Automatic Test Equipment (ATE) – High Technology Business Development

Coupling & Crosstalk: Testing the Supply Chain

change canstockphoto28381385_focalpoint_c350x350 Coupling & Crosstalk is my column in the MEPTEC Report. This column appears in the Spring 2018 edition on pages 8-9.

Electronic coupling is the transfer of energy from one circuit or medium to another. Sometimes it is intentional and sometimes not (crosstalk). I hope that this column, by mixing technology and general observations, is thought provoking and “couples” with your thinking. Most of the time I will stick to technology but occasional crosstalk diversions may deliver a message closer to home.

Testing the Supply Chain

Much the same as the world, test is not simply black or white but varying shades of grey and a jumble of colors. Test has continually responded to semiconductor technology challenges to provide the right solutions. As a result, the organizational placement and “supply chains” for test have rarely been Continue reading “Coupling & Crosstalk: Testing the Supply Chain”

Semiconductor Wafer Test Workshop 2015 Presentation – Are You Really Going To Package That?

Are You Really Going To Package That? - Ira Feldman and Debbora Ahlgren - SW Test 2015 — Click image to download presentation

I had the pleasure of presenting “Are You Really Going To Package That?” at the 25th annual Semiconductor Wafer Test Workshop (SW Test / SWTW) on Tuesday June 9, 2015. Debbora Ahlgren and I took this opportunity to step back and look at how old paradigms in test-cell integration may lead to suboptimal solutions.

In an effort to reduce the cost-of-test (COT), a number of customers are increasing the parallelism of logic wafer probe cards. However, due to the complexity such as pitch and number of probes, the pricing for these cards is reaching astronomical levels. We do not believe this trend is sustainable, let alone logical. The presentation suggested examples of alternative solutions. It is clear that critical solutions need to be optimized at the test cell, factory, and supply chain level not just at the consumable (probe card) level.

BiTS Workshop – The Next 15 Years

Thanks to the BiTS Committee for the hard work to make this a great event!

Wow! The Burn-in and Test Strategy (BiTS) Workshop just turned 15! The world of semiconductors has certainly changed over the years. And the BiTS Workshop has kept up with what is “Now & Next” in the burn-in and test of packaged integrated circuits (ICs). These achievements were celebrated in style by the more than three hundred participants at the recently held 2014 BiTS Workshop in Mesa, Arizona.

“When the BiTS Workshop started in 2000, there were no Continue reading “BiTS Workshop – The Next 15 Years”

SEMI ISS: Sense of Scale

Intel shows first fully patterned 450 mm semiconductor wafer at SEMI ISS 2013

Attending the SEMI Industry Strategy Symposium (ISS) is like drinking from a fire hose with the additional risk of whiplash. Don’t get me wrong, it is an exquisite fire hose but sometimes the data presented can be overwhelming at this conference of semiconductor supply chain executives. The majority of the attendees and presenters are executives from the SEMI member companies that develop the equipment, materials, processes, and technology used to build, test, and package semiconductors. And the executives present from the semiconductor manufacturers are typically the “end customers”.

The greatest value of SEMI ISS, beyond the networking, is the strategic overview of the entire semiconductor ecosystem. What are the market drivers, the technology needed, and the roadmap status of this industry? It is true that we all know where we need to head courtesy of Moore’s Law and the International Technology Roadmap for Semiconductors which attempts to keep us on that trajectory. The pressure of consumers ~~needing~~ wanting greater functionality at lower costs is relentless. Much of the technological detail of this ecosystem is addressed in a myriad of other forums throughout the year. ISS ties these technical requirements, development needs, and business needs back to the strategic direction and desires of the global marketplace.

The whiplash comes from Continue reading “SEMI ISS: Sense of Scale”

IEEE Semiconductor Wafer Test Workshop 2012 – Session 5 (Tuesday)

Semiconductor wafer test workshop swtw sign 500x352

Here are the highlights from Session Five “New Probe Card and Contact Technologies” of the 22nd annual IEEE Semiconductor Wafer Test Workshop (SWTW) from Tuesday June 12, 2012.

Tsutomu Shoji (Japan Electronics Materials Corp. ‐ Japan) and Takashi Naito (Advantest ‐ Japan), “Full Wafer Contact Breakthrough with Ultra‐High Pin Count”:

Awarded Best Overall Presentation

As the number of probes on probe cards increase due to greater parallelism, driven by the desire for one touchdown testing and the future transition to 450 mm wafers, the total force required to probe a wafer increases if there is no reduction in the force per probe. This wafer prober chuck needs to apply the required force by pushing the wafer against the probe card typically held in place by the structure of the prober. With 200K probes on a 450 mm wafer each requiring 5 gF this is approximately equal to 1 ton (2205 lbF) of applied force. To reduce these force requirements wafer chuck and prober structure, Advantest and JEM have Continue reading “IEEE Semiconductor Wafer Test Workshop 2012 – Session 5 (Tuesday)”

IEEE Semiconductor Wafer Test Workshop 2012 – Welcome & Session 1 (Monday)

Semiconductor wafer test workshop swtw sign 500x352

Here are the highlights from the Welcome and Session One “Process Improvements for HVM” of the 22nd annual IEEE Semiconductor Wafer Test Workshop (SWTW) from Monday June 11, 2012.

