Budget PCB Hotplate Options: Large, Medium, Small
November 09, 2023
Blog
Several years ago I ordered my first PCB, and soon after moved into the world of surface-mount devices, or SMD. In-house soldering means careful work with an iron or hot air gun, which worked well for what I was doing at the time.
In an attempt to improve my technique, especially in light of my RP2040 (7x7mm QFN-56 package) experimentation, I decided to purchase a soldering hot plate. Actually three:
- 65W Mini Hot Plate 56x56mm SMD Preheater from AliExpress ~$13
- 850W 200x200mm soldering hot plate from Amazon ~$62
- Uyue 946-1010 100x100mm hot plate from AliExpress ~$40
Note that the previous paragraph implies a thoughtful purchasing process. More accurately: I bought the cheapest hot plate I could find, then bought one that was too big, and finally settled on one that seems perfect (with a few caveats). I justified this extravagance by:
- These hot plates now count as article research (what you’re now reading)
- It’s about the same amount of money that I could have spent on a SainSmart mini MHP30 unit. Admittedly, this looks like an adorable little device, and can be found for less money if you shop around.
And yes, I (i.e. my business) paid for all three, which I am sometimes able to avoid with better planning. All that being said, let’s get into these devices:
1. Mini 56x56mm Hotplate - Tiny and Cheap
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Image Credit: Jeremy Cook
If you’re tight on cash and/or space, and you work primarily with very small PCBs, the Mini Hot Plate may meet your needs. It’s something of a bargain at around $13, though you’ll need to provide your own USB-C power source. This bit can easily cost more than the heater itself.
The device does, however, heat up quickly if you power it with a PD-capable supply at ~20VDC. The screws are an impediment to heating with a board hanging over the sides, but if you remove two screws on opposite corners you can slide in a larger PCB than in the stock configuration (not that I’m necessarily vouching for this method). Construction appears a bit cheap, and the interface may take some twiddling, but it works acceptably for extremely small devices.
100-200ºC heating speed: 55 seconds
Height: 39mm (1.5in)
2. Medium 100x100mm Hotplate – Just Right?
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Image Credit: Jeremy Cook
This format is especially interesting to me because 100x100mm is often the largest spec that bargain board houses allow without increasing prototype prices. I rarely deal with anything bigger, which makes this size a nice compromise in terms of table space versus functionality. It appears to be well-built, and the interface is a simple temperature setting.
Heating speed, like its surface area, is between the small and large models tested, which seems like a reasonable compromise. Given its lower height and smaller surface area I feel more comfortable working with it than the larger model.
100-200ºC heating speed: 84 seconds
Height: 131mm (5.2in)
Trying out a Uyue 946-1010 100mm x 100mm hotplate.
— Jeremy Cook 🤖 (@JeremySCook) October 30, 2023
Thoughts so far:
1. I like 100x100 surface area and gen build quality. Nice if it was a bit shorter. Have not tested GND.
2. I have much to learn WRGT solder plate usage and SMD parts in general. pic.twitter.com/6FiJvwoWwA
3. Large 200x200mm Hotplate – Large and Solid (But Maybe Too Much)
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Image Credit: Jeremy Cook
At the large end of the spectrum, for a still-rather-reasonable $62 you can get a 200x200mm hot plate. This device’s construction appears solid, and the temperature setting interface is straightforward like the medium model.
The device’s size, however, can also be a detriment. Its heating surface sticks up nearly 6 inches from the workbench, which, along with its massive surface area, made me nervous working with it. A large area would of course be necessary with larger boards, but it seems overkill for my needs.
100-200ºC heating speed: 208 seconds
Height: 144mm (5.7in)
Good for Assembly, Great for Disassembly and Modification
While it’s not terribly difficult to install parts with a hot air gun, I find taking them off to be more troublesome. With a hot plate you can heat the whole board up to a melted state, or to an almost-melted temperature, then finish the job with a heat gun. This makes parts removal and/or manipulation relatively easy.
Note that testing here has been done largely with stock settings. For example, it may be possible to increase heating speeds through advanced settings, though cooling would likely stay at a constant rate. Also, there is some bouncing and different temperature setting details between the units, so the times are approximate. Finally, I didn’t test for any grounding issues and the like.
Hot Plate Bottom Line
When you don’t have the money for a full reflow oven, and/or you want to interact with components while hot, this type of heater can be an attractive option. Among the devices tested, I prefer the 100x100mm Uyue 946-1010 hot plate, though I’d prefer it to be a bit shorter. Some sort of “surface hot” indicator toward the top of the surface on any of these devices would be a nice safety feature.
At the end of the day, my soldering technique is still far from perfect. I’d like to think that someday I’ll look back on the video posted here to consider how much I’ve learned!
