Electronics Assembly Knowledge, Vision & Wisdom
Investigation of Copper Sinter Material for Die Attach
Investigation of Copper Sinter Material for Die Attach
3 different copper powders were tested for their feasibility to use as die attach material for pressure sintering process without prior treatment with reducing agents such as hydrogen or formic acid.
Materials Tech

Materials Tech programs cover topics including:
Adhesives, Chemicals, Cleaning Solutions, Coatings, Components, Design, Embedded Technology, Fasteners, Finishes, Flex Circuits, Flip Chip, Fluxes, PC Fab, Solders, Solder Masks, Solder Paste and more.
Submit A Comment
Comments are reviewed prior to posting. You must include your full name to have your comments posted. We will not post your email address.

Your Name


Your Company


Your E-mail


Your Country


Your Comment



Authored By:
Christian Schwarzer, Michael Schnepf, Michael Kaloudis
UAS Aschaffenburg, Aschaffenburg, Germany

Ly May Chew
Heraeus Deutschland GmbH & Co.KG, Hanau, Germany

Thomas Stoll, Jörg Franke
Heraeus Deutschland GmbH & Co.KG, Hanau, Germany

Summary
Die attach on power semiconductor using lead-free technology has attracted considerable interest. Silver sintering has been considered as one of the most promising lead-free die attach solutions over the past years. Pressure silver sintering by far offers superior thermal and electrical conductivity properties which enables power electronics applications to operate at higher temperature. Although silver sintering is a promising technology, the high cost of silver increases the manufacturing cost and consequently impedes the wide adoption of this technology.

Copper is commonly used in the electronics industry mainly due to its unique properties such as good thermal and electrical conductivity. Hence, it is not surprising that recently there are several academic and industrial researches using copper as an alternative die attach material for sintering process. Nevertheless, copper sintering is usually requires an additional reducing process using hazardous gases such as hydrogen and formic acid to prevent copper oxidation as well as to increase the bonding strength.

In this study, we develop a safe-to-use micro-copper sinter paste for pressure sintering under inert atmosphere.

Conclusions
In summary, 3 different copper powders were tested for their feasibility to use as die attach material for pressure sintering process without prior treatment with reducing agents such as hydrogen or formic acid. The results illustrate that spherical-shaped copper powder was not able to create copper joints by pressure sintering process at 573 K with a pressure of 10 MPa for 3 min under N2 atmosphere. In contrast, it was possible to create copper joints by pressure sintering process using flake-shaped copper powders. The shear strength and the failure mode results show that copper flake 2 created stronger copper joint than copper flake 1. This study demonstrate that it is feasible to use copper paste as interconnect material for die attach application by pressure sintering process, even without reducing agents.

Initially Published in the SMTA Proceedings

Comments
No comments have been submitted to date.
Free Newsletter Subscription
Every issue of the Circuit Insight email newsletter will bring you the latest information on the issues affecting you and your company.

Insert Your Email Address

Directory Search


Program Search
Related Programs
bullet Trends for Printing Ultra Miniature Chips
bullet Impractical Stencil Aperture Designs to Enable M0201 Assembly
bullet Void Reduction Method for BTC Using Exposed Via in Pad
bullet Selecting Stencil Technologies to Optimize Print Performance
bullet Strain Measuring Technology in Board Level Assembly Process
bullet Impact of Alloy Composition on Shear Strength for Low Temperature Lead Free Alloys
bullet Stencil Printing for Challenging Heterogeneous Assembly Applications
bullet Qualitative Model Describing Hot Tear Above VIPPO and Other Design Elements
bullet FEA and Analysis for BGA-CGA Assemblies Under Thermal Cycling
bullet How Many Fiducials Per Stencil
More Related Programs