Re: F.cu connections to pins soldered on B.Cu
Most of the eyelets I saw with problems the solder took but the joint broke sometimes lifting the pad. Most of this was from vibration. I have seen plated through holes fail also. It is rare but it does happen. Resoldering it usually fixes it. Also be aware those boards are not soldered with 60/40 lead tin solder. When I worked in an electronics plant the alloy used was 63/37 it seemed a lot softer and the joints broke more easily.?
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Show quoted text
On Aug 2, 2018, at 2:07 AM, Craig Lundquist < craigl2@...> wrote: Thank you very much for taking the time to give an informative and useful reply. It has given me some things to consider.
?
The process I am considering using involves cutting copper wire to a few thousands longer than the thickness of the PCB board and pressing it in place from both sides resulting in a connection that is flush or nearly flush with the surface of the board. The advantages of this are low cost, use of easily available material and connections that could possibly be situated under components if absolutely necessary. Unfortunately, therefore, the cut and pressed ends of the wire which are exposed to be soldered would not be plated. Also, it seems the best workflow would be to place them after etching and drilling the board but before adding a solder mask rather than immediately before soldering. I guess the best option is to make sure they are well cleaned immediately before soldering. Another option might be to use silver solder wire or sterling silver wire which would not oxidize so quickly. This would also be an advantage for thermal vias given the greater heat transfer of silver. This is not so outlandish as it would seem at first glance - the cost with 20 gauge wire is less than two cents per "via" and for 24 gage wire less than a penny.
?
Craig
On Wed, Aug 1, 2018 at 08:20 PM, Paul Alciatore wrote:
Craig, I spent over 45 years of my life maintaining electronic equipment, many items in the tens and even hundreds of thousands of dollars range and most by major, well known companies like RCA and Sony. I have seen circuit boards that depended on staked on connections between a top and bottom foil layer. In virtually ALL of these circuit boards these connection devices were soldered on both the top and bottom foil layers. These connections were either eyelets, staked on pins that component leads could be attached to or simple "Z" wires (a piece of wire through the hole and bent down on both sides.. Many times I had to trace problems to a bad connection through these connections. Among the problems I have seen were the use of brass pins that sat around too long and developed a layer of oxide that did not "take" the solder, pads that just did not get soldered in the first place, and pins where the solder took but subsequently broke. I can not remember a single case where a plated through hole was bad. I can not remember a single case where a "Z" wire where the solder "took" that failed. All the failures that I had to repair were either on eyelets or on staked on pins.
In the vast majority of the problems that I can remember, the problem was the use of brass pins or eyelets that were NOT PLATED and which had developed a layer of oxide before they were inserted in the board. I guess the use of non plated components was an economy measure. In many of these cases it was plainly visible that the solder did not "take". There was an insulating layer between the eyelet or pin and the solder or the copper trace on the board. But in a significant number of them, the wave solder machine had successfully covered the staked on bottom of the eyelet or pin with an unbroken layer of solder and all looked OK. But when I dragged a soldering iron with a bit of melted solder on it over that staked on end, the solder was drawn completely off the eyelet of pin, exposing the oxidized surface. I had to first clean all that oxide off before re-soldering it or the same, bad connection would repeat.
I do not know the brand name of these eyelets or pins. But the common element that I saw was that they were NOT PLATED. It was not that they "came loose". They were still firmly attached to the board and ON TOP of the copper trace. But the oxide layer prevented conduction.
The really bad thing about this is that these bad joints were not discovered when the boards were made nor in the first few years of use. Many of them only became evident after 5 or 10 or more years of use. The were a time bomb, waiting to go off. Thus testing after manufacture would not have caught the problem.
My one piece of advise if you are going to use some kind of inserted connection between the top and bottom foil on a PCB is to USE PLATED wire or eyelets or pins. And by "plated" I mean SOLDER plated. do not use bare copper wire. Do not use bare brass pins. Pay the extra penny and get plated ones.
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Re: F.cu connections to pins soldered on B.Cu
Thank you very much for taking the time to give an informative and useful reply. It has given me some things to consider.
?
