Pure Technologies Introduces the Development of Two Low-Alpha Tin Products

Atlanta: May 1, 2004---Pure Technologies has announced the development and introduction of two low alpha tin products in response to a demand from customers worldwide who are utilizing the company's other low alpha emitting solders, metals and alloys.

The first product is a certified low alpha tin granular product for lead- free and lead alloy plating chemistry. Known as Tin Monoxide (SnO), this product is intended to enhance tin dissolve rates when immersed in an acid bath. As an addition to Pure Technologies ALPHA-Lo product line, the tin monoxide is available in an alpha emitter quality range from 0.05 cph/cm2 to <0.002 cph/cm2 and both 99.95% and 99.99% purity.

"Our customers have the need for Tin Monoxide in the production of significant quantities of plating chemistry for both Pb-free or lead alloy applications in the semi- conductor industry", said Jerry Cohn, President, Pure Technologies. "We are now able to produce and supply Tin Monoxide on demand and on time".

The other product is a certified low alpha tin profile for lead-free and lead alloy plating chemistry. Identified as Tinflake, the individual 0.5 in. (12.7mm) to 2 in. (25.4mm), randomly shaped tin morsels are designed to improve solubility rates and fully dissolve in an acid environment. The thin, irregular, three dimensional shapes of each Tinflake can allow full metal contact with the dissolve medium and helps prevent metal compaction. Tinflake is available in any quantity and in 99.95% and 99.99% purity. Alpha emitter quality is available from 0.05 cph/cm2 to <0.002 cph/cm2 as with all other ALPHA-Lo™ products produced by Pure Technologies.

"The introduction of these two new low-alpha tin products will further reduce the incidence of soft errors in high speed microprocessors and integrated circuits allowing faster, thinner and more dense memory devises using lower voltages", said Jerald Cohn, President of Pure Technologies. "Our products are unique to the industry because we can produce an alpha remitter of less than 0.002 alpha counts per square centimeter. Few of our competitors have that capability", Mr. Cohn concluded.

Pure Technologies solves “soft error” problems with ALPHA-Lo™ solder products

Atlanta, GA -

ALPHA-Lo™ solder products reduce the risk of “soft error” problems associated with Alpha particle emissions. Research has shown that Alpha emission levels above 5 MeV can cause “soft error” problems. When a “soft error” occurs, a microprocessor chip’s binary code becomes temporarily transposed (a “1” becomes a “0”). “Soft error” problems are particularly acute for applications where erroneous data can be life-threatening or costly, raising concerns over corporate liability. These applications include military hardware and guidance systems, avionics, banking and financial services, medical and automotive applications, as well as computers that handle sensitive data, including network servers.

Alpha particles are most commonly associated with the element Lead (Pb). Virtually all commercially processed Lead contains small amounts of naturally occurring radioactive isotopes which cause Alpha particle emissions. Solder products made from lead-free alloys can also suffer from Alpha particle emissions, primarily due to impurities in the refining process as well as improper handling and storage of these alloys.

Traditional die-up packaging techniques combined with low-alpha epoxies were generally successful in reducing Alpha emissions. However, with the advent of flip chips and other sub 0.25 micron processing technologies, the risk of “soft errors” has increased dramatically. The reason is two-fold: higher packaging densities; and chips now coming in closer contact with the solder material.

Various techniques have been utilized in recent years to reduce Alpha particle emissions. The latest advancement involves a proprietary evaporative process developed by Pure Technologies which solves the “soft error” problem by reducing or eliminating all radioactive isotopes. Pure Technologies’ evaporative purification process is highly cost effective, and is capable of reducing Alpha levels by a factor of 10 - 100, resulting in Alpha particle emissions of <0.001 CPH/CM2 with 99.99% elemental purity.

Recently, Jerry Cohn, President of Pure Technologies LLC, Atlanta, Georgia, described one very significant solder alloy issue that seems overshadowed by the deafening lead-free chorus: the dreaded alpha particle effects on new generations of ICs.

"These unwanted particles have a long history of being troublesome and that problem is spilling into mainstream semiconductor packaging. "Worse yet, the particles are found in many other metals, in solder alloys and in encapsulating materials, to name but a few." So what's the problem?

Soft Error Rates in Solder Bumped Packaging

Soft errors are a fact of life for small geometry devices. The contributions to soft errors come largely from trace radioactive contaminants in packaging materials, but can also come from metallization layers and the cosmic ray background. Reduction of the soft error rates to that of approximately the cosmic radiation in the air at sea level.

Soft Error Rates in Solder Bumped Packaging paper presented at the 1998 International Symposium on Advanced Packaging Materials by Dr. Mark W. Roberson. Member of Technical Staff MCNC is available for immediate delivery. Please see our contact form to request this paper and additional resource information of soft errors.