Semiconductor mold compound transfer system and associated methods

Patent metadata

Field	Value
Publication number	US-10199299-B1
Application number	US-201715670351-A
Country	US
Kind code	B1
Filing date	Aug 7, 2017
Priority date	Aug 7, 2017
Publication date	Feb 5, 2019
Grant date	Feb 5, 2019

Abstract

Mold compound transfer systems and methods for making mold compound transfer systems are disclosed herein. A method configured in accordance with a particular embodiment includes placing a sheet mold compound in a containment area defined by a tray cover, and dispensing a granular mold compound over the sheet mold compound. The sheet mold compound can have a first density and the overall granular mold compound can have a second density less than the first density. The method further comprises transferring the solid sheet carrying the dispensed grains to a molding machine without using a release film.

First claim

We claim:

1. A mold compound transfer system, comprising:
a tray cover defining a containment area;
a sheet mold compound spanning at least substantially across the containment area defined by the tray cover; and
a granular mold compound comprising a plurality of individual grains carried by the sheet mold compound and spanning at least across a majority of the sheet mold compound,
wherein the sheet mold compound has a first thickness and the granular mold compound has a second thickness less than the first thickness.

2. The system of claim 1 wherein a ratio by weight of the sheet mold compound to the granular mold compound is between about 3:1 and about 5:1.

3. The system of claim 1 wherein a ratio by weight of the sheet mold compound to the granular mold compound is about 4:1.

4. The system of claim 1 wherein the sheet mold compound and the individual grains have the same chemical composition.

5. The system of claim 1 wherein the sheet mold compound and the individual grains each include a resin material.

6. The system of claim 1 wherein the transfer system lacks a release film.

7. A mold compound transfer system, comprising:
a tray cover defining a containment area;
a sheet mold compound spanning at least substantially across the containment area defined by the tray cover; and
a granular mold compound comprising a plurality of individual grains carried by the sheet mold compound and spanning at least across a majority of the sheet mold compound,
wherein the combined thickness of the sheet mold compound and the granular mold compound is greater than or equal to 5 millimeters.

8. A method of transferring a mold compound without using a release film, the method comprising:
placing a solid sheet having a first weight in a containment area, wherein the solid sheet comprises a first mold material;
dispensing grains over the solid sheet such that the solid sheet carries the grains, wherein the grains have a second weight less than the first weight, and wherein the grains comprise a second mold material; and
transferring the solid sheet carrying the dispensed grains to a molding machine,
wherein the solid sheet has a first thickness and the dispensed grains have a second thickness less than or equal to the first thickness.

9. The method of claim 8 wherein transferring includes transferring the solid sheet carrying the dispensed grains without using a release film.

10. The method of claim 8 wherein the first mold material and the second mold material each include a flowable resin.

11. The method of claim 8 wherein the first mold material and the second mold material have the same chemical composition.

12. The method of claim 8 wherein the first weight is approximately three to five times greater than the second weight.

13. The method of claim 8 wherein the combined first and second thicknesses are about 5 millimeters or greater.

14. A method of transferring a mold compound without using a release film, the method comprising:
placing a solid sheet having a first weight in a containment area, wherein the solid sheet comprises a first mold material;
dispensing grains over the solid sheet such that the solid sheet carries the grains, wherein the grains have a second weight less than the first weight, and wherein the grains comprise a second mold material;
transferring the solid sheet carrying the dispensed grains to a molding machine, wherein transferring includes placing the solid sheet carrying the dispensed grains in the molding machine; and
reflowing the solid sheet and dispensed grains to form a uniform mold material over the wafer.

15. A method of forming a molded semiconductor wafer, the method comprising:
placing a solid sheet of first mold compound in a containment area;
placing grains of second mold compound over the solid sheet such that the grains are carried by the solid sheet;
pressing the grains of the second mold compound in a molding machine to form a hybrid mold compound including the solid sheet of first mold compound and a pressed layer of the second mold compound; and
based at least in part on a first weight of the first mold compound, determining a second weight of the second mold compound to be placed over the first mold compound.

16. The method of claim 15 wherein the hybrid mold compound defines an encapsulant over one or more dies.

17. The method of claim 15 , further comprising before pressing the grains, transferring the solid sheet to the molding machine without using a release film.

18. The method of claim 15 wherein the solid sheet of first mold compound has a first density and the grains of the second mold compound have a second density less than the first density.

Assignees

• Micron Technology Inc

Inventors

• Koh Kean Tat
• Choong Lien Wah

Classifications

• H10W74/111

  the semiconductor body being completely enclosed · CPC title

• H10W74/019

  using temporary auxiliary substrates (H10W74/017 takes precedence) · CPC title

• H10W74/016

  using moulds · CPC title

• H10W74/10

  characterised by their shape or disposition · CPC title

• H10W74/01 Primary

  Manufacture or treatment · CPC title