What is the core competency of PC Systems?
- June 29, 2010
- PC Systems
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Customer: “Do you sell hard drives?”
Us: “Unfortunately we do not, we are a electrical interconnect supplier.”
Customer: “…(silence)…I am not real sure what that means, but it sounds like you can’t help me. Thanks.”
This phone call occurs at least weekly. First, PC Systems does not stand for Personal Computer Systems, rather Paesano Connecting Systems, which alludes to how our company was originally started. The next question is “what is an electrical interconnect?”, which I often describe as: “If power/voltage/current needs to be transferred between two points we can provide the product to do that, regardless of complexity.”
What is the core competency of PC Systems? This is an interesting question, because as a team, we do everything we can to not pigeon-hole ourselves. We are constantly looking for alternative markets and adjacent technologies to broaden our footprint. This is where a significant portion of our harness and overmolded connector business has come from, but at the heart of our operations is our Flex Term department, particularly the window glass connector product line.
PC Systems develops products that electrically connect the vehicle wiring harness to the frit that is applied to automotive (and heavy equipment) window glass. This allows for a relatively high current, in automotive terms, to heat up the frit via resistance and consequently warm the glass providing a defrost function. There are multiple ways to connect the harness to this frit. Most of these include flowing solder from our connector onto the frit via a preform, clad clip of some kind, or reflow tab of solder. There are other methods as well, for example a mechanical/electrical connection via a snap, but that is another discussion. If you have ever had the inconvenience of needing to pull the window trim off your back window to fix a defroster, you likely have seen at least one of the methods for attaching a connector to glass. PC Systems has the capability to produce product that uses all of these methods mentioned above, but what we call the “preform and braid” product is our true core competency.
The reason we prefer preform and braid and continue to encourage our customers to use it is that it is functionally superior to other methods while at the same time providing a significant cost advantage. How is this possible? Quite frankly, it is a very simple product that can easily be automated. It is boring for Engineers, but music to the ears of Buyers. The reason it is functionally superior although simple is because the frit essentially uses the same design as it did when it was initially introduced. Solder sticks to the frit and not to the glass, therefore it is best that the solder “pad” is not defined by a fixed tin plated copper foot, rather it is allowed to move freely to be defined by the shape of the frit. This allows for flexible geometries and reduced frit widths which is preferred by the end user.
Also, the alternative to a “preform and braid” attachment is often to put a clad clip onto the braid, mechanically crimp the clip to the braid, and metallurgically bond the clip to the frit. This means there is no metallurgical bond from the frit to the braid, because the solder cladding is only on the bottom of the clip. This differs from the “preform and braid” in the fact that when the heat is applied to the preform, the braid will flood with solder in the immediate area of the heat and also flow down to the frit. This allows for a metallurgical bond between the braid and the frit.
Why is this a benefit?
One would imagine that inside the cabin of an automobile, hidden under a piece of trim, would be one of the least demanding environments for a product to reside. Anyone with automotive experience knows this isn’t true, although it is probably the least demanding location on the automobile itself. Ultimately, contaminants will work their way between the clip and the braid if only mechanically fastened. This is exacerbated by the temperature cycling that the part will see in application. As the temperature changes, the clip and braid will expand and contract at different rates, creating larger or tighter gaps between the material (due to CTE mismatch), and eventually work hardening and reducing the ductility of the clip. None of this is good, because we have to remember that we are sending around 20 amps through this braid. A high resistance at the point where the braid is attached to the frit could result in a hot spot which could reflow the solder or even worse result in fire. Who would have thought that your rear defrost unit could pose a safety risk?
I should preface this by saying that the layers of quality and safety paperwork that the automotive supply chain must complete should reduce the chance of spontaneous combustion of your rear windshield, but I think we are all aware of tires blowing off of Ford Explorers and the Toyotas that drive themselves.
Are there benefits to using methods other than “preform and braid”? Absolutely, which is why we offer all attachment methods to our customer. We just feel that “preform and braid” provides the best value for our customer and ultimately the end user.
Ironically, the method of using “preform and braid” is technically simple, but the frit and window design never are. Although it probably isn’t a surprise to you, customers are using the frit as antennas, reducing the frit width, trying to reduce the overall package of connectors and trim pieces, and reducing the size of the defroster grid to the point of not being able to see it in the window. In the end, the method of attachment of the connector is usually the last thing on the designer’s mind, which makes us happy to provide a product that is flexible enough to be designed around constraints and simple enough to be designed, built and shipped in less than a week, just in time for the IVER builds.