Feedthough/via that straddles (i.e., is bisected by) the cut edge of a PCB?

[Don Y]

I can't see any way to do this, reliably. So, imagine a house won't
let it through DRCs, regardless of diameter or weight of foil, etc.

Or, is there another (not exhorbitantly pricey) technology for precisely
cutting boards that would keep the structure (at least the part that is
not lost to the cut) mechanically (and thus electrically) intact?

Else, I will use another -- more expectantly reliable -- approach

[dalai lamah]

Post by Don Y
I can't see any way to do this, reliably. So, imagine a house won't
let it through DRCs, regardless of diameter or weight of foil, etc.
Or, is there another (not exhorbitantly pricey) technology for precisely
cutting boards that would keep the structure (at least the part that is
not lost to the cut) mechanically (and thus electrically) intact?
Else, I will use another -- more expectantly reliable -- approach

The keyword to look for is "castellated holes". The easier way to do it is
to find a manufacturer that explicitly supports them, and follow their
instructions. For example:

https://www.pcbway.com/pcb_prototype/What_are_Plated_Half_Holes_Castellated_Holes_.html

[Don Y]

Post by dalai lamah
The keyword to look for is "castellated holes". The easier way to do it is
to find a manufacturer that explicitly supports them, and follow their
https://www.pcbway.com/pcb_prototype/What_are_Plated_Half_Holes_Castellated_Holes_.html

Excellent! /Grazie tante/

A first pass through the description doesn't seem to EXPLICITLY say it but
it seems like they are implying that the drilling occurs ON the edge, and not
before milling? I.e., each drilling action results in ONE such "hole" -- not
two HALF holes (on adjoining panelized boards)

"...BEGINS with drilling ON the edge of the substrate..." (emphasis mine)

I will contact the vendor to see what the economic consequences are likely
to be. (and, will know how to search for others with similar capabilities!)

[Jasen Betts]

Post by Don Y

Post by dalai lamah
The keyword to look for is "castellated holes". The easier way to do it is
to find a manufacturer that explicitly supports them, and follow their
https://www.pcbway.com/pcb_prototype/What_are_Plated_Half_Holes_Castellated_Holes_.html

Excellent! /Grazie tante/
A first pass through the description doesn't seem to EXPLICITLY say it but
it seems like they are implying that the drilling occurs ON the edge, and not
before milling? I.e., each drilling action results in ONE such "hole" -- not
two HALF holes (on adjoining panelized boards)

Usually the cutting is with a 2mm router and the holes are much
smaller than that. so afterwards you only get one half of each hole.

I suppose you could do vee groove instead of routing but I'd worry aboout the
copper tearing when the boards are separated. (or maybe the copper
would damage or contaminate the saw so they refuse this)

as I unserstand it they are drilled at the same time as other plated
holes and slots and then after plating, etching, and mask the edges are cut.

Post by Don Y
"...BEGINS with drilling ON the edge of the substrate..." (emphasis mine)

I'm pretty sure they mean egde of your board outline.

[Don Y]

Post by Jasen Betts

Post by Don Y

Post by dalai lamah
The keyword to look for is "castellated holes". The easier way to do it is
to find a manufacturer that explicitly supports them, and follow their
https://www.pcbway.com/pcb_prototype/What_are_Plated_Half_Holes_Castellated_Holes_.html

Excellent! /Grazie tante/
A first pass through the description doesn't seem to EXPLICITLY say it but
it seems like they are implying that the drilling occurs ON the edge, and not
before milling? I.e., each drilling action results in ONE such "hole" -- not
two HALF holes (on adjoining panelized boards)

Usually the cutting is with a 2mm router and the holes are much
smaller than that. so afterwards you only get one half of each hole.
I suppose you could do vee groove instead of routing but I'd worry aboout the
copper tearing when the boards are separated. (or maybe the copper
would damage or contaminate the saw so they refuse this)
as I unserstand it they are drilled at the same time as other plated
holes and slots and then after plating, etching, and mask the edges are cut.

Post by Don Y
"...BEGINS with drilling ON the edge of the substrate..." (emphasis mine)

I'm pretty sure they mean egde of your board outline.

From the previously cited URL (reformatted for clarity):

"The traditional process for manufacturing plated half-holes typically
involves the following steps:
- drilling
- applying chemical copper to the panel
- image transfer
- pattern plating
- film stripping
- etching
- solder mask layer printing
- surface treatment
- hole formation
- contour milling.

