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Printed Wiring Board Industry: Part 1 - 1 Introduction and Overview

This industry profile refers to the printed wiring board (PWB) industry, SIC 3672.

A. What is a PWB?

A printed wiring board (PWB) is the foundation both literally and figuratively for virtually all electronics in the world. It is the platform upon which electronic components such as integrated circuit chips and capacitors are mounted. The PWB, or printed circuit board (PCB) provides both the physical structure for mounting and holding electronic components as well as the electrical interconnection between components. A PWB consists of a non-conducting substrate (typically fiberglass with epoxy resin) upon which a conductive pattern or circuitry is formed. Copper is the most prevalent conductor, although nickel, silver, tin, tin-lead, and gold may also be used as etch-resists or top-level metal. There are three types of PWBs: single-sided, double-sided, and multilayer. Single-sided boards have a conductive pattern on one side only, double-sided boards have conductive patterns on both faces, and multilayer boards consist of alternating layers of conductor and insulating material bonded together. The conductive layers are connected by plated through-holes, which are also used to mount and electrically connect components. PWBs may also be either rigid, flexible, or a combination of the two (rigid-flex).

When the electronic components have been mounted on the PWB, the combination of PWB and components is an electronic assembly, also called a printed wiring assembly (PWA). This assembly is the basic building block for all larger electronic systems, from toys to toasters to telecommunications.

These electronic systems, in turn, support every other critical technology in the United States. To quote the Council on Competitiveness from their 1991 Gaining New Ground report, "Electronic components are playing an especially important role in driving improvements in information and communication technologies, which in turn are enabling advances in all manufacturing and service industries."

PWBs play a crucial role in these improvements because advances in electronic packaging and interconnections reduce the size and cost of electronic devices while boosting performance. Progress in PWB technology and manufacturing drives U.S. competitiveness in both existing products and new technologies. The U.S. Department of Defense, the U.S. Department of Commerce, the Japanese Ministry of International Trade and Industry, and the European Community all include electronic systems and components on their critical technology lists.

Electronics drive productivity in almost every industry one electronics job determines the competitive strength of seven jobs in other industries. Electronics are critical in medical systems, defense technologies, information processing, intelligent manufacturing, propulsion, and materials processing. In addition, a number of new, emerging industries depend on advancing the technical capability of the PWB industry. These include artificial intelligence, biotechnology, digital imaging technology, high-density data storage, high-performance computing, medical devices and diagnostics, opto-electronics, and more. U.S. competitiveness in these new technologies will depend upon advanced PWB technology and manufacturing capability in the United States.

B. Independent vs. Captive Production

PWBs are produced by two types of manufacturers: independent and captive. An independent or merchant manufacturer produces PWBs for sale on the open market, to be used in electronic products such as TVs, computers, and so forth. Independent PWB manufacturers are thus competing with each other in a global market to secure orders or contracts from customers. Typically, independent PWB manufacturers bid on their ability to make a product as specified by the customer; the PWBs or electronic interconnection products are almost always custom designed.

A captive manufacturer is also known as an Original Equipment Manufacturer or OEM. These companies manufacture PWBs for use internally in their own electronic products. Texas Instruments and AT&T are examples of OEMs. Some OEMs, such as IBM, which in the past have been exclusively captive manufacturers, have recently entered the merchant market as well.

In the United States, the majority of PWBs are produced by independent manufacturers. Many OEMs have shut down their PWB operations and now buy their PWBs from independent manufacturers. Unfortunately, as OEMs shut down their PWB manufacturing, they also discontinue research and development on new PWB manufacturing technology, processes, and materials. Because the average independent PWB manufacturer is orders-of-magnitude smaller than most OEMs, the independent PWB manufacturer lacks sufficient resources to conduct research on any scale approaching what the OEMs used to accomplish. Thus, PWB technology development in the United States has slowed down considerably.

C. General Nature of Industry

PWB manufacturing is a highly technical, complicated operation requiring large equipment investments and over fifty process steps. Because PWBs are designed for individual, specific applications, the PWB manufacturing industry is not considered a commodity industry. However, like a commodity industry, the PWB industry is characterized by highly competitive global sourcing with very low profit margins. Designs for specific PWBs can be transmitted electronically virtually anywhere in the world for fabrication.

In the United States, unlike some other areas of the world, the PWB industry has made substantial investments in pollution prevention and control, and is continuing to spend an average of 2.1% and as much as five percent of sales on regulatory compliance and pollution prevention. These investments have paid off with significant pollution prevention successes. For example, the Institute for Interconnecting and Packaging Electronic Circuits (IPC) and several IPC members won EPA Stratospheric Ozone Protection Awards for research on eliminating ozone-depleting substances from PWB manufacturing and assembly. Several IPC members have also won EPA 33/50 Pollution Prevention Awards for their aggressive work on preventing pollution, and many IPC members have won state or local awards for their proactive pollution reduction efforts.


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