Tekmos' Blog

Tekmos makes replacements for obsolete parts. While we can recreate any old design, our biggest obstacle comes in the packaging of the obsolete parts. In many cases, the packages themselves are obsolete. An example is the BQFP (Bumpered Quad Flat Pack), which was a high pin count package originally developed by AT&T and Intel, and which reached its peak volumes with the Intel 80386SX processor. Today, we are unaware of any vendor that offers this package. Another package that gives us problems are the PLCC packages. The 20 pin is unavailable, and the 28, 68, and 84 pins have very limited availability.

A simple solution is to have customers change their PCB to accommodate a new package. But this has problems. Frequently, the demand for older products is driven by regulatory demands. The same regulations that demand the continued use of obsolete parts also require the use of the original PCBs. Changing the board can require a new, expensive, and time consuming qualification. Remaking the original packages also poses problems.

Older plastic packages require mechanical tooling to form them into the correct shapes. The three main tools are the book mold, which forms the package, the de-junk tool, which removes extruded plastic from between the leads, and a shear and form tool, which cuts the leads from the lead frame, and bends them into the correct shape. These tools are expensive, costing roughly $100K each. An older package may also require a leadframe, which is generally purchased in 50K minimum quantities. Remaking the package can cost on the order of $350K up front, provided you can locate an assembler willing to do it.

Alternatives are needed, and Tekmos offers several. One option is the use of a LGA package. LGA stands for Landed Grid Array, and can be thought of as a BGA type package without the balls. It looks like a PCB with plastic on one side. The parts are formed in a block, and cut apart with a saw, so packages of any size can be made. Tekmos uses this approach to replace smaller PLCC packages. Because the LGA packages are quite thin, they have a maximum size of about 10 mm. Larger packages would tend to warp, and become difficult to attach to the customer’s board.

A second option is adapter cards. These come in two varieties. One option is to use a pattern on the bottom of the adapter that matches up with the original package footprint. We then attach our circuit to the top of the adapter. Our circuit must use a smaller package than the adapter, but this is not a problem with current packaging technology. This approach has a difficulty in that the connections are made under the adapter card, and are difficult to inspect.

Tekmos has had an increase in ASIC products required for military applications. Because of this we have had to incorporate military screening and qualification procedures.

Tekmos follows military screening outlined in Mil-STD-883: Test Method 5004.13. This screening consists of tests dedicated to inspect the design, wafer fabrication, and device assembly of a product and is performed on the entire Lot of parts. The tests include Nondestructive Bond Pulls, Temperature Cycling, Electrical Parameter Tests, and more. So far Tekmos has had a 100% success rate on military screening 5004.13.

Unlike the initial screen procedures, the military qualification procedures are outlined in Mil-STD-883: Test Method 5005.17 and only use a small portion of the Lot for testing. Many of the tests are considered destructive, which ultimately means the parts no longer are active for customer use and must be scrapped. Qualification involves 5 groups of testing; Group A: Electrical, Group B: Mechanical and Environmental, Group C: Life Tests, Group D: Package, Group E: RHA (if applicable).

Group A testing is done in-house once production parts arrive from the dedicated assembler. Tekmos begins screening by performing an initial electrical test to remove any assembly rejects from the Lot. After Initial test, parts are then placed in ovens for a burn-in cycle in accordance with TM 1015, for 160 hours at 125ºC. While the parts are under burn-in, Tekmos constantly monitors the current output of the parts to ensure their electrical stability. Once completed, the parts will run through a tri-temperature screening with the same initial test used pre-burn-in. The parts are tested at 125ºC, 25ºC, and -55ºC to make certain the product is meeting the device specifications.

For Groups B and D, Tekmos sends off parts to an approved test house. These parts, although tested off-site, are constantly being tracked through various communication channels for accurate completion estimates and potential issues needing to be resolved. Once all parts have completed, the test house will send reports and certificates of conformance for the testing performed. The reports are then reviewed by the Production Engineer, Zachary Kolb, and Director of Quality, Kelsey Casto.

This October will be my 6th year as a Tekmos employee. Oh- how time flies. Tekmos has gotten to see me graduate college, buy my first house, get married, and so much more! So-I think it’s only fitting to write an article about my experience within the company and a few life changing principles I have learned in the many different roles as; Intern, Assembly Engineer, and Director of Quality.

I started at Tekmos in 2014 as an Engineering Intern helping the design and layout of Printed Circuit Boards (PCB). I was familiar with working on CAD programs, so I was able to pick up the PCB software easily, but there was one important lesson I still needed to learn; admitting to my mistakes. Not every PCB I designed was functional, which meant my 20 year old self made numerous arguments blaming others for the mistakes. After one failed (expensive) project and my countless excuses blaming others, Lynn Reed, President, sat down in my cubicle with me and shared some wisdom about taking ownership of my work, including the mistakes, because in the end the project is ultimately my responsibility. Those simple, self-explanatory words changed my view on how to embrace mistakes and take ownership. Yes, I still made mistakes on some PCBs, but my attitude towards failure had drastically changed.

