Autosplice expands SMiT shield clip family with introduction of the maxi-clip for handling larger, thicker RF shields

Citation

(2004), "Autosplice expands SMiT shield clip family with introduction of the maxi-clip for handling larger, thicker RF shields", Soldering & Surface Mount Technology, Vol. 16 No. 1. https://doi.org/10.1108/ssmt.2004.21916aad.010

Autosplice expands SMiT shield clip family with introduction of the maxi-clip for handling larger, thicker RF shields

Autosplice expands SMiT shield clip family with introduction of the maxi-clip for handling larger, thicker RF shields

Keywords: Surface mount technology

Autosplice has introduced the maxi-clip, the newest member of the innovative surface mount interconnect technology (SMiT) shield clip family of products. In combination with the earlier introduced standard shield clip and mini-clip products, the maxi-clip gives designers a complete set of solutions for handling the full spectrum of RF shield requirements. Like the standard shield clip and the mini-clip, the maxi-clip incorporates all advantages of the standard high-speed SMT placement and reflow soldering processes to effectively eliminate the hassles and inefficiencies of secondary hand soldering operations traditionally required for mounting EMI/RF shields.

According to Steve Fleming, Technical Marketing Manager at Autosplice, “The maxi- clip was developed in response to the growing industry need for mounting larger and thicker RF shields, especially where board space is not as much of a constraint. Just as the mini-clip provides the small size needed for mounting RF shields in pagers or cell phones, the maxi-clip provides the superior pull-strength and thickness capacity needed for securely holding the larger shields typically used in base-station assemblies or set-top boxes. The capacity of the maxi-clip to flexibly handle greater thicknesses also allows more process variability in the manufacturing of the RF shields by eliminating the need for tapering or precision deburring of the inserted edge. Coupled with the ability to use standard placement and reflow processes, the maxi-clip’s flexibility can significantly simplify manufacturing processes and reduce overall production costs.”

The maxi-clip provides a large nozzle pick-up area to optimise placement processes and asymmetrical base design to promote precise pad alignment. With four independent contact beams and four redundant contact points, the maxi-clip provides the ultimate in reliability and retention strength. In addition to the maxi-clip’s wide opening, long beam length and large deflection range assist in the shield insertion process and accommodate a wider range of shield thicknesses, while maintaining high normal forces.

Some of the other key benefits common to the SMiT maxi-clip, standard shield clip and the mini- clip include: multiple SMiT clips can be arranged in any configuration on the PCB to handle virtually any size or shape of RF shield. Overall design flexibility and cost tradeoffs can easily be balanced between the number and spacing of the shield clips and/or notching of the RF shield to reduce the distance between the shield and the PCB, thereby cost-effectively handling applications with frequency ranges up to 1.5 GHz and higher.

EIA packaging and ample surface area for vacuum-nozzle pick-up allow for the smooth handling and placement of the shield clips at sustained rates of up to 20,000 parts per hour on brand name equipment, such as FUJI, Panasonic, KME, and Sanyo. Maxi-clip, mini-clip and standard shield clips are designed to self-align by as much as a 20 per cent correction during standard reflow solder processes, while facilitating the formation of optimal solder fillets. EMI/RF shields can then be efficiently snapped into place between the clips’ spring loaded contacts at the end of the process, after all soldering, inspection, and cleaning have been already completed. Elimination of direct soldering allows EMI/RF shields to be manufactured with less expensive materials (such as nickel-plated steel vs BeCu) thereby saving up to 50 per cent in shield costs. Shield clip flexibility also can eliminate the need for expensive two-piece shield designs, such as “fence and lid” configurations, by allowing an optimal one-piece shield to be clipped in at the end of the process. The shield clip technology also accommodates more efficient rework and/or tuning of product designs by allowing the RF shields to be removed/ replaced up to 15 times without any loss of retention strength or stability.

Specifications for the new SMiT maxi-clip are as follows: overall dimensions of 0.127 in. wide × 0.346 in. long × 0.193 in. high is recommended for pad-size/paste-pattern surface area of 0.090 × 0.370 in. packaged in standard EIA 16 mm tape format (1,900 pieces on a 13 in. reel) ideal for mounting larger, thicker EMI/RF shielding such as used in base-station assemblies.

For further information, visit Web site: www.autosplice.com