replies interleaved. On 11/12/2020 11:03 AM, Dave wrote: Thanks for the info Harvey.
On 11/11/2020 6:23 PM, Harvey White wrote:
The answer is a qualified yes.? Most circuits use top and bottom parts with vias as needed. Great. Even though SMT uses less space and I could do multiple paths on one side, I see the other side a waste of space.
The other side does not become a waste of space with more complicated circuits.? Nor, if you're doing high frequency digital stuff, is the idea of a ground plane on the back a bad idea.? I *really* use both sides of the board.? If what you're doing is simple enough, then you can successfully route the board using one side only. However, you need to consider that the two circuits are going to be less than 1/16 of an inch apart, and then consider crosstalk between the two circuits.? If you were doing a 4 layer board, the ground and power planes would tend to act like ground planes, and you'd have less problems.? You don't, though. You are correct as this will not affect me.
The PC board makers don't know, and don't care what you do.? All they care is if (according to their rules) they can manufacture the board.? Shorts?? Overlapping ground planes?? bad labels? reversed connectors?? They don't know, and frankly, they don't care. Cheating for the manufacturers is that the there are two different designs on the? same board, separate (I think) and not connected any way to each other.? (or, I bet, two designs separated by a snap off, if they can do that).
You can make boards , like you say, that are panelized but in my case that costs more and in not needed.
I used SeeedStudio fabrication, which goes from EAGLE (they provide a CAM batch job to go to gerbers) almost directly.? Their price is 4.90 for any size HASL board, silk screened both sides, plated through holes up to 100 mm by 100 mm.? By designing the circuit with separate inputs and outputs (sides as appropriate), having a common ground pour, the circuits are essentially the same circuit I'd think, as far as they're concerned.? So for panelization, definitely no penalty.
Since you don't use both sides, then I'd do a ground pour on both sides, and that of course, would weld both circuits together. It's the same thing as a construction variant, where you either install a part or not.? They won't care.
How would that weld the two circuits together unless I ad a via? Will a thru hole for mounting it to a standoff act as a via?
Ground is ground, VCC is VCC, if they're the same it makes your layout easier, perhaps.
Now, if you have a small circuit board, say you can fit more than one on a 100 mm by 100 mm board, you can duplicate the pattern (in EAGLE, one way is to close the board, then copy and paste the board pattern).? Go completely across the board with lines on the milling layer, and you can have multiple designs (same design) on the same produced plate.
I have done that with design spark in the past but cut the paper to laminate it to my pcb copper boards (single sided). But now after paying only $18 ( $36 with shipping as I paid for speedier method ) for 200 of my first batch of small simple pcb's, I am going to have them made from now on.
I can understand that one.? Sadly, the designs I do tend to be a bit more complex.
Got more LED strips to substitute for backlights than I care to think about.? LED (1206) and resistor (0805) on the other. About nine LEDS on a side.? Length determined by the 100 mm cheapie limit.
I am going to start with 1206 resistors.
Decent enough, then, as I found, 0805 make for more parts on the board where needed. Harvey Thanks,
Dave
Harvey
On 11/11/2020 6:07 PM, Dave wrote:
I was thinking...my next pcb will be simple but will be all SMT components for my first time. I was curious if it is ok to put one circuit on one side of the 2 sided boards, and another on the other side? They would be 2 simple, yet different circuits. Is that something that has been done before? Is that kosher with the pcb makers that will make the board? Or is that cheating? In the end it would be a choice of what side to use by me and only one side would ever be used.
Thanks,
Dave
|
Re: Drill precision holes without CNC, was RoHS question
Mark, That is a clever idea to turn a drill? press upside down. Bertho ? ?
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From: [email protected] < [email protected]> On Behalf Of Mark Lerman Sent: Thursday, November 12, 2020 11:19 To: [email protected]Subject: Re: [homebrewpcbs] Drill precision holes without CNC, was RoHS question ?
A little late, but this is my solution to accurate pcb drilling < >
Mark
|
Re: Drill precision holes without CNC, was RoHS question
A little late, but this is my solution to accurate pcb drilling
<
>
Mark
At 11:19 PM 11/7/2020, you wrote:
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Show quoted text
"The registration holes
need to be exact, which is why I made an upside down drill press, which
is far more accurate (no parallax)."
I used a different technique to get the same benefit. FRP boards in the
thickness we use are somewhat transparent, you can see the drill bit from
the other side right down to the point of contact, thus no parallax, same
as above. To use a normal, bench mount drill press, I purchased a
single-board camera with NTSC output that I then fed into a small TV set.
