Why are through hole components still made?

Discussion in 'General Electronics Chat' started by spinnaker, Jan 20, 2013.

  1. spinnaker

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    Oct 29, 2009
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    Seems most manufacturers use SMD today. So then, why are through hole components still made?

    Are they still being used by engineers for prototype? Or do they just exist for the hobbyist?
     
  2. debe

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    For me any thing built with surface mount is throw away, not realy economical to repair. From a manufacturers point of view i gues its easy & cheep to manufacture. So there must still be a market for through hole components which i still prefer. Just my thaughts.
     
  3. crutschow

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    Many of them may be just left over stock from when through-hole ICs were common. I think few new devices are manufactured with through hole, since I would say 99.99% of all modern manufactured electronics are surface-mount. Makes it tough for the hobbyists.
     
  4. WBahn

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    They are made because there is still a market for them. There are lots of products still in production that are tooled for through hole and it is cheaper (or at least is perceived as being cheaper) overall to stay with through hole than retool for SMD. Eventually, as lines convert or companies go out of business or products are upgraded/overtaken, the demand for various types of through hole components will drop below sustainability levels and they will become obsoleted and disappear. This has already happened to lots of parts in lots of technologies, but just look at how long tubes were supported and available and you will have some idea of how long it will take through hole components to go away (almost) entirely.

    Sadly, there is not enough of a market associated with the hobbyists to keep something like basic through hole components in production. The capital costs, including ongoing maintenance of equipment and such, is too high for hobbyist volumes to justify keeping a line open.
     
  5. thatoneguy

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    Quite a few designs are still prototyped on either breadboard or with faster systems, wire wrap.

    Simulations are never perfect, and deciding PCB layout is a task of nearly the same complexity as the circuit itself when working with dozens of data and address lines.

    Many newer components are only available in SMD, either due to operating at very high speeds, or for heat dissipation via PCB.

    Through hole component availability went down for a bit around 2005, but now with PICAXE and Arduino type systems being cheap and easy to use and extremely popular, there has been a huge resurgence in hobbyists, most of which use through hole parts exclusively. Most all logic that can be used in low frequency apps (<2 Mhz) is available as through hole now.

    The actual packaging for through hole costs more, but ease of use and demand will keep them alive longer, until something simpler than "surfboard mount" can be used for breadboard type prototyping.
     
  6. spinnaker

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    So will we see through hole go away in our life time? If so, that is going to make it awfully difficult for the hobbyist.

    I just completed a very small project for SMD. Actually a hybrid of SMD and through hole. Through hole is almost mandatory for solderless breadboards. To see if my little circuit worked, I pretty much had to go straight to PCB.
     
  7. thatoneguy

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    Yes, but I am anticipating some sort of solderless breadboard for the larger SMD devices. If I knew exactly how it would work and function, I'd be selling them already. Once those exist at an affordable price, through hole components will go the same way point to point wiring did when PC Boards became economical.
     
  8. spinnaker

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    So some prototypes are down in through hole?

    This was my argument on the Diptrace forum. They tie the pattern to the schematic as opposed to the PCB.

    Some users like the fact the Bill of Materials is tied to the schematic. Which I understand.

    But you might want to design a prototype for through hole then switch to SMD. Certainly the hobbyist might do this.

    I am fine either way as long as their refresh from schematic did not overwrite your changes on the PCB. Even if you simply change a pad size, refresh over writes your changes.
     
  9. WBahn

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    For years, there have been carriers that convert SMD parts to DIP specifically for the purpose of enabling prototyping on solderless breadboards. Other carries convert higher pin count parts to PGA outlines.
     
  10. thatoneguy

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    True, but I've been trying to think of a way to use SOT-23 and similar SMT in a prototype environment closer to the final PCB. Some sort of solderless breadboard with clamp system like the adapters, but without the link of through hole and breadboard.

    Right now, the adapters to through hole are still rather spendy, though they are down from what they cost 5 years ago.
     
  11. bountyhunter

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    Sep 7, 2009
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    Just for me.

    And electronics makers in China and other places that make things that sell on ebay for $2.
     
  12. spinnaker

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    How would it work for caps, coils, resistors, transistors etc?
     
  13. thatoneguy

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    Clamping, just like the chip carriers for programmers, but 2 terminal. The hard part is figuring out how the interconnects would be put in place without a breadboard.
     
  14. spinnaker

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    doyouWouldn't you need a carrier for every smd?
     
