阅读说明：本技术 夹具框架组件、具有引线框架和夹具框架的半导体封装及其制造方法 (Jig frame assembly, semiconductor package having lead frame and jig frame, and method of manufacturing the same ) 是由 郑文健 吴美仪 M·格鲁贝尔 J·霍格劳尔 M·于尔斯 J·梅尔茨 T·迈尔 T·沙夫 于 2020-02-20 设计创作，主要内容包括：一种模制半导体封装包括引线框架,该引线框架具有一个或多个第一引线,该第一引线与管芯焊盘整体形成并且从焊盘沿第一方向向外延伸。半导体管芯在管芯的第一侧附着到管芯焊盘。夹具框架的金属夹具在管芯的第二侧附着到电源端子。与金属夹具整体形成的一个或多个第二引线从夹具沿不同于第一方向的第二方向向外延伸。模制化合物中嵌入管芯。第一引线和第二引线暴露于模制化合物的不同侧并且彼此不垂直交叠。在模制化合物之内,夹具从高于电源端子的第一水平过渡到与引线相同平面中的第二水平。(A molded semiconductor package includes a leadframe having one or more first leads integrally formed with a die pad and extending outwardly from the pad in a first direction. A semiconductor die is attached to the die pad at a first side of the die. The metal clip of the clip frame is attached to the power terminals at the second side of the die. One or more second leads integrally formed with the metal clip extend outwardly from the clip in a second direction different from the first direction. The die is embedded in the molding compound. The first and second leads are exposed to different sides of the mold compound and do not vertically overlap each other. Within the molding compound, the clip transitions from a first level above the power terminals to a second level in the same plane as the leads.)

1. A method of manufacturing a molded semiconductor package, the method comprising:

providing a lead frame including a die pad and one or more first leads integrally formed with and extending outwardly from the die pad in a first direction, the die pad and the one or more first leads being attached to an outer periphery of the lead frame;

attaching a first side of a semiconductor die to the die pad;

aligning a clip frame with the lead frame such that a first pre-bent metal clip of the clip frame is vertically aligned with power terminals of a second side of the semiconductor die opposite the first side, the clip frame further including one or more second leads integrally formed with the first pre-bent metal clip, extending outwardly from the first pre-bent metal clip in a second direction different from the first direction and attached to an outer perimeter of the clip frame;

attaching the first pre-bent metal clip to the power terminals of the second side of the semiconductor die;

embedding the semiconductor die in a mold compound such that the one or more first leads and the one or more second leads protrude from the mold compound in a substantially planar direction and do not vertically overlap each other; and

separating the one or more first leads from the outer periphery of the leadframe and the one or more second leads from the outer periphery of the clip frame outside of the mold compound.

2. The method of claim 1, wherein separating the one or more first leads from the periphery of the leadframe and the one or more second leads from the periphery of the clip frame outside of the mold compound comprises:

stamping the one or more first leads and the one or more second leads outside of the mold compound.

3. The method of claim 1, wherein separating the one or more first leads from the periphery of the leadframe and the one or more second leads from the periphery of the clip frame outside of the mold compound comprises:

cutting the one or more first leads and the one or more second leads outside of the mold compound.

4. The method of claim 1, further comprising:

attaching a second pre-bent metal clip of the clip frame to a control terminal of the second side of the semiconductor die,

wherein the clip frame further comprises a third lead extending outwardly from the second pre-bent metal clip and attached to the outer periphery of the clip frame,

wherein, after embedding the semiconductor die in the mold compound, the third leads protrude from the mold compound and do not vertically overlap the one or more first leads.

5. The method of claim 4, further comprising:

separating the third lead from the outer periphery of the clip frame outside of the mold compound via the same stamping process used to separate the one or more first leads from the outer periphery of the leadframe and the one or more second leads from the outer periphery of the clip frame.

6. The method of claim 1, wherein the one or more first leads protrude from a first side of the mold compound after being separated from the periphery of the leadframe, and wherein the one or more second leads protrude from a second side of the mold compound different from the first side after being separated from the periphery of the clip frame.

7. The method of claim 6, further comprising:

plating portions of the one or more first leads protruding from the first side of the mold compound and portions of the one or more second leads protruding from the second side of the mold compound to form wettable lead surfaces on different sides of the mold compound.

