Technical Library | 2022-08-08 15:06:06.0
Selective soldering has evolved to become a standard production process within the electronics assembly industry, and now accommodates a wide variety of through-hole component formats in numerous applications. Most through-hole components can be easily soldered with the selective soldering process without difficulty however some types of challenging components require additional attention to ensure that optimum quality is maintained. Several high thermal mass components can place demands on the selective soldering process, while the use of specialized solder fixtures, or solder pallets, often places additional thermal demand on the preheating process. Fine-pitch through-hole components and connectors place a different set of demands on the selective soldering process and typically require special attention to lead projection and traverse speed to minimize bridging between adjacent pins. Dual in-line memory module (DIMM) connectors, compact peripheral component interface (cPCI) connectors, coax connectors and other high thermal mass components as well as fine-pitch microconnectors, can present challenges when soldered into backplanes or multilayer printed circuit board assemblies. Adding to this challenge, compact peripheral component interface connectors can present additional solderability issues because of their beryllium copper base metal pins. Key Terms: Selective soldering, drop-jet fluxing, sustained preheating, flux migration, adjacent clearance, lead-to-hole aspect ratio, lead projection, thermal reliefs, gold embrittlement, solderability testing.
Technical Library | 2020-11-24 23:01:04.0
The miniaturization trend is driving industry to adopting low standoff components or components in cavity. The cost reduction pressure is pushing telecommunication industry to combine assembly of components and electromagnetic shield in one single reflow process. As a result, the flux outgassing/drying is getting very difficult for devices due to poor venting channel. This resulted in insufficiently dried/burnt-off flux residue. For a properly formulated flux, the remaining flux activity posed no issue in a dried flux residue for no-clean process. However, when venting channel is blocked, not only solvents remain, but also activators could not be burnt off. The presence of solvents allows mobility of active ingredients and the associated corrosion, thus poses a major threat to the reliability. In this work, a new halogen-free no-clean SnAgCu solder paste, 33-76-1, has been developed. This solder paste exhibited SIR value above the IPC spec 100 MΩ without any dendrite formation, even with a wet flux residue on the comb pattern. The wet flux residue was caused by covering the comb pattern with 10 mm × 10 mm glass slide during reflow and SIR testing in order to mimic the poorly vented low standoff components. The paste 33-76-1 also showed very good SMT assembly performance, including voiding of QFN and HIP resistance. The wetting ability of paste 33-76-1 was very good under nitrogen. For air reflow, 33-76-1 still matched paste C which is widely accepted by industry for air reflow process. The above good performance on both non-corrosivity with wet flux residue and robust SMT process can only be accomplished through a breakthrough in flux technology.
Technical Library | 2019-10-10 00:26:28.0
Voids are a plague to our electronics and must be eliminated! Over the last few years we have studied voiding in solder joints and published three technical papers on methods to "Fill the Void." This paper is part four of this series. The focus of this work is to mitigate voids for via in pad circuit board designs. Via holes in Quad Flat No-Lead (QFN) thermal pads create voiding issues. Gasses can come out of via holes and rise into the solder joint creating voids. Solder can also flow down into the via holes creating gaps in the solder joint. One method of preventing this is via plugging. Via holes can be plugged, capped, or left open. These via plugging options were compared and contrasted to each other with respect to voiding. Another method of minimizing voiding is through solder paste stencil design. Solder paste can be printed around the via holes with gas escape routes. This prevents gasses from via holes from being trapped in the solder joint. Several stencil designs were tested and voiding performance compared and contrasted. In many cases voiding will be reduced only if a combination of mitigation strategies are used. Recommendations for combinations of via hole plugging and stencil design are given. The aim of this paper is to help the reader to "Fill the Void."
Technical Library | 2019-10-24 06:29:59.0
Making your novel electronic item design ready for mass fabrication and printed circuit board assembly consists of a lot of steps as well as risks. I will provide a few recommendations about how to neglect pricey errors and how to reduce the time to promote your novel item designs. You can hire printed circuit board assembly services for this. As soon as you have accomplished your product as well as printed circuit board design, you wish to get started developing prototypes prior to you commit to big fabrication volume. A lot of design software packages, for instance, PCB layout design software, as well as an industrial design software program, possess simulation potentials incorporated. Carrying out a simulation facilitates curtailing numerous design mistakes prior to the first prototype is developed. In case you are developing an intrusive item, you might desire to think about a modular design wherein all of the chief functionalities are situated in individual modules. All through your testing, you could then swap modules that don’t cater to the design limits. Spinning individual modules would be swifter and more cost-effective in comparison to spinning a complete design. Counting on the design intricacy, you can mull over manually mounting printed circuit board elements to bank dollars. Nonetheless, for medium to big intricacy this procedure likely to be very time taking, typically in case you wish to create numerous prototypes. Hence it makes sense thinking about a contract manufacturer for the assembly. Whilst running miniature quantity fabrication runs, the fabrication setup expenditure will usually control the by and large prototype constructs expenditure. Whilst seeking a subcontractor, it is finest to choose a vendor that focuses on prototype builds to reduce the cost. Prototype printed circuit board fabricators characteristically join the circuit boards of a number of clients which efficiently shares the setup expenditure in the midst of some customers. The disadvantage is that you would characteristically only be able to want among numerous standard printed circuit board material thicknesses as well as sizes. Apart from choosing a supplier with low setup expenditure, choosing a firm that would moreover be capable to manage your whole fabrication runs curtails mistakes because switching fabricators have the chance of errors owing to a specific supplier interpreting fabrication design data in a different way. This manner your design is already translated into the particular machine data that implies little or no setup expenditure for your final fabrication. A few PCB manufacturers also provide printed circuit board design services that are awesome plus if you do not possess experience with the design. Moreover, these vendors would be capable to help you in case there are issues with your design folders and be capable to detect issues prior to the fabrication.
Technical Library | 2019-03-15 16:26:50.0
While there have been quite dramatic and evident improvements in almost every facet of manufacturing over the last several decades owing to the advent and mass adoption of computer automation and networking, there is one aspect of production that remains stubbornly unaffected. Massive databases track everything from orders, to inventory, to personnel. CAD systems allow for interactive and dynamic 3D rendering and testing, digital troubleshooting, and simulation and analysis prior to mass production. Yet, with all of this computational power and all of this networking capability, one element of production has remained thoroughly and firmly planted in the past. Nearly all manufacturing or assembly procedures are created, deployed, and stored using methodologies derived from a set of assumptions that ceased to be relevant fifty years ago. This set of assumptions, referred to below as the “Paper Paradigm” has been, and continues as the dominant paradigm for manufacturing procedures to this day. It is time for a new paradigm, one that accounts for the vastly different technological landscape of this era, one that provides a simple, efficient interface, deep traceability, and dynamic response to rapidly changing economic forces.This paper seeks to present an alternative. Instead of enhancing and improving on systems that became irrelevant with the invention of a database, instead of propping up an outdated, outmoded and inefficient system with incremental improvements; rewrite the paradigm. Change the underlying assertions to more accurately reflect our current technological capability. Instead of relying on evolutionary improvements, it is time for a revolution in manufacturing instructions.
Golden State is a contract manufacturer that makes wire harnesses, electromechanical assemblies (box builds, subassemblies, PCBAs, kits, etc.) and services (sorting, rework, value additive manufacturing engineering)
18220 Butterfield Blvd
Morgan Hill, CA USA
Phone: 5102268155
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