Industry Directory | Consultant / Service Provider / Manufacturer
PROPOX is a manufacturer of electronics, industrial automatics, telemetric systems, tools, modules and evaluation circuits used by the constructors of electronics.
New Equipment | Rework & Repair Equipment
BEST HeatShield Gel™ is a thermal shield water-based gel designed to be used in the PCB rework/repair or board assembly areas in order to provide thermal protection of electronic components. It is truly a revolutionary means to protect components. It
New Equipment | Solder Materials
A variety of printed circuit boards require protection of selected board areas during the Surface Finish or Assembly Process. A wide range of PEELABLE SOLDER MASKS, the SD 295X Series including the popular SD 2954 and SD 2955 provide such protection
Electronics Forum | Wed Aug 17 13:57:27 EDT 2005 | ppwlee
We have encountered what appears to be mask discoloration after wave soldering. The areas of concern coincide with the areas that were exposed selectively by fixtures during wave soldering, dominated by one date code of PCB with a slightly different
Electronics Forum | Thu Apr 22 18:07:38 EDT 1999 | Tom B.
| On various PCB's after building processes,such as reflow, flowsolder and wash. The soldermask on the PCB's have become discoloured, like a 'marble' effect all along the solder side of the board, it is lighter in contrast than normal, although when
Technical Library | 2019-09-19 00:28:48.0
The symbiotic relationship between solder masks and selective finishes is not new. The soldermask application is one of the key considerations to ensure a successful application of a selective finish. The selective finish is the final chemical step of the PCB manufacturing process, this is when the panels are at their most valuable and are unfortunately not re-workable. Imperfections are not tolerated, even if they are wholly cosmetic. Quality issues often manifest themselves in the form of a 'ping pong' conversation between the fabricators, the soldermask suppliers and the selective finish suppliers. Without tangible evidence these discussions are difficult to resolve and the selective finish process is usually regarded as responsible. This paper will focus on the chemical characteristics and use them to predict or identify potential issues before they occur rather than specifically name 'critical' soldermasks. It is also the intention of this paper to address the potential of a soldermask to react to common yield hiking practices like UV bumping and oven curing. It is hoped that this awareness will help fabricators to ensure maximum yields by asking the right questions. 'Critical’ soldermasks impact all selective finishes. In this paper, practical experience using immersion tin will be used to highlight the relationship between 'critical' soldermasks and some of the issues seen in the field. The paper will include a novel approach to identify re-deposited volatiles after the reflow.
Effects of reflow profile and thermal conditioning on intermetallic compound thickness for SnAgCu soldered joints. Effects of reflow profile and thermal conditioning on intermetallic compound thickness for SnAgCu soldered joints. The purpose
Heller Industries Inc. | https://hellerindustries.com/wp-content/uploads/2018/07/00600-228.pdf
. Nitrogen also may reduce discoloration caused by the higher temperatures and longer reflow times for lead-free pastes. Additionally, because lead-free joints tend to be duller than tin/lead joints, nitrogen can improve their appearance
Imagineering, Inc. | https://www.pcbnet.com/blog/5-signs-your-pcb-may-need-to-be-repaired-or-replaced/
. Reflow issues can be caused by improper reflow soldering surface-mount technology (SMT). You may notice some components lifting off the PCB due to uneven heating. 4
