Wire & Cable Assembly: Putting a Crimp on Costs

By Bob Grenke, Application Tooling Product Manager, Molex Incorporated and
Pat Kililan, Product Manager, Molex Incorporated

Quality expectations
Customer expectations, with regard to quality, have changed drastically and are rising at a faster rate than some production environments can respond to. Because of this, many companies are changing their quality structure, their systems, and even their underlying quality philosophy to accelerate the rate at which improvements can be made. Zero defects have become a requirement which is causing companies to strive harder than ever before to produce perfect products. To make matters even more difficult, customers are also demanding a faster turnaround time. This is putting pressure on manufacturers to provide their customers with a top quality product in a short period of time.

In the past, the industry has used both pull force and crimp height evaluation to ensure an acceptable quality crimp. Because of recent trends with crimping, other critical specifications are being explored, such as crimp width, CPK, and cross section analysis.

One response to this increasing need for excellent quality has been the introduction of the IPC/WHMA A-620 standard. The A-620 was recently introduced by IPC/WHMA as the most recent comprehensive standard for the cable and wire harness assembly industry. Many customers are using crimp terminal products that were developed over 20 years ago, where the primary goal was to put as many wire gauges into one terminal as possible with the least amount of tooling. While these crimp products have a long history of successful performance, the industry’s quality standard has changed in some markets. For this reason, connector companies may have to develop new crimp specifications that no longer put multiple wire gauges in a terminal to meet the A-620 standard, if required. Fortunately, the A620 standard is the only guideline that allows for customer flexibility, enabling a customer to make strategic business decisions that include whether or not to incur additional costs.

Pat Killian, product manager, Molex Incorporated, adds, "While the A-620 is a good standard and a great idea from a quality perspective, it does mean you may need more tooling to meet a class in the A-620 standard. This means more investments in crimp equipment and higher costs for the wiring harness manufacturer.”

To meet one of the three classes from the A-620 standard, multiple tools would be required due to the variation in wire insulation thickness. As the wire insulation thickness changes, the conductor crimp area is unaffected. However; the insulation crimp may look poor depending on how much material the terminals have in relation to the insulation thickness. The dilemma is this; you can either put multiple wire gauges in a terminal with a wide insulation specification  which in some combinations will not meet a class in the A-620  or, connector companies will need to reduce the amount of wire gauges in terminals, which will require an increase in tooling costs.

"This (A-620) signals a good effort toward continuous improvement in the wiring harness industry,” says Robert Grenke, application tooling product manager, Molex Incorporated. “As the quality crimp expectations are tightened, the industry will need to develop specialized terminal or tooling products. However, multiple tools will force contract manufacturers to spend more on tooling.”

With increasing competition from overseas and price pressures from customers, wire harness assembly companies may be concerned about adding costs to the manufacturing process.

Competition becomes harsh
Pricing has become a serious issue and is a constant struggle for both connector manufacturers and wire harness houses. More and more manufacturers are either outsourcing to other countries or moving overseas to try and stay as competitive as possible.

In particular, there seem to be three main pricing pressures that are affecting wire harness manufacturers:

1. Overseas CMs pricing structure in areas like China have put increased pressure on CMs in the U.S. and Mexico, resulting in lower margins. Also, the exchange rate is working against American companies right now.

2. An increase in raw material prices, such as copper, has caused an increase in terminal prices.

3. As higher crimp quality has been an issue, more types of tooling may be required, which increases a customer's investment and applied costs.

CMs will need to be more flexible and conduct a detailed cost analysis on the best way to process each production run to ensure they are as competitive as possible. No longer can anyone process all production runs the same way without understanding the true cost. Is it more cost effective to use a manual process, semi-automatic process, or a fully automatic process? CMs will need to understand what their current tooling inventories are and try to promote the usage of a terminal with their end customer, for which they already have tooling. Also, it will be important to understand which insulation thickness will provide the better insulation crimp. Many of the existing tools in the marketplace today have an insulation thickness range that allows for flexibility. In many cases, a specific thickness would allow the assembly to meet the A-620 standard.

It appears as if the next few years will be critical for the North American CM market. With the current global CM price pressures, everyone is looking to reduce costs and improve, or at least maintain, a high standard of quality. Many CMs are already reducing manufacturing costs through detail analysis of their current process. CMs more than ever will need to be working with their end customers and become a partner. Helping to design in the proper terminal and wire combinations will reduce the overall cost of the assembly to the end user, making it more competitive and providing a higher quality assembly. This strategy allows the CM to use existing tooling, reducing costs and improving their long-term economic condition.