Good question. Numerous studies have shown 0805 trending towards obsolescence. Of course, by the same token, through hole components went obsolete over 10 year ago.
Obsolescence is primarily an issue for active components, such as microprocessors and memory devices, where the capital costs are so intensive that the business model only makes sense if a very high volume of limited number of technologies is produced. In addition, there is theoretically no downside to going to smaller and smaller feature sizes (excluding reliability, but that's another topic). This does not apply to ceramic chip capacitors for several reasons.
Number one, and most important, is that smaller margins for passive components make component manufacturers much more receptive to the needs of small volume customers. Number two is that there are downsides to going to smaller components if you need high voltage (most 0603 components are only available in a maximum voltage of 16 or 25V). Number three, there are some passive component manufacturers that specialize in building strictly for the high rel market (as an example, most ceramic caps are still available in a SnPb finish). These buyers will tend to stick with larger case sizes for a some time into the future.
Dr. Craig D. Hillman
CEO & Managing Partner
DfR Solutions
Dr. Hillman's specialties include best practices in Design for Reliability, strategies for transitioning to Pb-free, supplier qualification, passive component technology and printed board failure mechanisms.
This question was recently asked by a customer to the SMTA. The following answer was provided by Tom Borkes.
I have not heard this as a definite decision by any of the component manufacturers. However, at best the 0805's will get more expensive as demand decreases. The 1208 (0.120 in. x 0.080 in. nominal) package that at one time was used en masse has just about gone away (I don't know, however, if they have stopped making them). The demand for 0805 is following suit, being replaced by still smaller packages (0603, 0402, 0201 and soon, perhaps 01005). The volume demand is from hand-held, wireless products that are constantly reducing size by going to smaller components.
Converting to 0603 for new products is easy (slightly smaller footprint) and probably prudent notwithstanding the suppliers' plans for the 0805.
Existing designed products are another story. You might want to check directly with the component manufacturers before relaying out the boards.
The 0805 chip capacitors for the most part are exempt from WEEE/RoHS, so I'm not sure the connection there.
Tom Borkes and Joe Belmonte
Joe Belmonte
Principal Consultant
ITM Consulting
Mr. Belmonte has been a process engineer and process engineering manager in the electronic manufacturing industry for over 25 years, with experience in all aspects of electronic product assembly operations. He is well-known throughout Asia and SE Asia for both his process work and teaching engagements.
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