New BPS Solutions Enhance Packaging, Testing, Assembly
| BPS Product Line |
› Dicing Solution and Oxide Removers
BPS-729 solution. This surfactant-based product effectively removes saw slurry through better wetting. Simultaneously removes oxide and prevents regrowth with little effect on underlying metal. Accommodates most existing tools without retrofits.
› Oxide Removers
BPS-172, BPS-170, BPS-100 and BPS-101 solutions. Designed for metal or aluminum oxide removal with low etch rates on most metals. Process time is usually less than five minutes. These are suitable for standard wet bench processes and wafers may be reworked without damaging films.
› Photo Resist and Flux Removers
BPS 125 and BPS-130 solutions. Remove photoresist, flux, flux residues, die attach residues and cured or partially cured polyimide. They do not attack passivation layers or most exposed metals. They also have a process time generally les than five minutes and are suitable for use in standard rinse tools. |
New from the Air Products Electronics Division is our BPS (Better Process Solutions) line of products. BPS wet chemistries are an efficient and simple way of removing metal oxides, photoresist, and flux from wafers without damaging the underlying metals - and allow the customer to lower costs through improved yield and lowered reruns.
Presently under evaluation at several customer fabs where they are proving to be quite effective, BPS materials could bring about a major change to backend packaging. Currently, most operations such as probe & test, flip chip, saw and wire bond see a variety of problems due to the presence of high oxide and organic residue levels. Air Products has discovered that it is beneficial to clean them first to make these operations more efficient. BPS solutions have short processing times and a much lower cost associated with them than current techniques.
Air Products developed the BPS line about a year ago with the support of Terence Q. Collier, president of CVInc., Dallas, Texas. Collier is an expert in packaging, testing, and assembly and now serves in a consulting role as an applications and sales engineer to Air Products.
Teaming with CVInc. allowed us to find some important applications based on our wet chemistry experience. Air Products has formulations for a variety of electronics applications, and, in addition, substantial high-volume manufacturing capabilities in Dallas, TX; Easton, Pa.; and Seoul, Korea, as well as global labs at Allentown, Pa., Dallas, Giheung, Korea; and Hsinchu, Taiwan.
By cleaning wafers with BPS wet chemistries as they enter backend operations, chipmakers can prolong the life of standard or high-end probes by as much as six months. If the probe is making 10,000 touchdowns on an as-yet uncleaned wafer, it gets dirty quickly. Also, cleaning reduces false readings when testing for electrical properties. Cleaning first increases accuracy, boosts yield, and reduces cycle time. We like to say, "Clean the wafer, not the probe card."
Pre-cleaning means that more wire bonds will stick versus trying to adhere to dirty or corroded pads. And, our BPS formulations are an advantage over plasma etching - pick the wrong plasma and you can damage the entire wafer.
With dicing and sawing, BPS solutions provide the benefits of traditional surfactant-based dicing solutions - effectively removing saw slurry through better wetting - while also removing metal oxides from bond pads and mitigating their regrowth. BPS products replace and outperform other available dicing solutions.
BPS wet chemistry brings a lot of advantages to flip chip assembly, mostly through improved cleaning.
Additional information on our BPS offering is available at www.airproducts.com/bps or contact Raj Ramamurthi at ramamur@airproducts.com. |