I built a small holder for the camera (about 1 inch cubed) plus a 45
degree angle mirror so that the debris from the drilling did not fall on
the camera and cover the lens. Looking up through the hole in the center
of the drill press table, I was able to position the board with one hand
and lower the drill with the other. Gravity works in the same direction
as drill force, so it was easy to position the board while it was resting
on the table and still provide firm support against the drilling. It
worked ell enough for a cheap, out-of-alignment harbor freight drill
press to make accurate holes. My approach does require the extra purchase
of a $40 or less mini board camera but eliminates the problem of keeping
the board from falling down when not drilling or of keep the board in
place against the force of drilling.
--
? ? ? ? ? ? ? ? ? ? ? ? ? ??
KINDNESS
is most VALUABLE when it is GIVEN
AWAY for
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?? FREE
|
Thanks for the info Harvey. On 11/11/2020 6:23 PM, Harvey White wrote: The answer is a qualified yes.? Most circuits use top and bottom parts with vias as needed. Great. Even though SMT uses less space and I could do multiple paths on one side, I see the other side a waste of space.
However, you need to consider that the two circuits are going to be less than 1/16 of an inch apart, and then consider crosstalk between the two circuits.? If you were doing a 4 layer board, the ground and power planes would tend to act like ground planes, and you'd have less problems.? You don't, though.
You are correct as this will not affect me.
The PC board makers don't know, and don't care what you do.? All they care is if (according to their rules) they can manufacture the board.? Shorts?? Overlapping ground planes?? bad labels? reversed connectors?? They don't know, and frankly, they don't care. Cheating for the manufacturers is that the there are two different designs on the? same board, separate (I think) and not connected any way to each other.? (or, I bet, two designs separated by a snap off, if they can do that).
You can make boards , like you say, that are panelized but in my case that costs more and in not needed.
Since you don't use both sides, then I'd do a ground pour on both sides, and that of course, would weld both circuits together. It's the same thing as a construction variant, where you either install a part or not.? They won't care.
How would that weld the two circuits together unless I ad a via? Will a thru hole for mounting it to a standoff act as a via?
Now, if you have a small circuit board, say you can fit more than one on a 100 mm by 100 mm board, you can duplicate the pattern (in EAGLE, one way is to close the board, then copy and paste the board pattern).? Go completely across the board with lines on the milling layer, and you can have multiple designs (same design) on the same produced plate.
I have done that with design spark in the past but cut the paper to laminate it to my pcb copper boards (single sided). But now after paying only $18 ( $36 with shipping as I paid for speedier method ) for 200 of my first batch of small simple pcb's, I am going to have them made from now on.
Got more LED strips to substitute for backlights than I care to think about.? LED (1206) and resistor (0805) on the other.? About nine LEDS on a side.? Length determined by the 100 mm cheapie limit.
I am going to start with 1206 resistors. Thanks, Dave
Harvey
On 11/11/2020 6:07 PM, Dave wrote:
I was thinking...my next pcb will be simple but will be all SMT components for my first time. I was curious if it is ok to put one circuit on one side of the 2 sided boards, and another on the other side? They would be 2 simple, yet different circuits. Is that something that has been done before? Is that kosher with the pcb makers that will make the board? Or is that cheating? In the end it would be a choice of what side to use by me and only one side would ever be used.
Thanks,
Dave
|
The answer is a qualified yes.? Most circuits use top and bottom parts with vias as needed.
However, you need to consider that the two circuits are going to be less than 1/16 of an inch apart, and then consider crosstalk between the two circuits.? If you were doing a 4 layer board, the ground and power planes would tend to act like ground planes, and you'd have less problems.? You don't, though.
The PC board makers don't know, and don't care what you do.? All they care is if (according to their rules) they can manufacture the board.? Shorts?? Overlapping ground planes?? bad labels? reversed connectors?? They don't know, and frankly, they don't care. Cheating for the manufacturers is that the there are two different designs on the? same board, separate (I think) and not connected any way to each other.? (or, I bet, two designs separated by a snap off, if they can do that).
Since you don't use both sides, then I'd do a ground pour on both sides, and that of course, would weld both circuits together. It's the same thing as a construction variant, where you either install a part or not.? They won't care.
Now, if you have a small circuit board, say you can fit more than one on a 100 mm by 100 mm board, you can duplicate the pattern (in EAGLE, one way is to close the board, then copy and paste the board pattern).? Go completely across the board with lines on the milling layer, and you can have multiple designs (same design) on the same produced plate.
Got more LED strips to substitute for backlights than I care to think about.? LED (1206) and resistor (0805) on the other.? About nine LEDS on a side.? Length determined by the 100 mm cheapie limit.
Harvey
toggle quoted message
Show quoted text
On 11/11/2020 6:07 PM, Dave wrote: I was thinking...my next pcb will be simple but will be all SMT components for my first time. I was curious if it is ok to put one circuit on one side of the 2 sided boards, and another on the other side? They would be 2 simple, yet different circuits. Is that something that has been done before? Is that kosher with the pcb makers that will make the board? Or is that cheating? In the end it would be a choice of what side to use by me and only one side would ever be used.
