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Plastic Flip-Chip-BGA Carrier With Microvias for Chip Scale Packaging



Jan Obrzut, M Jimarez


We evaluated a near-chip-scale package, that utilizes the flip-chip, plastic-ball-grid-array technology with microvias. The microvias were photolithographically patterned in built-up dielectric layers. We verified optimal conditions for photo-exposure and thermal cure process of the SLC, photoimageable dielectric layer, using dielectric relaxation spectroscopy measurements. The resulting composite material exhibited aging resistance and satisfactory dielectric properties. We also investigated several fiber-glass-epoxy laminates using dielectric spectroscopy, and identified a laminate material of low moisture absorption and exceptional immunity to the plated-fiber-defects. The photoimageable dielectric layer and the fiber-glass-epoxy laminates were selected to build the near-Chip Scale Package. The package was successfully fabricated using the flip-chip, plastic-ball-grid-array-microvia technology. The 4S2P structure with 256 BGA connections accommodated a chip with 700 C4 joints. Measurements of stress concentration and thermal expansiveness during thermal loading indicated that the mechanical construction of the package was optimally designed. The predictions of the materials dielectric evaluation and of mechanical modeling were verified by executing a series of standard reliability tests. It has been determined that this plastic Flip-Chip-BGA carrier with microvias is manufacturable and can satisfy the standard reliability requirements.
Proceedings Title
Proceedings of the International Conference on Electronic Assembly
Conference Dates
June 16-18, 1998
Conference Location
Atlanta, GA
Conference Title
International Conference on Electronic Assembly


ball grid array, chip scale packaging, dielectric relaxation, interfacial moisture, microvias, photoimageable dielectric, plastic chip carrier, polymer composites, stress testing


Obrzut, J. and Jimarez, M. (1998), Plastic Flip-Chip-BGA Carrier With Microvias for Chip Scale Packaging, Proceedings of the International Conference on Electronic Assembly, Atlanta, GA, [online], (Accessed June 22, 2024)


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Created June 2, 1998, Updated February 17, 2017