Tekmos' Blog

Tekmos offers Burn-In and Reliability Testing services.  The requirements can vary from part to part, and Tekmos can customize these services to meet your exact needs.

Burn-in

The failure rate of integrated circuits over time follows what is called the "bathtub" curve.  There is a high rate of infant mortality initial failures.  Then the failure rate drops, only to increase at the end of life due to wear out failures.  The reliability of a part can be enhanced by providing a burn-in at elevated temperatures prior to usage.  This burn-in is typically somewhere from 40 to 160 hours in length, and is done at a temperature of between 70ºC and 125ºC.  It is important that the parts be exercised during this burn-in.  It is also good to monitor the part performance during burning, so that the time point of failures can be detected.  That data can be used to set the optimum burn-in length.

One of the major costs of a burn-in is the boards used for the burn-in.  This is a tradeoff between the cost of the sockets on the boards, the number of boards needed, and the total number of parts to be burned in.  Major manufacturers with very high volumes will invest in high quality sockets that will cost from $50 to $100 per chip.  This socket cost adds up quickly.

In addition to the oven capacity, Tekmos also has in-house design and layout capability for both the burn-in boards and driver boards (if needed).

Reliability Testing 

There are several over-lapping reliability testing specifications.  Specifically, these are the JESD47I, the AEC-Q100, and the military Mil Spec 883.  These require subjecting several lots to stresses, and then looking for failures.  Some tests are for the die, and other tests check the packages.  Because of the standardization of the packages, the die tests are the most important.  And the main die test is the HTOL, or High Temperature Operating Life.  In this test, the parts are typically operated at 125ºC for 1000 hours.  If the parts cannot be tested in the oven, the parts will be periodically pulled from the oven, tested, and re-inserted back into the oven.  Common read points are at 48, 96, 168, 250, 500, and 1000 hours. 

Tekmos offers test and characterization services. As a fabless semiconductor company, Tekmos has an internal test facility, with testers ranging up to 320 pins in size. We offer access to these facilities and the engineers that run them.

Verification and Debug of ASICs 

Some customers have developed an ASIC, but lack the facilities to completely test it, or to debug it if there is a problem.  Our testers provide the means to verify the ASIC, and to debug it.  Also, our testers can be remotely accessed, allowing the customer engineer to exercise their part from the comfort of their own office. 

Verification of Brokered Parts 

Brokers have become very efficient in obtaining mature parts.  But there is always the question of if the parts are correctly marked,  and will they perform to specification.  Re-testing the parts is the best way to resolve those questions.

Test Program Creation 

Customers do not always have a test program for their parts.  In those cases, we can create one from scratch.  Starting from either design files or a data sheet, our engineers can write patterns that functionally exercise the parts.   

Product Characterization 

The question for all new parts is does the part meet all specifications over the temperature and voltage limits?  And the only way to find out is to measure it.  Tekmos can take your part, and measure the functionality, DC specifications, and AC specifications over the desired temperature range.  Then we consolidate the data into a report, that shows how well the new part works as compared to the specifications.  This service is useful for both new designs and to evaluate existing designs. 

Sometimes, a project needs additional engineering resources.  When that happens, Tekmos design engineers are available to help.

Digital ASIC Design

Working from your specifications, Tekmos can create digital designs and layouts in your preferred process technology.  We can also assist with IP selection and interfacing.

Mixed Signal ASIC Design

Not all designs are digital.  Tekmos can design the analog portions, and provide the design in either schematic form or a GDS layout in the process technology of your choice.

FPGA Design

Our designs are not just for ASICs.  We can also develop FPGA based designs, in any of the FPGA families.  Internally, it is our standard practice to implement our processors in an FPGA before we commit to silicon.  This has given us a great deal of experience in working within the FPGA environment.

IP Design 

Sometimes a design needs an IP block.  These are usually a specific peripheral to a processor, or a communications interface.  IP locks serve as an efficient way of partitioning a design so that multiple designers can work on the same project.  Many IP blocks can be purchased, while others need to be designed to meet a customer's specific requirements.  

Last month, Tekmos sent a representative to the annual meeting of the Space Parts Working Group. This is a meeting of government users of satellites, companies that make satellites, and component manufacturers that make parts for satellites. The meeting was for two days, and consisted of presentations from government users and the component manufacturers. It also presented a lot of networking opportunities.

Tekmos sells several products into the aerospace market. We are also working on upgrading our quality system from ISO9001 up to AS9100, which is now being required by some of our customers. After that, the next step is changing our products to offer an even higher level of reliability. And the first stage of that process is to determine what are the limits with current parts. And that is why we were at the Space Parts Working Group.

So, what did we learn? Being space related, radiation damage was a big topic. The higher the orbit, the greater the damage. As a subset of radiation, heavy ions are an increasing concern. Heavy ions are also a problem with the aviation market, and have been identified as a cause of commercial aviation engine failure in at least one instance. Another issue was bond wire integrity, as a result of corrosion, thermal cycle, and vibration during launch. And as with all semiconductor users, there were concerns about obsolescence and counterfeiting. These are all areas that will be addressed as we develop the next generation of Tekmos products.

Tekmos has announced the qualification and release of two of our microcontrollers, the TK68HC711D3 and TK68HC11D0. The micros were originally made at our provider Plessey Semiconductor. Plessey closed their 0.35u fab, and the designs were transferred to the X-Fab foundry located in Dresden, Germany. Originally each design had its own mask set. This reflected the fact that the parts were designed at separate times. When the designs were transferred to Dresden, the designs were merged onto a common substrate die. The new die was designed to support an optional Flash memory, which could be enabled through bond options.

There are no changes to the operation of either circuit, and each chip remains a drop-in replacement for the original NXP parts.

Having a drop-in replacement for parts has shown to be a very cost effective way to extend the life of products when the original component manufacturer discontinues a part. The availability of a drop-in replacement part eliminates the need to make the tough decision whether to redesign a printed circuit board or discontinue a product.

Tekmos continues to be the "go to" supplier when there are problems finding obsolete parts or when additional parts are needed after the date for EOL (End of Life) purchase has passed. Tekmos makes a variety of microcontrollers, microprocessors, and other miscellaneous standard products to satisfy these needs. Tekmos also continues to make custom ASIC replacement parts.

Customers are aware that buying from Tekmos ensures pin for pin, drop-in replacements that can be counted on to work in their applications, without worry about the quality of parts purchased on the grey market.