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Getting to Know Your Designer
In this issue, we examine how fabs work with their design customers, educating them on the critical elements of fabrication needed to be successful, as well as the many tradeoffs involved. How well do you really know your customer? What makes for a closer, more synchronized working relationship?
In this issue, the biggest names in PCB manufacturing share their economic outlook for the upcoming year and beyond. As you will see, they were all bullish on our industry, but there was some apprehension as well. No one wants to get burned by another the supply chain disruption.
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All About Flex: Plated Through-holes in Flexible CircuitsOctober 29, 2015 | Dave Becker, All Flex
Estimated reading time: 4 minutes
There is probably no more important feature than the plated through-hole (also called via or via hole) with regard to the reliability and integrity of a flexible circuit. The through-hole provides electrical connection between insulated layers and enables electrical functionality on double-sided and multilayer flexible circuits.
There are a number of methods that a flex circuit manufacturer may use when generating a via hole. For example, one can create through-holes on a panel with no circuit patterns defined, or one can insert the through-holes after the circuit traces have been imaged and etched. There are advantages and disadvantages for both situations, but the basics of creating a through-hole are the same.
The first step in via formation is to create a hole through the laminate. The hole can be created by mechanical drilling, laser drilling or punching. Once the hole has been drilled, an adhesive-based laminate will look similar to the diagram below:
Figure 1: Through-hole, side view.
Figure 1 depicts the case where a laminate consisting of copper foil, adhesive, dielectric, adhesive and copper foil are used. Adhesiveless laminates are also very popular and are produced with a variety of technologies that bond copper to dielectrics sans adhesive.
Electroplating is a process where metal ions are bonded to a metal surface. The process requires a voltage potential between a copper source (anode) and the plating target (copper circuit). Both the anode and copper circuit are immersed in a copper sulphate solution with an applied voltage potential. This promotes ion flow from the anode to the cathode (the circuit). Areas of a circuit panel with a voltage potential will get plated, so any part of a copper circuit that is electrically isolated will not get plated. Since copper layers are separated by dielectric materials, and there is no electrical charge going through the through-hole, electroplating between layers is not possible. In order to allow electroplating, a conductive “bridge” must be coated over the insulating layer.
The two most common methods for creating that conductive bridge are:
- Electroless copper plating
- Shadow plating
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After working for a capital equipment supplier for almost 50 years, I’ve found that the most important part of getting to know your vendor is good communication among all parties. While contact between fabricators of a constantly changing product line and the designers of those products may occur daily or weekly, conversations between you and your equipment supplier may be years apart. That lengthy gap often means that previous contacts may have been promoted, retired, or moved on to other opportunities. You may have also migrated to a new supplier with whom you have little or no history. In either case, you will be interacting with someone you are unfamiliar with (as they are with you). Therefore, it is essential for both sides to communicate clearly so expectations will align.
The opening session of the second day’s conference proceedings focused on global PCB trends and was introduced and moderated by Dr. Michele Stampanoni, vice president of strategic sales and business development at Cicor Group in Switzerland. He opened the session with Dr. Hayao Nakahara’s knowledgeable and enlightening video presentation on the IC substrates industry.
The 2024 Winter Conference of the EIPC took place January 30 and 31 at the IHK Academie in Villingen-Schwenningen, Germany. The keynote session will be reported separately. Here is my review of the first day’s conference proceedings.
Electrodeposition comes down to fundamentals. In the early days of plating, many users considered the nuances of metallization as black magic. Those days are long gone. Having a thorough understanding of the critical parameters that influence electrodeposition will determine success.
High Density Packaging User Group (HDP) is pleased to announce that Shikoku Chemicals Corporation (Shikoku) has become a member.