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Is it possible to solder SMT/SMD chips using a rework preheater (e.g. a Model 5040-XR3)? What "gotchas" go with this method of SMT/SMD soldering?

I know it's best to use a real reflow oven, but the rework preheaters are cheaper. I also know hot plates are even cheaper, but such hot plates make doing double sided PCBs almost impossible.

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  • \$\begingroup\$ Yes you can reflow with that, but a basic IR reflow oven would be cheaper and work better. \$\endgroup\$ Commented May 23, 2023 at 22:31

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It really depends on the chip, IC's with pads that are not exposed on the outside edges with high pitch counts like BGA's or LGAs are going to take some skill to solder. Other chips you can see the outside pins an inspect them, so its easier to tell if you got it right.

The preheater is best used when you have a design that has a lot of pads that are connected to ground or pads with little thermal relief. It also works for BGA's where the temperature profile must be followed closely to get correct soldering.

I would use a preheater anytime I had pins that were connected to ground to get the board temp up, it works well on connectors or IC's with a lot of ground pads.

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  • \$\begingroup\$ High pin count ICs on 4 or more layers (big amount of copper to heat!) are a nightmare. Without a preheater is quite easy to delaminate some pad… \$\endgroup\$ Commented May 24, 2023 at 6:59
  • \$\begingroup\$ That's actually the main reason why I bought one years ago was for QFPs that were 200 pin \$\endgroup\$
    – Voltage Spike
    Commented May 24, 2023 at 16:11
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You've linked to a rework station that has hot air and a soldering iron in addition to preheating.

They claim the preheating can be set as high as 400°C. How long it would last if you cranked it up that high is anyone's guess. It's not enclosed. You could preheat then use the hot air over specific areas of the board. I don't think this would be very satisfactory for more than a few small components, but that's a guess.

You can buy a small batch reflow oven for fair bit less than that and it will work "okay", especially with decent quality leaded solder paste.

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  • \$\begingroup\$ Thanks! I hesitate to use the heat gun (I actually already have one) for reflowing because it'll probably blow the part off the board. Where can you find cheaper reflow ovens? The ones I've been able to find are more expensive with mixed reviews \$\endgroup\$
    – P_B
    Commented May 23, 2023 at 22:46
  • \$\begingroup\$ @P_B Amazon wants ~$220 for a t962. Can probably get cheaper elsewhere. They're not great but can be modded and are much better than a preheater. \$\endgroup\$ Commented May 23, 2023 at 23:08
  • \$\begingroup\$ I have an unmodified T962. It's not as good as the conveyorized oven, but it's okay. The cold junction compensation doesn't but it's still good enough for some things. \$\endgroup\$ Commented May 24, 2023 at 7:40

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