Thanks,
Dave
|
I was thinking...my next pcb will be simple but will be all SMT components for my first time. I was curious if it is ok to put one circuit on one side of the 2 sided boards, and another on the other side? They would be 2 simple, yet different circuits. Is that something that has been done before? Is that kosher with the pcb makers that will make the board? Or is that cheating? In the end it would be a choice of what side to use by me and only one side would ever be used.
Thanks,
Dave
|
Re: Drill precision holes without CNC, was RoHS question
I used a mini air die grinder 1/8” collets perfect for PCB carbide bits and the right RPM 56,000. Only $27 at Harbor Freight. I bought mine about 30 years ago. ? Bertho ?
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From: [email protected] < [email protected]> On Behalf Of Harvey White Sent: Monday, November 9, 2020 14:33 To: [email protected]Subject: Re: [homebrewpcbs] Drill precision holes without CNC, was RoHS question ? I did put a transparency over the screen, laser printed one.? I have the plans for a video crosshair generator in the works, which would be much better.? The camera is an old security camera which runs off 12VDC or 24VAC.? The whole thing runs off 12VDC, so that's why I got the camera that I did.? Hamfest stuff a while back.? I used the rototool (Proxxon) because it's got a higher RPM, much better bearings, and a much better chuck than the dremel.? I did have a dremel on a stand, but the parallax was horrible.? The reason for making this as is?? I wanted a fixed setup that could be left in one piece.? The stand was from an old (and no, I didn't buy anything but the stand, all there was) Pace desoldering system.? I bought a second one and made an adaptor for the existing hot air desoldering system I have.? Then again, the metcal tips work even better with less trauma to the chip. You can argue that mine is a bit of overkill, but then again, why not? Harvey ? On 11/9/2020 1:10 AM, Mike wrote: Yes, I see from the photos that they are in principle much the same. A spinning drill bit that can be raised and lowered, a place slide the pcb around in any direction to reach each of the holes to be drilled, and a camera on the opposite side to have a consistent viewing angle. You are using a roto-tool to get higher rpm for the drill bit, a single axes slide with a stepper motor to advance and pull back the drill and a much fancier camera than I have. Plus yours, as you have said, has the drill upside down so that you see the board the same way as the camera does. Do you have crosshairs taped to the display screen? I needed them on mine because the axis of rotation of the drill bit is not parallel to the vertical axis. Yours does look very substantial. Mine can still be used as a regular drill press between circuit boards without any disassembly and reassembly. I wish I could post pictures of mine, but it is still locked up in a shipping container along with the rest of my workshop waiting for the new workshop to be finished. I added my approach just to provide people with an alternative so that they can choose which suits them best.
--
?????????????? KINDNESS is most VALUABLE when it is GIVEN AWAY for ?????????????????? FREE
|
Re: Drill precision holes without CNC, was RoHS question
I did put a transparency over the screen, laser printed one.? I
have the plans for a video crosshair generator in the works, which
would be much better.? The camera is an old security camera which
runs off 12VDC or 24VAC.? The whole thing runs off 12VDC, so
that's why I got the camera that I did.? Hamfest stuff a while
back.?
I used the rototool (Proxxon) because it's got a higher RPM, much
better bearings, and a much better chuck than the dremel.? I did
have a dremel on a stand, but the parallax was horrible.? The
reason for making this as is?? I wanted a fixed setup that could
be left in one piece.? The stand was from an old (and no, I didn't
buy anything but the stand, all there was) Pace desoldering
system.? I bought a second one and made an adaptor for the
existing hot air desoldering system I have.? Then again, the
metcal tips work even better with less trauma to the chip.
You can argue that mine is a bit of overkill, but then again, why
not?
Harvey
On 11/9/2020 1:10 AM, Mike wrote:
toggle quoted message
Show quoted text
Yes, I see
from the photos that they are in principle much the same. A
spinning drill bit that can be raised and lowered, a place
slide the pcb around in any direction to reach each of the
holes to be drilled, and a camera on the opposite side to have
a consistent viewing angle. You are using a roto-tool to get
higher rpm for the drill bit, a single axes slide with a
stepper motor to advance and pull back the drill and a much
fancier camera than I have. Plus yours, as you have said, has
the drill upside down so that you see the board the same way
as the camera does. Do you have crosshairs taped to the
display screen? I needed them on mine because the axis of
rotation of the drill bit is not parallel to the vertical
axis.
Yours does
look very substantial. Mine can still be used as a regular
drill press between circuit boards without any disassembly and
reassembly. I wish I could post pictures of mine, but it is
still locked up in a shipping container along with the rest of
my workshop waiting for the new workshop to be finished. I
added my approach just to provide people with an alternative
so that they can choose which suits them best.
--
??????????????
