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Method for the localized heating of bond pads for low-temperature wire bonding

IP.com Disclosure Number: IPCOM000012433D
Publication Date: 2003-May-07
Document File: 2 page(s) / 58K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for the localized heating of bond pads for low-temperature wire bonding. Benefits include improved yield and improved reliability.

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Method for the localized heating of bond pads for low-temperature wire bonding

Disclosed is a method for the localized heating of bond pads for low-temperature wire bonding. Benefits include improved yield and improved reliability.

Background

              Assembly can damage electronic packages that are sensitive to high temperatures. For example, typical wire bonding applications (such as with gold wires) require a temperature of 175ºC. The typical wire bonding process heats the die via the substrates (see Figure 1). Some electronic die components are damaged at a critical temperature below 125ºC.

              No conventional solution exists. As mentioned above, conventional assembly processes uniformly heat the entire assembly to 175ºC. In some assembly schemes, multiple packages are heated at the same time, increasing the thermal exposure of sensitive packages.

General description

              The disclosed method uses localized heat, such as laser heating, on the bond pads for wire bonding applications where the rest of the package remains at room temperature. The localized heating occurs prior to the formation of the wire bond. This procedure elevates the temperature of the bond pads to the required 175ºC to make a sound metallurgical bond without raising the temperature of the rest of the die significantly. One method to elevate the bond pad temperature locally is to use a laser.

              The key elements of the method include:

•             Low temperature wire bonding

• ...