Electronics Forum | Wed Aug 10 11:57:16 EDT 2005 | pr
Is the peelable mask (put on by the boardhouse) flat on the surface of the pcb? If so can you tell me the material name, so maybe I can find a picture? We have to print adhesive on the board, so the mask has to be flat. That is why Kapton from the b
Electronics Forum | Tue Aug 09 13:25:24 EDT 2005 | pr
From what I can gather, the annular rings are used for grounding when these boards are put in housings. A screw goes through the hole and is torqued down. If there is excess solder on the annular ring, the screw doesn't seat properly. The pallets cov
Industry News | 2018-12-08 03:29:29.0
SMT Dictionary – Surface Mount Technology Acronym and Abbreviation
Industry News | 2010-04-10 02:09:54.0
If a picture is worth a thousand words, the new H revision of IPC-A-600, Acceptability of Printed Boards, is a priceless work of art for fabricators and assemblers, particularly inspectors and product developers. IPC — Association Connecting Electronics Industries® announces the new releases of IPC-A-600H and its companion document the C revision of IPC-6012, Qualification and Performance Specification for Rigid Printed Boards.
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.
Thermal Spot Curing of Adhesives with Photonic Energy; a novel fiber delivery method of radiant heating to accelerate the polymerization of thermally active adhesives Thermal Spot Curing of Adhesives with Photonic Energy; A novel fiber delivery
Surface Mount Technology Association (SMTA) | https://www.smta.org/education/presentations/presentations.cfm
occurrence and the failure mode itself i.e. increase of leakage currents, electrochemical migration and corrosion. The parameters such as solder mask, residues from PCBA assembly process, and PCBA layout and components have an influence on the water layer
| https://www.smtfactory.com/PCBA-Cleaning-Machine-PCB-Defluxing-For-Best-Coating-and-Bonding-Effect-id43566387.html
. Clear greasy residue and flux burnt to form spots that customers can easily perceive as a defective product. Improve PCB reliability Reliability requirements are usually determined by the nature of the final product
