The development and manufacture of micro bga based products with a higher number of interconnections per board has been a trend in the electronics industry for some years. However, the use of such devices is increasing and components such as fpgas are becoming more popular due to their performance. And while this development creates exciting opportunities for designers and manufacturers, it also presents the electronics industry with serious skills issues.
Manufacturers of printed circuit boards are now being asked to produce boards featuring micro miniature devices on a large scale – pushing the boundaries of production to their limits.
Not so long ago, developing products with just one fpga per board was a major challenge. Today, companies like Exception are increasingly being asked by product developers to include several high density fpgas per board. The big challenge in the sector at the moment is being able to produce complex products consistently, whilst dealing with ever decreasing feature sizes and real estate on a scale never seen before.
Clearly, the adoption of this new generation of pcbs allows designers to create truly flexible fpgas that bring even greater processing power. This is a big challenge; there are myriad issues of a technical, design and commercial nature that must not be ignored.
While pcbs have previously been seen merely as a way of connecting electronic components together, they are now playing a far more active role in bringing electronic functionality. Functional integrity is a big term here. This flexibility is at the very heart of what makes fpgas so attractive to OEMs – the fact that products can be taken to market quickly and the fpgas programmed at low cost after the manufacturing stage is finished. This new generation of highly sophisticated pcbs is enabling functional integrity and bringing even greater power to fpgas.
As the level of complexity rises, so the number of pcb manufacturers capable of delivering this type of support diminishes. Investment in technology is a key prerequisite to working in the advanced high density interconnect world. Access to laser direct imaging to allow true definition of fine traces and spaces and registration of solder mask is vital as providing sub 50µm is becoming an everyday requirement.
Defined registration techniques also enable connection to connection, pad to pad and layer to layer interconnectivity: essential to providing reliable multilayer sequential solutions. In order to achieve the elusive sub 50µm vias, the latest laser technology is used, allowing accurate drilling through multiple dielectric and laminate materials such as FR4, HiTG FR4, BT epoxies or ceramics.