Jerry Broz (SWTW general conference chair) started with several sets of numbers: SWTW attendance (up), semiconductor revenue and wafer statistics (problems). and probe card market (up). The problem with semiconductor statistics are Continue reading “IEEE Semiconductor Wafer Test Workshop 2012 – Welcome & Session 1 (Monday)”

Silicon Valley Test Workshop – 2nd Year “Rocks”

2 5D? 3D? What? 3D IC Packaging - Ira Feldman — Click image to download presentation

Back for the second year (with a minor name change), the Silicon Valley Test Workshop is an unpolished gem. Looking past the rough edges (minor logistical issues), what really shines through is the interaction of the participants. This conference really has Continue reading “Silicon Valley Test Workshop – 2nd Year “Rocks””

Probe Card Cost Drivers from Architecture to Zero Defects

Click to download presentation — Click image to download presentation

As the final presenter at this week’s IEEE Semiconductor Wafer Test Workshop (SWTW), I outlined how critical it is to understand the true cost of a product’s architecture in “Probe Card Cost Drivers from Architecture to Zero Defects“. Without a proper understanding of these costs – especially for fully custom high technology products such as wafer test probe cards – it is impossible to maintain a sufficient gross margin. Gross margin is essential to maintain the health of a company and to fund the research & development required for innovation.

Many companies in the semiconductor test market have entered a period that Steve Newberry identified in his 2008 speech “Semiconductor Industry Trends: The Era of Profitless Prosperity?” that parallels the aluminum industry in the 1970’s. And without the means to fund innovation, companies have no future especially when faced with the double threat of Moore’s Law – increasingly harder technical requirements delivered at lower cost.

Yes, there were a few in the audience who appeared pleased since they are confident that their products are on the right path. There were others who may have been upset based upon their company’s direction. I would argue that a proper diagnosis – regardless of how disturbing – is essential to drive the proper cure.

There is plenty of opportunity in the test market and reasons for optimism. The key to long term prosperity is to really understand the fundamentals of the business and not be blinded by the technology.

I thank those who stayed for the entire conference and welcome your thoughts below. And I will be posting more about the conference (including my summaries) in the next few weeks.

Silicon Valley Test Conference – Something New & Overdue

Starting off something new is often challenging and difficult with many unknowns. Kudos to Nick Langston for creating the Silicon Valley Test Conference that was held last week. (November 8 & 9, 2010) It was the first test conference to actually take place in Silicon Valley. And yes there were some minor “bugs” like registration delays and a no-show by the audio visual contractor that should be solved in next year’s Rev 2.0. Even with a few rough edges, the quality of the presentations and the exhibitors shined through to make this a success.

The conference opened with an excellent keynote address by well-known industry expert Continue reading “Silicon Valley Test Conference – Something New & Overdue”

IEEE Semiconductor Wafer Test Workshop – Area Array Probing – Session Eight (Wednesday)

Here are the highlights from Session Eight – Area Array Probing of the 20th annual IEEE Semiconductor Wafer Test Workshop (SWTW) from Wednesday June 9th.

Senthil Theppakuttai, SV Probe, “Probing Assessment on Fine Pitch Copper Pillar Solder Bumps”:

Flip chips devices are shrinking from 150 µm to 35 µm pitch interconnect. At 150 µm pitch solder balls formed by deposition or electroplating, and stud bumping are typically found. However at tighter pitches down to 35 µm, copper (Cu) pillars with solder caps are the preferred termination. The copper pillars solve electro-migration issues and mechanical/thermal (CTE) mismatch found with solder balls and stud bumping.
Continue reading “IEEE Semiconductor Wafer Test Workshop – Area Array Probing – Session Eight (Wednesday)”

IEEE Semiconductor Wafer Test Workshop – Probe Potpourri – Session Seven (Tuesday)

Here are the highlights from Session Seven – Probe Potpourri of the 20th annual IEEE Semiconductor Wafer Test Workshop (SWTW) from Tuesday June 8th.

Boyd Daniels, Texas Instruments, “Very Low Cost Probe Cards – A Two Piece Approach”:

For their “catalog” parts – medium complexity, low volume, and medium number of devices – historically it has been cheaper to blind package (i.e. skip wafer test prior to packaging) and take the yield loss at package test. The main issue is the high initial cost and maintenance of probe cards is too high relative to the volume of parts to be tested.
Continue reading “IEEE Semiconductor Wafer Test Workshop – Probe Potpourri – Session Seven (Tuesday)”

IEEE Semiconductor Wafer Test Workshop – Parametric / Scribeline Probing – Session Six (Tuesday)

Here are the highlights from Session Five – Signal Integrity of the 20th annual IEEE Semiconductor Wafer Test Workshop (SWTW) from Tuesday June 8th.

