Progress in Adhesion and Adhesives, Volume 4

K. L. Mittal

• Publisher: Wiley-Scrivener
• Year: 2019
• ISBN:
  9781119625292
• Edition: 1
• Topic: Technology & Engineering
• Subtopic: Materials Science
• Index: Technology & Engineering

A solid collection of interdisciplinary review articles on the latest developments in adhesion science and adhesives technology

With the ever-increasing amount of research being published, it is a Herculean task to be fully conversant with the latest research developments in any field, and the arena of adhesion and adhesives is no exception. Thus, topical review articles provide an alternate and very efficient way to stay abreast of the state-of-the-art in many subjects representing the field of adhesion science and adhesives.

Based on the success of the preceding volumes in this series "Progress in Adhesion and Adhesives"), the present volume comprises 9 review articles published in Volume 6 (2018) of Reviews of Adhesion and Adhesives.

The subject of these reviews fall into the following general areas:

1. Adhesion to wood and wood bonds

2. Adhesive joints

3. Adhesion in microelectronic packaging

4. Surface modification

5. Contact angle, wettability and surface free energy.

The topics covered include: Adhesion phenomena in microelectronic packaging; adhesives for wood and lignocellulosic materials; adhesion to wood and lignocellulosic materials; adhesively bonded lap joints having bi-adhesive and modulus-graded bondlines; adhesion between compounded elastomers; applications of contact angle measurements in pharmaceuticals and foods; oxygen or ammonia plasma treatment of polyolefin surfaces; surface free energy determination of powders and particles; wood bonds; and dispersion adhesion forces between macroscopic objects.

Chapter 1
Adhesion Phenomena Pertaining to Thermal Interface Materials and Solder Interconnects in Microelectronic Packaging: A Critical Review

Dinesh P R Thanu^1*, Aravindha Antoniswamy², Roozbeh Danaei³ and Manish Keswani⁴

¹Department of Materials Science and Engineering, University of Arizona, Tucson, AZ 85721, USA

²Department of Materials Science and Engineering, University of Texas at Austin, TX 78712, USA

³School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99163, USA

⁴Department of Materials Science and Engineering, University of Arizona, Tucson, AZ 85721, USA

*Corresponding author: [email protected]

Abstract

High performance and diverse power computing needs in desktop, server, communication, automotive, and artificial intelligence microelectronic sectors demand microprocessors with different form factors and intricate package designs. For such complex package architectures, semiconductor chips in addition to microprocessor, such as in-package memory, transceivers or a combination of both are essential to attain maximum performance. Integrated Heat Spreader (IHS) assembly with thermal interface material (TIM) layers plays a vital role in providing heat dissipation for these integrated circuit chips and aids them to perform with maximum efficiency for a long duration. Additionally, for Ball Grid Array (BGA) semiconductor packages, interfacial adhesion quality of solder attach material is very critical in determining package quality and reliability. There are numerous challenges associated with developing and optimizing such an IHS assembly process and solder attach material for high volume manufacturing with good throughput, quality and yield. Here we provide a comprehensive review of the adhesion mechanisms and challenges of polymer TIMs to IHS-metal interface and various techniques proposed in the literature to enhance their adhesion. Complexities involved in solder attach adhesion including material selection and chip assembly interaction are reviewed in detail as well.

Keywords: Adhesion, ball grid array, integrated heat spreader, interconnect, microelectronic packaging, solder flux, thermal interface material

1.1 Introduction

Integrated Heat Spreader (IHS) assembly is an integral part of a microelectronic package to accomplish efficient thermal dissipation from one or more semiconductor chips and to attain overall device thermal performance [1–5]. State-of-the-art IHS assembly process is used in various application sectors including desktop, server, communication, automotive, and artificial intelligence. In an assembly process, semiconductor chips or dies are first placed on an organic or ceramic substrate. Front layer interconnect and an underfill layer are further used to hold the dies mechanically. Furthermore, an IHS is glued on the substrate to protect the die and aid with its heat dissipation [6–8]. During IHS assembly, a thermal interface material (TIM) is placed or dispensed on the surface of the die and an adhesive or sealant material is further applied and cured on the organic substrate layer (motherboard) to mechanically hold the IHS in place. A TIM layer is placed between the die and the IHS referred to as TIM₁ and between IHS and heat sink referred to as TIM₂ as shown in Figure 1. A Ball Grid Array or BGA package is a form of surface mount technology (SMT) that is being used increasingly for integrated circuits. It has become one of the most popular packaging alternatives for high input/output devices in the industry. Apart from the improvement in connectivity they offer, BGAs have other advantages. They offer a much lower thermal resistance between the silicon chips than the quad flat pack devices. This allows heat generated by the integrated circuit inside the package to be conducted out of the device on the PCB faster and more effectively. The whole bottom surface of the device can be used on a BGA as compared to just the perimeter on a Land Grid Array (LGA)package. BGA packages have solder balls pre-attached to the bottom of the substrate, hence resulting in a higher stand-off height compared to LGA packages.

Figure 1.1 Schematics of multiple thermal architectures. (a) Designs typically used in laptops without an IHS (b) Architectures used in desktop, server and high-end gaming applications with an IHS. I- Heat Sink; II-TIM₂; III- IHS; IV- TIM₁; V- Silicon Die; VI- Underfill; V...

Table of contents

• Cover
• Title Page
• Copyright
• Preface
• Chapter 1: Adhesion Phenomena Pertaining to Thermal Interface Materials and Solder Interconnects in Microelectronic Packaging: A Critical Review
• Chapter 2: Influence of Silicon-Containing Compounds on Adhesives for and Adhesion to Wood and Lignocellulosic Materials: A Critical Review
• Chapter 3: Recent Advances in Adhesively Bonded Lap Joints Having Bi-Adhesive and Modulus-Graded Bondlines: A Critical Review
• Chapter 4: Adhesion between Compounded Elastomers: A Critical Review
• Chapter 5: Contact Angle Measurements and Applications in Pharmaceuticals and Foods: A Critical Review
• Chapter 6: The Formation Processes of Functional Groups at Polyolefin Surfaces on Exposure to Oxygen or Ammonia Plasma: A Critical Review
• Chapter 7: Surface Free Energy Determination of Powders and Particles with Pharmaceutical Applications: A Critical Review
• Chapter 8: Understanding Wood Bonds–Going Beyond What Meets the Eye: A Critical Review
• Chapter 9: Dispersion Adhesion Forces between Macroscopic Objects–Basic Concepts and Modelling Techniques: A Critical Review
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