However, the above steps can result in decreased productivity and
performance of the product."

I would assume milling the already plated hole being the problem.

"Nowadays, the process of forming plated half-holes differs from
the usual traditional methods.

The process of forming plated half-holes begins with drilling
/on the edge of the substrate/.

Suggesting that the drill actually is on the physical edge of the
material, not an edge that will be created after milling.

"Therefore, it is crucial to use /specialized drilling equipment/
as any deficiencies in the equipment can affect all subsequent steps.

Again, I would assume this is required because there will be a bending
moment applied to the drill bit as it encounters material only on one
"side" of the bit. I.e., that it will want to bore a hole that is not
completely orthogonal to the board as it bends further from the intended
hole centerline as it proceeds further through the material.

Once the preparation is completed, the next step is copper plating
of the holes. Copper plating is equally essential as it ensures good
conductivity for the components on the circuit board.

Note that they don't mention "specialized MILLING equipment" (to preserve
already plated holes with extra care)

?

[Phil Hobbs]

Post by Don Y

Post by Jasen Betts

Post by Don Y

Post by dalai lamah
The keyword to look for is "castellated holes". The easier way to do it is
to find a manufacturer that explicitly supports them, and follow their
https://www.pcbway.com/pcb_prototype/What_are_Plated_Half_Holes_Castellated_Holes_.html

Excellent! /Grazie tante/
A first pass through the description doesn't seem to EXPLICITLY say it but
it seems like they are implying that the drilling occurs ON the edge, and not
before milling? I.e., each drilling action results in ONE such "hole" -- not
two HALF holes (on adjoining panelized boards)

Usually the cutting is with a 2mm router and the holes are much
smaller than that. so afterwards you only get one half of each hole.
I suppose you could do vee groove instead of routing but I'd worry aboout the
copper tearing when the boards are separated. (or maybe the copper
would damage or contaminate the saw so they refuse this)
as I unserstand it they are drilled at the same time as other plated
holes and slots and then after plating, etching, and mask the edges are cut.

Post by Don Y
"...BEGINS with drilling ON the edge of the substrate..." (emphasis mine)

I'm pretty sure they mean egde of your board outline.

"The traditional process for manufacturing plated half-holes typically
- drilling
- applying chemical copper to the panel
- image transfer
- pattern plating
- film stripping
- etching
- solder mask layer printing
- surface treatment
- hole formation
- contour milling.
However, the above steps can result in decreased productivity and
performance of the product."
I would assume milling the already plated hole being the problem.
"Nowadays, the process of forming plated half-holes differs from
the usual traditional methods.
The process of forming plated half-holes begins with drilling
/on the edge of the substrate/.
Suggesting that the drill actually is on the physical edge of the
material, not an edge that will be created after milling.
"Therefore, it is crucial to use /specialized drilling equipment/
as any deficiencies in the equipment can affect all subsequent steps.
Again, I would assume this is required because there will be a bending
moment applied to the drill bit as it encounters material only on one
"side" of the bit. I.e., that it will want to bore a hole that is not
completely orthogonal to the board as it bends further from the intended
hole centerline as it proceeds further through the material.
Once the preparation is completed, the next step is copper plating
of the holes. Copper plating is equally essential as it ensures good
conductivity for the components on the circuit board.
Note that they don't mention "specialized MILLING equipment" (to preserve
already plated holes with extra care)
?

That process wouldn’t leave copper hackles behind, so it obviously isn’t
universal.

Cheers

Phil Hobbs

[john larkin]

On Fri, 31 May 2024 04:57:58 -0700, Don Y

Post by Don Y

Post by Jasen Betts

Post by Don Y

Post by dalai lamah
The keyword to look for is "castellated holes". The easier way to do it is
to find a manufacturer that explicitly supports them, and follow their
https://www.pcbway.com/pcb_prototype/What_are_Plated_Half_Holes_Castellated_Holes_.html

Excellent! /Grazie tante/
A first pass through the description doesn't seem to EXPLICITLY say it but
it seems like they are implying that the drilling occurs ON the edge, and not
before milling? I.e., each drilling action results in ONE such "hole" -- not
two HALF holes (on adjoining panelized boards)

Usually the cutting is with a 2mm router and the holes are much
smaller than that. so afterwards you only get one half of each hole.
I suppose you could do vee groove instead of routing but I'd worry aboout the
copper tearing when the boards are separated. (or maybe the copper
would damage or contaminate the saw so they refuse this)
as I unserstand it they are drilled at the same time as other plated
holes and slots and then after plating, etching, and mask the edges are cut.

