Flux residues and other contamination can cause a short circuit due to moisture. The technical terms are: dendritic growth, electromigration, creep current etc. In addition, the conformal coating (the protective varnish) will not or will not adhere well to a [...]
This is described in the J-STD-001. The contamination that remains after soldering is mainly flux residue, but dust and other particles (hair, tin splashes, solder balls, finger spots, etc.) can also remain on the PCB. Is this allowed and how [...]
The IPC-A-610 is a standard for the final inspection of assembled electronics products, a kind of photo album with which you can evaluate complete assembled printed circuit boards. You will see the text next to the picture in the book [...]
The IPC-7711/7721 training is both a theory but above all a practical training. In the theory module, mainly Chapter 1 of the book is discussed. In practice, the participants learn how to solder wires together (splicing), how to solder and [...]
Nitrogen is known in machine soldering, but not yet in hand soldering. Hakko invented this. If you hand-solder with nitrogen, it is much easier than without nitrogen. The soldering tip does not oxidize (closed nitrogen atmosphere), the solder wetting is [...]
The melting point of lead-free solder is approximately 217 °C. But you cannot solder at this temperature! The soldering temperature should be approximately 100 ° C above the melting point. That means a total temperature of 317 °C. You also [...]
In the 7721 part of the IPC-7711/7721 is described how you can repair a plated through hole. Usually you use a eyelet / funnelet for this. There are special repair kits with which you can easily fix this. This is [...]
In the 7721 part of the IPC-7711/7721 it is described how you can repair a conductor/track. For example with a wire, or with a repair kit (frame with or without adhesive). How this is done is trained in the practical [...]
Both methods are described in the IPC-7711/7721. For large surfaces (THT, plated through holes, large SMD pads such as cooling surfaces) it is better to do this with the desoldering iron, while for small surfaces (SMD Chip 0402 and even [...]
IPC-7711/21 describes that underheating is especially necessary with thick multi-layer printed circuit boards that contain a lot of thermal mass (copper layers). You cannot solder on this PCBs without underheating. Of course, bottom heating is necessary for ceramic and metal [...]