My next important learning experience came after I got promoted to an Assembly Engineer. This promotion meant I was now transitioning into a role I had little knowledge in and leaving the comfort-ability of PCB designing. I had to embrace getting out of my comfort zone and take initiative on learning a subject outside of the classroom. Although- fellow Tekmos employees graciously helped along the way. Specifically Test Floor Technician, Phil Buck, who spent many patient hours explaining the assembly process of ICs, machine operations/troubleshooting, and even the importance of electrical safety while working on test floors. With his help, I learned how to get comfortable with my new role as an Assembly Engineer and be humble in times of the unfamiliarity.

Fast forward one year, VP of Operations, Jon Gehm, introduced me to the Quality Management System (QMS). Initially, I was assisting him with audit prepping and reorganization, but over time he encouraged me to take leadership on the AS9100 quality system upgrade and set a goal to become the Director of Quality at Tekmos. This encouragement really tested my self-confidence and I had to learn to push myself beyond my set boundaries. I had many learning curves on what it meant to be in a Director position, but it eventually led me to grow a voice in meetings, audits, improvement plans, and much more. Eventually I was promoted to Director of Quality and have been at this role since 2017.

Because of the leadership and environment at Tekmos I have learned how to admit to mistakes, embrace the uncomfortable, and gain self-confidence.

Although Quality Metrics sound uninteresting to the standard employee, any Quality representative should know that those metrics are the unsung heroes of a healthy company. Quality Metrics are also known as Key Performance Indicators (KPI's), which measures the success of a company based on meeting specific goals and targets set by Management.

Tracking KPI’s play a vital role in properly determining if a department is functioning correctly. Unlike a person’s relative opinion on a department’s status, i.e. “I think the Sales Department has been doing well this quarter”, Quality Metrics use a numerical value to assess the department, along with creating a target goal, i.e. “The Sales Department sent out 72 quotes this quarter, which surpassed the target goal of 60 quotes.” These numerical values help management evaluate the department quickly and bypass the possibility of a biased opinion.

Metrics also help determine trends occurring in the company. In the above example, if the Sales Department continues to surpass the target goal every quarter, this may be an indication to management that it is time to raise expectations. This could include, allowing more throughput on a production floor, incorporating additional capabilities, or taking on more projects. Of course, if metrics start to trend negatively, management will then have to discuss action plans to get the department healthy again. Implementing action plans first consist of asking the questions; What will be done to get back on track, What resources are required, Who is responsible for the new implementation, and When will the implementation be completed. These questions will initiate movement and gear people back towards success.

Tekmos has Quality Metrics in all core departments. Here are a just few; Average Response Time for Sales Inquires, Number of Supplier Late Deliveries, Raw Stock Cycle time to Finished Goods, and more. Tekmos’ metrics were chosen with the help of our President, VP of Operations, and myself – Director of Quality. Each of us brought different experience and understanding of the Organization to accurately assess what a “healthy” Tekmos should look like.

Tekmos’ Metric Practices;
-Establish beneficial Quality Metrics
-Set realistic target goals
-Perform quarterly reviews of Quality Metrics
-Address Action Plans when target goals are not met
-Adjust Quality Metrics and/or target goals, when applicable Tekmos continues to utilize the above Metric Practices to help eliminate potential risks and improve customer confidence in all department areas.

Since technology and applications seem to advance, it’s only fitting that Tekmos’ qualification testing advances as well. Within the last year, Tekmos has incorporated more reliability and qualification testing in our First Article Inspections, which brings customers more confidence and assurance for our design and manufacturing abilities.

Tekmos uses two generic qualification standards; MIL-STD-883 and JESD47. Both of these standards have compliance testing for the device’s Electrical Capability, Environmental Strains, Life Potential, and Package Assembly Integrity. These tests allow the device to be looked at from all angles and predict whether the device can survive under typical stresses seen in the semiconductor industry. However, some testing is dependent on the final application of the device. If the final application is prone to jolt movements but rarely exposed to alternating extreme temperatures, then a focus on the Package Assembly Integrity testing; I.E. Bond Pull Strength, Bond Shear, and Die Shear, might be more beneficial than the Environmental Strains; I.E. Temperature Cycling. Another testing dependent could be from a Product Change Notice (PCN). If a PCN is sent due to a Wafer Design Change, then it would be more useful to perform Electrical Capability testing rather than Package Assembly Integrity. Of course, if any time a customer desires a full qualification, then Tekmos will be happy to accommodate.

Incorporating these qualification tests has come with learning curves and challenges. One main challenge was our project management process had to be revamped to keep up with the additional testing. Majority of the qualification tests are performed by outside suppliers, which means there needs to be extra precaution on lead-time agreements, material management, cost evaluations, and final review of reports. As the Director of Quality, I have taken these new additions to project management as my responsibility. Within the last few months, I have been beta testing a new tool that captures all steps in the qualification process, as well as tracks lead-times and cost trends. Tekmos is hoping this implementation will reduce human error risks, and accurately assess upcoming qualifications.

A key player in our Qualification Testing has been our Product Engineer, Zachary Kolb. He was hired back in April of 2019 and has been the main person involved in First Article Inspections. Along with receiving my many pestering, if not annoying emails and phone calls, he is the mastermind behind the qualification tests performed at Tekmos. He is responsible for coordinating information and material with our suppliers, setup and testing of inhouse qualifications, and report generating. He has been a great asset to Tekmos and continues to help maintain structure and organization in device qualifications.

Kelsey Casto, Director of Quality