hot plate: is bigger better? - Page 1
Forum section: electronics / beginners

author: PinheadBE
author_rank: Regular Contributor
timestamp: May 03, 2025, 05:49:49 pm
content: Hi,On Chinese ressellers, I see hot plates with sizes going from 10x10cm to 20x20cm, all under 50 EUR or USD.As an hobbyist, I will not use it a lot, and mainly on relatively small pcb's.However, I can afford 50 EUR, and I'd prefer to be safe than sorry.All in all, is a 20x20cm - 800 W for 50 EUR a good choice, or is there a problem with it?All opinions welcome

author: ggchab
author_rank: Frequent Contributor
timestamp: May 05, 2025, 02:09:39 pm
content: I have a 20x20cm and a 10x10cm models. They both work very well. I have been using the 20x20 for many years.The 10x10 is more recent. It heats up faster for small PCB's.I add a small plate of aluminum on top of the heater to avoid damages with the flux.

author: gerbay
author_rank: Regular Contributor
timestamp: May 05, 2025, 02:24:37 pm
content: Can you give the link? Maybe we might want to get it too..

author: u666sa
author_rank: Frequent Contributor
timestamp: May 05, 2025, 02:47:54 pm
content: If it's something you will be using day to day, for example iPhone BGA work, or notebook BGA work (some people do BGA work without bottom preheat) then consider spending a bit more for something like this:You want a) thin profile, b) modularity, easy to put away from work area, c) good software preferably with pre-made profiles for preheating some of the often used consumer brands like iPhone and Samsung.

author: ejeffrey
author_rank: Super Contributor
timestamp: May 05, 2025, 05:05:59 pm
content: If you have the space and the budget, I always like to oversize -- usually a larger hot plate will have better uniformity at the center.

author: thm_w
author_rank: Super Contributor
timestamp: May 06, 2025, 12:49:56 am
content: If you are certain you will only build <10cm boards then 10x10 would be good, otherwise you'd have to play safe and get the larger one.https://www.eevblog.com/forum/reviews/recommendation-for-smd-hot-plate/https://www.eevblog.com/forum/reviews/small-size-reflow-hot-plates/Quote from: u666sa on May 05, 2025, 02:47:54 pmThat looks like it costs 10x as much, lol. Not related to what OP is asking for.

author: Whales
author_rank: Super Contributor
timestamp: May 06, 2025, 05:47:10 am
content: Last year I bought two hotplates for work from Aliexpress. The 10x10cm one is brilliant, the 15x15cm one sucks. It's slow to heat, slow to cool and the PID loop isn't tuned for it (it stops heating a good 10degC under target). I think they copied the electronics (including heater) to make the bigger one.EDIT: it was these ones.Aside: I like hotplates that have heat extending right to the edge (minimal bezel area). I often put through-hole components like connectors on one end of the board and SMD on the rest, then "hang" it off the edge of the hotplate if reworking it. Even the 1cm bezels on these units are a bit too much sometimes.

author: Haenk
author_rank: Super Contributor
timestamp: May 06, 2025, 10:37:38 am
content: I have one of those Aliexpress heatplates (20x20, only 32 EUR while on offer), and for that price, it does a halfway decent job.However, it uses 3(?) heating elements, attached to the aluminium plate. This will result in uneven thermal areas - or it needs to run for quite some time, to get some more evenly thermal distribution. I really considered bolting a thick copper plate on top to even out the temperature.If you don't need precise temperatures, it's OK.For precise temperatures, I got a Yihua 853A++ IR-preheater, with two sensors and bells and whistles. Also has a built-in fan to cool the thing down fast. The heatplate stays hot for a while, better don't touch...

author: PinheadBE
author_rank: Regular Contributor
timestamp: May 06, 2025, 11:35:37 am
content: This is the one (20x20cm) I had in mindhttps://vi.aliexpress.com/item/1005008804874727.html

author: ggchab
author_rank: Frequent Contributor
timestamp: May 06, 2025, 12:23:42 pm
content: That's the first one I bought some years ago and it works very well.

author: ggchab
author_rank: Frequent Contributor
timestamp: May 06, 2025, 12:27:07 pm
content: And this is the small one (10x10cm version):https://fr.aliexpress.com/item/1005007143808542.html?spm=a2g0o.order_list.order_list_main.473.546e5e5bCRyJCH&gatewayAdapt=glo2fra

author: timeandfrequency
author_rank: Frequent Contributor
timestamp: May 06, 2025, 01:49:46 pm
content: If you need to fiddle or hold a small board with both hands, a big plate would hinder the access from both side.