Post by Don Y
"...BEGINS with drilling ON the edge of the substrate..." (emphasis mine)

I'm pretty sure they mean egde of your board outline.

"The traditional process for manufacturing plated half-holes typically
- drilling
- applying chemical copper to the panel
- image transfer
- pattern plating
- film stripping
- etching
- solder mask layer printing
- surface treatment
- hole formation
- contour milling.
However, the above steps can result in decreased productivity and
performance of the product."
I would assume milling the already plated hole being the problem.
"Nowadays, the process of forming plated half-holes differs from
the usual traditional methods.
The process of forming plated half-holes begins with drilling
/on the edge of the substrate/.
Suggesting that the drill actually is on the physical edge of the
material, not an edge that will be created after milling.
"Therefore, it is crucial to use /specialized drilling equipment/
as any deficiencies in the equipment can affect all subsequent steps.
Again, I would assume this is required because there will be a bending
moment applied to the drill bit as it encounters material only on one
"side" of the bit. I.e., that it will want to bore a hole that is not
completely orthogonal to the board as it bends further from the intended
hole centerline as it proceeds further through the material.
Once the preparation is completed, the next step is copper plating
of the holes. Copper plating is equally essential as it ensures good
conductivity for the components on the circuit board.
Note that they don't mention "specialized MILLING equipment" (to preserve
already plated holes with extra care)
?

Just plop ordinary pth holes and have the outline or panelization
routing path saw them in half. It's no big deal. No special tools
needed.

Loading Image...

[Jasen Betts]

Post by Don Y

Post by Jasen Betts

Post by Don Y

Post by dalai lamah
The keyword to look for is "castellated holes". The easier way to do it is
to find a manufacturer that explicitly supports them, and follow their
https://www.pcbway.com/pcb_prototype/What_are_Plated_Half_Holes_Castellated_Holes_.html

Excellent! /Grazie tante/
A first pass through the description doesn't seem to EXPLICITLY say it but
it seems like they are implying that the drilling occurs ON the edge, and not
before milling? I.e., each drilling action results in ONE such "hole" -- not
two HALF holes (on adjoining panelized boards)

Usually the cutting is with a 2mm router and the holes are much
smaller than that. so afterwards you only get one half of each hole.
I suppose you could do vee groove instead of routing but I'd worry aboout the
copper tearing when the boards are separated. (or maybe the copper
would damage or contaminate the saw so they refuse this)
as I unserstand it they are drilled at the same time as other plated
holes and slots and then after plating, etching, and mask the edges are cut.

Post by Don Y
"...BEGINS with drilling ON the edge of the substrate..." (emphasis mine)

I'm pretty sure they mean egde of your board outline.

"The traditional process for manufacturing plated half-holes typically
- drilling
- applying chemical copper to the panel
- image transfer
- pattern plating
- film stripping
- etching
- solder mask layer printing
- surface treatment
- hole formation
- contour milling.
However, the above steps can result in decreased productivity and
performance of the product."
I would assume milling the already plated hole being the problem.
"Nowadays, the process of forming plated half-holes differs from
the usual traditional methods.
The process of forming plated half-holes begins with drilling
/on the edge of the substrate/.
Suggesting that the drill actually is on the physical edge of the
material, not an edge that will be created after milling.
"Therefore, it is crucial to use /specialized drilling equipment/
as any deficiencies in the equipment can affect all subsequent steps.
Again, I would assume this is required because there will be a bending
moment applied to the drill bit as it encounters material only on one
"side" of the bit. I.e., that it will want to bore a hole that is not
completely orthogonal to the board as it bends further from the intended
hole centerline as it proceeds further through the material.
Once the preparation is completed, the next step is copper plating
of the holes. Copper plating is equally essential as it ensures good
conductivity for the components on the circuit board.
Note that they don't mention "specialized MILLING equipment" (to preserve
already plated holes with extra care)

Possibly a bad translation from Chinese. doing hole plating after edge
milling seems like very difficult task.


Others say that only a specialised milling process is needed
Both copper and glass are hard to mill, copper is soft and gummy and glass
is hard and brittle, so the combination is real tricky.

