SYSTEM AND METHOD FOR ADHERING LARGE SEMICONDUCTOR APPLICATIONS TO PCB

Abstract

A system and method for reducing power losses in a semiconductor device, especially a photovoltaic cell. The system includes a semiconductor device that includes at least one conductive crossbar with a pattern and a substrate that includes similarly patterned supplemental crossbars. The crossbars are coated with the adhesive solder paste and superimposed on each other. The adhesive solder paste when heated forms a conductive path between the crossbars and the supplemental crossbars while simultaneously adhering the crossbars and the supplemental crossbars together. Thereafter an under-fill material is deposited into voids defined by gaps between the semiconductor device and the backplate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example and not limitation in the figures of the accompanying drawings, and in which:

FIG. 1 is a photovoltaic silicon wafer in accordance with the prior art;

FIG. 2 is a plan view of a substrate including a plurality of vias for applying under-fill to a photovoltaic cell, in accordance with the preferred embodiment of the present invention;

FIG. 3 is a cross section of a solar panel including a photovoltaic cell and substrate before being subjected to a solder reflow oven, in accordance with the preferred embodiment of the present invention;

FIG. 4 is a cross section of a solar panel including a photovoltaic cell and substrate after being subjected to a solder reflow oven, in accordance with the preferred embodiment of the present invention;

FIG. 5 is a cross section of a solar panel including a plurality of photovoltaic cells and substrate after being subjected to a solder reflow oven, in accordance with the preferred embodiment of the present invention; and

FIGS. 6A and 6B are cross sections of a solar panel assembly in a double chamber vacuum before and after a cover is applied, respectively, in accordance with the preferred embodiment.

Claims

1. A method of bonding a semiconductor device to a circuit board, the method comprising: assembling the semiconductor device and circuit board with a solder paste selectively interposed between the semiconductor device and circuit board, wherein the solder paste comprises an adhesive and a plurality of conductive metal particles;curing the solder paste sufficient to induce an adhesive force of at least 3 pounds per square inch; andsintering the conductive metal particles before the adhesive solidifies to electrically connect the semiconductor device and circuit board.

2. The method of claim 1, wherein the semiconductor device is a photovoltaic cell.

3. The method of claim 1, wherein the semiconductor device is a computer processor.

4. The method of claim 1, wherein the circuit board is a printed circuit board.

5. The method of claim 1, wherein the adhesive comprises an epoxy.

6. The method of claim 1, wherein the adhesive is selected from the group comprising: a meltable plastic, a urethane, an epoxy, a thermosetting polymer resin, a polyimide siloxane resin, a styrene allyl alcohol resin, a phenoxy polymer, or a combination thereof.

7. The method of claim 1, wherein the plurality of conductive metal particles comprise copper core, tin alloy coated metal particles.

8. The method of claim 7, wherein the conductive metal particles comprise substantially spherical particles.

9. The method of claim 1, wherein the plurality of conductive metal particles comprise: copper; aluminum; silver; gold, or a combination thereof.

10. The method of claim 1, wherein the plurality of conductive metal particles are coated with an alloy of two or more of the following metals: tin, bismuth, lead, silver, gold, indium, and antimony.

11. The method of claim 1, wherein the conductive metal particles are coated with tin, and a solder flux.

12. The method of claim 1, wherein the solder paste adhesive force of at least 3 pounds per square inch exists prior to the sintering step.

13. A method of bonding a semiconductor device to a circuit board, the method comprising: applying an adhesive solder paste to a semiconductor device or circuit board, wherein the adhesive solder paste comprises a plurality of conductive metal particles;assembling the semiconductor device and circuit board;heating the assembly of semiconductor device and circuit board sufficient to sinter the conductive metal particles to electrically connect the semiconductor device and circuit board.

14. The method of claim 13, wherein the adhesive solder paste comprises an epoxy.

15. The method of claim 14, wherein the method further comprises: heating the epoxy to initiate curing prior to the step of applying the adhesive solder paste to the semiconductor device or circuit board.

16. The method of claim 15, wherein the semiconductor device is a photovoltaic cell, and the conductive metal in the adhesive solder paste is a plurality of substantially spherical particles coated with lead free-tin alloy.

17. The method of claim 16, wherein the adhesive has an adhesive force of at least 2 pounds per square inch prior to the heating step.