BANNOCKBURN, IL, Nov. 3 - A group of leading vendors of solder today released white paper findings that "no significant difference" exists between a trio of heavily researched lead-free alloys. The lead-free pastes were found to result in less bridging but more voiding than a tin-lead eutectic control, the authors wrote.

In a 16-page report, the IPC Solder Products Value Council announced results of a down-select process of six tin-silver-copper solder pastes and subsequent PCB assembly comparing three of the alloys and a tin-lead solder paste.

The SVPC is made up of 17 solder vendors who aim to achieve worldwide consensus on a standard lead-free alloy. The paper details the second of a three-phase, $1 million program testing tin-silver-copper alloys.

Five solder manufacturers submitted paste samples for the anonymous testing, which was conducted by an independent party. The pastes studied: • 96.5/3.0/0.5 Tin/Silver/Copper. • 95.5/3.8/0.7 Tin/Silver/Copper. • 95.5/4.0/0.5 Tin/Silver/Copper.

Engent AAT,of Norcross, GA, tested one alloy per vendor using tin-lead eutectic paste as a control. Testing was performed on FR-4 boards using surface finishes of immersion silver, OSP, electroless nickel/immersion gold (ENIG) and bare copper and components with tin and tin-silver-copper finishes. Tests performed included: reproducibility of printed paste volume, solder paste wetting and spread, interconnect voiding.

Next, two major EMS companies, Flextronics and Solectron, built a total of 200 assemblies each, using the three SAC alloys and a tin-lead control. The companies then studied the three pastes for testability, rework and repair, handling and storage, printing, reflow and cleaning. There was "no significant difference" between the lead-free solders, they found. However, in general the tin-lead paste outperformed the lead-free alloys.

According to the report, "Submitted samples ... showed that, in general, the lead-free pastes were not as well-defined or as repeatable as tin-lead solder paste nor was their slump performance as good as tin-lead solder paste. This was most likely due to the use of a generic print process that was not optimized for each material.

The lead-free pastes also resulted in less bridging but more voiding than the control paste, the paper notes.

The final report is due in early 2005 and will include results and analysis of long-term and thermal-shock reliability testing.

"The SPVC is moving forward to complete this very detailed reliability testing program, in what we hope will be an alloy that industry can use with confidence," said Peter Palmer, SPVC chair and vice president of global marketing at Cookson Electronics.

SAN JOSE, Nov. 1 -- Global semiconductor sales rose to $18.4 billion in September, a sequential increase of 1%, the Semiconductor Industry Association reported today. Sales of PCs and cellphones appear to be stronger than expected and are boosting sales of microprocessors, DSP, flash memory devices and DRAMs.

Worldwide chip sales for the third quarter were $55.2 billion, up 3.2% from the second quarter and 27.4% from last year. Worldwide sales were up 33.2% for the first nine months.

"Despite evidence of an ongoing inventory correction in some segments of the industry, the September sales figures reflect continuing growth in demand for semiconductors," said SIA president George Scalise. "September is traditionally one of most consistently strong months for microchip sales as manufacturers of electronics products gear up for the holiday season.

"Slower growth or declining sales in a few market segments are signs of a continuing inventory correction by both semiconductor producers and customers. The ongoing inventory correction in these segments was the major factor in the September growth rate coming in near the low end of the historic range," Scalise said.

Chip sales in Europe and Asia were up 4.1% and 1.6%, respectively, while sales in the Americas and Japan declined 1.7% and 0.5%, respectively.

SMTA Seeks Papers for Medical Electronics Symposium
11-02-2004

Minneapolis, MN -- The SMTA has issued a call for papers for the Medical Electronics Symposium to be held April 26-27, 2005, in Minneapolis, MN.  Papers can be submitted until December 3.

Topics for the conference may include:

- Assembly Technology Challenges

- Manufacturing/Equipment Requirements

- Design Challenges: Power Management and DFX

- Assembly Failure Analysis Case Studies

- Six Sigma Projects

- Lean Manufacturing Projects

- Process Validation and Requirements: Qualification, Traceability, and Control

- Advanced Packaging for Medical Electronic

- Components/Packaging and Assembly Materials

- Substrate Materials

- Emerging Technologies for Medical Electronics

- Sensors/MEMS/Nanotechnology

- Business Regulations / Barriers to Entry for Medical Assembly

- Challenges in Outsourcing Medical Assembly

- RoHS and Environmental Constraints for Medical Products

The conference will explore medical electronic devices, components, packaging, assembly and business issues for major categories, such as diagnostics, imaging, monitoring, life support, implantable products, personal monitor/delivery devices and disposable electronics. Products addressed range from complex, powerful and expensive diagnostic machines to simple, mass-produced, use-once sensors. 

Submit abstracts and inquiries to SMTA director of education Kristin Nafstad: kristin@smta.org. Include the paper title, author's name and complete contact info. 

The results include a $23.1 million charge for the impairment of goodwill and a $1.8 million writeoff of
customer lists associated with the acquisitions of ETMA and AVT, respectively. TFAS also took a $1.6 million charge for excess inventory and transition issues relating to completion of the move of the display business from the company's factory in Manila to a factory in Beijing.
For the quarter, the cost of sales was $42.5 million, up from  $41 million last year. Gross margin was a loss of 0.1, versus 1.4 last year.
   
Jack Saltich, president and chief executive, said in a statement, "We have been concentrating our efforts this year on streamlining our global manufacturing operations and correcting issues in our Redmond factory. Optimizing our global infrastructure has taken a significant effort. I believe we are starting to see success from these endeavors."

Separately, TFS named Leslie Honda regulatory affairs director, a new post. Honda was vice president of quality and regulatory for ClearMedical Inc., a medical devices reprocessor.

The book-to-bill ratio for all types of boards was 1.08, meaning for every $100 of shipments, $108 in orders were booked, said IPC, which tracks the data. The trade group does not disclose the participants or their revenues. The book-to-bill ratio was 1.04 in August.

The ratios for rigid and flex boards were 1.01 and 1.38, respectively. The ratio is calculated by dividing the value of orders booked over the past three months by the value of sales billed. A ratio over 1.0 is considered an indicator of rising demand.

Overall September shipments rose 25.9% and bookings were up 18.1% year-on-year, IPC said. For the year, shipments are up 33.5%, bookings are up 35.2%. Sequentially, shipments were up 12.1%, bookings 16.6%.

"Both rigid and flex shipments are rebounding from the recession and are showing strong growth, but flex is growing at a faster rate than rigid," IPC said in a press release.

For the month rigid PCB shipments were up 12.2% but bookings fell 10.1%. Flexible circuit shipments were up 85.6% and bookings were 140.1% higher.

Year-to-date, rigid PCB shipments are up 23.3% and bookings are 16.8% higher, while flex shipments have grown 78.5% and bookings are up 106.5%.

The flexible circuit sales include some value-added services -- about 17%, says IPC.