Design-to-assembly project aids burn-in system

Dayford Designs, working with sister company TIS, has successfully completed a GBP 80,000 "design-to-assembly" project in weeks instead of months for Reltech of Dursley Gloucestershire.

Dayford Designs, working with sister company TIS, has successfully completed a GBP 80,000 "design-to-assembly" project in weeks instead of months for Reltech of Dursley Gloucestershire.

The highly specialised test equipment was part of a complete Midas 4500 dynamic burn-in test system.

The success of this initial project has now secured further valuable export orders for Reltech from SSMC in Singapore and NEC Semiconductors in Ireland.

The driver board system developed and assembled by Dayford provides electrical stimulation and signals to each Midas system, consisting of a large oven containing 48 burn-in boards.

The system as a whole is controlled and monitored by an integrated PC with the Midas Activity Windows based software.

Also designed by Dayford were the monitor subboards, providing a continuous functional check of the devices under test and an identification of any failures to the system PC.

The project comprised PCB design, fabrication, assembly and testing of 29 units, each consisting of a 12-layer motherboard and three daughter boards.

The first phase was to design the boards and build a one-off prototype system in only 4 weeks.

This tight time scale was achieved with a fully functional and tested system that met the project performance requirements first time.

Richard Bradley, technical director of Reltech Limited, said: "There were so many things that could have gone wrong.

I was expecting some problems given the very tight timescales.

The fact that it went so well is a testament to the team at Dayford.

The quality of the design, rigorous checking procedures, forward planning and communication with fabricators and TIS, all contributed to the success of this important project".

A key factor in the short time scale achieved was the identification and ordering of the key ICs and more unusual components against advance technical information and before the final design review.

Close liaison with PCB assembler TIS was also essential in order to highlight likely long-lead items.

Where alternatives were available immediately, this was communicated to the hardware design engineer who was able to redesign the circuits accordingly.

Available parts were secured on an open order basis, by TIS, against guaranteed delivery and the price later adjusted against final quantities when the design was complete.

Without this flexible co-operation the tight cost targets and time-scales would have posed a problem.

Layout of all the boards had also started in advance of the final design review in parallel with component procurement.

Engineering updates were circulated quickly round a "fast-feedback" loop including to other Reltech engineers, Dayford's PCB designers, and assemblers at TIS.

The number of revised component lists received during the layout process and time pressures gave plenty of opportunity for error.

Thorough checking procedures were maintained throughout before data was released for production.

Without this flexible approach, a similar project might well have taken many months.

Instead Dayford completed the project to specification and on time, first time, in under eight weeks.

The prototype system was presented to Reltech customers who were able to give the go-ahead to produce the remaining 28 systems - with zero changes to the PCBs.

Richard Bradley again: "The fact that no changes were required meant savings in design and tooling costs all down the line and more importantly savings on time.

Being able to deliver on time was the key to winning further orders.

The ability to design all the boards in parallel, speed of response and thoroughness in final design verification were all important factors in this success story.

We will definitely be coming back to Dayford for future projects".

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