Method for fabricating a packaging device for semiconductor die and semiconductor device incorporating same
View Patent ↗A substantially planar substrate having opposed major surfaces is provided. The substrate includes a through hole that extends between the major surfaces. The through hole is filled with a conductive interconnecting element. A conductive mounting pad and a conductive connecting pad are formed on different ones of the major surfaces in electrical contact with the conductive interconnecting element. The packaging device formed by the method has a volume that is only a few times that of the semiconductor die and can be fabricated from materials that can withstand high-temperature die attach processes. The packaging device can be configured as the only packaging device used in the semiconductor device or as a submount for a semiconductor die that requires a high-temperature die attach process.
1. A method for fabricating a device, the method comprising:
providing a substantially planar substrate having opposed major surfaces, the substrate comprising a through hole extending between the major surfaces;
providing a slug of an electrically conductive material;
squeezing the slug into the through hole whereby the slug is retained in the through hole by friction; and
forming an electrically conductive die mounting pad and an electrically conductive connecting pad on different ones of the major surfaces each pad being in electrical contact with the slug.
2. The method of claim 1 , additionally comprising attaching a semiconductor die to the die mounting pad.
3. The method of claim 2 , additionally comprising:
providing a packaging device, the packaging device including a conductive mounting surface; and
mounting the device in the packaging device, the mounting comprising attaching the connecting pad to the conductive mounting surface of the packaging device.
4. The method of claim 2 , in which:
providing a substrate comprises providing a wafer of which the substrate constitutes part; and
the method additionally comprises, after the filling, the forming and the attaching, singulating the wafer into individual devices.
5. The method of claim 4 , additionally comprising performing electrical testing prior to the singulating.
6. The method of claim 4 , additionally comprising performing electro-optical testing prior to the singulating.
7. The method of claim 2 , additionally comprising encapsulating the semiconductor die and at least a portion of the major surfaces of the substrate on which the die mounting pad is located.
8. The method of claim 1 , wherein the slug has a diameter that is smaller than a diameter of the through hole, the smaller diameter selected to provide a friction fit between the slug and the through hole.
9. The method of claim 8 , wherein the ends of the slug are located approximately flush with the opposed major surfaces.
10. The method of claim 1 , wherein the slug comprises tungsten.
11. The method of claim 1 , wherein the slug occupies at least a portion of a volume of the through hole.
12. The method of claim 11 , wherein an adhesive is used to hold the slug in the through hole.