Large Area Screen Printer and chip on board assembly techniques. Typical end-uses will be in computer memory boards, consumer Weltek International Inc. has announced a new large area screen printer. electronics, telecommunications equipment, microwave and digital The Model 2424D offers a simple and flexible design, a host of options, transmission gear and instrumentation. print area of 20 in. x 20 in. and 0.0005 in. accuracy. It accepts three frame The material will offer a low dielectric constant, a smooth mounting sizes up to 24 in. x 24 in. and operates in both on-contact and off-contact surface, uniform thickness and lower weight. It will allow small-hole modes. drilling, plasma milling and laser ablation, and will be available with Because of design flexibility, the 2424D is available as a semi-automatic specific coefficients of expansion (CTE) to meet different customer console or as a four post printer module for in-line applications. The needs. console is tubular and open. There are no panels, shrouds, or hanging Because it will be possible to 'tailor' the reinforcement material to wires to hide. All controls are packaged in a box small enough for UPS or specific values, it will offer improved performance and reliability, as well similar type shipment. The control box is the centrepiece of a simple two- as increased design flexibility, thus providing a cost-effective solution for step, 24-hour support service. both highly engineered and less specialised applications. Options include vision alignment, universal tooling fixture, electric The product will be compatible with all standard PCB production and squeegee drive and programmable set-up. Four frame head to table posts, assembly equipment. However, since it will have different characteristics ¾ in. squeegee rails and table surface flatness of ±0.0005 in./ft. provide from woven reinforcements, Du Pont is working with PCB laminators, the foundation for 0.0005 in. accuracy. fabricators, assemblers and users throughout the world to determine the Weltek International Inc.,1836 South Franklin Street, South Bend, Indiana optimum properties for the product. 46613, USA. Telephone: (219) 232 5400. Fax: (219) 232 2540. When finalised, the new material will be sold through PCB laminators in Europe, the United States and Asia Pacific. Scratch-resistant Diazo Film Du Pont de Nemours International SA, PO Box 50, 2 chemin du Pavilion, The launch of a new generation of phototool has been announced with CH-1218 Le Grand-Saconnex, Switzerland. Telephone: (022) 7175254. the introduction by Dynachem Electronic Materials (a division of Morton Fax: (022) 7176021. International Ltd.) of Ultra Yield Diazo Film. Offering what the company claims to be unprecedented scratch resistance and an in-built resistance to Manual Alignment Vision System — PC Based — Features chemicals, the film has been shown in full production trials to outperform 4 Alignment Strategies other phototools — even those with a protective laminate. AMI (Affiliated Manufacturers, Inc.) has introduced a new manual Ultra Yield has been designed primarily for use with liquid vision system for alignment of printed circuit boards to screens or stencils photoimageable solder masks, but is equally suitable for primary resists. on semi-automatic screen printers. The u-LignTM III allows the operator Its use eliminates the need for a time-consuming and expensive protective to select any one of four different alignment methods when setting up for laminate. fine pitch solder paste printing. It is even possible to use different A specially formulated polymer surface enables the film to resist the strategies in each camera window to accommodate different features at cuts and scratches which arise from repeated handling, offering the same time. Alignment is not limited to using fiducial marks or straight manufacturers scope for improvements in yield through damage prevention. edged pads, as virtually any part of a circuit pattern or repeated board Designed to be highly chemical resistant, the film eliminates the markings can be used to achieve precise alignment on every board. problem of image fade common with liquid photoimageable solder The four methods of alignment include the traditional dual crosshair masks, thus prolonging the life of the phototool. In primary imaging, the approach where images are boxed in, precision circles that can be size product's non-stick surface prevents resist chips adhering to the surface. adjusted, boundary or perimeter outline tracking that can duplicate any With high resolution capabilities, Ultra Yield offers quick, easy exposure shape, and an image overlay feature that uses a frame grabber to duplicate and development while its micromatte surface facilitates rapid drawdown. all features within the camera field-of-view. In addition, the u-Lign™ III MortonInternational,DynachemElectronicMaterials,ChesfordGrange, includes