Methods of manufacturing stacked semiconductor die assemblies with high efficiency thermal paths

Patent metadata

Field	Value
Publication number	US-2016013173-A1
Application number	US-201414330805-A
Country	US
Kind code	A1
Filing date	Jul 14, 2014
Priority date	Jul 14, 2014
Publication date	Jan 14, 2016
Grant date	—

Abstract

Method for packaging a semiconductor die assemblies. In one embodiment, a method is directed to packaging a semiconductor die assembly having a first die and a plurality of second dies arranged in a stack over the first die, wherein the first die has a peripheral region extending laterally outward from the stack of second dies. The method can comprise coupling a thermal transfer structure to the peripheral region of the first die and flowing an underfill material between the second dies. The underfill material is flowed after coupling the thermal transfer structure to the peripheral region of the first die such that the thermal transfer structure limits lateral flow of the underfill material.

First claim

1 . A method for packaging a semiconductor die assembly, the method comprising:
providing, a first die and a plurality of second dies arranged in a stack and attached to the first die, wherein the first die has a peripheral region extending laterally outward from the stack of second dies; positioning at least a portion of a thermal transfer structure at the peripheral region of the first die, wherein the thermal transfer structure comprises a thermally conductive material; and flowing an underfill material between the second dies after positioning the thermal transfer structure on the peripheral region of the first die, wherein the underfill material has a fillet extending laterally from the stack of second dies, wherein the lateral extension of the underfill material is limited by the thermal transfer structure, and wherein the fillet has an upper surface that is curved.

2 . The method of claim 1 wherein:
the thermal transfer structure comprises a first portion having a foundation configured to extend at least around a portion of the first die and a shoulder configured to be positioned over the peripheral region of the first die; and
positioning at least a portion of the thermal transfer structure on the peripheral region of the first die comprises attaching the foundation to a package support substrate and the shoulder to the peripheral region of the first die with a thermal interface material between the shoulder and the peripheral region of the first die.

3 . The method of claim 1 wherein:
the thermal transfer structure comprises a first portion having (a) a foundation configured to extend at least around a portion of the first die and be attached to a package support substrate and (b) a shoulder configured to be attached to an upper surface of the peripheral region;
positioning at least a portion of the thermal transfer structure on the peripheral region of the first die comprises attaching the foundation to a package support substrate and the shoulder to the peripheral region of the first die with a thermal interface material between the shoulder and the peripheral region of the first die; and
the method further comprises attaching a second portion of the thermal transfer structure to the first portion of the thermal transfer structure after flowing the underfill material, wherein first and second portions of the thermal transfer structure form a casing having a cavity in which the first die and the stack of second dies are positioned.

4 . The method of claim 3 wherein the first portion of the thermal transfer structure comprises a dam member and the second portion of the thermal transfer member comprises a cover.

5 . The method of claim 4 wherein the cover has a top and a sidewall pendent from the top, and the sidewall is attached to the dam member.

6 . The method of claim 4 wherein the dam member comprises a ring that surrounds the first die.

7 . The method of claim 3 wherein the first portion of the thermal transfer structure comprises a sidewall extending to a height of an uppermost second die and the second portion of the thermal transfer member comprises a top.

8 . The method of claim 1 wherein:
the thermal transfer structure comprises a sidewall, a top integrally formed with the sidewall, a cavity formed by the sidewall and the top, and an inlet;
the sidewall has a foundation configured to surround at least a portion of the first die and a shoulder configured to be positioned over the peripheral region of the first die;
positioning the thermal transfer structure on the peripheral region of the first die comprises attaching the foundation to a package support substrate and attaching the shoulder to the peripheral region of the die, wherein the stack of second dies is in the cavity; and
flowing the underfill material between the second dies comprises injecting the underfill material into the cavity via the inlet.

9 . The method of claim 8 wherein the inlet is a first passageway through a lower area of the sidewall and the outlet is a second passageway through an upper area of the sidewall.

10 . The method of claim 8 wherein the inlet is a first passageway through the top and the outlet is a second passageway through the top.

11 . The method of claim 1 wherein:
the thermal transfer structure comprises an inner casing having a first support and a top extending from the first support;
positioning at least a portion of the thermal transfer structure on the peripheral region of the first die comprises attaching the first support to the peripheral region of the die, wherein the stack of second dies is under the top of the casing; and
flowing the underfill material between the second dies comprises flowing the underfill material between the stack of second dies and the inner casing.

12 . The method of claim 11 wherein the inner casing further comprises a second support and the top has one end attached to the first support and another end attached to the second support, and wherein positioning the thermal transfer structure on the peripheral region of the first die comprises attaching the first and second supports to the peripheral region of the first die.

13 . The method of claim 11 wherein the thermal transfer structure further comprises an outer casing having a cavity, and the method further includes attaching the outer casing to a package support substrate and the inner casing such that the inner casing is received within the cavity of the outer casing.

14 . The method of claim 1 wherein the thermal transfer structure comprises a metal casing having a cavity, and wherein positioning at least a portion of the thermal transfer structure at the peripheral region of the first die comprises attaching a lower portion of the metal casing to the peripheral region of the first die with a thermal interface material such that the stack of second dies is in the cavity of the metal casing.

15 . The method of claim 14 wherein:
the metal casing comprises a metal ring and a metal cover;
positioning at least a portion of the thermal transfer structure at the peripheral region of the first die comprises attaching the ring to the peripheral region; and
the method further comprises attaching the metal cover to the ring after flowing the underfill material such that the stack of second dies is encased within the metal ring and the metal cover.

16 . The method of claim 14 wherein:
the metal casing comprises a metal sidewall, a metal top that together with the metal sidewall forms the cavity, and an inlet;
positioning at least a portion of the thermal transfer structure at the peripheral region of the first die comprises attaching the sidewall to the peripheral region; and
flowing an underfill material between the second dies comprises injecting the underfill material into the cavity via the inlet.

17 . The method of claim 1 , further comprising instilling a dielectric liquid within the casing after flowing the underfill material, wherein the dielectric liquid is thermally conductive.

18 . The method of claim 17 , further comprising at least partially curing the dielectric liquid within the cavity.

19 . A method for packaging a semiconductor die assembly, the method comprising:
providing a first die and a plurality of second dies arranged in a stack over the first die, wherein the first die has a peripheral region extending laterally outward from the stack of second dies; coupling a thermal transfer structure to the peripheral region of the first die; and flowing an underfill material betwee

Assignees

• Micron Technology Inc

Inventors

• Vadhavkar Sameer S
• Li Xiao
• Groothuis Steven K
• Li Jian
• Gandhi Jaspreet S
• Derderian James M
• Hembree David R

Classifications

• H10W90/736

  between a chip and a stacked lead frame, conducting package substrate or heat sink · CPC title

• H10W90/734

  between a chip and a stacked insulating package substrate, interposer or RDL · CPC title

• H10W90/732

  between stacked chips · CPC title

• H10W90/724

  between a chip and a stacked insulating package substrate, interposer or RDL · CPC title

• H10W90/722

  between stacked chips · CPC title