EPTE Newsletter from DKN Research #820, June 22, 2008 (www.dknresearch.com) Topics of the Week JPCA Show 2008 (Part II) The hot item at the convention this year was embedded components in the multilayer boards and flexible circuits. It seems to be a very ?fashionable? trend that started last year, and most of the major rigid board companies and flexible circuit manufacturers paraded their latest achievements from their technological departments. Material suppliers and machine manufacturers also threw their hats in the ring featuring some sales pitches that involved embedded components. There are two basic technologies used for embedded components. The first is forming passive components by screen-printing or photolithography inside or outside of the circuit boards. The concept is not very new, and the technology came to light and really took off several years ago at the IPC Expo in the U.S. The basic idea has not changed; however it has evolved and the accuracies and value of the passive components have become much larger. Mitsui Metal Smelting released 8 microns thick dielectric layers for Farady Flex and Fujikura Kasei announced that 50 are available as the dielectric constant of the screen printable ink. For circuit manufacturers it allows them to form larger capacitances in the same spaces on the substrates compared with traditional materials. Asahi Chemical Laboratory provides several carbon conductor inks for embedded resistors. These carbon inks cover 5 orders of resistors 100 ohms to 10 mega ohms in small spaces by the screen printing processes. The second basic technology used for embedded components involves mounting the chip components inside the multi-layer boards. During the early stages of the development process for the technology, actual chip devices for passive components were introduced. Today major circuit board manufacturers are trying to use semiconductor chips as the embedded components. Thin semiconductor chips are mounted in small cavities already prepared inside the multilayer boards. Because the wire-bonding technology has physical difficulties when covered by the other circuit layers, manufacturers began experimenting with new connection technologies. The flip-chip process is probably the most common technology used to make the connections for mounted chips. Toray Engineering, a major equipment supplier for the circuit board and assembling industry, launched new lines of flip chip bonding machines for both rigid substrates and thin flexible substrates. The automated bonding machines pick up the small thin chips from trays or diced wafers for large size circuit boards. One manager from Toray engineering told me they are selling a lot of flip chip bonding machines to new customers from circuit board companies, flex circuit manufacturers and OEM assembling companies. Toray Engineering representatives speculate these new customers use the machines for embedded semiconductor chips. I surveyed major rigid board manufacturers and flex circuit manufacturers inquiring about the latest progress with the embedded component technologies. Most manufacturers spoke about the advantages of their technologies, but few could provide clear answers relative to the reliabilities and actual production volumes. DNP, one of the major circuit board manufacturers in Japan, was the only company that provided actual samples of the circuit modules with embedded semiconductor chips. DNP representatives who worked the booth stated that they ship millions of embedded modules every month to a European cellular phone manufacturer. I came away from the exhibition feeling that embedded components are still in the R&D stage. Both circuit board manufacturers and their customers are wondering whether embedded components will be part of the industry main stream and if this technology is adopted what is the major process for the technology. Dominique K. Numakura DKN Research, www.dknresearch.com