8. The method of claim 1, wherein the lead frame is unbent.

9. The method of claim 1, wherein the jig frame includes alignment features to assist in alignment of the jig frame with the lead frame.

10. The method of claim 1, wherein the clip frame is stacked on top of the lead frame in the area of a mold runner used during embedding of the semiconductor die in the molding compound.

11. The method of claim 1, further comprising:

pressing the clip frame against the lead frame to provide a tight seal during embedding of the semiconductor die in the molding compound.

12. A molded semiconductor package, comprising:

a lead frame including a die pad and one or more first leads integrally formed with the die pad and extending outwardly from the die pad in a first direction;

a semiconductor die attached to the die pad at a first side of the semiconductor die;

a clip frame including a first metal clip attached to power terminals of a second side of the semiconductor die opposite the first side and one or more second leads integrally formed with the first metal clip and extending outwardly from the first metal clip in a second direction different from the first direction; and

a molding compound embedded in the semiconductor die,

wherein the one or more first leads and the one or more second leads are exposed to different sides of the molding compound and do not vertically overlap with each other,

wherein, within the mold compound, the first metal clip transitions from a first level above the power terminals of the second side of the semiconductor die to a second level in the same plane as the one or more first leads and the one or more second leads.

13. The molded semiconductor package of claim 12 wherein the clip frame further comprises a second metal clip attached to a control terminal of the second side of the semiconductor die and a third lead extending outwardly from the second metal clip, and wherein the third lead is exposed to one side of the mold compound and does not vertically overlap the one or more first leads.

14. The molded semiconductor package of claim 12, wherein the one or more first leads protrude from a first side of the mold compound, and wherein the one or more second leads protrude from a second side of the mold compound different from the first side.

15. The molded semiconductor package of claim 14 wherein portions of the one or more first leads protruding from the first side of the mold compound and portions of the one or more second leads protruding from the second side of the mold compound are at least partially plated to form wettable lead surfaces on different sides of the mold compound.

16. The molded semiconductor package of claim 12 wherein the first metal clip is bent at least two different places within the molding compound.

17. The molded semiconductor package of claim 12 wherein the semiconductor die is a power transistor die, wherein the power terminal of the first side of the power semiconductor die is a drain or collector terminal, wherein the power terminal of the second side of the power semiconductor die is a source or emitter terminal, and wherein the power semiconductor die is attached to the die pad in a drain-down or collector-down configuration.

18. The molded semiconductor package of claim 12 wherein the semiconductor die is a power transistor die, wherein the power terminal of the first side of the power semiconductor die is a source or emitter terminal, wherein the power terminal of the second side of the power semiconductor die is a drain terminal, and wherein the power semiconductor die is attached to the die pad in a source-down or emitter-down configuration.

19. The molded semiconductor package of claim 18 wherein the leadframe comprises additional leads attached to control terminals at the first side of the power semiconductor die, and wherein the additional leads are exposed to the same side of the molding compound as the one or more first leads.

20. The molded semiconductor package of claim 12 wherein the die pad and the first metal clip are bent in the same direction, and wherein the first metal clip is bent to a lesser extent than the die pad such that the one or more first leads integrally formed with the die pad and the one or more second leads integrally formed with the first metal clip terminate in the same plane and are configured for surface mounting on a first side of the molded semiconductor package.

21. The molded semiconductor package of claim 12 wherein the die pad is at least partially uncovered by the molding compound on a second side of the molded semiconductor package opposite the first side of the molded semiconductor package to provide a heat dissipation path on an opposite side of the molded semiconductor package configured for surface mounting.

22. A method of manufacturing a molded semiconductor package, the method comprising:

providing a leadframe panel comprising a plurality of unitary leadframes connected to one another, each unitary leadframe comprising a die pad and one or more first leads integrally formed with and extending outwardly from the die pad in a first direction, the die pad and the one or more first leads being attached to an outer periphery of the unitary leadframe;

attaching a separate semiconductor die to each of the die pads at a first side, each semiconductor die including a power supply terminal at a second side opposite the first side;

aligning a clip frame panel with the lead frame panel, the clip frame panel including a plurality of unit clip frames connected to each other, each unit clip frame including a first pre-bent metal clip vertically aligned with a corresponding power terminal of the second side of one of the semiconductor dies and one or more second leads integrally formed with the first pre-bent metal clip, extending outwardly from the first pre-bent metal clip in a second direction different from the first direction and attached to an outer periphery of the unit clip frame;

attaching each first pre-bent metal clip to the power terminals of the second side of a corresponding semiconductor die;

embedding the semiconductor die in a mold compound such that each of the one or more first leads and each of the one or more second leads protrude from the mold compound in a substantially planar direction and do not vertically overlap each other; and

separating each of the one or more first leads from the outer periphery of a corresponding unit leadframe and each of the one or more second leads from the outer periphery of a corresponding unit clip frame outside of the mold compound.

