I first started working in the wonderful world of high-tech manufacturing (which I now refer to as a disease) in wire and die bonding for the smartcard industry of the early 90s. I left that fledgling industry in the late 90s for the then-more mainstream SMT industry, and wound up at a Flextronics Product Introduction Center in Texas supporting PCB layout, R&D prototyping and pre-production for SMT products that would be going into mass production factories all over the world.
I've noticed over the years that the semiconductor industry and the SMT industry are desperately swimming towards each other. Recently I have seen a number of articles suggesting that there is a strong need for new materials that will further this merging of the laminate substrate and PCB industries. With the pitch of semiconductor die constantly shrinking, there is a need to reduce the pitches available on the laminate substrate, and this, in turn, will pressure the PCB industry to make finer geometries available at the PCB level.
Denser and Faster
With the ever-accelerating reduction in geometries and increasing speeds at the wafer level, manufacturers of laminate substrates are being asked to provide packages that are capable of delivering performance values that are approaching the point where they will exceed the capabilities of current materials and production techniques for cost-effective packaging. The next generation of materials and packages will need to provide better electrical characteristics, such as lower Er (Dk), lower loss tangents (Df) and the ability to work in higher-temperature environments. These materials would also need to lend themselves well to production techniques that would allow for feature sizes to down to 10 microns and below, and dielectric thicknesses of 25 microns and below.
In addition to the ability to provide these characteristics, these materials must also be cost-effective to produce, and utilize lower-cost processing for laminate substrate production than the current high-density solutions.
As an added feature, as long as we are daydreaming, these materials and the subsequent production processes would need to be such that the entry barriers to production of laminate substrates could be reduced to the point that smaller manufacturers would be capable of producing high-quality laminate substrates, in low volume, in very short lead times. In such a scenario, design and prototype cycle times could be reduced to something close to that for prototype PCBs today.
The technologies in use today that can produce such fine features as 20 micron pitch are true additive processes; many of the manufactures of these types of products apply proprietary dielectrics in order to achieve these geometries. ...
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