• SMTnet
  • »
  • Technical Library
  • »
  • Novel Approach to Void Reduction Using Microflux Coated Solder Preforms for QFN/BTC Packages that Generate Heat

Novel Approach to Void Reduction Using Microflux Coated Solder Preforms for QFN/BTC Packages that Generate Heat

Published:

August 7, 2019

Author:

Anna Lifton, Paul Salerno, Jerry Sidone, Oskar Khasalev

Abstract:

The requirement to reconsider traditional soldering methods is becoming more relevant as the demand for bottom terminated components (QFN/BTC) increases. Thermal pads under said components are designed to enhance the thermal and electrical performance of the component and ultimately allow the component to run more efficiently. Additionally, low voiding is important in decreasing the current path of the circuit to maximize high speed and RF performances. The demand to develop smaller, more reliable, packages has seen voiding requirements decrease below 15 percent and in some instances, below 10 percent.

Earlier work has demonstrated the use of micro-fluxed solder preforms as a mechanism to reduce voiding. The current work builds upon these results to focus on developing an engineered approach to void reduction in leadless components (QFN) through increasing understanding of how processing parameters and a use of custom designed micro-fluxed preforms interact. Leveraging the use of a micro-fluxed solder preform in conjunction with low voiding solder paste, stencil design, and application knowhow are critical factors in determining voiding in QFN packages. The study presented seeks to understand the vectors that can contribute to voiding such as PCB pad finish, reflow profile, reflow atmosphere, via configuration, and ultimately solder design.

A collaboration between three companies consisting of solder materials supplier, a power semiconductor supplier, and an electronic assembly manufacturer worked together for an in-depth study into the effectiveness of solder preforms at reducing voiding under some of the most prevalent bottom terminated components packages. The effects of factors such as thermal pad size, finish on PCB, preform types, stencil design, reflow profile and atmosphere, have been evaluated using lead-free SAC305 low voiding solder paste and micro-fluxed preforms. Design and manufacturing rules developed from this work will be discussed....

  • Download Novel Approach to Void Reduction Using Microflux Coated Solder Preforms for QFN/BTC Packages that Generate Heat article
  • To read this article you need to have Adobe PDF installed

You must be a registered user to talk back to us.

 

Company Information:

See Company Website »

Company Postings:

(5) technical library articles

  • Jan 17, 2023 - Introducing Closed-loop Nitrogen Control To Solder Reflow | Heller Industries Inc.
  • Jan 17, 2023 - How Challenging Conventional Wisdom Can Optimize Solder Reflow | Heller Industries Inc.
  • Jan 17, 2023 - The User Benefits of a Supplier Partnership | Heller Industries Inc.
  • Jan 17, 2023 - Vacuum Fluxless Reflow Technology for Fine Pitch First Level Interconnect Bumping Applications | Heller Industries Inc.
  • Jan 17, 2023 - Flux Management | Heller Industries Inc.
  • Browse Technical Library »

Novel Approach to Void Reduction Using Microflux Coated Solder Preforms for QFN/BTC Packages that Generate Heat article has been viewed 699 times

  • SMTnet
  • »
  • Technical Library
  • »
  • Novel Approach to Void Reduction Using Microflux Coated Solder Preforms for QFN/BTC Packages that Generate Heat
Jade Series Selective Soldering Machines

2023 IPC Certification Training Schedule Eptac