Application Of Soldermask
If you don't need solder masks in your board, please make a note of this in your fabrication drawing, readme.txt or in the notes of your online order. We can mix customized colours by mixing standard colours to make such shades as orange, pink, purple, etcetera. Please be aware that custom colours are normally created by mixing 'commonplace' mask colors by hand, so getting the exact same colour stability for orders made a number of weeks or months aside is unimaginable. Unfortunately, there aren't automated solder mask mixing machines like you might have used for paint at places like Home Depot or Sherwin Williams.
Even if mask alignment is shifted by the total 2mil tolerance, your whole copper pad must be still solderable. By default, we assume the entire board will be covered with solder mask, on each high and backside sides of the board.
As a common rule, we will resize masks clearances to be approximately 2mils larger on each side of the copper characteristic to make sure it isn't partially coated with mask. As with every thing else, there is a tolerance on the precise placement of the masks on a PCB. The tolerance for mask placement is ± 2mils (±zero.05mm) of its intended true place.
You'll need to tape off the encircling space on the PCB to keep the chemical agent localized to your target area. If you've plenty of boards to do or a lot of fine pitch areas, you may be higher off reordering the boards with the corrected masks file. The amount of effort and time required to strip the mask may be more expensive and messy than remaking the board. The most noticeable good thing about is that it makes your board look good!
Ok, that's not its most crucial job, however depending on your application, it may be. LPI masks is an epoxy-based polymer that's utilized over the complete PCB surface, prime and backside, and cured with a high depth UV lamp. The UV light passes by way of a clear movie containing darkened apertures over the areas the place you don't need the masks to adhere to the board.
Since these darkened areas will not enable light to remedy the mask behind them, the uncured masks could be washed off leaving masks solely the place needed. Registration tolerance on the LPI masks process is ± 2mils (± 0.05mm). To stop quick circuits and defend the copper traces on the board. You can select the popular solder mask color from those mentioned above.
Even when making use of conformal coating with a selective spray system, there's a danger of the material wicking underneath the component via capillary action. PCBs are generally engineered for a wide range of totally different fashions, so some areas of the board could also be vacant relying on the options of a specific model. That allows for larger economies of scale for bare board production, however can add complexity to the assembly course of. Spot mask, commonly referred to as “short-term solder masks”, can be used to protect open through-holes or “vias” in wave soldering.
Solder does not wet or stick with it, and it withstands soldering temperatures with out charring and effervescent. When you are done, the masks is both peeled off or washed off in your PCB cleansing course of.
If you could have any questions or doubts relating to the right solder masks colour for your application, you'll be able to all the time seek help of our customer support staff. With the pads away from solder, finish up the board by milling the holes and description. Remember to pick Holes and Outline and deselect Traces whenever you’re setting up your EAGLE file within the Bantam Tools software. As proven, the strategies of solder masks application out there rely in your PCB design and specific wants.
We will do our best to maintain the colour as constant as potential but anticipate some variation from order to order when using a customized color. Dry film follows the contours of the traces and copper features so will probably be barely raised over copper. Liquid Photo Imagable masks are applied as a liquid so the floor is naturally smoothed and leveled.