Here is the abstract you requested from the IMAPS_2010 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Development of a Low Voiding Solder Attach Process for Photovoltaic Cell Assemblies|
|Keywords: solder attach, low voiding, high volume|
|The level of competition for a share of the burgeoning solar cell market naturally drives companies towards low-cost, high-volume subcontractors. But the stringent operating requirements in a concentrated photovoltaic (CPV) application are more consistent with the process capabilities of lower volume manufacturers. Specifications for attach of PV cells as large as 1 cm² require the high thermal conductivity of a solder connection, along with minimal voiding in order to prevent current-crowding effects and thermal hotspots. These design aspects are most easily achieved through the use of lower volume, more labor-intensive batch processes such as vacuum reflow, often using expensive alloys such as 80Au20Sn. Crane Electronics in Redmond, WA, has developed an in-line solder reflow process for PV cell attach that uses standard, inexpensive solder alloys to address large die, low-voiding applications. This paper discusses the initial design and subsequent incremental improvement of that process, with supporting x-ray and yield data.|
|Ian Hardy, Senior Process Engineer
Crane Electronics Group