Reply by Don Y August 19, 20232023-08-19
On 8/15/2023 11:54 PM, Jasen Betts wrote:
> On 2023-08-15, Don Y <blockedofcourse@foo.invalid> wrote: >> On 8/14/2023 10:50 PM, Jasen Betts wrote: >>>> [I'm only looking for small quantities -- hundreds. >>>> I'll let someone else refine the process for bigger >>>> quantities (with commensurate investments] >>> >>> Any through hole parts? >> >> No. *Possibly* a couple of registration holes. > > perhaps thin phenolic paper or polyimide, it can be cut using blade in a > press, laser or water jet etc... or scissors for prototypes.
Thanks! I will see if I can find a house that has it available. Perhaps (in production) a die can be created to just stamp out the blanks prior to stuffing...
Reply by Jasen Betts August 16, 20232023-08-16
On 2023-08-15, Don Y <blockedofcourse@foo.invalid> wrote:
> On 8/14/2023 10:50 PM, Jasen Betts wrote: >>> [I'm only looking for small quantities -- hundreds. >>> I'll let someone else refine the process for bigger >>> quantities (with commensurate investments] >> >> Any through hole parts? > > No. *Possibly* a couple of registration holes.
perhaps thin phenolic paper or polyimide, it can be cut using blade in a press, laser or water jet etc... or scissors for prototypes. -- Jasen. &#127482;&#127462; &#1057;&#1083;&#1072;&#1074;&#1072; &#1059;&#1082;&#1088;&#1072;&#1111;&#1085;&#1110;
Reply by Phil Hobbs August 15, 20232023-08-15
On 2023-08-15 10:11, Don Y wrote:> On 8/14/2023 7:45 AM, Phil Hobbs wrote:
 >>> The boards don't have to be particularly sturdy as
 >>> they will be supported completely by their undersides.
 >>>
 >>> What sort of material might be suitable for this?
 >>>
 >>> [I'm only looking for small quantities -- hundreds.
 >>> I'll let someone else refine the process for bigger
 >>> quantities (with commensurate investments]
 >>
 >> We&rsquo;ve used Dirty PCBs for stuff like that in the long-ago time.
 >>
 >> https://dirtypcbs.com
 >>
 >> Dunno if they&rsquo;ve gone too far upmarket since.
 >
 > "Stuff like that" meaning "dirt cheap", "flimsy"?  Or, "unusual 
outlines"?
 >
 >
Dirt cheap, solder mask and silk screen optional, PTH also optional.  We 
built some breakout boards for prototyping.

(Small rectangular pads on a grid of 0.5 x 0.65 mm are super useful too.)

