New range of polymer thick film materials from Multicore-Asahi includes resistor inks for embedded passives

Citation

(1999), "New range of polymer thick film materials from Multicore-Asahi includes resistor inks for embedded passives", Microelectronics International, Vol. 16 No. 3. https://doi.org/10.1108/mi.1999.21816cad.010

New range of polymer thick film materials from Multicore-Asahi includes resistor inks for embedded passives

New range of polymer thick film materials from Multicore-Asahi includes resistor inks for embedded passives

Keywords Multicore, PTF

Multicore Solders Inc. has introduced a package of new generation polymer thick film materials in association with the world leaders, Asahi. A new and completely unique range of precision resistor inks enables embedded passives in the form of buried resistors. Via fill ink for pad-on-via and microvia-fill is also new, and directly solderable copper conductor inks and free line copper inks have been introduced. A new range of "ultra smooth" potentiometer inks enables integrated passive potentiometer tracks to be printed directly on the PWB surface.

A dedicated support center has been opened at Multicore's North American headquarters and research and manufacturing facility at Richardson, Texas to support the technology and provide training, applications, custom blending and prototyping services to customers. Ken Lewey, development manager, Advanced Products Division at MSI and an expert in this field, is to lead the center. Mr Isao Morooka, director of Asahi's PTF division, has worked closely with MSI to set up the center, which has been fully endorsed by Asahi.

The TU-00-8 series is a new and completely unique range of precision resistor inks specifically engineered to give extremely tight "as cured" tolerances and outstanding stability to subsequent build-up or assembly processes. Coefficients of variation (CVs) of less than 2 per cent have been achieved with resistors as small as 0.040" × 0,040" over large areas with R of less than 1 per cent on thermal cycling (­40°C/+125°C).

These exceptional properties amount to an enabling technology for embedded passives since buried resistors (resistors on a PWB inner layer) produced with these inks are able to fulfil the demanding cost performance criteria of this exciting new construction,

Further new materials technology targeted on high end board construction is via fill ink for pad on via/micro via fill, directly solderable copper conductor inks and fine line copper inks capable of 0.003" lines and spaces. The latter can be plated with full build electroless copper without catalysts or activators to give 2 milliohms/square for HDI additive circuitry construction. A special, plating tolerant, dielectric enables the system to be multilayered in much the same way as ceramic hybrids.

The BTU-00-7 potentiometer inks are a new addition to the range with improved "super smooth" surface to meet the increasing performance needs in the areas of rotational life, mechanical endurance and contact resistance variation (CRV). With TCRs of less than 200ppm/°C, this series is another enabling technology providing integrated passive potentiometer tracks printed directly on the PWB surface.