Browse Prior Art Database

Semiconductor Chip Joining

IP.com Disclosure Number: IPCOM000093537D
Original Publication Date: 1967-Oct-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 50K

Publishing Venue

IBM

Related People

Miller, LF: AUTHOR [+2]

Abstract

Mechanical stresses obtained during chip joining can be alleviated using soluble standoffs during the joining of the semiconductor chip to the support. Drawings A and B show the use of soluble standoffs in a solder reflow joining process. Drawings C and D show another use of soluble standoffs in a decal joining process. The soluble standoff can be composed of any of a large number of nontoxic, high-melting noncontaminated soluble salts such as potassium or sodium metasilicates. The soluble salts can be in the form of preforms or can be applied to the substrate by conventional coating techniques.

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Semiconductor Chip Joining

Mechanical stresses obtained during chip joining can be alleviated using soluble standoffs during the joining of the semiconductor chip to the support. Drawings A and B show the use of soluble standoffs in a solder reflow joining process. Drawings C and D show another use of soluble standoffs in a decal joining process. The soluble standoff can be composed of any of a large number of nontoxic, high-melting noncontaminated soluble salts such as potassium or sodium metasilicates. The soluble salts can be in the form of preforms or can be applied to the substrate by conventional coating techniques.

Drawing A shows insulating substrate 1 having continuous solder-coated conductors 2 on it. Soluble standoff 3 is located just at the position where semiconductor chip 4 is to be placed. Chip 4 having solder balls 5 supported on it is then positioned over and supported by standoff 3. The temperature is increased until balls 5 are melted and fused with conductors 2 to form conductive current paths between the electrodes of chip 4 and conductors 2. Standoff 3 provides support for chip 4 during the solder reflow, and is removed after such reflow by the use of an appropriate solvent. The final structure is shown in drawing B.

Drawing C shows substrate 6 having a depression for positioning semiconductor device 7 having electrodes 8. Decal 9 having conductive layers 10 on it is then pressed against device 7 and substrate 6. Soluble standoff 11, positio...