Conformity Magazine - December 2008 - (Page 35)

Once the electroless copper layer is deposited onto the plastic part, additional copper thickness can be deposited as required for EMI shielding performance, and/or can be finished with nickel, tin or gold to provide the functional metal coating to meet the full range of mechanical, electrical, environmental and appearance requirements. Typically, electroless plating is used to deposit thin metal coatings, from 0.00004” (1.0 µm) to 0.0005” (12.5 µm). If thicker coatings are required, electrolytic plating (also called electroplating) can be used to deposit thicker coatings of copper, nickel, tin, chrome, silver, and gold over the electroless copper plated part. Electroplating deposits at faster rates and lower costs compared to the same thickness of electroless plating; however, electroplating is a line-of-sight process that will yield wider thickness variation over a part than does electroless plating. Electroplating process can be used to deposit from 0.0002” (5.0 µm) to 0.003” (75 µm) or more metal thickness. Also, electroplating is used to produce decoratively plated plastic parts with available finishes, including nickel, bright and matte chrome, gold, copper and brass, to name a few. Selecting a plateable resin is among the most critical factors for a successful EMI shielding application. Table 1 lists common injection molded thermoplastic resins. It includes plateable as well as non-plateable resins, and some resin families that include both plateable and non-plateable grades. Some (but not all) non-plateable resins can be made plateable by custom blending a plating additive into the base resin. Examples of custom blending to produce plateable resins include polypropylene and polyphthalamide. Both resins are typically not plateable but, when custom blended with the plating additive, become plateable. Plating can be applied over the entire part as described above, or selectively, onto specified areas. There are several options for selective plating, depending on the required precision for the plating pattern, design, and the plastic resin, as noted below. Autocatalytic Plating Catalyst Spray plating catalyst onto the areas of the plastic part, using custom built paint masks to control the location of the catalyst. The chemical make-up of the catalyst draws copper metal out of the plating solution, and deposits copper uniformly onto the catalyzed area. Following electroless copper plating, electroless nickel plating can be applied to protect the copper from corrosion and abrasion. The plating catalyst thickness is approximately 0.001” (0.025 mm), and the electroless plating thickness is limited to 0.0001” (2.5 µm) to 0.00025” (6.25 µm). The plastic parts are never exposed to aggressive chemistries; therefore, the molded-in-color and texture of the plastic part are maintained through the process. Custom Shields & Precision Metal Parts Shield Design Options: Board-level Removable lid Multi-cavity Complex geometry Shielding Materials: Brass Steel Aluminum Titanium Nickel Silver Fotofab works with hundreds of alloys RF Shields & More… Whether you need a multi-cavity shield or a simple five-sided box, Fotofab has a solution for you. Visit our Shielding Design Guide at www.fotofab.com/RF. Have a shield or metal part ready for quote? Submit your specifications and drawing online. Of course, you can always call one of our Technical Sales Staff at (773) 463-6211 to discuss shielding material, plating, design options and cost saving ideas. Precision Metal Parts We work with hundreds of alloys ranging from 0.0002” (0.05mm) to 0.090” (2.29mm) thick. Fotofab offers chemically etched parts, laser cutting, plating, electro polishing, tape & reel packaging and more. Fast Delivery Fotofab understands the importance of a deadline. Our standard lead-time starts at 2 weeks with multiple expedite options available. You can even go from print-to-part as fast as same day! Ask about our 24-hour expedite service! For over 40 years, Fotofab has been manufacturing quality shields and precision metal parts. Would you like a copy of our “Design Guide to Photochemical Machining”? Visit us at www.fotofab.com/RF and we will send you a FREE copy. Prototype or production, think of Fotofab for your shielding needs. 3758 Belmont Avenue phone 773-463-6211 www.fotofab.com/RF Chicago, IL 60618 USA fax 773-463-3387 sales@fotofab.com Innovative solutions - exceptional capabilities DeCember 2008 Conformity 35 http://www.fotofab.com/RF http://www.fotofab.com/RF http://www.fotofab.com/RF http://www.fotofab.com/RF

Table of Contents Feed for the Digital Edition of Conformity Magazine - December 2008

Conformity Magazine - December 2008 Contents Editor's Note FCC Warns Regulatory Fee Payers About Potential "Phishing" Commission Prowls the Web to Enforce Its Regulations First DTV Rollout Initiated in Wilmington, NC New Standards List Released for the EU's Directive on the Safety of Toys ESD Association Call for Papers ESDA. JEDEC Announce Standards Development Cooperation Commission Releases Data on Local Telephone Competition The Future of ESD Testing ESD Open Forum Emerging Issues in Standards: China RoHS: One Year and Counting Challenges in Testing: Revisiting 10-Meter and 3-Meter Radiated Emission Measurements Design Fundamentals: Meeting the Shielding Challenges of Injection-Molded Plastics Focus On...Microwave Absorbers Buyer's Guide FDA Recalls Automated External Defibrillators FDA Revises Guidance on Medical Device Tracking Guidance Document Safety of Passive Implants Released FDA Offers Guidance on Marketing Diagnostic Ultrasound Systems EU Commission Issues Correction on Machinery Directive Standards Other CPSC Actions in the News Product Reviews IEC Standards Update UL Standards Update Looking Back: Items from Past Issues of Conformity Advertisers

Conformity Magazine - December 2008

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