The process I am considering using involves cutting copper wire to a few thousands longer than the thickness of the PCB board and pressing it in place from both sides resulting in a connection that is flush or nearly flush with the surface of the board. The advantages of this are low cost, use of easily available material and connections that could possibly be situated under components if absolutely necessary. Unfortunately, therefore, the cut and pressed ends of the wire which are exposed to be soldered would not be plated. Also, it seems the best workflow would be to place them after etching and drilling the board but before adding a solder mask rather than immediately before soldering. I guess the best option is to make sure they are well cleaned immediately before soldering. Another option might be to use silver solder wire or sterling silver wire which would not oxidize so quickly. This would also be an advantage for thermal vias given the greater heat transfer of silver. This is not so outlandish as it would seem at first glance - the cost with 20 gauge wire is less than two cents per "via" and for 24 gage wire less than a penny.
?
Craig
On Wed, Aug 1, 2018 at 08:20 PM, Paul Alciatore wrote:
Craig, I spent over 45 years of my life maintaining electronic equipment, many items in the tens and even hundreds of thousands of dollars range and most by major, well known companies like RCA and Sony. I have seen circuit boards that depended on staked on connections between a top and bottom foil layer. In virtually ALL of these circuit boards these connection devices were soldered on both the top and bottom foil layers. These connections were either eyelets, staked on pins that component leads could be attached to or simple "Z" wires (a piece of wire through the hole and bent down on both sides.. Many times I had to trace problems to a bad connection through these connections. Among the problems I have seen were the use of brass pins that sat around too long and developed a layer of oxide that did not "take" the solder, pads that just did not get soldered in the first place, and pins where the solder took but subsequently broke. I can not remember a single case where a plated through hole was bad. I can not remember a single case where a "Z" wire where the solder "took" that failed. All the failures that I had to repair were either on eyelets or on staked on pins.
In the vast majority of the problems that I can remember, the problem was the use of brass pins or eyelets that were NOT PLATED and which had developed a layer of oxide before they were inserted in the board. I guess the use of non plated components was an economy measure. In many of these cases it was plainly visible that the solder did not "take". There was an insulating layer between the eyelet or pin and the solder or the copper trace on the board. But in a significant number of them, the wave solder machine had successfully covered the staked on bottom of the eyelet or pin with an unbroken layer of solder and all looked OK. But when I dragged a soldering iron with a bit of melted solder on it over that staked on end, the solder was drawn completely off the eyelet of pin, exposing the oxidized surface. I had to first clean all that oxide off before re-soldering it or the same, bad connection would repeat.
I do not know the brand name of these eyelets or pins. But the common element that I saw was that they were NOT PLATED. It was not that they "came loose". They were still firmly attached to the board and ON TOP of the copper trace. But the oxide layer prevented conduction.
The really bad thing about this is that these bad joints were not discovered when the boards were made nor in the first few years of use. Many of them only became evident after 5 or 10 or more years of use. The were a time bomb, waiting to go off. Thus testing after manufacture would not have caught the problem.
My one piece of advise if you are going to use some kind of inserted connection between the top and bottom foil on a PCB is to USE PLATED wire or eyelets or pins. And by "plated" I mean SOLDER plated. do not use bare copper wire. Do not use bare brass pins. Pay the extra penny and get plated ones.
|
Re: F.cu connections to pins soldered on B.Cu
Craig, I spent over 45 years of my life maintaining electronic equipment, many items in the tens and even hundreds of thousands of dollars range and most by major, well known companies like RCA and Sony. I have seen circuit boards that depended on staked on connections between a top and bottom foil layer. In virtually ALL of these circuit boards these connection devices were soldered on both the top and bottom foil layers. These connections were either eyelets, staked on pins that component leads could be attached to or simple "Z" wires (a piece of wire through the hole and bent down on both sides.. Many times I had to trace problems to a bad connection through these connections. Among the problems I have seen were the use of brass pins that sat around too long and developed a layer of oxide that did not "take" the solder, pads that just did not get soldered in the first place, and pins where the solder took but subsequently broke. I can not remember a single case where a plated through hole was bad. I can not remember a single case where a "Z" wire where the solder "took" that failed. All the failures that I had to repair were either on eyelets or on staked on pins.
