-
- News
- Books
Featured Books
- design007 Magazine
Latest Issues
Current IssueAdvanced Packaging and Stackup Design
This month, our expert contributors discuss the impact of advanced packaging on stackup design—from SI and DFM challenges through the variety of material tradeoffs that designers must contend with in HDI and UHDI.
Rules of Thumb
This month, we delve into rules of thumb—which ones work, which ones should be avoided. Rules of thumb are everywhere, but there may be hundreds of rules of thumb for PCB design. How do we separate the wheat from the chaff, so to speak?
Partial HDI
Our expert contributors provide a complete, detailed view of partial HDI this month. Most experienced PCB designers can start using this approach right away, but you need to know these tips, tricks and techniques first.
- Articles
- Columns
Search Console
- Links
- Media kit
||| MENU - design007 Magazine
Slash Sheets and Material Selection
June 1, 2023 | I-Connect007 Editorial TeamEstimated reading time: 2 minutes
In a recent I-Connect007 survey to PCB designers, about one third of respondents said they consult IPC’s so-called slash sheets, such as IPC-4101/126, that contain a variety of information about PCB materials. But many designers say these specs don’t contain enough information. Some ask their fabricator to pick a material, and still others say, “It’s an RF board, and I always use supplier X for RF.” What’s the best process for selecting your PCB materials?
Doug Sober helped pioneer the development of IPC’s first slash sheets in 1996 for IPC-4101 Specification for Base Materials for Rigid and Multilayer Printed Boards and we asked him to discuss slash sheets—what they are, what they are not, and why PCB designers might benefit from an IPC materials guide developed specifically for designers.
Andy Shaughnessy: Doug, let’s start with your work with IPC and slash sheet development.
Doug Sober: I started in the laminate and prepreg business in 1978 for General Electric and was sent to my first IPC meeting in 1980. I got heavily involved right away with the task groups regarding specifications for laminates, prepregs, copper foils, glass fabric, resin coated foil, etc. The first standard we did was IPC-4101, but it did not just come out of thin air. We had a document from the military called MIL-S-13949H that had requirements for base materials. The requirements were physical such as flex strength and peel strength, electrical such as Dk and Df, thermal such as Tg and solder float, and environmental such as moisture absorption and fungus resistance. After IPC-4101 was all finished, it had specification sheets for simple FR-4s and polyimide base materials of various types.
The military had these specification sheets which described specific base materials and, as laminate and prepreg producers, we had to qualify our products to the requirements of the sheets. With specification sheet 21, for example, a bevy of lab tests proved that we met the requirements. Then the Defense Electronics Supply Center (DESC) would list our product by commercial name on their qualified product list (QPL). For example, Westinghouse’s FR-4 product 65M38 as listed on the QPL for specification sheet 21. Once a year, Lowell Sherman or Dave Corbett from DESC came to audit each base material supplier. When the 3-11 subcommittee created IPC-4101, we duplicated MIL-S-13949 because we wanted the military to sign off on it, discontinue their document, and use IPC-4101 in its place. In 1996, with the help of Dave Bergman negotiating with the military higher-ups, IPC-4101 was launched and Mil-S-13949 was discontinued.
To read this entire conversation, which appeared in the May 2023 issue of Design007 Magazine, click here.
Suggested Items
Book Excerpt: The Printed Circuit Assembler’s Guide to... Low-Temperature Soldering, Vol. 2, Chapter 5
12/23/2024 | I-Connect007 Editorial TeamChapter 5 introduces the advantages of using low-temperature soldering for through-hole components, including cost efficiency, reliability improvement, and reduced warpage. Also covered: the evaluation of different fluxes and the performance of HRL3 in wave soldering and selective soldering processes.
Overview of Soldering Systems With Vacuum
12/18/2024 | Dr. Paul Wild, Rehm Thermal Systems GmbHWhen soldering electronic assemblies, the focus of the vacuum application is on the removal of volatile substances from the solder joints and the associated reduction of pore formation. Particularly in the thermal management of power electronics components, pores can cause so-called hotspots with higher temperatures due to their poor heat conduction. These hotspots can lead to overheating of the components on the one hand and to thermally induced destruction of the solder structure on the other.
I-Connect007 Editor’s Choice: Five Must-Reads for the Week
12/13/2024 | Andy Shaughnessy, I-Connect007This week, Peter Tranitz discusses the upcoming Pan-European Electronics Design Conference, set for Jan. 29-30 in Vienna, Austria. Pete Starkey brings us a review of the most recent EIPC Technical Snapshot webinar, which featured a global PCB maker update by Dr. Hayao Nakahara. Don't miss our interview with Manfred Huschka, who explains how companies can begin their own China Plus One plan. Stan Farnsworth breaks down photonic soldering and discusses its use in soldering materials that are not typically compatible. I also enjoyed Dan Beaulieu’s discussion on the value of consistency, and why just showing up for work is half the battle, especially in an inconsistent, evolving industry like ours.
Advancing Photonic Soldering
12/11/2024 | Nolan Johnson, SMT007 MagazineStan Farnsworth, director of customer satisfaction at PulseForge, discusses the advancements in photonic soldering that highlight its energy efficiency and versatility. Over the past two years, the company has refined its applications for flexible substrates and energy reduction, finding that photonic soldering allows the processing of materials that typically aren’t thermally compatible and offers significant energy savings compared to traditional methods.
Indium Introduces New ROL0 and Halogen-free Flux-cored Wire
12/11/2024 | Indium CorporationIndium Corporation announced the global availability of CW-807RS, a new high-reliability, halide- and halogen-free flux-cored wire that improves wetting speeds and cycle times for electronics assembly and robot soldering applications.