KINDNESS
is
most VALUABLE
when
it is GIVEN
AWAY for
?????????????????? FREE
|
Re: Drill precision holes without CNC, was RoHS question
Yes, I see from the photos that they are in principle much the same. A spinning drill bit that can be raised and lowered, a place slide the pcb around in any direction to reach each of the holes to be drilled, and a camera on the opposite side to have a consistent viewing angle. You are using a roto-tool to get higher rpm for the drill bit, a single axes slide with a stepper motor to advance and pull back the drill and a much fancier camera than I have. Plus yours, as you have said, has the drill upside down so that you see the board the same way as the camera does. Do you have crosshairs taped to the display screen? I needed them on mine because the axis of rotation of the drill bit is not parallel to the vertical axis.
Yours does look very substantial. Mine can still be used as a regular drill press between circuit boards without any disassembly and reassembly. I wish I could post pictures of mine, but it is still locked up in a shipping container along with the rest of my workshop waiting for the new workshop to be finished. I added my approach just to provide people with an alternative so that they can choose which suits them best.
--
?????????????? KINDNESS
is
most VALUABLE when
it is GIVEN
AWAY for
?????????????????? FREE
|
Re: Drill precision holes without CNC, was RoHS question
That, and I couldn't do plated through holes (the chemistry
seemed excessive).? SInce I was doing 100 pin TQFP (0.5mm
spacing), depending on whether or not I got the toner transfer
exactly right (and I swear it was environmental factors)....? I
got good boards or bad ones.? I did boards in production lots, and
of course, with toner transfer, you do one at a time.? So I did a
board, cleaned it up (before etching), cleaned it up (after
etching), drilled the registration holes, epoxied it, then drilled
it and hoped that the holes matched.? (the upside down drill press
was needed....).? Once that was done, stitched the board top and
bottom together, then built it, and hoped that there were no
breaks in the tracks I hadn't found.?
Once I started producing boards that had a higher parts density
(and I did 10/10 boards), I just couldn't do it myself.? It was
time to get the boards made elsewhere.?
Harvey
On 11/8/2020 7:49 PM, Bertho wrote:
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Show quoted text
That sounds very familiar!
Bertho
?
?
Thanks.? Linear rail platform, linear stepper, stopping
points are settable (in use).? Worked well until I started
making PC boards that were too complicated to produce here.
Harvey
?
On 11/8/2020 12:04 AM, Bertho wrote:
Nice setup!
?
?
?
We're talking variations on a theme.?
Mine seems to be more elaborate, but then again, I could
throw stuff at it.
/g/homebrewpcbs/album?id=86511
Harvey
?
On 11/7/2020 11:19 PM, Mike wrote:
"The
registration holes need to be exact, which is why I
made an upside down drill press, which is far more
accurate (no parallax)."
I
used a different technique to get the same benefit.
FRP boards in the thickness we use are somewhat
transparent, you can see the drill bit from the
other side right down to the point of contact, thus
no parallax, same as above. To use a normal, bench
mount drill press, I purchased a single-board camera
with NTSC output that I then fed into a small TV
set. I built a small holder for the camera (about 1
inch cubed) plus a 45 degree angle mirror so that
the debris from the drilling did not fall on the
camera and cover the lens. Looking up through the
hole in the center of the drill press table, I was
able to position the board with one hand and lower
the drill with the other. Gravity works in the same
direction as drill force, so it was easy to position
the board while it was resting on the table and
still provide firm support against the drilling. It
worked ell enough for a cheap, out-of-alignment
harbor freight drill press to make accurate holes.
My approach does require the extra purchase of a $40
or less mini board camera but eliminates the problem
of keeping the board from falling down when not
drilling or of keep the board in place against the
force of drilling.
--
??????????????
KINDNESS
is
most VALUABLE
when it is GIVEN AWAY for
??????????????????
FREE
|
Re: Drill precision holes without CNC, was RoHS question
That sounds very familiar! Bertho ?
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Show quoted text
From: [email protected] < [email protected]> On Behalf Of Harvey White Sent: Sunday, November 8, 2020 10:54 To: [email protected]Subject: Re: [homebrewpcbs] Drill precision holes without CNC, was RoHS question ? Thanks.? Linear rail platform, linear stepper, stopping points are settable (in use).? Worked well until I started making PC boards that were too complicated to produce here. Harvey ? On 11/8/2020 12:04 AM, Bertho wrote: Nice setup! ? ? ? We're talking variations on a theme.? Mine seems to be more elaborate, but then again, I could throw stuff at it. /g/homebrewpcbs/album?id=86511 Harvey ? On 11/7/2020 11:19 PM, Mike wrote: "The registration holes need to be exact, which is why I made an upside down drill press, which is far more accurate (no parallax)." I used a different technique to get the same benefit. FRP boards in the thickness we use are somewhat transparent, you can see the drill bit from the other side right down to the point of contact, thus no parallax, same as above. To use a normal, bench mount drill press, I purchased a single-board camera with NTSC output that I then fed into a small TV set. I built a small holder for the camera (about 1 inch cubed) plus a 45 degree angle mirror so that the debris from the drilling did not fall on the camera and cover the lens. Looking up through the hole in the center of the drill press table, I was able to position the board with one hand and lower the drill with the other. Gravity works in the same direction as drill force, so it was easy to position the board while it was resting on the table and still provide firm support against the drilling. It worked ell enough for a cheap, out-of-alignment harbor freight drill press to make accurate holes. My approach does require the extra purchase of a $40 or less mini board camera but eliminates the problem of keeping the board from falling down when not drilling or of keep the board in place against the force of drilling.
