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The Wikipedia article on wave soldering does not give any information on its history. What was the first computer circuit board to use this process?

I am specifically looking for computers that were commercially-available to other people or companies, not products built for one's own use.


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    Are you asking about personal computers, or any computer?
    – Jon Custer
    Mar 18, 2021 at 16:17
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    @JonCuster: For this question, any kind of computer. But it should be something that others could buy, so no prototypes.
    – DrSheldon
    Mar 18, 2021 at 16:25
  • And, you want to distinguish between wave flow and reflow soldering?
    – Jon Custer
    Mar 18, 2021 at 16:26
  • @JonCuster: The first in which wave soldering was used, whether or not reflow was also a factor.
    – DrSheldon
    Mar 18, 2021 at 16:33
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    epdtonthenet.net/article/8488/50-years-of-wave-solder.aspx gives that wave soldering was invented around 1956. "Allan Barnes, Vic Elliot and Ralph Strauss applied for a patent for this new invention on Oct 3rd 1956 and this was granted on July 23rd 1958" So this gives a oldest time for the first computer.
    – UncleBod
    Mar 18, 2021 at 17:08

1 Answer 1

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The modern PCB, as we know it, was a war time development and so was wave soldering as a way to lower production cost while maintaining consistent quality. All this predates computers, so when computer production became serious manufacturing, that is more than single unit with special to type board, PCBs and wave soldering was used. While not the first, IBM's 1960 Standard Modular System makes a great example:

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The basic idea was to produce a system of basic building blocks that could be produced in (comparably) large quantities using more efficient production technologies - Including wave soldering. DEC later took that idea to create their Flip-Chip modules. But wave soldering was not only used by IBM, or DEC, but any other computer company of the late 1950s early 1960s as well. Had a HP2116A of the mid 1960s at my desk a few days ago: wave soldered boards as well.

Long Story Short:

As soon as computers were produced in quantities past a hand full, wave soldering was a tool of choice

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    If PCBs and wave soldering has already been a thing that early, then why those mini computers still used wire wrapped backplane? What limited the size and complexity of PCB at that time? Or, what made PCB so expensive that economy of scale was so significant (today a batch as small as 100 is already considered by some as "production" ) Jun 9, 2022 at 10:18
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    @user3528438 Multiple reasons a) A mini like a PDP-1 has 100 boards, many of them duplicates, while there is only one backplane. B) Variants of the same machine (and there were many) would be build using mostly the same boards, but need different backplanes. C) Upgrades would need new backplanes (backplanes aren't busses, but the machine itself). D) Backplanes were huge compared to boards, so production is more complicated. E) Last but not least: PCB of that time did not provide the density wiring could (just see above, how big these traces are). PCB were only single layer, two layer at most
    – Raffzahn
    Jun 9, 2022 at 10:49

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