[john larkin]

On Sat, 1 Jun 2024 00:28:02 -0000 (UTC), Jasen Betts

Post by Jasen Betts

Post by Don Y

Post by Jasen Betts

Post by Don Y

Post by dalai lamah
The keyword to look for is "castellated holes". The easier way to do it is
to find a manufacturer that explicitly supports them, and follow their
https://www.pcbway.com/pcb_prototype/What_are_Plated_Half_Holes_Castellated_Holes_.html

Excellent! /Grazie tante/
A first pass through the description doesn't seem to EXPLICITLY say it but
it seems like they are implying that the drilling occurs ON the edge, and not
before milling? I.e., each drilling action results in ONE such "hole" -- not
two HALF holes (on adjoining panelized boards)

Usually the cutting is with a 2mm router and the holes are much
smaller than that. so afterwards you only get one half of each hole.
I suppose you could do vee groove instead of routing but I'd worry aboout the
copper tearing when the boards are separated. (or maybe the copper
would damage or contaminate the saw so they refuse this)
as I unserstand it they are drilled at the same time as other plated
holes and slots and then after plating, etching, and mask the edges are cut.

Post by Don Y
"...BEGINS with drilling ON the edge of the substrate..." (emphasis mine)

I'm pretty sure they mean egde of your board outline.

"The traditional process for manufacturing plated half-holes typically
- drilling
- applying chemical copper to the panel
- image transfer
- pattern plating
- film stripping
- etching
- solder mask layer printing
- surface treatment
- hole formation
- contour milling.
However, the above steps can result in decreased productivity and
performance of the product."
I would assume milling the already plated hole being the problem.
"Nowadays, the process of forming plated half-holes differs from
the usual traditional methods.
The process of forming plated half-holes begins with drilling
/on the edge of the substrate/.
Suggesting that the drill actually is on the physical edge of the
material, not an edge that will be created after milling.
"Therefore, it is crucial to use /specialized drilling equipment/
as any deficiencies in the equipment can affect all subsequent steps.
Again, I would assume this is required because there will be a bending
moment applied to the drill bit as it encounters material only on one
"side" of the bit. I.e., that it will want to bore a hole that is not
completely orthogonal to the board as it bends further from the intended
hole centerline as it proceeds further through the material.
Once the preparation is completed, the next step is copper plating
of the holes. Copper plating is equally essential as it ensures good
conductivity for the components on the circuit board.
Note that they don't mention "specialized MILLING equipment" (to preserve
already plated holes with extra care)

Possibly a bad translation from Chinese. doing hole plating after edge
milling seems like very difficult task.
Others say that only a specialised milling process is needed
Both copper and glass are hard to mill, copper is soft and gummy and glass
is hard and brittle, so the combination is real tricky.

Every PCB is routed to size. It's routine.

This is easy.

[Don Y]

Post by Jasen Betts

Post by Don Y
"Therefore, it is crucial to use /specialized drilling equipment/
as any deficiencies in the equipment can affect all subsequent steps.
Note that they don't mention "specialized MILLING equipment" (to preserve
already plated holes with extra care)

Possibly a bad translation from Chinese. doing hole plating after edge
milling seems like very difficult task.

Dunno. I was trying to gauge the added complexity/labor/time to estimate
what the likely premium might be. E.g., hard to imagine drilling individual
boards -- or just "1 up" panelized being cheap.

Post by Jasen Betts
Others say that only a specialised milling process is needed
Both copper and glass are hard to mill, copper is soft and gummy and glass
is hard and brittle, so the combination is real tricky.

I'll toss together a sample design -- same overall size -- with a row of 15mil
vias NEAR the edge. And, the exact same design with the board outline shifted
(so board remains EXACTLY the same size, holes, foils) so that the vias are
bisected by the board edge and see what the difference is in small quantities
and then in "rightmost column" buys.

If they flinch, I'll increase via diameter and try again -- until its
not worth the approach.

[Jasen Betts]

Post by Don Y

Post by Jasen Betts

Post by Don Y
"Therefore, it is crucial to use /specialized drilling equipment/
as any deficiencies in the equipment can affect all subsequent steps.
Note that they don't mention "specialized MILLING equipment" (to preserve
already plated holes with extra care)

Possibly a bad translation from Chinese. doing hole plating after edge
milling seems like very difficult task.

Dunno. I was trying to gauge the added complexity/labor/time to estimate
what the likely premium might be. E.g., hard to imagine drilling individual
boards -- or just "1 up" panelized being cheap.

Post by Jasen Betts
Others say that only a specialised milling process is needed
Both copper and glass are hard to mill, copper is soft and gummy and glass
is hard and brittle, so the combination is real tricky.

I'll toss together a sample design -- same overall size -- with a row of 15mil
vias NEAR the edge. And, the exact same design with the board outline shifted
(so board remains EXACTLY the same size, holes, foils) so that the vias are
bisected by the board edge and see what the difference is in small quantities
and then in "rightmost column" buys.
If they flinch, I'll increase via diameter and try again -- until its
not worth the approach.

There's a checkbox for casellation on their quote form, (click
customised service and advanced options) it seems to
add about $16 if you want 5 boards, and about $350 if you want 500 boards

I don't know if you're buying sharper (or special) router bits, shorter
board stacks, or a slower feed rate with the extra dollars, but I
doubt it's buying extra process steps.

[Don Y]

Post by Jasen Betts

Post by Don Y
I'll toss together a sample design -- same overall size -- with a row of 15mil
vias NEAR the edge. And, the exact same design with the board outline shifted
(so board remains EXACTLY the same size, holes, foils) so that the vias are
bisected by the board edge and see what the difference is in small quantities
and then in "rightmost column" buys.
If they flinch, I'll increase via diameter and try again -- until its
not worth the approach.

There's a checkbox for casellation on their quote form, (click
customised service and advanced options) it seems to
add about $16 if you want 5 boards, and about $350 if you want 500 boards

I tried a bunch of different options and couldn't come to a concensus.
I have to sit down and put a *real* design through the process and
pick REAL options to see what the consequences are likely to be.

But, $LIFE keeps getting in the way. :< I need to clear some of my
backlog so I can focus on specific problems -- right now, finish writing
a grammar for another project that should have only taken a few days
to complete, were it not for the distractions. :-/

Post by Jasen Betts
I don't know if you're buying sharper (or special) router bits, shorter
board stacks, or a slower feed rate with the extra dollars, but I
doubt it's buying extra process steps.

Yeah, but tying up existing equipment for more EFFECTIVE time per board
equates to the same thing. I have to assume longer lead times are
likely a result of them trying to sneak a troublesome job in between
easier jobs, a bit at a time.

[john larkin]

On Wed, 29 May 2024 05:55:24 -0700, Don Y

Post by Don Y
I can't see any way to do this, reliably. So, imagine a house won't
let it through DRCs, regardless of diameter or weight of foil, etc.
Or, is there another (not exhorbitantly pricey) technology for precisely
cutting boards that would keep the structure (at least the part that is
not lost to the cut) mechanically (and thus electrically) intact?
Else, I will use another -- more expectantly reliable -- approach

It's called castelleaton, or mouse bites. I do it fairly often. Works
fine.

Our PCB houses don't like the drill to be any smaller than 16 mils.

https://www.dropbox.com/sh/te3csdd2mlszvfe/AAAnJ5c8DMAJPQkwWbN3FeNra?dl=0

[John R Walliker]

Post by john larkin
On Wed, 29 May 2024 05:55:24 -0700, Don Y

Post by Don Y
I can't see any way to do this, reliably. So, imagine a house won't
let it through DRCs, regardless of diameter or weight of foil, etc.
Or, is there another (not exhorbitantly pricey) technology for precisely
cutting boards that would keep the structure (at least the part that is
not lost to the cut) mechanically (and thus electrically) intact?
Else, I will use another -- more expectantly reliable -- approach

It's called castelleaton, or mouse bites. I do it fairly often. Works
fine.
Our PCB houses don't like the drill to be any smaller than 16 mils.
https://www.dropbox.com/sh/te3csdd2mlszvfe/AAAnJ5c8DMAJPQkwWbN3FeNra?dl=0

I recently had a few hundred small adapter boards made by a UK
manufacturer with plated castellated edges. The finished hole diameter
was 0.7mm, board thickness was 0.8mm.
The only problem was that the part of the hole that was meant to be
cut away remained partly in place as a copper burr. I did need to
trim these away with a scalpel. The manufacturer had warned me that
this would probably happen and would only make the boards on that
basis. Larger holes would have been fine.
John