Jay Thomas, Grund Technical Solutions, LLC., “Probe Cards with Modular Integrated Switching Matrices”:

For the last 30 years, most scribeline parametric testing has been approximately 85% Current-Voltage (I-V) testing and 15% Capacitance-Voltage (C-V) testing. For these types of tests a 10 MHz bandwidth switch matrix has been sufficient.

However, some of the larger fabs such as HP, IBM, and Intel have started performing pulsed Current-Voltage (PIV) and electrostatic discharge (ESD) testing. These customers started this type of testing about four years ago unknown to Agilent & Keithley (the two largest DC parametric tester suppliers). This PIV and ESD testing requires high frequency switch matrices with 1 GHz bandwidth. [For more about ESD testing please see Jay’s second presentation below in this session.]
Continue reading “IEEE Semiconductor Wafer Test Workshop – Parametric / Scribeline Probing – Session Six (Tuesday)”

IEEE Semiconductor Wafer Test Workshop – Standards and Methods – Session Four (Monday)

Here are the highlights from Session Four – Standards and Methods of the 20th annual IEEE Semiconductor Wafer Test Workshop (SWTW).

Mark McLaren, Integrated Technology Corporation, “Metrology Solutions for Very Large Probe Cards”:

Over the past few years as the number of memory devices to be tested in parallel has increased so has the size of probe cards to support this multisite testing. A few years ago memory probe cards grew to 440 mm diameter and recently they increased to 480 mm diameter. Now a similar growth in size has been seen for non-memory applications. Even though the parallelism (number of devices to be tested at once) has increased (but not on the scale of memory parallelism), the size increases have been the result of pushing more testing from package test to wafer test. These additional tests have required more local test resources (circuitry close to the device being tested) which require more real estate on probe cards.
Continue reading “IEEE Semiconductor Wafer Test Workshop – Standards and Methods – Session Four (Monday)”

IEEE Semiconductor Wafer Test Workshop – High Temperature Probing – Session Two (Monday)

Here are the highlights from Session Two – High Temperature Probing of the 20th annual IEEE Semiconductor Wafer Test Workshop (SWTW)

Keith Breinlinger, FormFactor, “Addressing the Operating Challenges of Full Wafer Contactors”:

Keith started by providing a real good analogy of the challenge of wafer probing in terms of contacting the edge of each sheet of papers in a sixteen high foot stack. He used the new full wafer probe cards SmartMatrix (DRAM) and the TouchMatrix (NAND FLASH) as the basis of his presentation.
Continue reading “IEEE Semiconductor Wafer Test Workshop – High Temperature Probing – Session Two (Monday)”

IEEE Semiconductor Wafer Test Workshop – Opening Session (Sunday)

The 20th annual IEEE Semiconductor Wafer Test Workshop (SWTW) started this evening. Rumor has it that attendance is over 240 this year which is a vast improvement over last year’s 160 or so attendees. At the peak the conference had almost hit 600. Things started off well with a reception where I had the chance to catch up with many industry friends and colleagues.

After dinner, Jerry Broz the General Chair kicked things off with the “Probe Year in Review”. In summary:
Continue reading “IEEE Semiconductor Wafer Test Workshop – Opening Session (Sunday)”

Pass or Fail? The Limits of Integrated Circuit Testing

Balancing test coverage versus test cost. What does a test failure mean? Value of yield increase

… and how it impacts your bottom line!

A poorly implemented semiconductor test cell may pass integrated circuit (IC) parts that are either defective or have marginal performance. They can cause the electronic devices in which they will be assembled to either malfunction or completely fail. However, two other conditions require evaluation. Having false negative test “escapes” is expensive in terms of final product test failures, warranty costs, customer dissatisfaction, etc. In turn, the false positive test escapes needs to be balanced against the cost of false negative failures where otherwise good parts fail the tests and are discarded. Test engineers, product managers, quality engineers, and operational managers needs to make either implicit or explicit decisions as to the proper balance in adjusting the test limits. The goal is to cost effectively approach “zero defects” without “throwing out the baby with the bath water”.

A test process generally categorizes the item or device being tested as “pass” or “fail”. Sometimes passing devices are graded (typically by speed or other desired quality) and failing devices are often grouped by failure mode. “Coverage” is how well a particular test process measures the functionality and specifications of a given device. If every feature and specification is tested then it is said to have 100% test coverage. However, exhaustive testing is usually expensive due to long test times which translates in to operational costs including the depreciation of the test system and greater test setup complexity (equipment and development cost). Sometimes complete coverage is not possible or practical so there needs to be a trade-off between coverage and cost.

Continue reading “Pass or Fail? The Limits of Integrated Circuit Testing”