A Study on the Thermomechanical Reliability Risks of Through-Silicon-Vias in Sensor Applications

Reliability risks for two different types of through-silicon-vias (TSVs) are discussed in this paper. The first is a partially-filled copper TSV, if which the copper layer covers the side walls and bottom. A polymer is used to fill the rest of the cavity. Stresses in risk sites are studied and ranke...

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Bibliographic Details
Main Authors: Shuai Shao, Dapeng Liu, Yuling Niu, Kathy O’Donnell, Dipak Sengupta, Seungbae Park
Format: Article
Language:English
Published: MDPI AG 2017-02-01
Series:Sensors
Subjects:
TSV
Online Access:http://www.mdpi.com/1424-8220/17/2/322
Description
Summary:Reliability risks for two different types of through-silicon-vias (TSVs) are discussed in this paper. The first is a partially-filled copper TSV, if which the copper layer covers the side walls and bottom. A polymer is used to fill the rest of the cavity. Stresses in risk sites are studied and ranked for this TSV structure by FEA modeling. Parametric studies for material properties (modulus and thermal expansion) of TSV polymer are performed. The second type is a high aspect ratio TSV filled by polycrystalline silicon (poly Si). Potential risks of the voids in the poly Si due to filling defects are studied. Fracture mechanics methods are utilized to evaluate the risk for two different assembly conditions: package assembled to printed circuit board (PCB) and package assembled to flexible substrate. The effect of board/substrate/die thickness and the size and location of the void are discussed.
ISSN:1424-8220