4 ms·

It's a great hack and a cool demo that may have (very) limited real-life niche applications, but it's not really worth it unless you only make a couple of PCB p

by Renaud 4y ago

It's a great hack and a cool demo that may have (very) limited real-life niche applications, but it's not really worth it unless you only make a couple of PCB per year and can't afford a small oven. Where this is great is that you can finely control the temperature of the board since you're in control of the current you pump into it. Where it's not great is that it uses a full layer and could cause issues if any of your PCB needs special considerations, when using high frequency clocks or RF (say implementing a switch mode power supply can be quite sensitive to how your layers are composed). You also end-up with either a floating layer or a ground layer that has a long path instead of a real ground plane. That could also create noise issues. If you assemble a few PCB a year, a PCB oven is fairly cheap. You can make one with a regular US$50 oven and a PID control kit or just buy a dedicated one like the T-962 (that can be further hacked and improved) for about US$250 from Aliexpress. But that hack is still cool and Carl Bugeja's channel[1] has lots of fun projects that push PCB to new limits for hobbyists, showing what you can achieve with flex PCB in particular and using them as mechanical interfaces for creating motors, actuators, etc. It's a great channel! [1]: https://www.youtube.com/@CarlBugeja https://www.youtube.com/@CarlBugeja

Animats 4y ago
> dedicated (reflow oven) like the T-962 The trouble with the T-962 is that the stock units heat so unevenly that you can scorch the center of the board while getting cold solder joints near the edges. I have one of those with the mods for improved firmware and better thermocouple references. It's OK. The firmware runs the fan all the time, even during heating, which improves the heat distribution. There's a better mod which adds a second fan. A number of companies in China made clones of those things, but none of them seem to have done a redesign to make a better one at roughly the same price. Now there seems to be a new generation of these things, with more fan power. That's a step forward. No idea if they're any good. (There are reflow oven review sites, as bogus as mattress review sites.) There ought to be a good $200 reflow oven by now. You can buy good small reflow ovens from the US and Germany, but prices are upwards of US$3000.
- fest 4y ago
  There are relatively affordable vapor phase ovens- at $WORK I arranged the purchase of Vapor Phase One- it works really well. However, some people are more sensitive to the resulting smell.
  - amelius 4y ago
    Sensitive as in a allergic reaction or a headache? Or just a dislike of the smell?
    - fest 4y ago
      From what I gathered- just dislike, mixed with some concerns. I didn't smell anything apart from the usual flux smell, but I have very little sense of smell.
  - lightedman 4y ago
    My issue with vapor-phase is that it tends to cause a lot of tombstoned or sleeping components. It's pretty good for multi-leg components like power ICs and processors and BGA components, but not so good on two-conductor resistors, capacitors, jumpers, etc. This is mostly because with vapor-phase you can't really control the thermal profile of the reflow.
    - fest 4y ago
      My understanding is that Galden vapor is dense, so you get a layer of hot vapor near the fluid, with lower temperature further from fluid (where there is less vapor)- the required thermal profile is maintained by controlling position of the boards..
IshKebab 4y ago
> Can't afford a small oven. You don't even need that; you can solder PCBs in a frying pan. It works very well. I never even tried an oven to be honest because a frying pan worked so well and Adafruit or someone like that said it was better than a toaster oven. Although I do have induction hobs now. Not sure if a PCB would be too happy about that. But if not you can buy a portable mini hob for like £15. It's a really cool tech demo though.
- amelius 4y ago
  Put the frying pan only works for single-sided PCBs ;)
  - IshKebab 4y ago
    That is true, but I think most hobby PCBs are single sided.
    - makapuf 4y ago
      Not necessarily single copper sided, but they tend to be single side for components.
      - IshKebab 4y ago
        That's called single layer and roughly nobody is doing single layer boards.
        lightedman 4y ago
        Single layer is absolutely used en-masse. Track lighting circuitry is one example. LED lighting is another.
- namibj 4y ago
  Clothes iron.
- 4b11b4 4y ago
fest 4y ago
Perhaps the particular T962a was just a bad product, but at $WORK we just could not get it working reliably across many types of PCBs- it really required tuning the profile to each type of PCB (small, large, black solder mask vs green, etc)- and yes, a colleague spent a day or two installing the cold junction compensation mod. From what I saw- there was just too large variance in IR emissivity/absorption of the PCBA and their thermal properties, which resulted in scorched connectors on one batch and raw/non-molten paste on another batch- with exactly the same profile. I achieved much better results with just a (convection) toaster oven and multimeter thermocouple- I only added PID controller because I started using the oven for drying something as well.

by Renaud 4y ago

Animats 4y ago

> dedicated (reflow oven) like the T-962 The trouble with the T-962 is that the stock units heat so unevenly that you can scorch the center of the board while getting cold solder joints near the edges. I have one of those with the mods for improved firmware and better thermocouple references. It's OK. The firmware runs the fan all the time, even during heating, which improves the heat distribution. There's a better mod which adds a second fan. A number of companies in China made clones of those things, but none of them seem to have done a redesign to make a better one at roughly the same price. Now there seems to be a new generation of these things, with more fan power. That's a step forward. No idea if they're any good. (There are reflow oven review sites, as bogus as mattress review sites.) There ought to be a good $200 reflow oven by now. You can buy good small reflow ovens from the US and Germany, but prices are upwards of US$3000.

fest 4y ago
There are relatively affordable vapor phase ovens- at $WORK I arranged the purchase of Vapor Phase One- it works really well. However, some people are more sensitive to the resulting smell.
- amelius 4y ago
  Sensitive as in a allergic reaction or a headache? Or just a dislike of the smell?
  - fest 4y ago
    From what I gathered- just dislike, mixed with some concerns. I didn't smell anything apart from the usual flux smell, but I have very little sense of smell.
- lightedman 4y ago
  My issue with vapor-phase is that it tends to cause a lot of tombstoned or sleeping components. It's pretty good for multi-leg components like power ICs and processors and BGA components, but not so good on two-conductor resistors, capacitors, jumpers, etc. This is mostly because with vapor-phase you can't really control the thermal profile of the reflow.
  - fest 4y ago
    My understanding is that Galden vapor is dense, so you get a layer of hot vapor near the fluid, with lower temperature further from fluid (where there is less vapor)- the required thermal profile is maintained by controlling position of the boards..

IshKebab 4y ago

> Can't afford a small oven. You don't even need that; you can solder PCBs in a frying pan. It works very well. I never even tried an oven to be honest because a frying pan worked so well and Adafruit or someone like that said it was better than a toaster oven. Although I do have induction hobs now. Not sure if a PCB would be too happy about that. But if not you can buy a portable mini hob for like £15. It's a really cool tech demo though.

amelius 4y ago
Put the frying pan only works for single-sided PCBs ;)
- IshKebab 4y ago
  That is true, but I think most hobby PCBs are single sided.
  - makapuf 4y ago
    Not necessarily single copper sided, but they tend to be single side for components.
    - IshKebab 4y ago
      That's called single layer and roughly nobody is doing single layer boards.
      - lightedman 4y ago
        Single layer is absolutely used en-masse. Track lighting circuitry is one example. LED lighting is another.
namibj 4y ago
Clothes iron.
4b11b4 4y ago

fest 4y ago

Perhaps the particular T962a was just a bad product, but at $WORK we just could not get it working reliably across many types of PCBs- it really required tuning the profile to each type of PCB (small, large, black solder mask vs green, etc)- and yes, a colleague spent a day or two installing the cold junction compensation mod. From what I saw- there was just too large variance in IR emissivity/absorption of the PCBA and their thermal properties, which resulted in scorched connectors on one batch and raw/non-molten paste on another batch- with exactly the same profile. I achieved much better results with just a (convection) toaster oven and multimeter thermocouple- I only added PID controller because I started using the oven for drying something as well.