Electrical conduction of anisotropic conductive adhesives: effect of size distribution of conducting filler particles

We analyze the electrical resistance of an anisotropic conductive film (ACF) sandwiched between two conducting plates as a function of applied load by extending a published model of Shi et al [1]. In this analysis we also calculate the plate separation as a function of applied pressure when a collection of particles are trapped between two plates. The case of conducting particles with a general size distribution shows two new important results: (a) we find that the resistance of a bond or a contact is independent of the number of conducting particles under the contact pad when the particle size distribution is Gaussian, which is very much in contrast to the case of uniform sized particles; (b) also, only a very small fraction of conducting particles participate in the electrical conduction of ACF products where the actual particle size distribution can be described as a Gaussian. We show that the experimental data supports the validity of this analysis. While this analysis confirms some of our basic notions of ACF, the surprising result of constant resistance forces us to reevaluate our long-held concept of attaching much importance to the total number of particles in a bond.

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Electroconductive rubber. Mechanism of electrical conduction in electrical conducting filler-polymer compose materials.

NIPPON GOMU KYOKAISHI ◽

10.2324/gomu.58.561 ◽

1985 ◽

Vol 58 (9) ◽

pp. 561-568

Author(s):

KEIZO MIYASAKA

Keyword(s):

Electrical Conduction ◽

Conducting Filler ◽

Electrical Conducting

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Electrical conduction and reliability of anisotropic conductive adhesives filled with Ag/Cu-coated epoxy composite particles

2006 8th International Conference on Solid-State and Integrated Circuit Technology Proceedings ◽

10.1109/icsict.2006.306653 ◽

2006 ◽

Author(s):

Lei Zhihong ◽

He Ying ◽

Gao Licong

Keyword(s):

Electrical Conduction ◽

Epoxy Composite ◽

Composite Particles ◽

Conductive Adhesives

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A theory for plastic-bonded materials with a bimodal size distribution of filler particles

Modelling and Simulation in Materials Science and Engineering ◽

10.1088/0965-0393/12/3/004 ◽

2004 ◽

Vol 12 (3) ◽

pp. 407-421 ◽

Cited By ~ 37

Author(s):

B E Clements ◽

E M Mas

Keyword(s):

Size Distribution ◽

Bimodal Size Distribution ◽

Bonded Materials ◽

Filler Particles

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Metal Coated Polymer Particles for Electronic Packaging

International Symposium on Microelectronics ◽

10.4071/isom-2010-ta3-paper1 ◽

2010 ◽

Vol 2010 (1) ◽

pp. 000066-000071

Author(s):

Ionel Halaciuga ◽

Keith Redford ◽

Dan V. Goia

Keyword(s):

Size Distribution ◽

Chain Length ◽

Palladium Catalyst ◽

Polymer Particles ◽

Conductive Adhesives ◽

Nickel Metal ◽

Economic Issues ◽

Significant Challenge ◽

Pre Treatment ◽

Different Thickness

Anisotropic conductive adhesives (ACA) are widely used as interconnect materials in the manufacturing of LCD screens. To be integrated in a broader range of interconnect applications several technical and economic issues still need to be addressed. One significant challenge is to encapsulate polymer particles with well controlled modal diameter and size distribution into continuous, compact, and uniform conductive metallic shells. This presentation describes a method to deposit layers of nickel with different thickness (30 – 120 nm) onto monosized polymer particles ranging in size from 1 to 10 micrometers. The novelty of the approach consists in a pre-treatment of the epoxy functionalized polymer particles with linear polymeric amines. We show that by increasing amine chain length the distribution of the palladium catalyst, and consequently the adhesion and distribution of nickel metal deposited, can be improved dramatically. The effect of several plating parameters is discussed and illustrated.

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Biochar as a Conducting Filler to Enhance Electrical Conduction Monitoring for Concrete Structures

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.847.149 ◽

2020 ◽

Vol 847 ◽

pp. 149-154

Author(s):

Siti Kamaluddin ◽

Denni Kurniawan ◽

Muhammad Saifullah Abu Bakar ◽

Zuruzi Abu Samah

Keyword(s):

Electrical Conduction ◽

Crack Detection ◽

Building Materials ◽

Concrete Structures ◽

Moisture Diffusion ◽

Spectroscopic Studies ◽

Moisture Loss ◽

Electrically Conducting ◽

Conducting Filler ◽

Ionic Movement

Smart and resilient concrete structures will require building materials such as cements that sense flaws. One mechanism of crack detection in structures is monitoring their electrical conduction. Two mechanisms of charge in cement is ionic movement and moisture diffusion. Carbon rich electrically-conducting char is produced by pyrolyzing rice husks and can be used to enhance electrical conduction in cement. This paper studies the evolution of electrical properties in ordinary Portland cement added with up to 15 wt% rice husk-derived biochar. Resistance of cements decreased with increasing biochar addition while moisture loss and resistance both increase as curing time increases. Cement with 15 wt% biochar experiences the largest moisture loss and the most conducting. This suggest charge transport along percolation paths of biochar particles is dominant mechanism in these materials. Electron microscopy and energy dispersive spectroscopic studies reveal formation of Ettringite phase and good wetting/bonding at the interface of biochar particles and cement.

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