Title :
Multilayer high density flex technology
Author :
Chou, Bill ; Beilin, Solomon ; Jiang, Hunt ; Kudzuma, David ; Lee, Mike ; McCormack, Mark ; Massingill, Tom ; Peters, Mike ; Roman, Jim ; Takahashi, Yasuhito ; Wang, Vincent
Author_Institution :
Fujitsu Comput. Packaging Technol. Inc., San Jose, CA, USA
Abstract :
The industrial trend of shrinking microelectronic devices while increasing the density of interconnections places great demands on the substrates upon which these devices are packaged. Multilayer flex circuits will provide the interconnection densities needed to meet these demands in a wide range of packaging and interconnection technologies. This paper discusses the development of ultra-high density flexible circuits. Processes and materials to fabricate fine line pitches from 12.5 μm to 40 μm are examined. Various microvia structures, through hole and blind via, are demonstrated. A test vehicle was designed and built for BGA packages to illustrate the density capability. A four-layer structure is demonstrated by using Z-connection to connect two layer pairs. Electrical, mechanical, and reliability test results are presented to show the selection of flex substrate material, Z-connection methodology and fabrication processes. A cost comparison of high-density flex to alternative substrates is discussed to identify potential
Keywords :
ball grid arrays; fine-pitch technology; flip-chip devices; integrated circuit interconnections; integrated circuit packaging; microassembling; multichip modules; substrates; surface mount technology; 12.5 to 40 micron; BGA packages; MCM; Z-connection methodology; blind via; cost comparison; fabrication processes; fine line pitches; flex substrate material; four-layer structure; interconnection densities; microvia structures; multilayer flex circuits; multilayer high density flex technology; reliability test; substrates; through hole; ultra-high density flexible circuits; Circuit testing; Flexible electronics; Flexible printed circuits; Integrated circuit interconnections; Materials reliability; Materials testing; Microelectronics; Nonhomogeneous media; Packaging; Vehicles;
Conference_Titel :
Electronic Components and Technology Conference, 1999. 1999 Proceedings. 49th
Conference_Location :
San Diego, CA
Print_ISBN :
0-7803-5231-9
DOI :
10.1109/ECTC.1999.776353