:: budget ultrasonic cleaner partial review

[3roomlab]

hi folks,

i got meself a small ultrasonic cleaner, and here is what it looks like and some action pics.

overall the unit is very well made, stainless steel. but the screw holes are kinda off slightly, dont think i be opening it again lol. the fets look like fairchild copies (seems to be a push pull config). the driver is 4nF capacitive transducer (rated 80w). and a very low tech PCB, tiny crappy fuse. the transformers feel warm post operation, so it must be really lossy thermally.

the heater seems to be somehow "gunked" around the metal bin using some silicone gunk and a rink of what appears to be foiled tape (see where a red wire disappears to the rear). they way i see it, i think if i have a insulation tester, i think this heater will fail insulation tests . well at least the sonic parts works really well for a cheap but really handy parts cleaner.

[3roomlab]

action pics. (look at the pic with my hand in it, its really a tiny space 10cm deep, 15x13cm across). pic 0099, once turned on, the ALU foil IMMEDIATELY busted into holes, and pic 0107 ... just after about 3 minutes ! dang ... i dipped my fingers into the bin to stir the bottle while it was on ... but felt nothing (flesh must be a good ultrasonic damper!)

price wise, i got this sea shipped from china and it costs about approx USD50++.

have anyone tried to use this to "wash" dirty PCB?

[Rerouter]

Thanks for that..

Very long pinky nail.. 

[wiss]

Where did you buy it? Link?

[a210210200]

I sure hope the internal chassis grounding is proper. (It does have a earthed plug right?)

[aargee]

Putting your hand into the water with it on and you will probably feel nothing but the ultrasonics will be attacking your bones.

I have a dentist friend with early onset arthritis in his finger joints specifically due to him prodding and poking instruments in his ultrasonic bath.

[rx8pilot]

I have a 7 gallon commercial ultra-sonic. It is a high quality unit that has delicate controls, frequency sweep, etc. I tried to use it to clean PCB's out of the oven. I think that it was damaging some components because our test PCBs were not reliable. I had tried various power and time, DI water, and some expensive task specific detergents from a company called Alconox.

No doubt the PCB's were totally clean, but I was never confident in the process , so I stopped using it for PCB's.

[a210210200]

Putting your hand into the water with it on and you will probably feel nothing but the ultrasonics will be attacking your bones.

I have a dentist friend with early onset arthritis in his finger joints specifically due to him prodding and poking instruments in his ultrasonic bath.

Also because ultrasonic frequencies are so high you can't actually hear the actual energy level being emitted by a bath and hearing damage is possible to your hearing in general even if you don't hear it you might feel the effects after being exposed for a while. I get headaches sitting in the same room as a huge sonicator at work so I tend not to stick around when people are using it in that area.

The ideal way to use a ultrasound cleaner is to have a separate room or box to isolate the sound but since I work at a university "ideal" and "safety" are not very common.

I have a 7 gallon commercial ultra-sonic. It is a high quality unit that has delicate controls, frequency sweep, etc. I tried to use it to clean PCB's out of the oven. I think that it was damaging some components because our test PCBs were not reliable. I had tried various power and time, DI water, and some expensive task specific detergents from a company called Alconox.

Some mechanical components or even anything remotely mechanical (mems, crystals, ...) could conceivably be damaged by sonication.

Alconox is awesome stuff I used it in a clean room environment for entrance cleaning equipment/tools (where you actually have to check the water drop contact angle and keep washing until it is measurably clean enough) now I use it for tough cleaning jobs at home and if you can soak anything in it the oil/dirt will come off and it will feel very clean (touching it by hand to check ruins the perfect cleanliness but whatever).

[3roomlab]

Where did you buy it? Link?

i bought it from TAOBAO. it approx costs me USD50+++
http://item.taobao.com/item.htm?spm=a230r.1.14.37.zpC52t&id=41233889247&ns=1&abbucket=2#detail

i think the same model is re-sold by many actual retail shops rebadged.

[3roomlab]

I have a 7 gallon commercial ultra-sonic. It is a high quality unit that has delicate controls, frequency sweep, etc. I tried to use it to clean PCB's out of the oven. I think that it was damaging some components because our test PCBs were not reliable. I had tried various power and time, DI water, and some expensive task specific detergents from a company called Alconox.

No doubt the PCB's were totally clean, but I was never confident in the process , so I stopped using it for PCB's.

i think at sub millimeter level, the "implosive" cavitation of vacuum pockets is very destructive. for this unit, i do not think it is operating at maximum power, but seeing the ALU foil gone "holey" instantly, the surface effects is legit for sure. when i have more time, maybe i will try to experiment more with it ... similar to piezo humidity evaporators ... it seem the "attack" power is more nearer to water surface.

[a210210200]

i think at sub millimeter level, the "implosive" cavitation of vacuum pockets is very destructive. for this unit, i do not think it is operating at maximum power, but seeing the ALU foil gone "holey" instantly, the surface effects is legit for sure. when i have more time, maybe i will try to experiment more with it ... similar to piezo humidity evaporators ... it seem the "attack" power is more nearer to water surface.

Even with frequency sweeps especially once you put something into the bath all sorts of reflections will occur and hotspots will form similar to how a microwave sucks at uniformity just even worse since the object can be highly reflective and complex (sticking a PCB into a microwave is probably going to end worse though).

[3roomlab]

what do you try to clean off from the oven fresh PCB? flux?

[geppa.dee]

Where did you buy it? Link?

i bought it from TAOBAO. it approx costs me USD50+++
http://item.taobao.com/item.htm?spm=a230r.1.14.37.zpC52t&id=41233889247&ns=1&abbucket=2#detail

i think the same model is re-sold by many actual retail shops rebadged.

Is there a way to buy on Taobao if one can't read (or speak ftm) Chinese?

[rx8pilot]

what do you try to clean off from the oven fresh PCB? flux?

Yes, flux. I have since moved to a no-clean flux that is less active. If I keep the boards and components stored correctly, it is ok. The lead-free Kester Kester paste I was using cannot be left on the PCB for very long without causing problems.

[3roomlab]

i see. i read that lead free based solder have more corrosive flux.

i tried to use lead free, but i just cant get it. the blob just turns matte everytime.

what do you buzz the PCB with? normal dish washer liquids? or it has to be special flux removers meant for ultrasonic buzzers? hmmm ... ok but you said it didnt work out :/

[rx8pilot]

The flux was water soluble so we used DI water for most of the experiments. We did try some of the high-end detergents from Alconox that are designed for ultrasonic washing of PCB's. I think that if I stuck with it, I could have figured it out. It's a matter of getting it clean with a low ultrasonic power to prevent damage. The problem that I say was that damage is not visible. We had to put the PCB's in pseudo-service and the failure rate was much higher than non-ultrasonic cleaned PCB's. Not even sure what was damaged specifically since the boards sorta worked, just not reliable.

It looked like a huge project so I ran for my life..... ;-)