Background

The power semiconductor package includes a power semiconductor die embedded in a molding compound. Electrical connections in the mold compound are formed between the terminals of the power semiconductor die and the package leads. The leads are part of a leadframe to which the power semiconductor die is attached. Some types of power semiconductor packages use metal clips to connect the source terminal on the top side of the power semiconductor die to the lead post of the leadframe. The clamp assembly typically includes two parts: the metal clip itself and the lead post. The two parts are typically soldered together, thus requiring a pad area for attaching the clip to the lead frame. The clip pad area consumes space on the lead frame because attaching the clip to the lead frame is done by soldering, diffusion soldering, or similar processes. The contact area required by the clip cannot be used for additional die area in the package. Also, the clip attachment process is done in a serial fashion, and is therefore slow and costly. Furthermore, the gate terminal of the power semiconductor is typically contacted by bonding wires, which requires additional process steps with additional equipment investment and different requirements on the surfaces on the die and the leadframe.

Accordingly, there is a need for an improved contact structure for a power semiconductor package.

Disclosure of Invention

According to an embodiment of a method of manufacturing a molded semiconductor package, the method comprises: providing a lead frame including a die pad and one or more first leads integrally formed with and extending outwardly from the die pad in a first direction, the die pad and the one or more first leads being attached to an outer periphery of the lead frame; attaching a first side of a semiconductor die to the die pad; aligning a clip frame with the lead frame such that a first pre-bent metal clip of the clip frame is vertically aligned with power terminals of a second side of the semiconductor die opposite the first side, the clip frame further including one or more second leads integrally formed with the first pre-bent metal clip, extending outwardly from the first pre-bent metal clip in a second direction different from the first direction and attached to an outer perimeter of the clip frame; attaching the first pre-bent metal clip to the power terminals of the second side of the semiconductor die; embedding the semiconductor die in a mold compound such that the one or more first leads and the one or more second leads protrude from the mold compound in a substantially planar direction and do not vertically overlap each other; and separating the one or more first leads from the outer periphery of the leadframe and the one or more second leads from the outer periphery of the clip frame outside of the mold compound.

Separating the one or more first leads from the outer perimeter of the leadframe and the one or more second leads from the outer perimeter of the clip frame outside of the mold compound may include: stamping the one or more first leads and the one or more second leads on an outside of the mold compound, or cutting the one or more first leads and the one or more second leads on an outside of the mold compound.

Separately or in combination, the method may further comprise: attaching a second pre-bent metal clip of the clip frame to a control terminal of the second side of the semiconductor die, wherein the clip frame further comprises a third lead extending outwardly from the second pre-bent metal clip and attached to the outer perimeter of the clip frame, wherein, after embedding the semiconductor die in the mold compound, the third lead protrudes from the mold compound and does not vertically overlap the one or more first leads.

Separately or in combination, the method may further comprise: separating the third lead from the outer periphery of the clip frame outside of the mold compound via the same stamping process used to separate the one or more first leads from the outer periphery of the leadframe and the one or more second leads from the outer periphery of the clip frame.

Individually or in combination, the one or more first leads may protrude from a first side of the mold compound after being separated from the outer periphery of the leadframe, and the one or more second leads may protrude from a second side of the mold compound different from the first side after being separated from the outer periphery of the clip frame.

Separately or in combination, the method may further comprise: plating portions of the one or more first leads protruding from the first side of the mold compound and portions of the one or more second leads protruding from the second side of the mold compound to form wettable lead surfaces on different sides of the mold compound.

The lead frame may be unbent, alone or in combination.

Individually or in combination, the clip frame may include alignment features to assist in alignment of the clip frame with the lead frame.

Separately or in combination, the clip frame may be stacked on top of the leadframe in the area of the mold runners used during embedding of the semiconductor die in the molding compound.