In the vast majority of the problems that I can remember, the problem was the use of brass pins or eyelets that were NOT PLATED and which had developed a layer of oxide before they were inserted in the board. I guess the use of non plated components was an economy measure. In many of these cases it was plainly visible that the solder did not "take". There was an insulating layer between the eyelet or pin and the solder or the copper trace on the board. But in a significant number of them, the wave solder machine had successfully covered the staked on bottom of the eyelet or pin with an unbroken layer of solder and all looked OK. But when I dragged a soldering iron with a bit of melted solder on it over that staked on end, the solder was drawn completely off the eyelet of pin, exposing the oxidized surface. I had to first clean all that oxide off before re-soldering it or the same, bad connection would repeat.
I do not know the brand name of these eyelets or pins. But the common element that I saw was that they were NOT PLATED. It was not that they "came loose". They were still firmly attached to the board and ON TOP of the copper trace. But the oxide layer prevented conduction.
The really bad thing about this is that these bad joints were not discovered when the boards were made nor in the first few years of use. Many of them only became evident after 5 or 10 or more years of use. The were a time bomb, waiting to go off. Thus testing after manufacture would not have caught the problem.
My one piece of advise if you are going to use some kind of inserted connection between the top and bottom foil on a PCB is to USE PLATED wire or eyelets or pins. And by "plated" I mean SOLDER plated. do not use bare copper wire. Do not use bare brass pins. Pay the extra penny and get plated ones.
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Re: F.cu connections to pins soldered on B.Cu
I will mention as well that for board to board interconnect, like in this situation with a Pro-Mini onto a main board, where possible use machine pin sockets and pins (aka, turned pin) rather than the usual square pin ones, they have a lower profile, look better, make better contact, don't come apart so easily, and importantly for DIY, the sockets can very easily be soldered top and bottom as the plastic block does not sit against the PCB directly.
On Wed, Aug 1, 2018 at 1:02 PM, Vagulus <rick@...> wrote:
One of the proprietary breakouts is the Arduino Pro Mini - the brains of the operation - which has a footprint like this
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Re: F.cu connections to pins soldered on B.Cu
I am currently in the early stages of experimenting with do-it-yourself rivets as per this article:
?
I am curious to know what kind of rivets you have seen come loose and what kind of PCB material they were used on (FR4 or phenolic). Also, were they soldered in place?
?
Craig
On Tue, Jul 31, 2018 at 07:14 PM, keith wrote:
I would use the wire. I have seen rivets come loose and break the circuit. A single strand is usually enough or 22 -24 gauge tinned wire
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Re: F.cu connections to pins soldered on B.Cu
Not sure if this is what you are trying to do but I use WIREWRAP PINS
for all sorts of fun toys.
and when I want to make double sided boards on the kitchen table I line two boards up with
wirewrap pins and stick the two boards together with double sided carpet tape.
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Re: F.cu connections to pins soldered on B.Cu
On Tue, 31 Jul 2018 18:02:05 -0700, you wrote: I have done dual sided PC boards. As you have been told, in the industry, the copper plating is extended through the hole, thus connecting top and bottom layers. Generally, without special equipment, that's not posible to do at home. You have two major possibilities. One is to sit a board sufficiently off the motherboard that you can solder the pins on both sides. This is generally a bit nasty to do. Another would be to get single inline sockets for the daughterboard, and plug in the daughterboard to that. The disadvantage is that the daughterboard would sit higher than might be convenient. The advantage is that you can unplug it. Since this puts all the connections on the bottom, which is not always convenient, I use a via (small hole intended to be plated though) to connect the top and bottom. Since homebuilt boards do not have plated through holes, I take some bare #26 copper wire (tinned), and stitch the top and bottom of the board together at the vias only. Naturally, this means that you cannot have a via under a chip, resistor, capacitor, or anything that sits flat on either side of the board. I solder both sides of a run (about a foot of wire), then clip them off close (but not flush) to the board. If you want, crimping the wire over on the board is reasonable. Eyelets could be used, but they have to be copper plated, and you must solder them well top and bottom. Since they take up additional space (and should be staked), they are useful only for large boards. There have been reliability problems with eyelets in the past, so while possible, they are not really recommended. Harvey My project involved several proprietary breakouts attached to a main PCB.? They are physically mounted on the top of the board and the pins are? soldered on the B.Cu layer (as I believe is normal).? That's where I get lost!?
