Industry News | 2012-06-09 14:33:06.0
To help designers and board assemblers address the challenges of working with new materials and smaller, finer-pitch components, IPC – Association Connecting Electronics Industries® released the B revision of IPC-7525, Stencil Design Guidelines.
Industry News | 2013-01-02 16:01:34.0
A Convenienient and informative online tutorial about Design and Assembly Process Challenges for Bottom Terminations Components
Technical Library | 2015-08-25 13:51:27.0
The stencil printing process is one of the most critical processes in the electronic production. Due to the requirement: "faster and smaller" it is necessary to place components with different paste volume close together without regard to solder paste printing. In our days it is no longer possible to control the solder paste volume only by adjustment of the aperture dimensions. The requirements of solder paste volumes for specific components are realized by different thicknesses of metal sheets in one stencil with so called step stencils. The step-down stencil is required when it is desirable to print fine-pitch devices using a thinner stencil foil, but print other devices using a thicker stencil foil. The paper presents the innovative technology of step-up and step-down stencils in a laser cutting and laser welding process. The step-up/step-down stencil is a special development for the adjustment of solder paste quantity, fulfilling the needs of placement and soldering. This includes the laser cutting and laser welding process as well as the resulting stencil characteristics and the potential of the printing process.
Technical Library | 2023-07-25 16:50:02.0
Some of the new handheld communication devices offer real challenges to the paste printing process. Normally, there are very small devices like 01005 chip components as well as 0.3 mm pitch uBGA along with other devices that require higher deposits of solder paste. Surface mount connectors or RF shields with coplanarity issues fall into this category. Aperture sizes for the small devices require a stencil thickness in the 50 to 75 um (2-3 mils) range for effective paste transfer whereas the RF shield and SMT connector would like at least 150 um (6 mils) paste height. Spacing is too small to use normal step stencils. This paper will explore a different type of step stencil for this application; a "Two-Print Stencil Process" step stencil. Here is a brief description of a "Two-Print Stencil Process". A 50 to 75 um (2-3 mils) stencil is used to print solder paste for the 01005, 0.3 mm pitch uBGA and other fine pitch components. While this paste is still wet a second in-line stencil printer is used to print all other components using a second thicker stencil. This second stencil has relief pockets on the contact side of the stencil any paste was printed with the first stencil. Design guidelines for minimum keep-out distances between the relief step, the fine pitch apertures, and the RF Shields apertures as well relief pocket height clearance of the paste printed by the first print stencil will be provided.
SMT Express, Volume 2, Issue No. 3 - from SMTnet.com Volume 2, Issue No. 3 Thursday, March 16, 2000 Featured Article Return to Front Page Stencil Design for Mixed Technology Through-hole / SMT Placement and Reflow by William E. Coleman, Photo
SMT Express, Issue No. 3 - from SMTnet.com Volume 1, Issue No. 3 Wednesday, August 18, 1999 Featured Article Return to Previous Page BGA REWORK Earl Moon Proof Of Design (POD) SOLDER PASTE APPLICATION (WHEN AND AS SPECIFIED) Select
Surface Mount Technology Association (SMTA) | https://www.smta.org/knowledge/webinars.cfm
Improving SMT Stencil Printing Yields Chrys Shea $200.00 2013 Design for Manufacturing (DfM) Cheryl Tulkoff $200.00 2013 Voiding Control and Reliability of Solder Joints with Backward Compatibility | Bonus Presentation
PCB Libraries, Inc. | https://www.pcblibraries.com/forum/top-10-smt-new-product-stories-of-2014_topic1520_post6150.html
: NC520 is a no clean, halogen-free solder paste designed for the most demanding high-density electronic assemblies. It offers excellent wetting, improved printing, and reduces voiding
