Frost & Sullivan – Selective Soldering for Circuit Board Assembly

Continued globalization of business models, overcapacity (underutilization of manufacturing facilities), and low profit margins being the key challenges in the electronic manufacturing services (EMS) industry, different strategies are adopted by the EMS providers to address these issues.

Working along these lines, Florida-based MC Assembly is a mid-tier EMS provider which adopts a disciplined business model to tackle the challenges in the EMS industry efficiently.

With state-of-the-art production facilities in the USA and Mexico, the key business differentiators of MC Assembly include its customer-focused approach (which is evident from the long-term relationships with its customers, many of which have been doing business for 5 to 10 years) to selecting and servicing clients, RF (radio frequency) manufacturing and test capability.

The core competencies of the company are directed at delivering superior services with higher levels of value to customer relationships, fostering closer ties to their supply chain partners as well as manufacturing and testing higher levels of systems integration.

MC Assembly’s services include design for test and design for manufacturing engineering support services, pin through-hole and surface mount PCB assemblies, complex subassemblies, complete box builds, direct fulfillment and warranty/repair services. These services are directed at their targeted markets including the industrial, medical, A&D (aerospace and defense), networking and telecommunication industries.

Jake Kulp, vice president of sales and marketing at MC Assembly told spoke with Technical Insights regarding the company’s manufacturing processes for selective soldering. MC Assembly has employed numerous ERSA Versaflow selective soldering machines for over 6 years. The fountain-type selective soldering machines enables MC Assembly to achieve focused selective soldering without masking or booting (protecting) the sensitive SMT components or areas on the PCB. The ERSA machines are provided with cameras to visually monitor the soldering process. According to Kulp, the preheat function and the control/automation level offered by the fountaintype selective soldering machines are extremely beneficial in many applications that normally would require very time consuming hand operations.

Due to the fact that MC Assembly is involved in industries such as industrial, medical and aerospace/defense which utilize boards with heavy ground plans, it is vital that the selective soldering machines be utilized to minimize secondary operations and have a minimum amount of human touch.

Kulp indicated that MC Assembly employs selective soldering technology for mixed media type PCBs, boards with a heavy ground plane (the preheat functionality of selective soldering is helpful for such type of boards) and boards where hand soldering would prove very difficult due to component placement and accessibility to place a soldering iron in the correct spot to ensure a good solder joint. Kulp believes that the selective soldering technology is not driven by specific end-user markets as much as it is dependent on the technology required for the board design, the power requirement of the application, and the capabilities of the board designers.

MC Assembly has also incorporated selective soldering technology into its wave soldering process. MC Assembly’s use of precision wave pallets that incorporate exotic metals and hold-downs enables the company to expand the capabilities of traditional wave soldering to avoid secondary hand operations.

Kulp also mentioned that selective soldering technology is beneficial over hand soldering with regards to higher volume lot size manufacturing and for surge capacity, with greater repeatability and quality since secondary operations are removed.

MC Assembly still employs a large degree of hand soldering for different applications as volumes may not warrant other options or the board design may not have enough secondary operations that would lend itself to automation or precision wave pallets. In other cases where some rework may be required, boards which have been selectively soldered must be hand soldered as hand soldering is faster and more cost effective. In many instances, volume seems to be a major restraint to automate and many of MC Assembly’s customers are asking for smaller lot size deliveries.

Additionally, as the company grows in the aerospace and defense marketplace, the very small and spotty board requirements make hand soldering the only good option to support their customer needs.

MC Assembly has dedicated automated selective soldering machines for leadfree and leaded soldering. The same machine could be configured for either lead or for lead-free solder, but solder bath conversions can be a long process. MC Assembly manages these decisions by paying close attention to the order horizon and balancing its capital equipment needs against its customer’s firm demands. While some EMS companies publicize running both lead and lead free soldering in the same machine suggesting a quick and easy change over process, MC Assembly prefers to manage capacity with a longer view towards its customers needs.

Details: Jake Kulp, VP of Sales & Marketing, MC Assembly, 2755 Kirby Circle, Palm Bay, FL 32905. Phone: 321-253-0541; Ext 3774. E-mail: URL: