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Does anyone know the process that IBM used to make this PCB

Does anyone know the process that IBM used to make this PCB

2017-10-07 by Rob

Does anyone know the process that IBM used to make this PCB
http://www.learnmorsecode.com/3380/index.html

30 years ago I was a computer programmer on an IBM system 34.

IBM service technicians would sometimes open up the machine covers
and I saw some really strange circuit boards inside.
They did not look like anything found in any other electronic appliances.
It looked like there was no etched traces on the IBM circuit boards that
had square blocks..and every square block had solder in them..regardless if
there actually was a component in the holes.
  All the components seemed to line up like houses on city streets.

Recently I stumbled onto an IBM 3380 disk drive analog servo board
and made these pictures with real up close details revealing what the 
strange boards
were really made of... sort of.
It turns out that the IBM PCBs had extremely thin traces on both sides 
of the PCB
and in some places there was 3 traces in the space between  the solder 
squares
and
that space was no wider than a penny.
These traces would terminate at solder pads but would disappear from 
view.....
never being actually visible touching a solder pad.
Does anyone know what process made this circuit board?

Re: [Homebrew_PCBs] Does anyone know the process that IBM used to make this PCB

2017-10-07 by Stefan Trethan

This should be well within the capabilities of ordinary photo process, even back then.
The traces do not disappear, they go into the pads just as you would expect.
For example the one highlighted with the blue arrow goes to the pad immediately above the arrow.

What is unusual is the design restrictions placed on this.
I know nothing about how these were designed but the way the traces are routed leads me to believe they were drawn automatically with some early PC software rather than by hand.
It looks to me as if the software worked with something similar to a netlist that made connections between a grid of pads according to some predetermined rules on how to route a trace.
This would be possible with very limited processing and especially graphical display power, possibly even in something more similar to a spreadsheet form rather that the "visual" CAD we are used to now.
Again this is just speculation.

I do not know if there was a process advantage to always having all the holes in place.
Perhaps the pattern of holes was pre-punched on the raw stock and through hole plated beforehand.
This way the board manufacturing would completely avoid those more complicated steps.

I have seen boards before that seemed to have an abundance of unnecessary on-grid square pads similar to this in old computers, but never ones with 100% pad fill like a breadboard.

ST

Show quoted textHide quoted text
On Sat, Oct 7, 2017 at 5:34 AM, Rob roomberg@... [Homebrew_PCBs] <Homebrew_PCBs@yahoogroups.com> wrote:


Does anyone know the process that IBM used to make this PCB
http://www.learnmorsecode.com/3380/index.html

30 years ago I was a computer programmer on an IBM system 34.

IBM service technicians would sometimes open up the machine covers
and I saw some really strange circuit boards inside.
They did not look like anything found in any other electronic appliances.
It looked like there was no etched traces on the IBM circuit boards that
had square blocks..and every square block had solder in them..regardless if
there actually was a component in the holes.
All the components seemed to line up like houses on city streets.

Recently I stumbled onto an IBM 3380 disk drive analog servo board
and made these pictures with real up close details revealing what the strange boards
were really made of... sort of.
It turns out that the IBM PCBs had extremely thin traces on both sides of the PCB
and in some places there was 3 traces in the space between the solder squares
and
that space was no wider than a penny.
These traces would terminate at solder pads but would disappear from view.....
never being actually visible touching a solder pad.
Does anyone know what process made this circuit board?


RE: [Homebrew_PCBs] Does anyone know the process that IBM used to make this PCB

2017-10-07 by Tony Smith

Dunno how the boards are made, but that’s called SLT - Solid Logic Technology.


I think the idea behind the boards was traces are vertical in one direction, and horizontal on the flip side.  You can still get protoboards to do this.  As Stefan says it was an early attempt to automate everything (especially production) I think the board were designed by placing the little modules and the passives, then taking out the lines they didn’t need.


The extra pads were left because ‘why not’ – it’s easier to leave them than to remove them (probably a standard mask) plus it makes rework easier.


I did come across a good website on these once that will probably show me how wrong I remember it, might see if I can find it.


Tony
Show quoted textHide quoted text
From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] 
Sent: Saturday, 7 October 2017 2:34 PM
To: Homebrew_PCBs@yahoogroups.com
Subject: [Homebrew_PCBs] Does anyone know the process that IBM used to make this PCB

 


Does anyone know the process that IBM used to make this PCB
http://www.learnmorsecode.com/3380/index.html

30 years ago I was a computer programmer on an IBM system 34.

IBM service technicians would sometimes open up the machine covers  
and I saw some really strange circuit boards inside.
They did not look like anything found in any other electronic appliances.
It looked like there was no etched traces on the IBM circuit boards that
had square blocks..and every square block had solder in them..regardless if
there actually was a component in the holes.
 All the components seemed to line up like houses on city streets.

Recently I stumbled onto an IBM 3380 disk drive analog servo board
and made these pictures with real up close details revealing what the strange boards
were really made of... sort of.
It turns out that the IBM PCBs had extremely thin traces on both sides of the PCB
and in some places there was 3 traces in the space between  the solder squares
and
that space was no wider than a penny.
These traces would terminate at solder pads but would disappear from view.....
never being actually visible touching a solder pad.
Does anyone know what process made this circuit board?

Re: [Homebrew_PCBs] Does anyone know the process that IBM used to make this PCB

2017-10-07 by Harvey Altstadter

Ton,

The SLT refers to the silver colored modules that are on the boards. 
These were thick film hybrid circuits with aluminum covers. The modules 
were manufactured on an automated production line. Here is a reference: 
http://www.chipsetc.com/the-ibm-slt---solid-logic-technology.html.

I think the layout on the board was done to accommodate the SLT modules 
with their square shape.� The conductors on the board look something 
like a process that was used on some boards by the company I worked for. 
These were not etched conductors, but rather they were thin wires that 
were laid down on a layer of uncured resin. The way the wires were 
connected to the pads way by ending them in the area of the through 
hole, and when the hole was drilled and plated, the wires were connected 
together. I think the pads were plated on also. The wires were literally 
drawn by a pen like stylus that fed the wire through a center hole. 
Where there were crossovers, they wires look like they did on old 
schematics with their looped crossovers. These boards don't appear to 
use crossovers, probably because the crossovers are inside the SLT 
modules. I know we used those type boards for development, but I don't 
remember if we actually used them in production. These boards: 
http://www.hitachi-chemical.com/products_pwb_05.htm from Hitachi are 
similar to the ones we used, and the name Multiwire sounds familiar to 
me, we might have used the forerunners of this process.

Harvey


On 10/6/2017 9:33 PM, 'Tony Smith' ajsmith1968@... [Homebrew_PCBs] 
wrote:
Show quoted textHide quoted text
>
>
>   Dunno how the boards are made, but that\u2019s called SLT - Solid Logic
>   Technology.
>
>
>   I think the idea behind the boards was traces are vertical in one
>   direction, and horizontal on the flip side.� You can still get
>   protoboards to do this.� As Stefan says it was an early attempt to
>   automate everything (especially production) I think the board were
>   designed by placing the little modules and the passives, then taking
>   out the lines they didn\u2019t need.
>
>
>   The extra pads were left because \u2018why not\u2019 \u2013 it\u2019s easier to leave
>   them than to remove them (probably a standard mask) plus it makes
>   rework easier.
>
>
>   I did come across a good website on these once that will probably
>   show me how wrong I remember it, might see if I can find it.
>
>
>   Tony
>
>
> *From:*Homebrew_PCBs@yahoogroups.com 
> [mailto:Homebrew_PCBs@yahoogroups.com]
> *Sent:* Saturday, 7 October 2017 2:34 PM
> *To:* Homebrew_PCBs@yahoogroups.com
> *Subject:* [Homebrew_PCBs] Does anyone know the process that IBM used 
> to make this PCB
>
>
> Does anyone know the process that IBM used to make this PCB
> http://www.learnmorsecode.com/3380/index.html
>
> 30 years ago I was a computer programmer on an IBM system 34.
>
> IBM service technicians would sometimes open up the machine covers
> and I saw some really strange circuit boards inside.
> They did not look like anything found in any other electronic appliances.
> It looked like there was no etched traces on the IBM circuit boards that
> had square blocks..and every square block had solder in 
> them..regardless if
> there actually was a component in the holes.
> �All the components seemed to line up like houses on city streets.
>
> Recently I stumbled onto an IBM 3380 disk drive analog servo board
> and made these pictures with real up close details revealing what the 
> strange boards
> were really made of... sort of.
> It turns out that the IBM PCBs had extremely thin traces on both sides 
> of the PCB
> and in some places there was 3 traces in the space between� the solder 
> squares
> and
> that space was no wider than a penny.
> These traces would terminate at solder pads but would disappear from 
> view.....
> never being actually visible touching a solder pad.
> Does anyone know what process made this circuit board?
>
>
>
>
>
>
>
>
>

RE: [Homebrew_PCBs] Does anyone know the process that IBM used to make this PCB

2017-10-07 by Tony Smith

Oh, I knew SLT meant the modules, I guess I could have been clearer.

 

The idea of having vertical & horizontal traces on opposite sides of the board was an older idea, I thought they designed the modules to match.

 

The boards themselves were just punched phenolic, some apparently were multi-layer (with ground & power), I don’t know how that worked, you couldn’t have vias everywhere.  Not that they really needed it given the low speeds, maybe it made wiring easier.

 

This was the original stuff: https://www.cs.auckland.ac.nz/historydisplays/FourthFloor/Packaging/PackagingImages/IBM1620Boards.jpg, same idea with the SLT modules: http://www.chipsetc.com/uploads/1/2/4/4/1244189/2744349_orig.jpg.  I can’t remember the magic words to find that PCB prototype stuff, someone re-invents it every so often.

 

The multi-wire stuff you’re describing sounds like a different process, maybe it came along later?  Running wires like that was probably cheaper & faster than etching PCBs, a bit like wire-wrapping I guess.

 

Tony
Show quoted textHide quoted text
From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] 
Sent: Saturday, 7 October 2017 5:05 PM
To: Homebrew_PCBs@yahoogroups.com
Subject: Re: [Homebrew_PCBs] Does anyone know the process that IBM used to make this PCB

 

Ton,

The SLT refers to the silver colored modules that are on the boards. These were thick film hybrid circuits with aluminum covers. The modules were manufactured on an automated production line. Here is a reference: http://www.chipsetc.com/the-ibm-slt---solid-logic-technology.html.

I think the layout on the board was done to accommodate the SLT modules with their square shape.  The conductors on the board look something like a process that was used on some boards by the company I worked for. These were not etched conductors, but rather they were thin wires that were laid down on a layer of uncured resin. The way the wires were connected to the pads way by ending them in the area of the through hole, and when the hole was drilled and plated, the wires were connected together. I think the pads were plated on also. The wires were literally drawn by a pen like stylus that fed the wire through a center hole. Where there were crossovers, they wires look like they did on old schematics with their looped crossovers. These boards don't appear to use crossovers, probably because the crossovers are inside the SLT modules. I know we used those type boards for development, but I don't remember if we actually used them in production. These boards: http://www.hitachi-chemical.com/products_pwb_05.htm from Hitachi are similar to the ones we used, and the name Multiwire sounds familiar to me, we might have used the forerunners of this process.

Harvey

 

On 10/6/2017 9:33 PM, 'Tony Smith' ajsmith1968@... [Homebrew_PCBs] wrote:

  


Dunno how the boards are made, but that’s called SLT - Solid Logic Technology.


I think the idea behind the boards was traces are vertical in one direction, and horizontal on the flip side.  You can still get protoboards to do this.  As Stefan says it was an early attempt to automate everything (especially production) I think the board were designed by placing the little modules and the passives, then taking out the lines they didn’t need.


The extra pads were left because ‘why not’ – it’s easier to leave them than to remove them (probably a standard mask) plus it makes rework easier.


I did come across a good website on these once that will probably show me how wrong I remember it, might see if I can find it.


Tony


 


From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] 
Sent: Saturday, 7 October 2017 2:34 PM
To: Homebrew_PCBs@yahoogroups.com
Subject: [Homebrew_PCBs] Does anyone know the process that IBM used to make this PCB

 


Does anyone know the process that IBM used to make this PCB
http://www.learnmorsecode.com/3380/index.html

30 years ago I was a computer programmer on an IBM system 34.

IBM service technicians would sometimes open up the machine covers  
and I saw some really strange circuit boards inside.
They did not look like anything found in any other electronic appliances.
It looked like there was no etched traces on the IBM circuit boards that
had square blocks..and every square block had solder in them..regardless if
there actually was a component in the holes.
 All the components seemed to line up like houses on city streets.

Recently I stumbled onto an IBM 3380 disk drive analog servo board
and made these pictures with real up close details revealing what the strange boards
were really made of... sort of.
It turns out that the IBM PCBs had extremely thin traces on both sides of the PCB
and in some places there was 3 traces in the space between  the solder squares
and
that space was no wider than a penny.
These traces would terminate at solder pads but would disappear from view.....
never being actually visible touching a solder pad.
Does anyone know what process made this circuit board?

Re: [Homebrew_PCBs] Does anyone know the process that IBM used to make this PCB

2017-10-11 by Dave Daniel

Robyn,

For what it's worth, I have a pop-up canopy that we can use if needed. 
It is 10' x 10' or 12' x 12'. I used to use it at the Lyons Outdoor 
Games festival when I did the kayak scoring.

Dave

On 10/7/2017 3:45 AM, 'Tony Smith' ajsmith1968@... [Homebrew_PCBs] 
wrote:
>
> Oh, I knew SLT meant the modules, I guess I could have been clearer.
>
> The idea of having vertical & horizontal traces on opposite sides of 
> the board was an older idea, I thought they designed the modules to match.
>
> The boards themselves were just punched phenolic, some apparently were 
> multi-layer (with ground & power), I don\u2019t know how that worked, you 
> couldn\u2019t have vias everywhere.  Not that they really needed it given 
> the low speeds, maybe it made wiring easier.
>
> This was the original stuff: 
> https://www.cs.auckland.ac.nz/historydisplays/FourthFloor/Packaging/PackagingImages/IBM1620Boards.jpg, 
> same idea with the SLT modules: 
> http://www.chipsetc.com/uploads/1/2/4/4/1244189/2744349_orig.jpg. I 
> can\u2019t remember the magic words to find that PCB prototype stuff, 
> someone re-invents it every so often.
>
> The multi-wire stuff you\u2019re describing sounds like a different 
> process, maybe it came along later?  Running wires like that was 
> probably cheaper & faster than etching PCBs, a bit like wire-wrapping 
> I guess.
>
> Tony
>
> *From:*Homebrew_PCBs@yahoogroups.com 
> [mailto:Homebrew_PCBs@yahoogroups.com]
> *Sent:* Saturday, 7 October 2017 5:05 PM
> *To:* Homebrew_PCBs@yahoogroups.com
> *Subject:* Re: [Homebrew_PCBs] Does anyone know the process that IBM 
> used to make this PCB
>
> Ton,
>
> The SLT refers to the silver colored modules that are on the boards. 
> These were thick film hybrid circuits with aluminum covers. The 
> modules were manufactured on an automated production line. Here is a 
> reference: 
> http://www.chipsetc.com/the-ibm-slt---solid-logic-technology.html.
>
> I think the layout on the board was done to accommodate the SLT 
> modules with their square shape.  The conductors on the board look 
> something like a process that was used on some boards by the company I 
> worked for. These were not etched conductors, but rather they were 
> thin wires that were laid down on a layer of uncured resin. The way 
> the wires were connected to the pads way by ending them in the area of 
> the through hole, and when the hole was drilled and plated, the wires 
> were connected together. I think the pads were plated on also. The 
> wires were literally drawn by a pen like stylus that fed the wire 
> through a center hole. Where there were crossovers, they wires look 
> like they did on old schematics with their looped crossovers. These 
> boards don't appear to use crossovers, probably because the crossovers 
> are inside the SLT modules. I know we used those type boards for 
> development, but I don't remember if we actually used them in 
> production. These boards: 
> http://www.hitachi-chemical.com/products_pwb_05.htm from Hitachi are 
> similar to the ones we used, and the name Multiwire sounds familiar to 
> me, we might have used the forerunners of this process.
>
> Harvey
>
> On 10/6/2017 9:33 PM, 'Tony Smith' ajsmith1968@... 
> <mailto:ajsmith1968@...> [Homebrew_PCBs] wrote:
>
>
>       Dunno how the boards are made, but that\u2019s called SLT - Solid
>       Logic Technology.
>
>
>       I think the idea behind the boards was traces are vertical in
>       one direction, and horizontal on the flip side.  You can still
>       get protoboards to do this.  As Stefan says it was an early
>       attempt to automate everything (especially production) I think
>       the board were designed by placing the little modules and the
>       passives, then taking out the lines they didn\u2019t need.
>
>
>       The extra pads were left because \u2018why not\u2019 \u2013 it\u2019s easier to
>       leave them than to remove them (probably a standard mask) plus
>       it makes rework easier.
>
>
>       I did come across a good website on these once that will
>       probably show me how wrong I remember it, might see if I can
>       find it.
>
>
>       Tony
>
>
>     *From:*Homebrew_PCBs@yahoogroups.com
>     <mailto:Homebrew_PCBs@yahoogroups.com>
>     [mailto:Homebrew_PCBs@yahoogroups.com]
>     *Sent:* Saturday, 7 October 2017 2:34 PM
>     *To:* Homebrew_PCBs@yahoogroups.com
>     <mailto:Homebrew_PCBs@yahoogroups.com>
>     *Subject:* [Homebrew_PCBs] Does anyone know the process that IBM
>     used to make this PCB
>
>
>     Does anyone know the process that IBM used to make this PCB
>     http://www.learnmorsecode.com/3380/index.html
>
>     30 years ago I was a computer programmer on an IBM system 34.
>
>     IBM service technicians would sometimes open up the machine covers
>     and I saw some really strange circuit boards inside.
>     They did not look like anything found in any other electronic
>     appliances.
>     It looked like there was no etched traces on the IBM circuit
>     boards that
>     had square blocks..and every square block had solder in
>     them..regardless if
>     there actually was a component in the holes.
>      All the components seemed to line up like houses on city streets.
>
>     Recently I stumbled onto an IBM 3380 disk drive analog servo board
>     and made these pictures with real up close details revealing what
>     the strange boards
>     were really made of... sort of.
>     It turns out that the IBM PCBs had extremely thin traces on both
>     sides of the PCB
>     and in some places there was 3 traces in the space between  the
>     solder squares
>     and
>     that space was no wider than a penny.
>     These traces would terminate at solder pads but would disappear
>     from view.....
>     never being actually visible touching a solder pad.
>     Does anyone know what process made this circuit board?
>
>
>
>
>
>
>
>
>
>
>
>
>
> 



---
This email has been checked for viruses by Avast antivirus software.
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Re: [Homebrew_PCBs] Does anyone know the process that IBM used to make this PCB

2017-10-11 by Rob

Who is Robyn ?
My daughter's name is Robyn.
Show quoted textHide quoted text
On 10/11/2017 04:17 AM, Dave Daniel kc0wjn@... [Homebrew_PCBs] wrote:
>
> Robyn,
>
> For what it's worth, I have a pop-up canopy that we can use if needed. 
> It is 10' x 10' or 12' x 12'. I used to use it at the Lyons Outdoor 
> Games festival when I did the kayak scoring.
>
> Dave
>
> On 10/7/2017 3:45 AM, 'Tony Smith' ajsmith1968@... 
> [Homebrew_PCBs] wrote:
>>
>> Oh, I knew SLT meant the modules, I guess I could have been clearer.
>>
>> The idea of having vertical & horizontal traces on opposite sides of 
>> the board was an older idea, I thought they designed the modules to 
>> match.
>>
>> The boards themselves were just punched phenolic, some apparently 
>> were multi-layer (with ground & power), I don\u2019t know how that worked, 
>> you couldn\u2019t have vias everywhere.  Not that they really needed it 
>> given the low speeds, maybe it made wiring easier.
>>
>> This was the original stuff: 
>> https://www.cs.auckland.ac.nz/historydisplays/FourthFloor/Packaging/PackagingImages/IBM1620Boards.jpg, 
>> same idea with the SLT modules: 
>> http://www.chipsetc.com/uploads/1/2/4/4/1244189/2744349_orig.jpg. I 
>> can\u2019t remember the magic words to find that PCB prototype stuff, 
>> someone re-invents it every so often.
>>
>> The multi-wire stuff you\u2019re describing sounds like a different 
>> process, maybe it came along later? Running wires like that was 
>> probably cheaper & faster than etching PCBs, a bit like wire-wrapping 
>> I guess.
>>
>> Tony
>>
>> *From:*Homebrew_PCBs@yahoogroups.com 
>> [mailto:Homebrew_PCBs@yahoogroups.com]
>> *Sent:* Saturday, 7 October 2017 5:05 PM
>> *To:* Homebrew_PCBs@yahoogroups.com
>> *Subject:* Re: [Homebrew_PCBs] Does anyone know the process that IBM 
>> used to make this PCB
>>
>> Ton,
>>
>> The SLT refers to the silver colored modules that are on the boards. 
>> These were thick film hybrid circuits with aluminum covers. The 
>> modules were manufactured on an automated production line. Here is a 
>> reference: 
>> http://www.chipsetc.com/the-ibm-slt---solid-logic-technology.html.
>>
>> I think the layout on the board was done to accommodate the SLT 
>> modules with their square shape.  The conductors on the board look 
>> something like a process that was used on some boards by the company 
>> I worked for. These were not etched conductors, but rather they were 
>> thin wires that were laid down on a layer of uncured resin. The way 
>> the wires were connected to the pads way by ending them in the area 
>> of the through hole, and when the hole was drilled and plated, the 
>> wires were connected together. I think the pads were plated on also. 
>> The wires were literally drawn by a pen like stylus that fed the wire 
>> through a center hole. Where there were crossovers, they wires look 
>> like they did on old schematics with their looped crossovers. These 
>> boards don't appear to use crossovers, probably because the 
>> crossovers are inside the SLT modules. I know we used those type 
>> boards for development, but I don't remember if we actually used them 
>> in production. These boards: 
>> http://www.hitachi-chemical.com/products_pwb_05.htm from Hitachi are 
>> similar to the ones we used, and the name Multiwire sounds familiar 
>> to me, we might have used the forerunners of this process.
>>
>> Harvey
>>
>> On 10/6/2017 9:33 PM, 'Tony Smith' ajsmith1968@... 
>> <mailto:ajsmith1968@...> [Homebrew_PCBs] wrote:
>>
>>
>>       Dunno how the boards are made, but that\u2019s called SLT - Solid
>>       Logic Technology.
>>
>>
>>       I think the idea behind the boards was traces are vertical in
>>       one direction, and horizontal on the flip side.  You can still
>>       get protoboards to do this.  As Stefan says it was an early
>>       attempt to automate everything (especially production) I think
>>       the board were designed by placing the little modules and the
>>       passives, then taking out the lines they didn\u2019t need.
>>
>>
>>       The extra pads were left because \u2018why not\u2019 \u2013 it\u2019s easier to
>>       leave them than to remove them (probably a standard mask) plus
>>       it makes rework easier.
>>
>>
>>       I did come across a good website on these once that will
>>       probably show me how wrong I remember it, might see if I can
>>       find it.
>>
>>
>>       Tony
>>
>>
>>     *From:*Homebrew_PCBs@yahoogroups.com
>>     <mailto:Homebrew_PCBs@yahoogroups.com>
>>     [mailto:Homebrew_PCBs@yahoogroups.com]
>>     *Sent:* Saturday, 7 October 2017 2:34 PM
>>     *To:* Homebrew_PCBs@yahoogroups.com
>>     <mailto:Homebrew_PCBs@yahoogroups.com>
>>     *Subject:* [Homebrew_PCBs] Does anyone know the process that IBM
>>     used to make this PCB
>>
>>
>>     Does anyone know the process that IBM used to make this PCB
>>     http://www.learnmorsecode.com/3380/index.html
>>
>>     30 years ago I was a computer programmer on an IBM system 34.
>>
>>     IBM service technicians would sometimes open up the machine covers
>>     and I saw some really strange circuit boards inside.
>>     They did not look like anything found in any other electronic
>>     appliances.
>>     It looked like there was no etched traces on the IBM circuit
>>     boards that
>>     had square blocks..and every square block had solder in
>>     them..regardless if
>>     there actually was a component in the holes.
>>      All the components seemed to line up like houses on city streets.
>>
>>     Recently I stumbled onto an IBM 3380 disk drive analog servo board
>>     and made these pictures with real up close details revealing what
>>     the strange boards
>>     were really made of... sort of.
>>     It turns out that the IBM PCBs had extremely thin traces on both
>>     sides of the PCB
>>     and in some places there was 3 traces in the space between  the
>>     solder squares
>>     and
>>     that space was no wider than a penny.
>>     These traces would terminate at solder pads but would disappear
>>     from view.....
>>     never being actually visible touching a solder pad.
>>     Does anyone know what process made this circuit board?
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>
>
> <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient&utm_term=icon> 
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>
> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
>

RE: [Homebrew_PCBs] Does anyone know the process that IBM used to make this PCB

2017-10-11 by Tony Smith

If she needs a pop-up canopy, then Dave’s your man.

 

I do believe that wasn’t meant for us.

 

Tony
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From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] 
Sent: Thursday, 12 October 2017 1:07 AM
To: Homebrew_PCBs@yahoogroups.com
Subject: Re: [Homebrew_PCBs] Does anyone know the process that IBM used to make this PCB

 



Who is Robyn ?
My daughter's name is Robyn.




On 10/11/2017 04:17 AM, Dave Daniel kc0wjn@... [Homebrew_PCBs] wrote:

  

Robyn,

For what it's worth, I have a pop-up canopy that we can use if needed. It is 10' x 10' or 12' x 12'. I used to use it at the Lyons Outdoor Games festival when I did the kayak scoring.

Dave

On 10/7/2017 3:45 AM, 'Tony Smith' ajsmith1968@gmail.com [Homebrew_PCBs] wrote:

  

Oh, I knew SLT meant the modules, I guess I could have been clearer.

 

The idea of having vertical & horizontal traces on opposite sides of the board was an older idea, I thought they designed the modules to match.

 

The boards themselves were just punched phenolic, some apparently were multi-layer (with ground & power), I don’t know how that worked, you couldn’t have vias everywhere.  Not that they really needed it given the low speeds, maybe it made wiring easier.

 

This was the original stuff: https://www.cs.auckland.ac.nz/historydisplays/FourthFloor/Packaging/PackagingImages/IBM1620Boards.jpg, same idea with the SLT modules: http://www.chipsetc.com/uploads/1/2/4/4/1244189/2744349_orig.jpg.  I can’t remember the magic words to find that PCB prototype stuff, someone re-invents it every so often.

 

The multi-wire stuff you’re describing sounds like a different process, maybe it came along later?  Running wires like that was probably cheaper & faster than etching PCBs, a bit like wire-wrapping I guess.

 

Tony

 

 

From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] 
Sent: Saturday, 7 October 2017 5:05 PM
To: Homebrew_PCBs@yahoogroups.com
Subject: Re: [Homebrew_PCBs] Does anyone know the process that IBM used to make this PCB

 

Ton,

The SLT refers to the silver colored modules that are on the boards. These were thick film hybrid circuits with aluminum covers. The modules were manufactured on an automated production line. Here is a reference: http://www.chipsetc.com/the-ibm-slt---solid-logic-technology.html.

I think the layout on the board was done to accommodate the SLT modules with their square shape.  The conductors on the board look something like a process that was used on some boards by the company I worked for. These were not etched conductors, but rather they were thin wires that were laid down on a layer of uncured resin. The way the wires were connected to the pads way by ending them in the area of the through hole, and when the hole was drilled and plated, the wires were connected together. I think the pads were plated on also. The wires were literally drawn by a pen like stylus that fed the wire through a center hole. Where there were crossovers, they wires look like they did on old schematics with their looped crossovers. These boards don't appear to use crossovers, probably because the crossovers are inside the SLT modules. I know we used those type boards for development, but I don't remember if we actually used them in production. These boards: http://www.hitachi-chemical.com/products_pwb_05.htm from Hitachi are similar to the ones we used, and the name Multiwire sounds familiar to me, we might have used the forerunners of this process.

Harvey

 

On 10/6/2017 9:33 PM, 'Tony Smith' ajsmith1968@... [Homebrew_PCBs] wrote:

  


Dunno how the boards are made, but that’s called SLT - Solid Logic Technology.


I think the idea behind the boards was traces are vertical in one direction, and horizontal on the flip side.  You can still get protoboards to do this.  As Stefan says it was an early attempt to automate everything (especially production) I think the board were designed by placing the little modules and the passives, then taking out the lines they didn’t need.


The extra pads were left because ‘why not’ – it’s easier to leave them than to remove them (probably a standard mask) plus it makes rework easier.


I did come across a good website on these once that will probably show me how wrong I remember it, might see if I can find it.


Tony


 


From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] 
Sent: Saturday, 7 October 2017 2:34 PM
To: Homebrew_PCBs@yahoogroups.com
Subject: [Homebrew_PCBs] Does anyone know the process that IBM used to make this PCB

 


Does anyone know the process that IBM used to make this PCB
http://www.learnmorsecode.com/3380/index.html

30 years ago I was a computer programmer on an IBM system 34.

IBM service technicians would sometimes open up the machine covers  
and I saw some really strange circuit boards inside.
They did not look like anything found in any other electronic appliances.
It looked like there was no etched traces on the IBM circuit boards that
had square blocks..and every square block had solder in them..regardless if
there actually was a component in the holes.
 All the components seemed to line up like houses on city streets.

Recently I stumbled onto an IBM 3380 disk drive analog servo board
and made these pictures with real up close details revealing what the strange boards
were really made of... sort of.
It turns out that the IBM PCBs had extremely thin traces on both sides of the PCB
and in some places there was 3 traces in the space between  the solder squares
and
that space was no wider than a penny.
These traces would terminate at solder pads but would disappear from view.....
never being actually visible touching a solder pad.
Does anyone know what process made this circuit board?


 
















 

 


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Re: [Homebrew_PCBs] Does anyone know the process that IBM used to make this PCB

2017-10-11 by Dave Daniel

Yeah, that was a mistake on my part - I was one off in my email list. 
Too early in the morning.

DaveD

On 10/11/2017 11:18 AM, 'Tony Smith' ajsmith1968@... 
[Homebrew_PCBs] wrote:
>
> If she needs a pop-up canopy, then Dave\u2019s your man.
>
> I do believe that wasn\u2019t meant for us.
>
> Tony
>
> *From:*Homebrew_PCBs@yahoogroups.com 
> [mailto:Homebrew_PCBs@yahoogroups.com]
> *Sent:* Thursday, 12 October 2017 1:07 AM
> *To:* Homebrew_PCBs@yahoogroups.com
> *Subject:* Re: [Homebrew_PCBs] Does anyone know the process that IBM 
> used to make this PCB
>
>
>
> Who is Robyn ?
> My daughter's name is Robyn.
>
>
> On 10/11/2017 04:17 AM, Dave Daniel kc0wjn@... 
> <mailto:kc0wjn@...> [Homebrew_PCBs] wrote:
>
>     Robyn,
>
>     For what it's worth, I have a pop-up canopy that we can use if
>     needed. It is 10' x 10' or 12' x 12'. I used to use it at the
>     Lyons Outdoor Games festival when I did the kayak scoring.
>
>     Dave
>
>     On 10/7/2017 3:45 AM, 'Tony Smith' ajsmith1968@...
>     <mailto:ajsmith1968@...> [Homebrew_PCBs] wrote:
>
>         Oh, I knew SLT meant the modules, I guess I could have been
>         clearer.
>
>         The idea of having vertical & horizontal traces on opposite
>         sides of the board was an older idea, I thought they designed
>         the modules to match.
>
>         The boards themselves were just punched phenolic, some
>         apparently were multi-layer (with ground & power), I don\u2019t
>         know how that worked, you couldn\u2019t have vias everywhere.  Not
>         that they really needed it given the low speeds, maybe it made
>         wiring easier.
>
>         This was the original stuff:
>         https://www.cs.auckland.ac.nz/historydisplays/FourthFloor/Packaging/PackagingImages/IBM1620Boards.jpg,
>         same idea with the SLT modules:
>         http://www.chipsetc.com/uploads/1/2/4/4/1244189/2744349_orig.jpg.
>         I can\u2019t remember the magic words to find that PCB prototype
>         stuff, someone re-invents it every so often.
>
>         The multi-wire stuff you\u2019re describing sounds like a different
>         process, maybe it came along later?  Running wires like that
>         was probably cheaper & faster than etching PCBs, a bit like
>         wire-wrapping I guess.
>
>         Tony
>
>         *From:*Homebrew_PCBs@yahoogroups.com
>         <mailto:Homebrew_PCBs@yahoogroups.com>
>         [mailto:Homebrew_PCBs@yahoogroups.com]
>         *Sent:* Saturday, 7 October 2017 5:05 PM
>         *To:* Homebrew_PCBs@yahoogroups.com
>         <mailto:Homebrew_PCBs@yahoogroups.com>
>         *Subject:* Re: [Homebrew_PCBs] Does anyone know the process
>         that IBM used to make this PCB
>
>         Ton,
>
>         The SLT refers to the silver colored modules that are on the
>         boards. These were thick film hybrid circuits with aluminum
>         covers. The modules were manufactured on an automated
>         production line. Here is a reference:
>         http://www.chipsetc.com/the-ibm-slt---solid-logic-technology.html.
>
>         I think the layout on the board was done to accommodate the
>         SLT modules with their square shape.  The conductors on the
>         board look something like a process that was used on some
>         boards by the company I worked for. These were not etched
>         conductors, but rather they were thin wires that were laid
>         down on a layer of uncured resin. The way the wires were
>         connected to the pads way by ending them in the area of the
>         through hole, and when the hole was drilled and plated, the
>         wires were connected together. I think the pads were plated on
>         also. The wires were literally drawn by a pen like stylus that
>         fed the wire through a center hole. Where there were
>         crossovers, they wires look like they did on old schematics
>         with their looped crossovers. These boards don't appear to use
>         crossovers, probably because the crossovers are inside the SLT
>         modules. I know we used those type boards for development, but
>         I don't remember if we actually used them in production. These
>         boards: http://www.hitachi-chemical.com/products_pwb_05.htm
>         from Hitachi are similar to the ones we used, and the name
>         Multiwire sounds familiar to me, we might have used the
>         forerunners of this process.
>
>         Harvey
>
>         On 10/6/2017 9:33 PM, 'Tony Smith' ajsmith1968@...
>         <mailto:ajsmith1968@...> [Homebrew_PCBs] wrote:
>
>
>               Dunno how the boards are made, but that\u2019s called SLT -
>               Solid Logic Technology.
>
>
>               I think the idea behind the boards was traces are
>               vertical in one direction, and horizontal on the flip
>               side.  You can still get protoboards to do this. As
>               Stefan says it was an early attempt to automate
>               everything (especially production) I think the board
>               were designed by placing the little modules and the
>               passives, then taking out the lines they didn\u2019t need.
>
>
>               The extra pads were left because \u2018why not\u2019 \u2013 it\u2019s easier
>               to leave them than to remove them (probably a standard
>               mask) plus it makes rework easier.
>
>
>               I did come across a good website on these once that will
>               probably show me how wrong I remember it, might see if I
>               can find it.
>
>
>               Tony
>
>
>             *From:*Homebrew_PCBs@yahoogroups.com
>             <mailto:Homebrew_PCBs@yahoogroups.com>
>             [mailto:Homebrew_PCBs@yahoogroups.com]
>             *Sent:* Saturday, 7 October 2017 2:34 PM
>             *To:* Homebrew_PCBs@yahoogroups.com
>             <mailto:Homebrew_PCBs@yahoogroups.com>
>             *Subject:* [Homebrew_PCBs] Does anyone know the process
>             that IBM used to make this PCB
>
>
>             Does anyone know the process that IBM used to make this PCB
>             http://www.learnmorsecode.com/3380/index.html
>
>             30 years ago I was a computer programmer on an IBM system 34.
>
>             IBM service technicians would sometimes open up the
>             machine covers
>             and I saw some really strange circuit boards inside.
>             They did not look like anything found in any other
>             electronic appliances.
>             It looked like there was no etched traces on the IBM
>             circuit boards that
>             had square blocks..and every square block had solder in
>             them..regardless if
>             there actually was a component in the holes.
>              All the components seemed to line up like houses on city
>             streets.
>
>             Recently I stumbled onto an IBM 3380 disk drive analog
>             servo board
>             and made these pictures with real up close details
>             revealing what the strange boards
>             were really made of... sort of.
>             It turns out that the IBM PCBs had extremely thin traces
>             on both sides of the PCB
>             and in some places there was 3 traces in the space
>             between  the solder squares
>             and
>             that space was no wider than a penny.
>             These traces would terminate at solder pads but would
>             disappear from view.....
>             never being actually visible touching a solder pad.
>             Does anyone know what process made this circuit board?
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>     Image removed by sender.
>     <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient&utm_term=icon>
>
>     	
>
>     Virus-free. www.avast.com
>     <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient&utm_term=link>
>
>
>
>
>
>
> 



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