Solder Paste Printing: Quality Assurance Methodology


Reading time ( words)

Solder paste printing is known as one of the most difficult processes to quality assure in electronic manufacturing. The challenge increases as the technology development moves toward a mix between large modules and small chip components on large and densely populated printed circuit boards. Having a process for quality assurance of the solder paste print is fast becoming a necessity. This article describes a method to ensure quality secured data from both solder paste printers and inspection machines in electronic assembly manufacturing. This information should be used as feedback in order to improve the solder paste printing process.

Introduction

This article has its roots in the need to improve capacity and quality levels at an electronics manufacturing site. Solder paste printing was identified early on as an area that needed to be secured with many of the new demands put onto the process by recent development in the manufactured products’ technology level.

A. The Solder Paste Printing Process

Solder paste printing is one of the most critical processes in electronic manufacturing. The purpose of the process is to apply the correct amount of paste, at the correct position, with the correct form and to do this every time a print is performed. Even though the process can be considered relatively simple, the quality results of the print together with the PCB provide the foundation for the rest of the surface mount process. A good print result is a prerequisite for a good soldering result, while a poor print will lead to additional process issues as the product travels through the manufacturing chain.

The printing process has the following demands and properties:
• Solder paste properties: the viscosity drops when the paste is handled
• Stencil surface friction: must be relatively high to force the paste to roll instead of skid
• Squeegee surface friction: shall be relatively low in order to allow for the paste to roll and release properly when lifted

Read The Full Article Here

Editor's Note: This article originally appeared in the May 2015 issue of SMT Magazine.

Share




Suggested Items

Real Time with... IPC APEX EXPO 2023: Automotive Electrification

02/08/2023 | Real Time with...IPC APEX EXPO
Nolan Johnson talks with Senior Product Manager Chris Nash of Indium Corporation, who discusses Durafuse LT, a novel solder paste mixed alloy system with highly versatile characteristics that enable energy savings, high-reliability, low-temperature, step soldering, and assemblies with large temperature gradients. It also provides superior drop shock performance to conventional low-temperature solders, outclassing BiSn or BiSnAg alloys, and performing better than SAC305 with optimum process setup.

Real Time with … IPC APEX EXPO 2023: Mycronic Extends Reach

01/11/2023 | Nolan Johnson, I-Connect007
Clemens Jargon, senior vice president of High Flex at Mycronic, shares his thoughts about the company’s performance in 2022 (it was a strong year), plans for the new year (turnkey solutions), and what visitors to the Mycronic booth at the show can expect to see in the company’s state-of-the-art Iris™ 3D AOI vision technology.

Five-Star Reflow Recipes: Q&A With Rob Rowland

12/28/2022 | Andy Shaughnessy, I-Connect007
In this Q&A, Rob Rowland, director of engineering at Axiom Electronics, discusses his new IPC APEX EXPO Professional Development course, “Reflow Profiling Simplified,” on how to create a standardized methodology to accurately generate new reflow soldering profiles. Rob explains, “In this class, I’ll explain how I approached this work to help others develop similar methodologies for creating their own reflow soldering profiles. My presentation also includes the basic reflow profile recipes I have been using for the past 20 years.”



Copyright © 2023 I-Connect007 | IPC Publishing Group Inc. All rights reserved.