--
?????????????? KINDNESS is most VALUABLE when it is GIVEN AWAY for ?????????????????? FREE
|
Re: Drill precision holes without CNC, was RoHS question
Thanks.? Linear rail platform, linear stepper, stopping points
are settable (in use).? Worked well until I started making PC
boards that were too complicated to produce here.
Harvey
On 11/8/2020 12:04 AM, Bertho wrote:
toggle quoted message
Show quoted text
Nice setup!
?
?
?
We're talking variations on a theme.?
Mine seems to be more elaborate, but then again, I could
throw stuff at it.
/g/homebrewpcbs/album?id=86511
Harvey
?
On 11/7/2020 11:19 PM, Mike wrote:
"The
registration holes need to be exact, which is why I
made an upside down drill press, which is far more
accurate (no parallax)."
I
used a different technique to get the same benefit.
FRP boards in the thickness we use are somewhat
transparent, you can see the drill bit from the other
side right down to the point of contact, thus no
parallax, same as above. To use a normal, bench mount
drill press, I purchased a single-board camera with
NTSC output that I then fed into a small TV set. I
built a small holder for the camera (about 1 inch
cubed) plus a 45 degree angle mirror so that the
debris from the drilling did not fall on the camera
and cover the lens. Looking up through the hole in the
center of the drill press table, I was able to
position the board with one hand and lower the drill
with the other. Gravity works in the same direction as
drill force, so it was easy to position the board
while it was resting on the table and still provide
firm support against the drilling. It worked ell
enough for a cheap, out-of-alignment harbor freight
drill press to make accurate holes. My approach does
require the extra purchase of a $40 or less mini board
camera but eliminates the problem of keeping the board
from falling down when not drilling or of keep the
board in place against the force of drilling.
--
??????????????
KINDNESS
is
most VALUABLE
when it is GIVEN AWAY for
??????????????????
FREE
|
Re: Drill precision holes without CNC, was RoHS question
toggle quoted message
Show quoted text
From: [email protected] < [email protected]> On Behalf Of Harvey White Sent: Saturday, November 7, 2020 23:44 To: [email protected]Subject: Re: [homebrewpcbs] Drill precision holes without CNC, was RoHS question ? We're talking variations on a theme.? Mine seems to be more elaborate, but then again, I could throw stuff at it. /g/homebrewpcbs/album?id=86511 Harvey ? On 11/7/2020 11:19 PM, Mike wrote: "The registration holes need to be exact, which is why I made an upside down drill press, which is far more accurate (no parallax)." I used a different technique to get the same benefit. FRP boards in the thickness we use are somewhat transparent, you can see the drill bit from the other side right down to the point of contact, thus no parallax, same as above. To use a normal, bench mount drill press, I purchased a single-board camera with NTSC output that I then fed into a small TV set. I built a small holder for the camera (about 1 inch cubed) plus a 45 degree angle mirror so that the debris from the drilling did not fall on the camera and cover the lens. Looking up through the hole in the center of the drill press table, I was able to position the board with one hand and lower the drill with the other. Gravity works in the same direction as drill force, so it was easy to position the board while it was resting on the table and still provide firm support against the drilling. It worked ell enough for a cheap, out-of-alignment harbor freight drill press to make accurate holes. My approach does require the extra purchase of a $40 or less mini board camera but eliminates the problem of keeping the board from falling down when not drilling or of keep the board in place against the force of drilling.
--
?????????????? KINDNESS is most VALUABLE when it is GIVEN AWAY for ?????????????????? FREE
|
Re: Drill precision holes without CNC, was RoHS question
We're talking variations on a theme.?
Mine seems to be more elaborate, but then again, I could throw
stuff at it.
/g/homebrewpcbs/album?id=86511
Harvey
On 11/7/2020 11:19 PM, Mike wrote:
toggle quoted message
Show quoted text
"The
registration holes need to be exact, which is why I made an
upside down drill press, which is far more accurate (no
parallax)."