One of the proprietary breakouts is the Arduino Pro Mini - the brains of the operation - which has a footprint like this
Assume I have a two-layer PCB:? most of the pins of the Pro Mini are connected to traces on B.Cu but some must connect to traces on F.Cu.? As illustrated, this footprint is just a collection of standard pads.? How do they connect through the fibreglass of the board?
I guess this is a silly question to those of you in the know, but it has me stumped.? I cannot find anything on the Net or in any literature which explains this mystery.? I hope one or more of you can help.
Thanks
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Re: F.cu connections to pins soldered on B.Cu
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Re: F.cu connections to pins soldered on B.Cu
I would use the wire. I have seen rivets come loose and break the circuit. A single strand is usually enough or 22 -24 gauge tinned wire
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On Jul 31, 2018, at 9:52 PM, James < bitsyboffin@...> wrote: In industry holes are plated with copper ("plated through holes").? This is not something you can easily do yourself at home, instead you can just solder both sides where possible, or use a via (small hole moving a trace from one side to the other) with a bit of wire or micro rivet.
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Re: F.cu connections to pins soldered on B.Cu
In industry holes are plated with copper ("plated through holes").? This is not something you can easily do yourself at home, instead you can just solder both sides where possible, or use a via (small hole moving a trace from one side to the other) with a bit of wire or micro rivet.
On Wed, Aug 1, 2018 at 1:02 PM, Vagulus <rick@...> wrote: My project involved several proprietary breakouts attached to a main PCB.? They are physically mounted on the top of the board and the pins are? soldered on the B.Cu layer (as I believe is normal).? That's where I get lost!?
One of the proprietary breakouts is the Arduino Pro Mini - the brains of the operation - which has a footprint like this
Assume I have a two-layer PCB:? most of the pins of the Pro Mini are connected to traces on B.Cu but some must connect to traces on F.Cu.? As illustrated, this footprint is just a collection of standard pads.? How do they connect through the fibreglass of the board?
I guess this is a silly question to those of you in the know, but it has me stumped.? I cannot find anything on the Net or in any literature which explains this mystery.? I hope one or more of you can help.
Thanks
|
F.cu connections to pins soldered on B.Cu
My project involved several proprietary breakouts attached to a main PCB.? They are physically mounted on the top of the board and the pins are? soldered on the B.Cu layer (as I believe is normal).? That's where I get lost!? One of the proprietary breakouts is the Arduino Pro Mini - the brains of the operation - which has a footprint like this  Assume I have a two-layer PCB:? most of the pins of the Pro Mini are connected to traces on B.Cu but some must connect to traces on F.Cu.? As illustrated, this footprint is just a collection of standard pads.? How do they connect through the fibreglass of the board? I guess this is a silly question to those of you in the know, but it has me stumped.? I cannot find anything on the Net or in any literature which explains this mystery.? I hope one or more of you can help. Thanks
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Re: Trace width for Toner Transfer Etching
Great method Sead.? I found 50:50 acetone and ethanol works best with the xerox toner I use. Pure acetone melts the toner too much so experimentation is needed.
?
Cruise ship companies kindly provide all the excellent glossy brochure paper I could want.
Ian
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Re: Stenciling / template
White laser toner
<
>
At 07:03 PM 7/9/2018, you wrote:
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On Mon, 9 Jul 2018 16:59:31
-0400, you wrote:
>Not sure if this is an on-Topic post, but thought maybe someone here
may be
>able to recommend a way to grab
>an image via a photo and using photoshop make a stencil or impression
of
>sorts for a stereo indicator dial on glass where the letting came
off:
>
>
>
Good luck on that.
>I'm told this was maybe silkscreened originally, but I have found
pictures
>online of the original lettering on real products:
>
>
Didn't look at this, but that's ok.
>
>I thought maybe import them into photoshop or something, then cut out
the
>stuff needed and remove the excess,
>after enlarging it. Then resize based on the original dimensions of
the
>glass and line up with the original markings.
>
Which you can do.
>If that can all be done, how would I go about making it into a
stencil? Or
>would it be easier to print it on clear
>sticky sheets and just stick it on? The lettering is white, so I
guess it
>would have to be a color printer?
You have a real problem with the white lettering.? The problem is
that
inkjet printers (and laser printers) rely on the white paper to
produce the white in the print.?