author: MathWizard
author_rank: Super Contributor
timestamp: May 08, 2025, 03:59:40 pm
content: I have an old coffee machine, the hotplate is not very big, and has a raised rim around it. But has anyone had luck using old CM's as hotplates ? I want to try making some temperature controller circuits, and timers/etc. It will be good practice for modding a toaster oven I have.

author: nonius_
author_rank: Contributor
timestamp: May 08, 2025, 05:14:17 pm
content: I suppose the size (and power) you need depends on the kind of work you do. For over three decades I've used a chemistry hotplate (with magnetic stirrer, which doesn't get used) which does everything I require of it. It's even possible to add an external temperature probe (PT100, if I remember correctly). Heating power is about 600W. It warms up very quickly.This hotplate does everything I require of it. Doesn't get used often, but often enough that I wouldn't want to be without it. The price was right too, as it was found in the waste container of my old school. Was thrown away because the stainless steel coverplate (that should be over the ceramic round disk) was missing. But it works fine without this.Before that, I've used an old electrical iron (clothes iron, i.e. 'strijkbout') mounted up-side down in the vise when I needed a hotplate. That worked fine too.Many ways to skin a catNot sure if bigger is better. As long as it's big enough for the jobs you do is all that should matter. With a small hotplate you can't do big jobs, but with a large hotplate you can do small jobs. But it takes a lot of wasted, unnecessary energy to heat up a large hotplate. Guess everyone has to decide for himself what is the optimal size....

author: ejeffrey
author_rank: Super Contributor
timestamp: May 08, 2025, 05:39:58 pm
content: Quote from: MathWizard on May 08, 2025, 03:59:40 pmStandard consumer drip coffee machine hot plates don't get very hot. They are heated with the same heater that boils the water, but with a thermostat such that once the cooling effects of the input water supply are gone, regulates the temperature to something < 100C. I don't think the plastic housing would survive a mod to allow it to go hotter. Doing so would probably require a complete mechanical rebuilt. By the time you did that and added an adjustable thermal regulator you would basically only be reusing a steel disc and a nichrome wire.

author: MathWizard
author_rank: Super Contributor
timestamp: May 08, 2025, 08:10:19 pm
content: I already cut away a bunch of plastic, but yeah I can cut away all of it and mount it on some old scrap metal. It has a SMPS in it, way bigger than is needed for the LCD timer/etc.I tried to remove a main GPU BGA one time, just with my cheap 858 hotair station, and it didn't work, but at least I don't think I damaged the PCB. That was with some preheating in the toaster oven. I want to try it with a either the coffee machine helped underneath, or a 500W construction lamp I have (maybe it's only 3-400W).Is there any type of putty or anything, people can put on the PCB to get better contact, but still be effective at heat transfer when using hotplates ?If the coffeeM doesn't really work, I should get some old used lab hotplate.

author: thm_w
author_rank: Super Contributor
timestamp: May 09, 2025, 12:05:49 am
content: Quote from: MathWizard on May 08, 2025, 08:10:19 pmIn another thread sand was discussed.But neither coffee plate or lab hotplate will work well, what you want is an IR preheater. The 500W lamp could be useful for that, if it doesn't blind you.

author: Haenk
author_rank: Super Contributor
timestamp: May 09, 2025, 10:10:16 am
content: Quote from: PinheadBE on May 06, 2025, 11:35:37 amI got this one:https://vi.aliexpress.com/item/1005007694589794.html(Same, but maybe cheaper?)Btw. the bottom enclosure plate was not grounded on mine, I added a cable. Beeped out the rest of the device, everything else seemed OK.

author: PinheadBE
author_rank: Regular Contributor
timestamp: May 13, 2025, 01:57:05 pm
content: I just received mine.https://vi.aliexpress.com/item/1005008804874727.htmlHas anyone figured out the meaning of the parameters in the menu?P, I, D, Rz, T ?RT (Auto-tuning) ?OFC ?The instructions provided does not explain it, even not in the original Chinese....

author: thm_w
author_rank: Super Contributor
timestamp: May 13, 2025, 10:16:30 pm
content: Quote from: PinheadBE on May 13, 2025, 01:57:05 pmDid you bother to ask the seller?PID are common settings for a PID controller, you can google that. I would not touch them.T might be temperature offset for calibration, or OFC (offset correction?).RT is some kind of self tuning routine yes.