I used a
different technique to get the same benefit. FRP boards in the
thickness we use are somewhat transparent, you can see the
drill bit from the other side right down to the point of
contact, thus no parallax, same as above. To use a normal,
bench mount drill press, I purchased a single-board camera
with NTSC output that I then fed into a small TV set. I built
a small holder for the camera (about 1 inch cubed) plus a 45
degree angle mirror so that the debris from the drilling did
not fall on the camera and cover the lens. Looking up through
the hole in the center of the drill press table, I was able to
position the board with one hand and lower the drill with the
other. Gravity works in the same direction as drill force, so
it was easy to position the board while it was resting on the
table and still provide firm support against the drilling. It
worked ell enough for a cheap, out-of-alignment harbor freight
drill press to make accurate holes. My approach does require
the extra purchase of a $40 or less mini board camera but
eliminates the problem of keeping the board from falling down
when not drilling or of keep the board in place against the
force of drilling.
--
??????????????
KINDNESS
is
most VALUABLE
when
it is GIVEN
AWAY for
?????????????????? FREE
|
Re: Drill precision holes without CNC, was RoHS question
"The registration holes need to be exact, which is why I made an upside
down drill press, which is far more accurate (no parallax)."
I used a different technique to get the same benefit. FRP boards in the thickness we use are somewhat transparent, you can see the drill bit from the other side right down to the point of contact, thus no parallax, same as above. To use a normal, bench mount drill press, I purchased a single-board camera with NTSC output that I then fed into a small TV set. I built a small holder for the camera (about 1 inch cubed) plus a 45 degree angle mirror so that the debris from the drilling did not fall on the camera and cover the lens. Looking up through the hole in the center of the drill press table, I was able to position the board with one hand and lower the drill with the other. Gravity works in the same direction as drill force, so it was easy to position the board while it was resting on the table and still provide firm support against the drilling. It worked ell enough for a cheap, out-of-alignment harbor freight drill press to make accurate holes. My approach does require the extra purchase of a $40 or less mini board camera but eliminates the problem of keeping the board from falling down when not drilling or of keep the board in place against the force of drilling.
--
?????????????? KINDNESS
is
most VALUABLE when
it is GIVEN
AWAY for
?????????????????? FREE
|
When I made double sided boards, I didn't do electroplating, but did epoxy the top and bottom boards together.? The registration holes need to be exact, which is why I made an upside down drill press, which is far more accurate (no parallax).
The electroplating/positive resist, (they reversed the negatives photographically, I think they used kodalith and KPR, it was a long time ago), well, they did tin plated boards with the persulphate.
My preferred etchant was cupric chloride once I discovered it. But then again, I was using toner transfer and immersion tin plating of the boards.
Harvey
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On 11/6/2020 6:41 AM, Tony Smith wrote: Electroplating after applying a resist is a good idea. That'd work just fine.
I was never keen on ammonium persulphate, as a cheapskate hobbyist the mixture didn't last, unlike ferric chloride that lasts for ages, or even better (& cheaper!) cupric chloride that you can regenerate. And it doesn't stain everything brown either.
I have used graphite to electroplate non-conductive things, that's pretty simple. Vias might be a bit fiddly.
Tony
-----Original Message-----
From: [email protected] <[email protected]> On Behalf
Of Harvey White
Sent: Monday, 2 November 2020 3:06 AM
To: [email protected]
Subject: Re: [homebrewpcbs] RoHS question
It may have gotten more expensive over time. It was about 30 USD for a pint
the last time I bought it, and it does have some nasty stuff in it. It does work
well on a clean board, though.
One method of making PC boards was to put down a layer of positive
photoresist over a bare board, expose it with a positive of the artwork so
that when developed, copper would be exposed where you wanted there to
be a track. You'd then electroplate tin on the board, strip the resist and etch
it. You would have to use something like ammonium persulphate, which
does not attack tin. Regular Ferric chloride and CuCl etchants will not work.
If you were making double sided boards with plated through holes you'd drill
the holes first, dunk the board in a graphite solution, plate one ounce of
copper over that, then add resist and etch as normal. The tin plating would
also cover the inside of the plated through holes.
Haven't used any of these, I did toner transfer for double sided boards,
stitched top and bottom together, with the top and bottom boards being half
thickness and produced separately.
Harvey
On 11/1/2020 4:57 AM, Tony Smith wrote:
I never tried tin plating PCBs, from memory the stuff was expensive,
hard to get and went "off" quickly. Seemed like a lot of hassle for
little reward, I just sprayed boards with clear lacquer.
Out of curiosity I looked up chemical tin plating, and of course ENIG
comes up. The 'N' is nickel, and the 'G' is gold. Explains why it's
expensive I guess.
The other type of chemical nickel plating is a nickel phosphor
coating, not good for PCBs but ok for machinery parts.
It's occurred to me that if you were into milling PCBs you could
electroplate the copper board beforehand. I wonder if anyone does that.
Tony
-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of
Dave
Sent: Friday, 30 October 2020 1:58 AM
To: [email protected]
Subject: Re: [homebrewpcbs] RoHS question
Tony,
I tinned some of my first home made pcb's but never again. And
the boards
I ordered are of the ENIG variety. No rocket science comes out of my hobby.