Combined (using C, M, Y, and K) where C = cyan, M = magenta Y =
yellow, and K = black), you get a reasonable range of colors, this
is
the subtractive color palette, not the additive (light sources)
one.
So no, you can't get white out of this.? if you (had) to do white,
you
would have to do silk screen, or white wax, or white ink.? No
printers
that I know of will do this for you.?
Silk screen is a stencil that produces whatever color the ink used
happens to be.? I know of no printer that uses white wax (there
might
be some).? White ink needs a stencil to make it work.? That's
a
photostencil at this resolution and size.
Now, if you were willing to use another color, say green, blue, or
something other than white, you could print this on something like
Pulsar paper, making a decal, and then transfer it that way.
Harvey
>
>
>Steve Hearns
>Technotronic Dimensions, VT [USA]
>
>1.518.663.3421 (MAIN)
>1-877-817-9885 (Voice / Fax Toll Free - US Only)
>E-Mail: Steve@...
|
Attempt at paste stencil using dry film resist and aluminium cookware
Thought I'd share a couple images of my first attempt at making a solder paste stencil.
Images in this album...
I have seen people do this with cutting and straightening old aluminium cans, but since I don't drink much from cans I went and bought some disposable aluminium trays from the local cheap shop, about $1 US each.
I cut out a flat section of the tray large enough and used 800 grit wet sand paper and a spritzer bottle of water to quickly sand one side in case there was some coating, then I cleaned it with methylated sprits and applied the dry film.? For film application I did it exactly as I do for PCB material, use the spritzer water bottle and squeegee the film on then cool iron, I documented this some time ago in my tips n tricks (), since then Big Clive has made some videos showing basically the same process if you youtube it, I think he uses a fancy piezo mister, I just use a dollar store water spritzer bottle.
The artwork was exported as a gerber from DipTrace and run through my script? to generate a positive PDF (pads opaque) and exposure was exactly as for PCB (22 seconds in my case), developing etc also as for PCB.
The back side of the sheet was covered in clear packing tape and the artwork touched up with etch resist pen.
Etching was done with HCl and H2O2, no specific ratio I just covered the sheet in HCl and added "a dash" of H2O2 from my rather old 35% bottle (which is probably nowhere even remotely 35% any more).
Fuming was copious so as well I was outside.? Etching was fairly rapid, but not as quick or vigorous as I had expected, it was difficult to judge how far through it was, I think next time I would etch it upside down with the resist side at the bottom I think that would make it easier to judge done-ness.? Ad-hoc agitation was provided by manual sloshing of the container.? No time was recorded but I estimate it took about 7-10 minutes.??
On removing the etch which looked good from the top it was evident that a fair undercut had occurred, and that some areas were better than others, because it's undercut and the resist is quite dark, this isn't so apparent from the top side during etching.
Removing the packing tape was quite easy, I had been concerned it might stick too strongly but it doesn't seem to be the case, next time I would be more careful not to have tape wrap over the edge, but still leave a little bit to make grabbing it to peel off easier.
An acetone bath was used to strip the resist.
The result clearly has room for improvement, I'm not sure that reducing the arpertures further than the DipTrace default is necessary bu more careful exposure and and being quicker to remove it from the etch are needed.? I have not attempted to use the stencil (mainly because I don't have any solderpaste on hand currently) but I think at least 50% of the QFN patterns are usable and possibly most of them would work without too much rework after reflow, I think all the passives (mostly 0603) would be fine on all the patterns.
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Re: Stenciling / template
On Mon, 9 Jul 2018 22:02:01 -0400, you wrote: Sounds interesting.
All I have right now are black mono printers, so I guess I would have to at
some point go to the local printer. No, you don't. Print black mono on a transparency. Get the white film, should be available in any art store or craft store. Generally, they say to run the sandwich of the film and transparency through when printing a blank page. The film adheres to the toner on the transparency, and then the transparency is used as a backing to a plastic bar (or whatever you need to make the plastic piece). Harvey
Unless you want to try it for me.
It does work on PC boards for a replacement for white silk screen. You just don't need to buy the Pulsar film. H. I probably should wait to hear from the
customer , but if I have a price ready and color options,
that would at least be a start.
