Unit 3 Garlands Trading Estate, Cadley Road, Collingbourne Ducis, Wiltshire, SN8 3EB UK

Mil-Std Testing

Today I would like to discuss how Force supports the requests we receive for Mil-Std 883 or similar qualified products.

To those unfamiliar with Mil-Std 883 it is simply a standard that establishes uniform methods of controls and procedures for testing microelectronic devices, that are intended for use within military, space, and aerospace systems. It includes numerous environmental and mechanical tests that ensure the assembled batches of semiconductor devices meet a uniform level of quality and reliability and are thus suitable for end application.

There is a dizzying array of tests that devices can be subjected to which depend on a customer’s environmental, mechanical and electrical requirements. Obviously, device type factors heavily into the equation also and I have included a sample table below from Mil-Std 883 which gives an overview of the test methods (TMs) that a class Q(B), Class V (S) and Class Y(S) devices are subjected to.

The most important aspect of any of the solution requests we get is ensuring the customer gets a full coverage against their requirement with no concessions. To that end Force can offer the full range of Mil-Std 883 test methods however over the years we have seen significant shifts in the requalification process and traditionally our customers request a Class Q (class level B screen). Force has also developed a high reliability plastic screen trademark called Relplas™ for those customers who can accept a non-hermetic solution however need the quality and reliability that Mil processing offers (the process flow for that can be found here).

I’ll briefly take those still with me through a rough overview of what a class B screen consists of and outline the purpose of the various test methods (Note: this is far from a complete or comprehensive description). After the die has been visually inspected and die attached within the cavity a internal visual precap inspection is performed. This checks for any product deformities under high magnification prior to the lid seal. The batch then moves onto a Temperature Cycle which places the products in a thermal cycle chamber and transitions them between hot and cold temperatures to attempt to induce a failure.

Next, they enter constant acceleration testing in which they are placed in a centrifuge and a fixed value acceleration is applied to simulate the real environmental conditions again in the attempt to expose any mechanical or structural weaknesses. After a extensive external visual inspection to check for any damage sustained, the product moves onto an electrical test prior to entering Burn-In. Burn in testing is essentially a process that is used to detect early failures often referred to as infant mortality in semiconductors. The devices are exercised under high temperature and voltage for an extended period of time (160 hours at 125°C Minimum) to remove any weak devices prior to customer delivery.

A final Electrical test is then conducted that confirms the product conforms to the datasheet characteristics the customer has ordered against. Fine and Gross leak testing is then undertaken which confirms through a combination of a pressure chamber and a Freon bath that the product is sealed to specification and resistant to both the ingress of moisture and other contaminants. A final visual is then performed before the batch is ready for laser mark, document preparation and shipment to customer.

Should the customer have requested it the batch will then continue to M5005 group testing. That however something to be discussed another day.

The short and end of it though is that Force can offer the full range of Mil-Std 883 testing on our replacement solutions either to class classification grade or our customers custom drawings. Should you wish to discuss our test capabilities or product offerings further then please reach out to us at sales@forcetechnologies.co.uk or alternatively we are available on the phone or even live chat.

As always if you have any parts you would like evaluated or would like to discuss your testing requirements we are here to help.