Separately or in combination, the method may further comprise: pressing the clip frame against the lead frame to provide a tight seal during embedding of the semiconductor die in the molding compound.

According to an embodiment of a molded semiconductor package, the molded semiconductor package may comprise: a lead frame including a die pad and one or more first leads integrally formed with the die pad and extending outwardly from the die pad in a first direction; a semiconductor die attached to the die pad at a first side of the semiconductor die; a clip frame including a first metal clip attached to power terminals of a second side of the semiconductor die opposite the first side and one or more second leads integrally formed with the first metal clip and extending outwardly from the first metal clip in a second direction different from the first direction; and a molding compound embedded in the semiconductor die, wherein the one or more first leads and the one or more second leads are exposed to different sides of the molding compound and do not vertically overlap each other, wherein the first metal clip transitions from a first level above the power terminals of the second side of the semiconductor die to a second level in the same plane as the one or more first leads and the one or more second leads within the molding compound.

The clip frame may further include, alone or in combination, a second metal clip attached to a control terminal of the second side of the semiconductor die, and a third lead extending outward from the second metal clip, and the third lead may be exposed to one side of the mold compound and not vertically overlapping the one or more first leads.

Individually or in combination, the one or more first leads may protrude from a first side of the mold compound, and the one or more second leads may protrude from a second side of the mold compound different from the first side.

Separately or in combination, at least partially plating portions of the one or more first leads protruding from the first side of the mold compound and portions of the one or more second leads protruding from the second side of the mold compound to form wettable lead surfaces on different sides of the mold compound.

The first metal clip may be bent at least two different places within the molding compound, either alone or in combination.

Individually or in combination, the semiconductor die may be a power transistor die, the power terminal of the first side of the power semiconductor die may be a drain or collector terminal, the power terminal of the second side of the power semiconductor die may be a source or emitter terminal, and the power semiconductor die may be attached to the die pad in a drain-down or collector-down configuration.

Individually or in combination, the semiconductor die may be a power transistor die, the power terminal of the first side of the power semiconductor die may be a source or emitter terminal, the power terminal of the second side of the power semiconductor die may be a drain terminal, and the power semiconductor die may be attached to the die pad in a source-down or emitter-down configuration.

Separately or in combination, the leadframe may include additional leads attached to control terminals at the first side of the power semiconductor die, and the additional leads may be exposed to the same side of the mold compound as the one or more first leads.

Individually or in combination, the die pad and the first metal clip are bent in the same direction, and the first metal clip is bent to a lesser extent than the die pad, such that the one or more first leads integrally formed with the die pad and the one or more second leads integrally formed with the first metal clip terminate in the same plane and are configured for surface mounting on a first side of the molded semiconductor package.

Individually or in combination, the die pads are at least partially uncovered by the molding compound on a second side of the molded semiconductor package opposite the first side of the molded semiconductor package to provide a heat dissipation path on an opposite side of the molded semiconductor package configured for surface mounting.

According to an embodiment of a method of manufacturing a molded semiconductor package, the method comprises: providing a leadframe panel comprising a plurality of unitary leadframes connected to one another, each unitary leadframe comprising a die pad and one or more first leads integrally formed with and extending outwardly from the die pad in a first direction, the die pad and the one or more first leads being attached to an outer periphery of the unitary leadframe; attaching a separate semiconductor die to each of the die pads at a first side, each semiconductor die including a power supply terminal at a second side opposite the first side; aligning a clip frame panel with the lead frame panel, the clip frame panel including a plurality of unit clip frames connected to each other, each unit clip frame including a first pre-bent metal clip vertically aligned with a corresponding power terminal of the second side of one of the semiconductor dies and one or more second leads integrally formed with the first pre-bent metal clip, extending outwardly from the first pre-bent metal clip in a second direction different from the first direction and attached to an outer periphery of the unit clip frame; attaching each first pre-bent metal clip to the power terminals of the second side of a corresponding semiconductor die; embedding the semiconductor die in a mold compound such that each of the one or more first leads and each of the one or more second leads protrude from the mold compound in a substantially planar direction and do not vertically overlap each other; and separating each of the one or more first leads from the outer periphery of a corresponding unit lead frame and each of the one or more second leads from the outer periphery of a corresponding unit clip frame outside of the mold compound.

Those skilled in the art will recognize additional features and advantages upon reading the following detailed description, and upon viewing the accompanying drawings.