A introduction of sFCCSP — Fine pitch low profile FCCSP solution

As for mainstream portable application (Mobile Phone, Tablet, Handset Gamer), the higher density (array IO pitch <= 100um), higher thermal performance (better theta JA than overmold FCCSP) and lower profile (compare with overmold FCCSP) is necessary for package developing. As to satisfy the marketing needs, some suitable solution can be considered: Utilize Cu Pillar Bump to satisfy the fine pitch request; and also with the exposed die FCCSP to cover the lower profile & better thermal performance. As to come out an easy way to recognize the package type of this combination, the package type of “sFCCSP” (SPIL proposed FCCSP-Exposed Die Cu Pillar FCCSP) had be called for further discussion. In general, Cu Pillar was the fine pitch solution of FCCSP (<130um bump pitch), as the next generation of low IO(<200) application flip chip solution, Cu Pillar can provide a feasibility for better electrical performance but reasonable cost (design-in is necessary), and upcoming challenge is the ELK protection for 40nm / 28nm even finer IC technology. As regard the exposed die FC solution, it is obvious to realize the benefit of skipping overmold 60∼80um thickness for package total height reduction. Of course, the trade-off is either back side surface bleeding or package warpage. In this report, there is a test vehicle to show how we overcome the potential ELK crack & Die bleeding & package warpage issue to approach the mainstream technology for portable market.