Gold-to-gold TAB ILB with a laser

Author

Spletter, Phil

Author_Institution

Microelectron. & Comput. Technol. Corp., Austin, TX, USA

Volume

17

Issue

4

fYear

1994

fDate

11/1/1994 12:00:00 AM

Firstpage

554

Lastpage

558

Abstract

A new method for bonding gold plated TAB leads to gold bumps is presented. This method uses a frequency doubled Nd:YAG laser which provides energy in both the visible (0.533 μm) and near IR (1.064 μm) spectra. This combination of wavelengths overcomes the difficulty of bonding gold with only 1.064 μm radiation where 98% of the radiation is reflected. In the method presented in this paper, 0.533-μm radiation, of which 25-50% is absorbed by gold, is used to heat the gold which becomes more absorptive to the 1.064-μm radiation that is used to form the bond. Bonding experiments were conducted and samples were exposed to environmental testing. While there were initial bond failures, 85% of the bonds did not degrade during environmental exposure indicating the potential for the process

Keywords

environmental testing; failure analysis; gold; integrated circuit reliability; laser beam applications; lead bonding; tape automated bonding; 0.533 micron; 1.064 micron; Au; Au bumps; Au plated TAB leads; Au-to-Au TAB ILB; YAG:Nd; YAl5O12:Nd; bond failures; environmental testing; frequency doubled Nd:YAG laser; inner lead bonding; Absorption; Bonding; Copper; Degradation; Frequency; Gold; Heating; Optical pulse generation; Temperature; Tin;

fLanguage

English

Journal_Title

Components, Packaging, and Manufacturing Technology, Part B: Advanced Packaging, IEEE Transactions on

Publisher

ieee

ISSN

1070-9894

Type

jour

DOI

10.1109/96.338722

Filename

338722