  15. thatoneguy

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    A clamp of sorts, yes, that's where my idea sort of falls apart. ;)
     
  16. WBahn

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    Like you've said, maybe someone will think og something clever and make a fortune. I see two really big hurdles, though. The first, touched on above, is that unlike the handful of centeral components, like a MCU or such, if you try to work with general SMD components you go from needing carries for one or at most a few components to needing to deal with dozens or even on the order of a hundred components. I can imagine some kind of a gang carrier that has, say, a dozen slots that you drop your choice of 0603 parts into and then clamp them all at once and there is a dip header to plug into a bread board. Maybe something similar for SOT-23. But this approach runs up against the other issue and that is that more and more prototyping is being done on faster and faster circuits and even circuits that are only being run at low speed are using ICs that are increasingly fast and therefore more sensitive to parasitics on the I/O pins.

    What I see happening (and I'm not by any means a fan of it) is that we will become increasingly reliant on simulations to prototype our work. The good part of this is that, just like the world of IC design when it went through the same shift big time a couple of decades ago, the simulators and the models will go from having a passing resemblence to how the real components work to being very, very good models of how they work and over the whole range of the principle parameters such as supply voltage and temperature.

    When I first started designing ICs, I was amazed how close the simulations came to what we saw in the lab when the chip came back and today it is almost unreal. When the sim says that I should expect a bias voltage, let's say, to be 1.384V, the real chip is seldom more than a few mV away from that. Then again, in order to achieve that each transistor is modeled by a subcircuit with literally hundreds of components in it.
     
  17. atferrari

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    I think I was able to grasp the whole WBann, except the words in bold. Could you rephrase that sentence?
     
  18. atferrari

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    Thinking of the hobby in ten years time, I asume that a hobbyist should be able to:

    1 - learn to simulate well the intended circuit using the best circuit simulator (available to him).

    2 - Go straight to a PCB that by that time should be not very expensive to produce AND easy to produce. (Everything is relative compared to...)

    3 - Understand that reworking the PCB would be most probably a necessary step, maybe more than once. I wish we could hear how many successful / completed (hobbyst) designs were done in the original PCB without any additional connection/component. Not many, I guess.
     
  19. ErnieM

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    If you wander over to EBay you can find many inexpensive adapters, such as these:

    [​IMG] [​IMG][​IMG]

    The first two will fit into a solderless breadboard (just not the one on the right) using some pins:

    [​IMG]
    DO NOTE these particular pins may be too wide for solderless breadboards. They will probably spread the connectors inside the board making those holes suspect for any other device.

    I haven't willingly used a solderless breadboard in many decades, I prefer to use PCB breadboards made on FR-4 material with double sided plated thru pads on a 0.1" grid, such as these:

    [​IMG]
    I have a decided preference for SMD parts when breadboarding: I solder parts down and keep the board even for an experiment. Years later there it will be for reference or another launching point.

    The pins work great with these, either directly soldered in, or with the sockets shown above. I've gotten away from making sockets for each chip, I just solder the pins in directly. When a chip needs to be changed I just unsolder it from the adapter board and replace it there.

    I keep a supply of 30AWG solid insulated wire for interconnections. This is easily stripped with an old manual wire wrap tool I've had forever. These are now on the pricy side, but may be worth it if you value your time. I also keep some solid uninsulated 26AWG wire for things like power buses. This can be tacked down to pads to keep it in place for long runs.

    For things like resistors and capacitors I try to keep to the "0805" size (.08" long by .04" wide). This size works great with 0.1" pads as they span a pair of pads allowing wires thru the holes to go to other places, though commonly one end goes to an IC pin so it is just soldered directly to that IC pad.

    Small transistors like SOT-23's also work well on 0.1" pads, put them down on a diagonal and they just touch three pads. Larger transistors such as SOT-89's also attach well as the 3 leads just fit on three adjacent pads.

    Some sort of magnifier is very handy too. I have a microscope but a magnifying glass on an arm with a light would also be good.

    My soldering iron has the smallest tip Hakko sells for my series. The station also has a hot air gun which is best for desoldering: when soldering it tends to blow parts right off the board.

    Tweezers: get a good pair, the tips don't have to be very fine, blunt tips are better for most parts.
     
  20. thatoneguy

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    I was thinking along these lines for a "solderless breadboard" concept:

    [​IMG]

    Which cost a bit more
     
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