 The conventional wisdom of out-sourcing circuit card assemblies has changed in the last 15 years. Many military and aerospace suppliers are at a crossroads on how to manufacture their high/mix low-to-medium-volume circuit cards. Although many of them have in house circuit card assembly capabilities (CCA) staffing, and managing low volume production does not yield high profit or guarantee technology insertion for items such as small packaging density, soldering tech nology, or procurement process changes.
For those military and aerospace suppliers who do not have CCA capability or who are just beginning board products, there is an endless supply of CCA manufacturers to choose from. Choosing the correct vendor or outsourcing partner is crucial. Here are a few items to consider:
- What stage are you in the design cycle?
- Who should perform critical design steps?
- When should you involve the manufacturing partner?
Many articles address specific details on the design and manufacturing processes, yet not many articles show the benefit of involving the manufacturer as a partner or solution supplier. My aim is to answer some of the questions related to the out-- sourcing partnership. First, the earlier the involvement of the manufacturer, the greater the return on such intangibles as component and material selection, lead time performance, obsoles-cence, and realistic scheduling for delivery.
Next, manufacturers should start with complimentary outsource partner. Choosing the right partner and involving him early in the design process will help resolve and minimize long-term problems.
Company experts should ask:
- Can the design even be manufactured?
- Are the package densities available?
- Can the supplier place the types of components selected using automated nology and controlled processes?
Early involvement by the manufacturer as part of the integrated product team(IPT) minimizes the negative impact caused by these issues. In the event the design cannot be compromised, it allows the manufacturing team time to develop new processes, new tooling, or new
technologies. Remember, capital planning can be an 18-month activity ... if developers miss the planning window.
In addition, many outsource partners offer post-design capability. Many offer board-layout services using the latest com- ponent libraries. This enables the manufac- turer to work directly with the printed wiring board (PWB) suppliers to reduce and keep board-layout constraints to a minimum. This helps reduce the costs of raw a printed wiring boards. Some manufacturers also offer component design services, such as application-specific integrated circuits Layne Shumaker (ASICs), while others offer component screening services for commercial off the shelf (COTS) components.
The reality of components and materials
Component assembly processes and technology have improved tremendously over the past 30 years. Component selection used in the design may not require the use of fully qualified parts. In many cases, due to lower volumes and higher test costs, fully qualified parts are no longer available in all package types. Many suppliers offer industrial quality parts that meet the military and aerospace requirements. Although I am not a proponent of source control drawings, these drawings allow material suppliers to provide off-the-shelf components that can be screened for unique test requirements like DPA, PIND and RLAT.
These tests can be specified at the designer’s discretion. Outside test services are becoming more popular and are easily administered by the manufacturers’procurement departments. Many of the large component distributors even provide these services by managing their own test house suppliers.
We find managing the bill of materials from prototyping through production centralizes the oursource partners ability to work with the initial design and production teams to assure materials availability and processes creation and validation. In addition, many documentation errors can be corrected during the prototyping process. Many of the components are defined incorrectly, resulting in loss of parts, incorrect
package configurations (i.e. flatpak versus gull wing), and lack of availability. Some outsource partners do not have the ability to lead form components. This can be an expensive mistake. Look for universal lead forming equipment.
One additional tip: use electronic copies of the parts lists to minimize manufacturing process time ¡X from procurement and quoting, to automated placement, to first article inspection, and finishing with customer acceptance of the product. If your partner uses paper ¡X explore methods to change.
It is easy to forget materials requirements planning (MRP), and electronic parts lists help to load these fundamental system requirements. Each project and product is at a different phase in a product life cycle.
The use of a flexible MRP system should include the abilit y to use consigned or provide full turnkey procurement of parts and materials. Although it is desirable to start product development in the lab and finish at an outside assembly house for prototyping,low rate initial production (LRIP), or production, it is important to know that costs can be contained or reduced by ordering parts at the time of initial development. Manufacturers may use many items procured for production during the long-term or no cost. Many times minimum buys or automated equipment processes drive the quantity of components procured for production. There are benefits to using production-grade parts such as placing a single purchase order or buying bulk material issues, such as tape and reel or tubes. Parts ordered at the time of prototyping are stocked and available for production.
One strategic question when selecting your partner is “Do they have the ability to demonstrate process compliance?” Many outsourcing suppliers do not possess documented processes for controlling customer-supplied documentation. How does the supplier handle non-recurring activities or how is the process set-ups validated? Are processes in-place to support repeatable techniques required for the- aerospace environment?
ISO-9000 has created a standard base line for validating the suppliers under standing of assembly. Can the supplier live up to the task? How detailed or specific is their quality program? It is imperative there is a closed-loop system for addressing non-conformance to process? Does the than one source? How do customers view the supplier? Can the supplier assemble in low volume and do they have processes in place to support low volume prototyping versus low volume production?
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