:)
On 10/28/2020 3:08 PM, Tony Smith wrote:
Yes, we're in violent agreement.
Unless you're a manufacturer, RoHS (or whatever your local flavour
is) isn't a problem.
Space vehicles are exempt from these regulations, I guess they
figure not many of them are going to wind up in a landfill. For the
tin whiskers, the problem wasn't lead-free solder, it's the tin
plating on the copper tracks, something even hobbyists do. I think
they nickel plate stuff like spacecraft PCBs now.
Dunno if there is a chemical solution to do nickel plating on copper
like you do with tin, but electroplating nickel is really easy.
Tony
|
Electroplating after applying a resist is a good idea. That'd work just fine.
I was never keen on ammonium persulphate, as a cheapskate hobbyist the mixture didn't last, unlike ferric chloride that lasts for ages, or even better (& cheaper!) cupric chloride that you can regenerate. And it doesn't stain everything brown either.
I have used graphite to electroplate non-conductive things, that's pretty simple. Vias might be a bit fiddly.
Tony
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Show quoted text
-----Original Message-----
From: [email protected] <[email protected]> On Behalf
Of Harvey White
Sent: Monday, 2 November 2020 3:06 AM
To: [email protected]
Subject: Re: [homebrewpcbs] RoHS question
It may have gotten more expensive over time. It was about 30 USD for a pint
the last time I bought it, and it does have some nasty stuff in it. It does work
well on a clean board, though.
One method of making PC boards was to put down a layer of positive
photoresist over a bare board, expose it with a positive of the artwork so
that when developed, copper would be exposed where you wanted there to
be a track. You'd then electroplate tin on the board, strip the resist and etch
it. You would have to use something like ammonium persulphate, which
does not attack tin. Regular Ferric chloride and CuCl etchants will not work.
If you were making double sided boards with plated through holes you'd drill
the holes first, dunk the board in a graphite solution, plate one ounce of
copper over that, then add resist and etch as normal. The tin plating would
also cover the inside of the plated through holes.
Haven't used any of these, I did toner transfer for double sided boards,
stitched top and bottom together, with the top and bottom boards being half
thickness and produced separately.
Harvey
On 11/1/2020 4:57 AM, Tony Smith wrote:
I never tried tin plating PCBs, from memory the stuff was expensive,
hard to get and went "off" quickly. Seemed like a lot of hassle for
little reward, I just sprayed boards with clear lacquer.
Out of curiosity I looked up chemical tin plating, and of course ENIG
comes up. The 'N' is nickel, and the 'G' is gold. Explains why it's
expensive I guess.
The other type of chemical nickel plating is a nickel phosphor
coating, not good for PCBs but ok for machinery parts.
It's occurred to me that if you were into milling PCBs you could
electroplate the copper board beforehand. I wonder if anyone does that.
Tony
-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of
Dave
Sent: Friday, 30 October 2020 1:58 AM
To: [email protected]
Subject: Re: [homebrewpcbs] RoHS question
Tony,
I tinned some of my first home made pcb's but never again. And
the boards
I ordered are of the ENIG variety. No rocket science comes out of my hobby.
:)
On 10/28/2020 3:08 PM, Tony Smith wrote:
Yes, we're in violent agreement.
Unless you're a manufacturer, RoHS (or whatever your local flavour
is) isn't a problem.
Space vehicles are exempt from these regulations, I guess they
figure not many of them are going to wind up in a landfill. For the
tin whiskers, the problem wasn't lead-free solder, it's the tin
plating on the copper tracks, something even hobbyists do. I think
they nickel plate stuff like spacecraft PCBs now.
Dunno if there is a chemical solution to do nickel plating on copper
like you do with tin, but electroplating nickel is really easy.
Tony
|
It may have gotten more expensive over time.? It was about 30 USD for a pint the last time I bought it, and it does have some nasty stuff in it.? It does work well on a clean board, though.
One method of making PC boards was to put down a layer of positive photoresist over a bare board, expose it with a positive of the artwork so that when developed, copper would be exposed where you wanted there to be a track.? You'd then electroplate tin on the board, strip the resist and etch it.? You would have to use something like ammonium persulphate, which does not attack tin. Regular Ferric chloride and CuCl etchants will not work.
If you were making double sided boards with plated through holes you'd drill the holes first, dunk the board in a graphite solution, plate one ounce of copper over that, then add resist and etch as normal.? The tin plating would also cover the inside of the plated through holes.
Haven't used any of these, I did toner transfer for double sided boards, stitched top and bottom together, with the top and bottom boards being half thickness and produced separately.
Harvey
toggle quoted message
Show quoted text
On 11/1/2020 4:57 AM, Tony Smith wrote: I never tried tin plating PCBs, from memory the stuff was expensive, hard to
get and went "off" quickly. Seemed like a lot of hassle for little reward,
I just sprayed boards with clear lacquer.
