White Papers

Check the box next to each paper you want to download. You may download as many papers as you wish. After selecting papers and completing the contact information form on this page, the paper(s) will be e-mailed to you at the e-mail address you provide.

Papers about die bonder

• Evaluation of Test Protocol for Eutectic Die-Attach Using High Power LEDs

  by Amanda Hartnett, Daniel Evans Jr., Don Beck, Seth Homer

  High-power semiconductor devices, such as high-brightness LEDs, must be mounted using a robust die-attach material that can handle the temperature fluctuations generated by the chip and mechanical stresses due to CTE mismatches between the die material and substrate to which it is mounted. The selected material must also comply with current legislation, which restricts manufactured products containing numerous materials due to environmental concerns, including some that were historically popular in this application. Eutectic gold-tin (AuSn) materials meet these requirements, and process recommendations for their implementation will be presented. Utilizing Palomar Technologies’ die bonder, AuSn solder preforms and solder paste will be placed/dispensed and reflowed using a Pulse Heat System (PHS). Evaluation methods comparing these means of eutectic die-attach to a pre- plated AuSn die will be discussed. Technical generalizations will be detailed to explain the derivation of test method as well as hypotheses of results.

  gold-tin solder, LED, die bonder, solder preforms, solder paste, automated pick-and-place, eutectic die-attach, solder spread

  [Permanent Link to this Paper]

  Posted on 14 Oct 2011

• Process and Reliability Advantages of AuSn Eutectic Die-Attach

  by Steve Buerki, Amanda Hartnett

  High-power semiconductor devices must be mounted using a robust die-attach material that can handle the temperature fluctuations generated by the chip and mechanical stresses due to CTE mismatches between the die material and the substrate it is mounted to. Traditionally, various die-attach products, such as metal-filled conductive epoxies, high lead-containing solders, and gold-silicon solders, have been sufficient to mount the chip and have it perform reliably for the life of the device it operates. However, the trend toward increasing heat generation, the demand for compact devices, the enactment of RoHS and REACH legislation, and the transition to GaAs chips, limit the use of conventional materials. The demand for high reliability in power devices, in light of these industry trends, has led engineers to evaluate various new materials for their die-attachment. The use of a high temperature solder preform is proposed and demonstrated for use as a die-attach material in high power devices. The suggested solder preforms are eutectic gold-tin and may be implemented for high volume or lab quantity adoption using a Palomar Technologies’ die bonder. This equipment is capable of handling the complete die-attach process, including high-accuracy pick-and-place of substrates, eutectic gold-tin preforms, and components; eutectic die-attach; and pulsed-heat reflow using a computer controlled Pulse Heat Stage (PHS). Each of these steps is precisely controlled to offer a near void-free eutectic die-attach between the device and its substrate. This is critical for thermal and electrical stability in high power applications. When the substrates, preforms, and components are supplied in high volume packaging, the assembly line can be fully automated, which enables a reduction in the cost of ownership and improves process yields. Assembly applications suited for this process include, but are not limited to, high-brightness LEDs, power amplifiers, LASER diodes, VCSELS, lid attach, MEMS, RF packages, IGBT modules and wafer scale packaging.

  wafer scale packaging, pb-free, eutectic die-attach, automated pick-and-place, solder preforms, die bonder, AuSn solder

  [Permanent Link to this Paper]

  Posted on 5 Nov 2009

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