FLIP CHIP ON ORGANIC BOARD TECHNOLOGY USING MODIFIED ANISOTROPIC CONDUCTIVE FILMS AND ELECTROLESS NICKEL/GOLD BUMP

• 영문명: FLIP CHIP ON ORGANIC BOARD TECHNOLOGY USING MODIFIED ANISOTROPIC CONDUCTIVE FILMS AND ELECTROLESS NICKEL/GOLD BUMP
• 발행기관: 한국마이크로전자및패키징학회
• 간행물 정보: 『마이크로전자 및 패키징학회지』제6권 제2호, 13~21쪽, 전체 9쪽
• 주제분류: 공학 > 산업공학
• 파일형태: PDF
• 발행일자: 1999.06.30

영문 초록

Flip chip assembly directly on organic boards offers miniaturization of package size as well as reduction in interconnection distances resulting in a high performance and cost-competitive Packaging method. This paper describes the investigation of alternative low cost flip-chip mounting processes using electroless Ni/Au bump and anisotropic conductive adhesives/films as an interconnection material on organic boards such as FR-4. As bumps for flip chip, electroless Ni/Au plating was performed and characterized in mechanical and metallurgical point of view. Effect of annealing on Ni bump characteristics informed that the formation of crystalline nickel with Ni₃P precipitation above 300℃ causes an increase of hardness and an increase of the intrinsic stress resulting in a reliability limitation. As an interconnection material, modified ACFs composed of nickel conductive fillers for electrical conductor and non-conductive inorganic fillers for modification of film properties such as coefficient of thermal expansion(CTE) and tensile strength were formulated for improved electrical and mechanical properties of ACF interconnection. The thermal fatigue life of ACA/F flip chip on organic board limited by the thermal expansion mismatch between the chip and the board could be increased by a modified ACA/F. Three ACF materials with different CTE values were prepared and bonded between Si chip and FR-4 board for the thermal strain measurement using moire interferometry. The thermal strain of ACF interconnection layer induced by temperature excursion of 80℃ was decreased with decreasing CTEs of ACF materials.

목차

1. INTRODUCTION

2. EXPERIMENT

3. RESULTS AND DISCUSSION

4. CONCLUSIONS

REFERENCES