Once it became clear that the previous etchant solution was not going to work, regular ferric acid was purchased. Ferric acid has its pros and cons. Ferric acid needs special disposal considerations because it can't be flushed down the drain however it is the most commonly known board etchant for a good reason.
Two boards were etched at the same time in a shallow bath of the acid at room-temperature. Ideally, etching would take place in a large bath of warmed acid.
The resulting boards looked nice and seemed like a successful etch. Some of the sensor boards on the left side of the picture did not turn out well but they were poorly transferred and therefore not the fault of the etching.
The used acid was stored in a labeled container. It can be reused with other boards and keeping it safely stored will make disposal easy later.
Not all of the traces were perfect. Under magnification, it was easy to see some of the problems. The broken pad won't be a problem because there will still be plenty to adhere to while soldering but the broken trace next to it will have to be bridged with solder or a conductive paint. This was the worst spot on any part of the boards. Considering I haven't made a circuit board in nearly a decade, this was pretty successful.
The areas where toner needed to be cut seemed to have etched well. Stirring the acid during the etching process may have helped etch into the narrow valley. If this had not worked, it would have been possible to manually cut the copper with a blade.
Small breaks in the traces, like in the picture below, may be difficult to repair since the clearances to the next tracks were so small. In reality, this is a problem the board design more than the etching process. The traces were too thin and the clearances were too low. Another revision to the board was in order.
Acetone was used to wipe away the black toner to reveal the copper underneath. Acetone was used simply because it was handy, in the past, I have done this step with a scrubby pad and elbow grease.
Downloads:
The rest of the posts for this project have been arranged by date
First time here?
Completed projects from year 1
Completed projects from year 2
Completed projects from year 3
Disclaimer for http://24hourengineer.blogspot.com/ and 24hourengineer.com
This disclaimer must be intact and whole. This disclaimer must be included if a project is distributed.
All information in this blog, or linked by this blog, are not to be taken as advice or solicitation. Anyone attempting to replicate, in whole or in part, is responsible for the outcome and procedure. Any loss of functionality, money, property or similar, is the responsibility of those involved in the replication.
All digital communication regarding the email address 24hourengineer@gmail.com becomes the intellectual property of Brian McEvoy. Any information contained within these messages may be distributed or retained at the discretion of Brian McEvoy. Any email sent to this address, or any email account owned by Brian McEvoy, cannot be used to claim property or assets.
Comments to the blog may be utilized or erased at the discretion of the owner. No one posting may claim property or assets based on a post.
This blog, including pictures and text, is copyright to Brian McEvoy.
2017-05-07 (Su)
Two boards were etched at the same time in a shallow bath of the acid at room-temperature. Ideally, etching would take place in a large bath of warmed acid.
There is a second board beneath the dark acid
The resulting boards looked nice and seemed like a successful etch. Some of the sensor boards on the left side of the picture did not turn out well but they were poorly transferred and therefore not the fault of the etching.
Etched board
The used acid was stored in a labeled container. It can be reused with other boards and keeping it safely stored will make disposal easy later.
Used ferric acid
Not all of the traces were perfect. Under magnification, it was easy to see some of the problems. The broken pad won't be a problem because there will still be plenty to adhere to while soldering but the broken trace next to it will have to be bridged with solder or a conductive paint. This was the worst spot on any part of the boards. Considering I haven't made a circuit board in nearly a decade, this was pretty successful.
Broken pad and trace
The areas where toner needed to be cut seemed to have etched well. Stirring the acid during the etching process may have helped etch into the narrow valley. If this had not worked, it would have been possible to manually cut the copper with a blade.
Cut toner and etched pads
Small breaks in the traces, like in the picture below, may be difficult to repair since the clearances to the next tracks were so small. In reality, this is a problem the board design more than the etching process. The traces were too thin and the clearances were too low. Another revision to the board was in order.
A very small break in a very small trace in a very tight spot
Acetone was used to wipe away the black toner to reveal the copper underneath. Acetone was used simply because it was handy, in the past, I have done this step with a scrubby pad and elbow grease.
Exposed copper
Downloads:
- Arduino firmware
- OpenSCAD code
- STL printable models
- STL printable pipe dividers
- Python Last-Man-Standing program
The rest of the posts for this project have been arranged by date
First time here?
Completed projects from year 1
Completed projects from year 2
Completed projects from year 3
Disclaimer for http://24hourengineer.blogspot.com/ and 24hourengineer.com
This disclaimer must be intact and whole. This disclaimer must be included if a project is distributed.
All information in this blog, or linked by this blog, are not to be taken as advice or solicitation. Anyone attempting to replicate, in whole or in part, is responsible for the outcome and procedure. Any loss of functionality, money, property or similar, is the responsibility of those involved in the replication.
All digital communication regarding the email address 24hourengineer@gmail.com becomes the intellectual property of Brian McEvoy. Any information contained within these messages may be distributed or retained at the discretion of Brian McEvoy. Any email sent to this address, or any email account owned by Brian McEvoy, cannot be used to claim property or assets.
Comments to the blog may be utilized or erased at the discretion of the owner. No one posting may claim property or assets based on a post.
This blog, including pictures and text, is copyright to Brian McEvoy.
2017-05-07 (Su)
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