a measurement feature that allows precise measuring of live Warrington, Cheshire WA1 4RQ. Telephone: (0925) 824105. Fax: (0925) images. The system's space saving design houses an industrial quality PC within the printer. A single monitor displays both camera image windows Phototool Film System and the pull-down control menus for quick and easy set-up. Du Pont Electronics has expanded its range of phototool films for the AMI, P.O. Box 5049, North Branch, NJ 08876, USA. Telephone:(908)722 printed circuit board industry with the introduction of a new photoplotter 7100. Fax: (908) 722 5082. film based on hybrid chemistry. Intended for the imaging of high density printed circuit boards, the new Solder Coating Process for High Density PCBs PCQR-7 'Rocket' film is a high contrast, negative-working film which is Shipley has developed a chemical solder coating process for high sensitive to blue-green light at 488 nm and has been specially designed for aspect ratio boards and lines and spaces below 50 microns. Solderposit use in argon and He-Cd laser photoplotters. However, it also produces produces a uniform tin/lead deposit on any copper surface — including excellent results in cameras, contact frames, step-and-repeat devices and fine pitch features and hole 'knees' —without 'bridging' or 'plugging', image modifiers. resulting in excellent long-term solderability and increased manufacturing The new film is coated on dimensionally stable, 0.18 mm 'Cronalar' yields. film base and has Du Pont's 'X-Stat' static guard protection to minimise The process is ideal for the production of complex surface mount dust and dirt pick-up. It can be used under both red and amber safe-lights, device (SMD) circuit boards, providing a flat, co-planar surface, even on provides excellent line edge sharpness and has broad exposure and pad sizes of less than 0.60 mm. processing latitudes. Solderposit is based on an immersion, non-electrolytic, solder plating Completing the new phototool system offering are two new rapid process that deposits a fuseable tin/lead coating on all copper surfaces by access processors. The 28C and 37C Mark 2 processors are both easy to a chemical displacement reaction with the copper. A specified deposit operate, feature microprocessor control for 'set-and-forget' operation, thickness of between 4 and 8 microns is achieved by a single pass, thus have an automatic replenishment system and combine high quality with eliminating surface tension topography associated with conventional low operating costs. The 28C Mark 2 processor is suitable for film widths multi-pass operations. The process has been used successfully in production of up to 71 cm. The larger 37C Mark 2 processor accepts films with a environments for manufacturing boards with 0.5 mm diameter holes at a maximum width of 95 cm. 22:1 aspect ratio and for fine pitch technology down to 0.015 mm lines and Du Pont de Nemours International SA, PO Box 50, 2 chemin du Pavilion, 0.038 spaces. CH-1218 Le Grand Saconnex, Switzerland. Telephone: (022) 7175254. Alloy composition is controlled accurately to deposit 65% tin and 35% Fax:(022)717 6021. lead throughout the process. The subsequent fused deposit is qualified to IPC-S-804A and MIL-STD-202F for solderability. Non-woven Reinforcement Material for PCBs The solder coating process comprises two short stages: immersion tin/ lead plating of solder-masked panels followed by a fusing sequence. Du Pont is developing a proprietary, non-woven, paper-based material Fusing of the plated surfaces can be achieved by infra-red, hot oil, vapour to replace glass fibre and ceramic reinforcements in printed circuit board phase, etc. (PCB) substrates. Called Thermount, the material is made from 100% aramid fibre and is Shipley Europe Ltd, Herald Way, Coventry CV3 2RQ, England. Telephone: intended for fine line printed circuit boards using the latest surface mount (0203) 457203. Fax: (0203) 440331.
Circuit World – Emerald Publishing
Published: Mar 1, 1992
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.
All for just $49/month
Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly
Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.
Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.
Read from thousands of the leading scholarly journals from SpringerNature, Wiley-Blackwell, Oxford University Press and more.
All the latest content is available, no embargo periods.
“Hi guys, I cannot tell you how much I love this resource. Incredible. I really believe you've hit the nail on the head with this site in regards to solving the research-purchase issue.”Daniel C.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud
“I must say, @deepdyve is a fabulous solution to the independent researcher's problem of #access to #information.”@deepthiw
“My last article couldn't be possible without the platform @deepdyve that makes journal papers cheaper.”@JoseServera