Technical Library | 2007-01-31 14:10:17.0
This white paper is suitable for both new and experienced users. It is a practical education in the use and misuse of auger valves for solder paste dispensing.
Technical Library | 2019-06-03 21:07:34.0
The objective of this White Paper is to provide users of the above products in the electronics industry a clear understanding of the different types of stencil cleaning paper/fabrics that are currently available. Fine pitch applications are more the norm now and so the performance of stencil cleaning rolls is more critical than ever before. This White Paper will give solder paste stencil printing engineers and purchasing professionals an insight into the main products on the market, thereby enabling them to make informed decisions.
Technical Library | 1999-05-07 10:47:00.0
White residue remaining after cleaning circuit board assemblies can be caused by a variety of chemicals and reactions. Rosin and water-soluble fluxes, circuit board resins and epoxies, component materials and other contamination all contribute to this complex chemistry. This paper discusses many of the sources of the residues that seem to be an ever-increasing occurrence.
Technical Library | 2023-11-14 19:33:57.0
Wave soldering is an established technology and is commonly used where large unit volumes occur with low product variety. However, if a wave soldering machine is getting old or if technological changes or new PCB designs limits its manufacturing capabilities, consideration should be given to whether selective soldering would be a better choice. Anyone who deals with soldering through-hole and surface mount mixed-technology printed circuit assemblies will quickly discover that a selective soldering machine is not only less expensive that wave soldering, but selective soldering also offers the opportunity to meet customer requirements with significantly more flexibility. One such company is Thomas Preuhs GmbH. Located in Geislingen, Germany, Thomas Preuhs GmbH manufactures a variety of electronic assemblies for solar and HVAC data systems, automotive and white goods products as well as electric drive systems.
Technical Library | 2019-09-24 15:41:53.0
This paper focuses on three different coating material groups which were formulated to operate under high thermal stress and are applied at printed circuit board manufacturing level. While used for principally different applications, these coatings have in common that they can be key to a successful thermal management concept especially in e-mobility and lighting applications. The coatings consist of: Specialty (green transparent) liquid photoimageable solder masks (LPiSM) compatible with long-term thermal storage/stress in excess of 150°C. Combined with the appropriate high-temperature base material, and along with a suitable copper pre-treatment, these solder resists are capable of fulfilling higher thermal demands. In this context, long-term storage tests as well as temperature cycling tests were conducted. Moreover, the effect of various Cu pre-treatment methods on the adhesion of the solder masks was examined following 150, 175 and 200°C ageing processes. For this purpose, test panels were conditioned for 2000 hours at the respective temperatures and were submitted to a cross-cut test every 500 h. Within this test set-up, it was found that a multi-level chemical pre-treatment gives significantly better adhesion results, in particular at 175°C and 200°C, compared with a pre-treatment by brush or pumice brush. Also, breakdown voltage as well as tracking resistance were investigated. For an application in LED technology, the light reflectivity and white colour stability of the printed circuit board are of major importance, especially when high-power LEDs are used which can generate larger amounts of heat. For this reason, a very high coverage power and an intense white colour with high reflectivity values are essential for white solder masks. These "ultra-white" and largely non-yellowing LPiSM need to be able to withstand specific thermal loads, especially in combination with high-power LED lighting applications. The topic of thermal performance of coatings for electronics will also be discussed in view of printed heatsink paste (HSP) and thermal interface paste (TIP) coatings which are used for a growing number of applications. They are processed at the printed circuit board manufacturing level for thermal-coupling and heat-spreading purposes in various thermal management-sensitive fields, especially in the automotive and LED lighting industries. Besides giving an overview of the principle functionality, it will be discussed what makes these ceramic-filled epoxy- or silicone-based materials special compared to using "thermal greases" and "thermal pads" for heat dissipation purposes.
Technical Library | 2016-01-12 11:07:56.0
With the increasing demand of device miniaturization, high speed, more memory, more function, low cost, and more flexibility in device design and manufacturing chain, YINCAE has published a white paper on a first individual solder joint encapsulant which can eliminate underfilling process with at least five times solder joint increase and provide more flexibility for fine pitch and high density application. In order to meet the demand of manufacturing of high speed and low cost, YINCAE has invented a room temperature stable and jettable solder joint encapsulant adhesive – SMT 266. The invention of SMT 266 has allowed our customers to have more flexibility in their high-speed production line such as worry free on the work life of adhesive and workable jetting process.
Technical Library | 2023-05-22 17:46:29.0
Over the past several years, much research has been performed and published on the benefits of stencil nano-coatings and solvent under wipes. The process improvements are evident and well-documented in terms of higher print and end-of-line yields, in improved print volume repeatability, in extended under wipe intervals, and in photographs of the stencil's PCB-seating surface under both white and UV light. But quantifying the benefits using automated Solder Paste Inspection (SPI) methods has been elusive at best. SPI results using these process enhancements typically reveal slightly lower paste transfer efficiencies and less variation in print volumes to indicate crisper print definition. However, the improvements in volume data do not fully account for the overall improvements noted elsewhere in both research and in production.
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