Semiconductor apparatus manufacturing method

Abstract

The semiconductor apparatus includes a semiconductor chip, and a source electrode and a gate electrode which are formed on the semiconductor chip and electrically connected with a lead frame. The source electrode is electrically connected with the lead frame by being laser-welded with a thin-film shaped connecting portion formed at an end of the lead frame. This enables the provision of a semiconductor apparatus with enhanced productivity and yields which exhibits high electrical operability and reliability.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, advantages and features of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:

FIG. 1A is a perspective view of a semiconductor apparatus according to an embodiment of the present invention;

FIGS. 1B and 1C are cross-sectional views along line IB-IB in FIG. 1A;

FIG. 2 is a cross-sectional view along line II-II in FIG. 1A, showing a semiconductor apparatus according to the embodiment of the present invention;

FIGS. 3A and 3B are views to describe a semiconductor apparatus manufacturing method according to the embodiment of the present invention;

FIGS. 4A and 4B are views showing another example of a semiconductor apparatus according to the embodiment of the present invention, which are a perspective view and a cross-sectional view when using a ribbon-like connecting member, respectively;

FIGS. 5A and 5B are views showing another example of a semiconductor apparatus according to the embodiment of the present invention, which are a perspective view and a cross-sectional view when using a wire, respectively;

FIGS. 6A and 6B are a view showing a connecting portion after dimpling and a view showing the step of laser welding using the connecting portion after dimpling, respectively;

FIG. 7 is a view showing a lead frame in another example of a semiconductor apparatus according to the embodiment of the present invention;

FIG. 8 is a bird's-eye view of a semiconductor apparatus (Small Out-line Package (SOP)—8 packages) disclosed in Oono; and

FIGS. 9A and 9B are cross sectional views along lines IVA-IVA and IVB-IVB, respectively, in FIG. 7, showing the semiconductor apparatus disclosed in Oono.

Claims

1. A manufacturing method of a semiconductor apparatus, comprising: forming a thin-film shaped connecting area on a connecting portion electrically connected with an external lead; andwelding the connecting area of the connecting portion and an electrode on a semiconductor chip by laser welding.

2. The manufacturing method of a semiconductor apparatus according to claim 1, wherein a thickness ratio of the connecting area with respect to the electrode is in a range of 5 to 30.

3. The manufacturing method of a semiconductor apparatus according to claim 2, wherein a contact area of the connecting portion with the electrode is determined based on a thickness of the connecting portion and desired current and resistance values.

4. The manufacturing method of a semiconductor apparatus according to claim 1, wherein the external lead includes the connecting portion at one end of the external lead.

5. The manufacturing method of a semiconductor apparatus according to claim 1, wherein a wire having at one end a connecting portion including the connecting area is used as a connecting member to electrically connect with an external lead by laser-welding the connecting portion of the wire and the electrode.

6. The manufacturing method of a semiconductor apparatus according to claim 1, wherein a thin-film conductive ribbon is used as a connecting member to electrically connect with an external lead by laser-welding the connecting portion of the thin-film conductive ribbon and the electrode.

7. The manufacturing method of a semiconductor apparatus according to claim 1, wherein the connecting portion includes a dimple in the connecting area, and the dimple is laser-welded for connecting the connecting portion and the electrode.

8. The manufacturing method of a semiconductor apparatus according to claim 5, wherein another end of the connecting member and the external lead are laser-welded.

9. The manufacturing method of a semiconductor apparatus according to claim 1, further comprising: a nonconductive cover layer in close proximity to the electrode,wherein an area of the connecting portion is larger than an exposed area of the electrode from the nonconductive cover layer.

10. The manufacturing method of a semiconductor apparatus according to claim 1, wherein laser-welding is performed by applying laser light to a plurality of positions on the connecting portion.

11. The manufacturing method of a semiconductor apparatus according to claim 1, wherein the electrode is formed of a metal containing at least one of aluminum and copper.

12. The manufacturing method of a semiconductor apparatus according to claim 1, wherein the connecting portion is made of a material containing at least one metal selected from the group consisting of aluminum, copper, gold, silver, palladium and nickel.

13. The manufacturing method of a semiconductor apparatus according to claim 1, wherein the connecting portion is formed of nickel-plated copper or copper alloy.

14. The manufacturing method of a semiconductor apparatus according to claim 1, comprising: an opening formed in the connecting area of the connecting portion, anda bonding material filled in the opening in the connecting area of the connecting portion,wherein laser light is applied to an area including the bonding material to laser-weld the bonding material and the electrode.

15. The manufacturing method of a semiconductor apparatus according to claim 14, wherein a melting point of the bonding material is lower than a melting point of a material of the connecting area of the connecting portion.

16. The manufacturing method of a semiconductor apparatus according to claim 14, wherein the bonding material contains aluminum and the material of the connecting area of the connecting portion contains copper.

17. The manufacturing method of a semiconductor apparatus according to claim 1, wherein the semiconductor chip is mounted on a die pad of a first lead frame, andthe external lead is formed on a second lead frame different from the first lead frame.

18. The manufacturing method of a semiconductor apparatus according to claim 18, wherein the semiconductor chip includes a transistor including a gate electrode and a source electrode on a top surface and a drain electrode on a bottom surface,a drain lead is integrated with the die pad, andthe external lead includes a source lead electrically connected with the source electrode.

19. The manufacturing method of a semiconductor apparatus according to claim 18, wherein the transistor includes a metal-oxide-semiconductor (MOS) transistor.