Thick-film chip resistors have been the preferred low-cost, surface-mounted design (SMD) solution since the introduction of surface-mount technology. In the past, thin-film resistive technology has been reserved for precision applications where noise, stability, or temperature has significant adverse effects on a design.
However, the cost difference between thick-film and thin-film has forced engineers to compromise on the performance of their designs to keep costs down or to obtain the desired performance at a very high cost.
Also, with advances in automotive markets and the industrial expansion of developing countries like China, sulfur sulfide is becoming a major area of concern for long-term reliability. Low-cost thick-film chip resistors are porous and very susceptible to silver sulfide.
Manufacturers have dealt with this issue by introducing products with higher palladium content. This solution improves the long-term reliability of the parts, but this security comes with a higher cost and without a guarantee that sulfur will not cause the part to fail.
Recently, advances in high-speed sputtering techniques and looser parameters have allowed certain manufacturers, like {complink 12878|Stackpole Electronics Inc.}, to offer low-cost thin-film alternatives. Thin-film provides inherent advantages, including low noise, more stability, and being impervious to sulfur.
Some of these parts also allow you to go down a case size and obtain the same power rating. The only place these parts don't belong is in humid environments. Given these advantages, why wouldn't someone be attracted to this technology?
Hi Brian, interesting points you raise and it seems that many, if not all of the barriers to entry for thin-film chip products have been eliminated. The main and maybe only reason I could see as to why thick-chip is still more popular is the initial outlay of capital required by the manufacturer to implement a thin-chip process. Also, the manufacturer may have to have the necessary real estate within the facility to include a thin-chip process, and if not may have to do a build-out. It would make sense that thin-chip resistors would become the norm based on all the advantages and now lower manufacturing costs. Looks like a winner to me and I would expect in the long run, they will become the norm.
Brian,I think in the long-run (2-3 yrs from now) thin-chips will be used in most electronic products. If you observed the technological trends things are getting slimmer which answered the space issue of the consumers.