Steve Hearns
Technotronic Dimensions, VT [USA]
WWW.TECHNOTRONIC-DIMENSIONS.COM
1.518.663.3421 (MAIN)
1-877-817-9885 (Voice / Fax Toll Free - US Only)
E-Mail: Steve@...
|
Re: Stenciling / template
Steve,
FWIW. Here is an idea that is from far left field.
Coat the glass with photoresist, and print your pattern on a transparency in mirror image. Image the photoresist with the printed side of the transparency against the resist. The photo resist works in negative mode, so that when the photoresist is developed, it will be clear where you want your printed characters. Once developed and thoroughly dried, coat the photoresist with white epoxy ink.Wipe the ink off, so that all that remains is in the openings in the photoresist. When the epoxy is cured, strip the photoresist, and you will be left with the pattern you want, deposited on the back of the glass, where it is safe from wear.
This is highly speculative, and probably needs a few tries to see if it even would work.
(The other) Harvey
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On 7/9/2018 7:02 PM, Steven Hearns wrote: Sounds interesting.
All I have right now are black mono printers, so I guess I would have to at some point go to the local printer.
Unless you want to try it for me. I probably should wait to hear from the customer , but if I have a price ready and color options,
that would at least be a start.
Steve Hearns
Technotronic Dimensions, VT [USA]
WWW.TECHNOTRONIC-DIMENSIONS.COM
1.518.663.3421 (MAIN)
1-877-817-9885 (Voice / Fax Toll Free - US Only)
E-Mail: Steve@...
--
Webmaster, Parts-Link: ()
Group Moderator:
TV-Repair ()
Monitor-Repair ()
----- Original Message ----- From: "Harvey White" <madyn@...>
To: <[email protected]>
Sent: Monday, July 09, 2018 8:55 PM
Subject: Re: [homebrewpcbs] Stenciling / template
On Mon, 09 Jul 2018 17:42:42 -0700, you wrote:
Yes, there is a white toner, but it is a specialty item. There is a lot more of it available than when it first came out, back when I was doing imprinting. You have to start with the correct make and model of laser printer. Yet another idea.? Print on transparency film, black.? Use white
transfer film (use for color overlays on a laser printed piece of
paper) to transfer everything to white.? You can get gold, silver,
etc.? It's the same thing that Pulsar uses for silk screen lettering.
It has to be imprinted over the laser toner, so all of this is exposed
to wear, and has to be protected by either a spray coating or behind
something.
Harvey
Or they make CMYKW laser printers, now.
Kind of expensive for a one-of project.
Have you thought about having a sign shop cut it out in white vinyl? I've successfully cut and applied some pretty thin stuff. Mirror cut and put on the inside, of course.
Or you could have it reverse cut, stick to the glass, sand blast it a bit to give it a bit of tooth, spray paint in white, then peel the vinyl mask off.
I have a vinyl cutter and sandblaster, so that is how I do this.
|
Re: Stenciling / template
Sounds interesting.
All I have right now are black mono printers, so I guess I would have to at some point go to the local printer.
Unless you want to try it for me. I probably should wait to hear from the customer , but if I have a price ready and color options,
that would at least be a start.
Steve Hearns
Technotronic Dimensions, VT [USA]
WWW.TECHNOTRONIC-DIMENSIONS.COM
1.518.663.3421 (MAIN)
1-877-817-9885 (Voice / Fax Toll Free - US Only)
E-Mail: Steve@...
--
Webmaster, Parts-Link: ()
Group Moderator:
TV-Repair ()
Monitor-Repair ()
toggle quoted message
Show quoted text
----- Original Message ----- From: "Harvey White" <madyn@...> To: < [email protected]> Sent: Monday, July 09, 2018 8:55 PM Subject: Re: [homebrewpcbs] Stenciling / template On Mon, 09 Jul 2018 17:42:42 -0700, you wrote:
Yes, there is a white toner, but it is a specialty item. There is a lot more of it available than when it first came out, back when I was doing imprinting. You have to start with the correct make and model of laser printer. Yet another idea. Print on transparency film, black. Use white
transfer film (use for color overlays on a laser printed piece of
paper) to transfer everything to white. You can get gold, silver,
etc. It's the same thing that Pulsar uses for silk screen lettering.
It has to be imprinted over the laser toner, so all of this is exposed
to wear, and has to be protected by either a spray coating or behind
something.
Harvey
Or they make CMYKW laser printers, now.