Cheers

Phil Hobbs

-- 
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com
Reply by Don Y August 15, 20232023-08-15
On 8/15/2023 7:27 AM, John Walliker wrote:
> Having complex external shapes in FR4 never seems to be a problem for
It's not a question of whether or not they can *do* it but, rather, what the cost penalty is. I'm looking for *really* cheap.
> manufacturers, but some don't like large internal cutouts. Others are OK > with these. In one design I linked the internal cutout to the outside with a > 2mm wide channel so that everything could be cut without lifting the router bit.
(I'm trying to identify similar shapes that I can convey easily) Imagine routing a board with the outline of the digit '8'. Or, '2' (note the tight internal angle on the bottom right) to keep eliminate the need to lift the tool to route an internal void.
> Some manufacturers will fit as many repetitions as possible onto one panel > for a fixed price.
Yes. Panelizing a nice regular shape is easier than something more obscure. How tightly could you pack '2's onto a panel? (That;s actually an interesting problem. I'll see what my panelizing software comes up with for a solution... I wonder how many options it explores?) What's the minimum distance between to ensure you don't chip a board edge? etc.
> I recently had a small double-sided design with a complex routed > outline manufactured with about 190 repetitions on a single 130x210mm panel > for about GBP100 in total.
Those would be tiny boards. I'm looking at an enclosing polygon of maybe 100mm x 70mm (but, a fair bit of that being "space")
> Here are the details for a larger single-sided panel. > https://www.pcbpanel.co.uk/panel-f-single-sided-conventional.html > You can probably do a lot better in China, especially if you use resin > bonded paper.
It might be better to populate and then cut. But, that limits the houses that can do that. OTOH, it might afford better panelizing options for the different boards (on a single panel).
Reply by Don Y August 15, 20232023-08-15
On 8/14/2023 8:12 AM, Lasse Langwadt Christensen wrote:
> mandag den 14. august 2023 kl. 16.35.38 UTC+2 skrev Don Y: >> I have to make some dirt cheap boards. I can >> lay them out single-sided. But, need to be able >> to mill/route the outlines to relatively complex >> shapes (e.g., donuts, concave curves, etc.) >> >> One approach is to laser cut the boards -- if the >> material chosen isn't too "robust" -- instead of >> having the boardhouse deal with this. >> >> The boards don't have to be particularly sturdy as >> they will be supported completely by their undersides. >> >> What sort of material might be suitable for this? >> >> [I'm only looking for small quantities -- hundreds. >> I'll let someone else refine the process for bigger >> quantities (with commensurate investments] > > upload some gerbers to jlcpcb, I suspect shipping will be more that a 100 boards
Yes, that's the only sure way to get hard numbers. I would have prefered if folks would clearly state their capabilities instead of trying to swat at them by submitting different outlines and waiting to see where the pain creeps in. [I've had this problem when dealing with custom devices from Japanese vendors; they want you to tell them what you *want* whereas most designers look at what things "cost" and adjust their "wants", accordingly.] Rectangular boards being the cheapest.
Reply by John Walliker August 15, 20232023-08-15
On Tuesday, 15 August 2023 at 15:08:58 UTC+1, Don Y wrote:
> On 8/14/2023 10:50 PM, Jasen Betts wrote: > >> [I'm only looking for small quantities -- hundreds. > >> I'll let someone else refine the process for bigger > >> quantities (with commensurate investments] > > > > Any through hole parts? > > No. *Possibly* a couple of registration holes.
Having complex external shapes in FR4 never seems to be a problem for manufacturers, but some don't like large internal cutouts. Others are OK with these. In one design I linked the internal cutout to the outside with a 2mm wide channel so that everything could be cut without lifting the router bit. Some manufacturers will fit as many repetitions as possible onto one panel for a fixed price. I recently had a small double-sided design with a complex routed outline manufactured with about 190 repetitions on a single 130x210mm panel for about GBP100 in total. Here are the details for a larger single-sided panel. https://www.pcbpanel.co.uk/panel-f-single-sided-conventional.html You can probably do a lot better in China, especially if you use resin bonded paper. John
Reply by Don Y August 15, 20232023-08-15
On 8/14/2023 7:45 AM, Phil Hobbs wrote:
>> The boards don't have to be particularly sturdy as >> they will be supported completely by their undersides. >> >> What sort of material might be suitable for this? >> >> [I'm only looking for small quantities -- hundreds. >> I'll let someone else refine the process for bigger >> quantities (with commensurate investments] > > We&rsquo;ve used Dirty PCBs for stuff like that in the long-ago time. > > https://dirtypcbs.com > > Dunno if they&rsquo;ve gone too far upmarket since.
"Stuff like that" meaning "dirt cheap", "flimsy"? Or, "unusual outlines"?
Reply by Don Y August 15, 20232023-08-15
On 8/14/2023 10:50 PM, Jasen Betts wrote:
>> [I'm only looking for small quantities -- hundreds. >> I'll let someone else refine the process for bigger >> quantities (with commensurate investments] > > Any through hole parts?
No. *Possibly* a couple of registration holes.
Reply by Don Y August 15, 20232023-08-15
On 8/15/2023 5:21 AM, Clive Arthur wrote:

>> What sort of material might be suitable for this? >> >> [I'm only looking for small quantities -- hundreds. >> I'll let someone else refine the process for bigger >> quantities (with commensurate investments] > > I used some thin single-sided FR4 once, IIRC 0.4mm but it may have been less. > It was thin enough to cut with scissors, which we did.
Excellent. I am assuming the ease of cutting won't affect the price of having it done by the board fabricator; they see it as another step in the process (and, possibly difficult depending on the actual geometries of the outlines I choose). OTOH, "thinner" means other techniques may be more appropriate to cut it (though scissors would probably be too labor intensive and inaccurate). Thanks!
Reply by Clive Arthur August 15, 20232023-08-15
On 14/08/2023 15:35, Don Y wrote:
> I have to make some dirt cheap boards.&nbsp; I can > lay them out single-sided.&nbsp; But, need to be able > to mill/route the outlines to relatively complex > shapes (e.g., donuts, concave curves, etc.) > > One approach is to laser cut the boards -- if the > material chosen isn't too "robust" -- instead of > having the boardhouse deal with this. > > The boards don't have to be particularly sturdy as > they will be supported completely by their undersides. > > What sort of material might be suitable for this? > > [I'm only looking for small quantities -- hundreds. > I'll let someone else refine the process for bigger > quantities (with commensurate investments]
I used some thin single-sided FR4 once, IIRC 0.4mm but it may have been less. It was thin enough to cut with scissors, which we did. -- Cheers Clive