Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [solder-mask]

The traditionally green coating which protects copper on PCBs from oxidation and shorting due to solder. Use this tag for PCB design questions and soldering questions which require attention to the mask layer.

When soldering BGA devices, an important decision is whether to use soldermask-defined (abbreviated SMD, not the same as "Surface Mount Device") or non-soldermask-defined (NSMD) pads.

Some PCB manufacturers offer minimal spec boards without soldermask.

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What is the purpose of solder mask expansion?

I see recommendations of 2-4 mils for solder mask expansion. But why is it necessary?
ajs410
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How to remove solder mask?

I'd like to reuse a PCB in non-intended way and I have to remove the green solder mask to expose the copper traces in 1 x 3 cm area. Is there any safe method to do it without damaging the traces? I've tried acetone first, then a bunch of other…
csadam
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Why would metal from a pad be *underneath* the solder mask in a footprint specification?

One of TI's new regulators has a rather unusual footprint, with several pads (7-13 in this instance) requiring that the pad metal extend under the solder mask. This is in contrast to the usual case where the solder mark starts some distance…
Damien
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Solder Mask and Cream in Eagle

I've got this part specification for the Paste Mask excerpted from the datasheet: There's a lot of lingo in this short paragraph that I would like to better understand conceptually. Specifically I want to know how to implement the prescribed…
vicatcu
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Questions on mass-production soldering

Wave soldering I am trying to understand how wave soldering works. Unfortunately the Wikipedia article has has left me unsure about the process: Is the entire board with its components quasi-immersed in liquid solder while it passes through the…
ARF
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Solder Mask Color Code

Is there standard that recommend guidance of particular colors of solder mask? A while back I was told by a local assembler that BLUE typically indicates the circuit is ROHS compliant. Yet my Google foo does not find any supporting evidence. Were my…
mpflaga
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Will "hot plate" reflow soldering work without a solder resist coating?

With a successful through-hole design under my belt I am now ready to try fabricating a board that uses surface-mount components. I have been reading about this, and have gathered that the DIY crowd has gotten reasonable results with "hot plate"…
Kaelin Colclasure
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Traces in connector's solder keep out area

I'm designing with a Molex 87438-0443 connector whose PCB footprint includes a 'solder keep out area' between each pair of copper pads for each connector lead. It appears that the manufacturer wanted a discontinuity between the connector's signal…
calcium3000
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Strange Solder Spots on PCB

I was tearing down some old CD drives and while taking a look to the PCB I found two pointy solder spots, connected to the first pin of each side of a chip which makes me think is an EEPROM. There seems to be no trace connecting to these. What are…
GmodCake
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Gerber - is my understanding of solder mask layer (GTS / GBS) correct?

I've just had a PCB manufactured for me, but it seems like the solder mask is only applied to where the copper is. I'm trying to figure out if it's my fault or not. According to my understanding there supposed to be solder mask everywhere on the…
Mike
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Soldermask at home?

I am interested in putting that nice green / red soldermask on the PCBs that I make at home. The problem is I can't find a lot of information on it, like where to buy it, etc. Do any hobbyists actually do this, or is it only for the…
A.R.
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Solder Mask on fPCB starting to degrade

I have a flex-PCB that is acting as a sensor bus for one of my projects. I started getting some wonky readings from one of the sensors, but I found that if I removed the sensor from the bus (with minimal heat) the sensor was working fine. Before…
thron of three
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Super glue as solder mask?

Wondering if super glue could be safely used on a PCB to cover exposed traces or jumper wires. I know it’s non conductive but is there any type of damage that could occur? I normally use green solder mask that cures with UV light but ran out and…
user140123
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Optional feature in PCB layout of MMCX board edge connector. What's it for?

I'm designing a circuit requiring MMCX board edge connectors, specifically using the Molex 73415-0961 jack. When looking through the datasheet for suggested PCB layout, I see mention of an additional optional feature. But there's no mention of…
Kjon VALIS
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Minimum solder mask ridge (sliver) for DFN package?

What is better: No solder mask at all under the fine pitch component with thermal pad or shrink the thermal pad to leave room for a solder mask ridge around the thermal pad? I am making the layout for a surface mount DFN 12+1 pin package (Dual…
Henning Larsen
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