Kind of expensive for a one-of project.
Have you thought about having a sign shop cut it out in white vinyl? I've successfully cut and applied some pretty thin stuff. Mirror cut and put on the inside, of course.
Or you could have it reverse cut, stick to the glass, sand blast it a bit to give it a bit of tooth, spray paint in white, then peel the vinyl mask off.
I have a vinyl cutter and sandblaster, so that is how I do this.
|
Re: Stenciling / template
On Mon, 09 Jul 2018 17:42:42 -0700, you wrote: Yes, there is a white toner, but it is a specialty item. There is a lot more of it available than when it first came out, back when I was doing imprinting. You have to start with the correct make and model of laser printer. Yet another idea. Print on transparency film, black. Use white transfer film (use for color overlays on a laser printed piece of paper) to transfer everything to white. You can get gold, silver, etc. It's the same thing that Pulsar uses for silk screen lettering. It has to be imprinted over the laser toner, so all of this is exposed to wear, and has to be protected by either a spray coating or behind something. Harvey
Or they make CMYKW laser printers, now.
Kind of expensive for a one-of project.
Have you thought about having a sign shop cut it out in white vinyl? I've successfully cut and applied some pretty thin stuff. Mirror cut and put on the inside, of course.
Or you could have it reverse cut, stick to the glass, sand blast it a bit to give it a bit of tooth, spray paint in white, then peel the vinyl mask off.
I have a vinyl cutter and sandblaster, so that is how I do this.
|
Re: Stenciling / template
On Tue, 10 Jul 2018 00:09:54 +0000, you wrote: On Mon, 9 Jul 2018 16:59:31 -0400, you wrote:
Not sure if this is an on-Topic post, but thought maybe someone here may be
able to recommend a way to grab an image via a photo and using photoshop
make a stencil or impression of sorts for a stereo indicator dial on glass
where the letting came off: You gave me an idea, which might be workable. Print a reverse stencil/background where everything is black and transparent, lettering being transparent. Then back that up with whatever white color you want. It might even be possible to simply paint the letter color if the chemicals don't allow the image to run. So perhaps: Print a reverse image on a transparency. Spray paint the transparency, and see if the toner runs (or not). Plan B: print as above, back it up with a piece of white paper or a white painted object (like another transparency painted white). The result is exatctly what you want. Harvey
Some trophy shops are able to print the plates that are attached to trophies
as well as engrave them. They generally use what's called sublimation
printing. I don't know if they can print white - think maybe not - but they
could print black over a silver colored plate and you'd be left with silver
(pretty close to white) numbers.
So if you make a Photoshop of the dial in black (or whatever you want) and
leave the numbers clear (white?) you could get a plate printed and you could
then cut it out and smooth the edges. Maybe that's one way to at least get
close.
Also, I don't see why they can't print on glass... tho printing on a
relatively small round piece might be harder than printing on a larger
rectangular plate. You could being take a piece of glass and the dial to one
and ask. Test on the glass plate before risking the actual glass dial.
One drawback to this... the printing isn't quite as crisp as you might want
if you inspect it closely. Then again, it isn't expensive either.
Hope that helps.
HEY! Come to think of it, they should be able to print on a copper PCB as
well as on those metal plates they use. Might be some possibilities there for
printing a PCB mask for etching. But I don't think you'd want to do 3 mil
traces with 3 mil spacing. Biggest question in my mind would be their ability
to print exactly 1:1 from the file they're given.
Jim H
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Re: Stenciling / template
I would call it close enough to on topic, as you are asking about methods that are the same we might use for etching metal or PCBs.
Yes, there is a white toner, but it is a specialty item. There is a lot more of it available than when it first came out, back when I was doing imprinting. You have to start with the correct make and model of laser printer.
Or they make CMYKW laser printers, now.
Kind of expensive for a one-of project.
Have you thought about having a sign shop cut it out in white vinyl? I've successfully cut and applied some pretty thin stuff. Mirror cut and put on the inside, of course.
Or you could have it reverse cut, stick to the glass, sand blast it a bit to give it a bit of tooth, spray paint in white, then peel the vinyl mask off.
I have a vinyl cutter and sandblaster, so that is how I do this.
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Steven Greenfield AE7HD
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Steven Greenfield AE7HD