layer of laminated foil is provided between the upper surface of the insulating ceramic substrate and the chip module, the laminated foil is provided with through holes connected to the corresponding chip or the edge ceramic substrate at positions corresponding to the chip module control port, collector and emitter, the upper surface of the laminated foil is provided with a filling copper layer that penetrates into the through holes and is electrically connected to the chip module, the upper surface of the filling copper layer is etched with a wiring pattern, and the filling copper layer is covered with a solder resist layer for protecting the wiring pattern; the edge ceramic substrate is provided with welding points serving as pins of the IPM package structure body; the chip module comprises a driver chip, an IGBT chip and a FWD chip.

Description

Technical Field

[0001] The present invention relates to the technical field of IPM packaging, and in particular to an embedded IPM packaging structure without a lead frame. Background Art

[0002] Intelligent Power Module (IPM), short for Intelligent Power Module, is a power-driven semiconductor package structure that combines power electronics and integrated circuit technologies. Compared to traditional discrete semiconductor packages, IPMs are gaining increasing popularity due to their high integration and reliability. Traditional IPMs typically assemble various electronic components on a planar substrate. However, as semiconductor packaging structures evolve towards smaller and more integrated designs, increasing the integration and size of IPMs is a growing concern for engineers.

[0003] In addition, in the existing traditional IPM packaging structure, the driver chip and IGBT chip are fixed at specific positions on the lead frame and DBC respectively. The electrical connection between the IGBT chip, FWD chip and driver chip often uses bonding wires, resulting in problems such as wire collapse, which has become a difficulty in IPM production. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a lead-frame-free embedded IPM packaging structure with a smaller volume and the ability to further improve the module power density in response to the above-mentioned defects of the prior art.

[0005] The objective of the present invention is achieved through the following technical solution: a leadframe-free embedded IPM packaging structure, comprising an IPM packaging structure body, the IPM packaging structure body mainly comprising an insulating ceramic substrate and a chip module arranged on the insulating ceramic substrate, and a layer of laminated foil is provided between the upper surface of the insulating ceramic substrate and the chip module, the laminated foil is provided with through holes corresponding to the positions of the chip module control port, collector and emitter, respectively, which are connected to the corresponding chip or insulating ceramic substrate, the upper surface of the laminated foil is provided with a filling copper layer that penetrates into the through holes and is electrically connected to the chip module, the upper surface of the filling copper layer is etched with a wiring pattern, and the filling copper layer is covered with a solder resist layer for protecting the wiring pattern; the insulating ceramic substrate is provided with welding points serving as the pins of the IPM packaging structure body.

[0006] Furthermore, the chip module includes a driver chip, an IGBT chip and a FWD chip.

[0007] Furthermore, the insulating ceramic substrate includes an upper copper layer, an insulating ceramic layer and a lower copper layer which are arranged in sequence.

[0008] Furthermore, the filling copper layer is filled into the corresponding through hole by electroplating.

[0009] The beneficial technical effects of the present invention are: by etching a wiring pattern on the top surface of the copper filler layer, the present invention solves the existing problems of bond wire collapse, significantly reduces the module size, and further improves the module's power density. Furthermore, by replacing the lead frame with solder joints, which perform the lead frame's electrical function, the module's production costs can be further reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a schematic diagram of the insulating ceramic substrate and chip arrangement of the present invention;

[0011] Figure 2 Schematic diagram of the position of the laminated foil of the present invention;

[0012] Figure 3 Schematic diagram of the punching positions of the laminated foil of the present invention;

[0013] Figure 4 It is a schematic diagram of the overall structure of the present invention. DETAILED DESCRIPTION

[0014] In order to enable those skilled in the art to more clearly understand the objectives, technical solutions and advantages of the present invention, the present invention is further described below with reference to the accompanying drawings and embodiments.

[0015] In the description of the present invention, it should be understood that the orientations or positional relationships indicated by terms such as “upper”, “lower”, “left”, “right”, “inside”, “outside”, “horizontal” and “vertical” are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, rather than indicating or implying that the device or component referred to must have a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0016] This patent adopts a lead frame-less chip embedded packaging structure and uses filled copper etched wiring to replace traditional bonding wires to solve problems such as bonding wire collapse. Moreover, since no lead frame is required, the space occupied by the module is greatly reduced, effectively reducing the space occupied by the peripheral circuit IPM.

