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Project:PCB Making: Difference between revisions

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# Photoresist Copper-clad board [http://www.maplin.co.uk/Module.aspx?ModuleNo=2033 Maplin product page (code FA61R)].
# Photoresist Copper-clad board [http://www.maplin.co.uk/Module.aspx?ModuleNo=2033 Maplin product page (code FA61R)].
# Sodium silicate [http://www.maplin.co.uk/Module.aspx?ModuleNo=2085 Maplin product page (code AP01B)]. - full bottle purchased 05-Aug-2010
# Universal PCB Developer (Sodium Metasilicate Pentahydrate) [http://www.maplin.co.uk/Module.aspx?ModuleNo=2085 Maplin product page (code AP01B)]. - full bottle purchased 05-Aug-2010
# Ferric chloride [http://www.maplin.co.uk/Module.aspx?ModuleNo=2097 Maplin product page (code XX12N)].
# Ferric chloride [http://www.maplin.co.uk/Module.aspx?ModuleNo=2097 Maplin product page (code XX12N)].
# Methylated spirits [http://www.wickes.co.uk/Methylated-Spirits/invt/600343 Wickes product page (code 600343)].
# Methylated spirits [http://www.wickes.co.uk/Methylated-Spirits/invt/600343 Wickes product page (code 600343)].
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[[File:UV_Exposure.jpg|400px]]
[[File:UV_Exposure.jpg|400px]]
<br>
<br>
2. The photo sensitive coating weakens as a result of exposure, and is rinsed off with a 10% sodium silicate solution. (1-2 minutes)
2. The photo sensitive coating weakens as a result of exposure, and is rinsed off with a 10% sodium of "Universal PCB Developer". (1-2 minutes)
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[[File:RemovalExposedPhotoSensitiveArea.jpg|400px]]
[[File:RemovalExposedPhotoSensitiveArea.jpg|400px]]
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The chemicals can be returned to their respective bottles, and the small residue in the tubs used in the process should be rinsed out in the sink.
The chemicals can be returned to their respective bottles, and the small residue in the tubs used in the process should be rinsed out in the sink.


Once spent, the sodium silicate solution can be poured down the drain. The ferric chloride on the other hand, must be taken to a Harzadous Disposal Unit, or, deactivated according to this [[Projects/Deactivating a ferric chloride solution|method]].
Once spent, the Universal PCB Developer solution can be poured down the drain. The ferric chloride on the other hand, must be taken to a Harzadous Disposal Unit, or, deactivated according to this [[Projects/Deactivating a ferric chloride solution|method]].


== Real life example ==
== Real life example ==
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* Expose in the UV box.
* Expose in the UV box.


* Developing the photoresist in a sodium silicate solution.
* Developing the photoresist in a Universal PBC Developer solution.


[[File:TQFP32_DIL32_PhotoresistDevelopment.jpg|400px]]
[[File:TQFP32_DIL32_PhotoresistDevelopment.jpg|400px]]
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== Notes ==
== Notes ==
=== Universal PCB Solution ===
According to the [http://www.chilternconnections.co.uk/ZENCART/HANDSSHEETS/Etching%20Products/PDSM_MSDS.pdf safety datasheet] of the PCB photoresist developer (Universal PCB Developer, manufactured by Chiltern Connections Ltd and sold by Maplin), the compound is Sodium Metasilicate Pentahydrate, containing the hazardous ingredient Disodium Metasilicate at a concentration of 58%.


=== Artwork ===
=== Artwork ===