Out of curiosity I looked up chemical tin plating, and of course ENIG comes
up. The 'N' is nickel, and the 'G' is gold. Explains why it's expensive I
guess.
The other type of chemical nickel plating is a nickel phosphor coating, not
good for PCBs but ok for machinery parts.
It's occurred to me that if you were into milling PCBs you could
electroplate the copper board beforehand. I wonder if anyone does that.
Tony
-----Original Message-----
From: [email protected] <[email protected]> On Behalf
Of Dave
Sent: Friday, 30 October 2020 1:58 AM
To: [email protected]
Subject: Re: [homebrewpcbs] RoHS question
Tony,
? I tinned some of my first home made pcb's but never again. And the boards
I ordered are of the ENIG variety. No rocket science comes out of my hobby.
:)
On 10/28/2020 3:08 PM, Tony Smith wrote:
Yes, we're in violent agreement.
Unless you're a manufacturer, RoHS (or whatever your local flavour is)
isn't a problem.
Space vehicles are exempt from these regulations, I guess they figure
not many of them are going to wind up in a landfill. For the tin
whiskers, the problem wasn't lead-free solder, it's the tin plating on
the copper tracks, something even hobbyists do. I think they nickel
plate stuff like spacecraft PCBs now.
Dunno if there is a chemical solution to do nickel plating on copper
like you do with tin, but electroplating nickel is really easy.
Tony
|
I sometimes use soldering tweezers to solder parts. The trick is to use your tweezers to hold down the part (one tine of curved tweezers works well) after tinning & fluxing both pads. Gets harder as the parts get smaller, as usual.
Tony
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-----Original Message-----
From: [email protected] <[email protected]> On Behalf
Of Harvey White
Sent: Friday, 30 October 2020 4:20 AM
To: [email protected]
Subject: Re: [homebrewpcbs] SMT Resistor Sizes
I tin one pad for small parts, touch the pad with the soldering iron tip an use it
for a stop. Then with tweezers, slide the chip onto the pad. Then solder the
other end, being aware that the heat on the other pad could transfer over to
the first pad and melt the solder there. Be quick.
One student I had was employed part time. He tried to solder SMT resistors
using a set of soldering tweezers to do both sides at once. It caused much
amusement amongst the other technicians. I fixed that by explaining a
better method, certainly soldering one side at a time.
On larger TQFP chips, make sure that you solder one pin on one side then
solder the opposite side. Soldering one side completely can pull the chip out
of alignment.
I found a set of anti-static tweezers from Amazon worked well for holding
parts.
Harvey
On 10/29/2020 1:01 PM, keith wrote:
For the smaller components I hold them down with a toothpick and tack
a couple leads , then solder them
On Oct 29, 2020, at 12:32 PM, Dave <theschemer@...> wrote:
?Ok, just a followup on my looking for physically large sized SMT resistors. I researched yet again and realize that the physical size is based on the max
watt rating, which I already knew (but probably forgot). And for my first
attempts of making SMT boards I want large sized components for ease or
working with them. So using a 0.120 inch length resistor (3/4 watt) where I
only need a 1/4 watt resistor is the only way to do it. So now that I looked at
ebay yet again I see I can get what I need at least in most of the sizes I desire
for now.
Dave
|
I never tried tin plating PCBs, from memory the stuff was expensive, hard to
get and went "off" quickly. Seemed like a lot of hassle for little reward,
I just sprayed boards with clear lacquer.
Out of curiosity I looked up chemical tin plating, and of course ENIG comes
up. The 'N' is nickel, and the 'G' is gold. Explains why it's expensive I
guess.
The other type of chemical nickel plating is a nickel phosphor coating, not
good for PCBs but ok for machinery parts.
It's occurred to me that if you were into milling PCBs you could
electroplate the copper board beforehand. I wonder if anyone does that.
Tony
toggle quoted message
Show quoted text
-----Original Message-----
From: [email protected] <[email protected]> On Behalf
Of Dave
Sent: Friday, 30 October 2020 1:58 AM
To: [email protected]
Subject: Re: [homebrewpcbs] RoHS question
Tony,
? I tinned some of my first home made pcb's but never again. And the boards I ordered are of the ENIG variety. No rocket science comes out of my hobby. :)
On 10/28/2020 3:08 PM, Tony Smith wrote:
Yes, we're in violent agreement.
Unless you're a manufacturer, RoHS (or whatever your local flavour is)
isn't a problem.
Space vehicles are exempt from these regulations, I guess they figure
not many of them are going to wind up in a landfill. For the tin
whiskers, the problem wasn't lead-free solder, it's the tin plating on
the copper tracks, something even hobbyists do. I think they nickel
plate stuff like spacecraft PCBs now.
Dunno if there is a chemical solution to do nickel plating on copper
like you do with tin, but electroplating nickel is really easy.
Tony
|
Bertho