[0017] like Figure 1-4As shown, the present invention discloses a lead frame-free embedded IPM package structure, comprising an IPM package structure body, the IPM package structure body mainly comprising an insulating ceramic substrate 1 and a chip module arranged on the insulating ceramic substrate 1, and a layer of laminated foil 2 is provided between the upper surface of the insulating ceramic substrate 1 and the chip module, the laminated foil 2 is provided with through holes 3 connected to the corresponding chip or insulating ceramic substrate at positions corresponding to the chip module control port, collector and emitter, and a layer of laminated foil 2 is provided on the upper surface of the laminated foil 2 that penetrates into the through holes 3 and connects to the chip module. The filling copper layer 4 is electrically connected to the IPM block, and the switching control of the IGBT by the driver chip is realized through the filling copper layer 4; the upper surface of the filling copper layer 4 is etched with a wiring pattern to replace the traditional bonding wire, and the filling copper layer 4 is covered with a solder resist layer 5 to protect the internal filling copper layer during welding and prevent the etched filling copper line from being damaged; the insulating ceramic substrate 1 is provided with welding points 6 as the pins of the IPM package structure body, and the welding points replace the pins of the traditional IPM. It can be directly soldered to the external circuit PCB board through the welding points, which greatly reduces the material cost of the IPM.

[0018] Reference Figure 1-4 As shown, the chip module includes a driver chip 7, an IGBT chip 8, and a FWD chip 9. The insulating ceramic substrate 1 comprises an upper copper layer, an insulating ceramic layer, and a lower copper layer, arranged in that order. The copper filler layer 4 is electroplated into the corresponding through-holes 3. In this technical solution, the driver chip 7, IGBT chip 8, and FWD chip 9 are all fixed to the insulating ceramic substrate. Since the IPM module's IGBT chip and FWD chip have electrodes on their surfaces, these electrodes are located at the locations where the laminated foil is punched. The copper filler layer connects to the driver chip, ensuring the product's electrical circuit.

[0019] The packaging method process flow of this IPM packaging structure is as follows: first, the FWD and IGBT are bonded by printing, then reflow solidification is performed, and then covered with laminated foil, and holes are punched at the electrical positions corresponding to the laminated foil. The hole positions are covered with filled copper by electroplating, and then a wiring pattern that meets the electrical performance of the IPM is etched. Finally, a protective solder mask layer is covered on the etched filled copper.

[0020] This invention utilizes a leadframe-less chip embedded package structure, replacing traditional bonding wires with copper-filled etched flat wires to address issues such as bond wire collapse. Furthermore, since a leadframe is not required, the module footprint is significantly reduced, effectively reducing the space occupied by the peripheral circuitry (IPM). Furthermore, solder joints replace the leadframe, replacing its electrical function, further reducing module production costs.

[0021] The specific embodiments described herein are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical concepts disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A leadframe-less embedded IPM package structure, comprising an IPM package structure body, characterized in that: The IPM package structure body mainly includes an insulating ceramic substrate and a chip module arranged on the insulating ceramic substrate, and a layer of laminated foil is provided between the upper surface of the insulating ceramic substrate and the chip module. The laminated foil is respectively provided with through holes connected to the corresponding chip or insulating ceramic substrate at positions corresponding to the chip module control port, collector and emitter. The upper surface of the laminated foil is provided with a filling copper layer that penetrates into the through holes and is electrically connected to the chip module. The upper surface of the filling copper layer is etched with a wiring pattern, and the filling copper layer is covered with a solder resist layer for protecting the wiring pattern; the insulating ceramic substrate is provided with welding points serving as the pins of the IPM package structure body.

2. The leadframe-less embedded IPM package structure according to claim 1, wherein: The chip module includes a driver chip, an IGBT chip and a FWD chip.

3. The leadframe-less embedded IPM package structure according to claim 1 or 2, wherein: The insulating ceramic substrate comprises an upper copper layer, an insulating ceramic layer and a lower copper layer which are arranged in sequence.

4. The leadframe-less embedded IPM package structure according to claim 3, wherein: The filling copper layer is filled into the corresponding through hole by electroplating.

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