Technical Library | 1999-05-06 15:36:33.0
The success of surface-mount technology has not meant the end of through-hole connectors. For reasons ranging from availability to user concerns over reliability, through-hole connectors remain widely used.
Technical Library | 2020-05-07 03:46:27.0
The selective soldering process 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 optimum quality control is maintained. Several high thermal mass components can place demands on the selective soldering process, while the use of specialized solder fixtures and/or pallets often places an 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 due to their beryllium copper termination pins.
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 | 2007-09-27 16:18:15.0
Considerable interest exists in the process known as the pinin- paste, or the Alternative Assembly and Reflow Technology (AART) process. The AART process allows for the simultaneous reflow of both odd-form and through hole devices as well as surface mount components. This process has several advantages over the typical mixed technology process sequence that includes wave soldering and/or hand soldering, often in addition to reflow soldering.
Technical Library | 2011-03-10 18:59:02.0
History shows that the electronics assembly industry is always up for a good challenge. This was proven with the successful move from through-hole to SMT assembly, the elimination of CFCs from the cleaning process and implementation of lead
Technical Library | 2009-12-14 20:27:54.0
Solder paste is the most recognized form of solder used in electronics assembly today. A surface mount application depends on solder paste to attach the components to the circuit board. However, solder paste may not be the only solution. This is especially true when working with through-hole components or very large devices that require more solder than can be supplied by printed solder paste. In fact, quite often a PCB involves mixed technology that requires more than one form of solder. Solder paste is used for the surface mount components and solder preforms are utilized to attach the leads on through-hole components, avoiding wave or selective soldering.
Technical Library | 2015-02-27 17:06:01.0
The drive towards fine pitch technology also affects the soldering processes. Selective soldering is a reliable soldering process for THT (through hole) connectors and offers a wide process window for designers. THT connectors can be soldered on the top and bottom side of boards, board in board, PCBs to metal shields or housing out of plastic or aluminum are today's state of the art. The materials that are used to make the solder connections require higher temperatures. Due to the introduction of lead-free alloys, the boards need more heat to get the barrels filled with solder. This not only affects the properties of the flux and components, but the operation temperatures of solder machines become higher (...)First the impact of temperature will be discussed for the separate process steps and for machine tooling. In the experimental part measurements are done to verify the accuracy that can be achieved using today's selective soldering machines. Dedicated tooling is designed to achieve special requirements with respect to component position accuracy.
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 | 2008-03-18 12:36:31.0
This paper examines the construction of a notebook mainboard with more than 2000 components and no wave soldering required. The board contains standard SMD, chipset BGAs, connectors, through hole components and odd forms placed using full automation and soldered after two reflow cycles under critical process parameters. However, state of the art technology does not help if the process parameters are not set carefully. Can all complex BGAs, THTs and even screws be soldered on a single stencil? What will help us overcome bridging, insufficient solder and thombstoning issues? This paper will demonstrate the placement of all odd shape components using pin-in-paste stencil design and full completion of the motherboard after two reflow cycles.
Technical Library | 2017-08-17 12:28:30.0
At SMT assembly, flux outgassing/drying is difficult for devices with poor venting channel, and resulted in insufficiently dried/burnt-off flux residue for no-clean process. Examples including: Large low stand-off components such as QFN, LGA Components covered under electromagnetic shield which has either no or few venting holes Components assembled within cavity of board Any other devices with small open space around solder joints
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)
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