Oven for baking compoentents? - Page 1
Forum section: electronics / general

author: vespaman
author_rank: Contributor
timestamp: September 19, 2023, 01:51:46 pm
content: Hi Guys,I find that I need to get something for dealing with MSL3-5 components, since purchasing small volumes for each run is super tedious and costly.I run a very small manufacturing, and really only want entry level. But since it also needs to be baking for some time, I'd like something that has some sort of isolation, and does not heat up the whole house as a bi product.Open to build/modify something.I guess someone must have done something similar, but searching for "baking" does not bring the results I'd like... :-)Or:- alternative, is there some dry cabinet solutions?How do you deal with this in general?

author: jmelson
author_rank: Super Contributor
timestamp: September 19, 2023, 02:16:20 pm
content: I have a toaster oven I use for reflow, controlled by a ramp and soak thermocouple controller. To bake out components and blank boards. I spread them out on the rack and then set the temperature to 50C for 30-60 minutes, and then go to 70C for at least an hour. This works fine.Jon

author: Jackster
author_rank: Frequent Contributor
timestamp: September 19, 2023, 02:23:22 pm
content: Cheapass way of doing it without buying an oven if you do the assembly yourself...Get some moisture barrier bags, pull out as many components as you need, and seal the bag with a heat sealer.You can get or reuse those cards with the moisture level indicators to tell you if you are getting close or have passed the threshold.Use a desiccant pouch in each bag.Plus, store the pouches in a box with a half-decent seal. Does not have to be perfect but I use ReallyUsefulStorageBoxes (UK plastic box manufacturer) and a few desiccant pouches in each box.You will find that you don't have to bake if you do this unless you have level 6 components or leave a bag out too long.I have some tube bags here that I just fold over the ends and I kid you not they are still under the 5% indicator with just a single desiccant pouch and they are not in a storage box.Ideally, keep your manufacturing area below 50% RH as well.I only do this for my own projects of course...

author: vespaman
author_rank: Contributor
timestamp: September 19, 2023, 05:08:04 pm
content: OK, that is of course a good start - try to keep them dry as long as possible! I try to avoid moisture sensitive devices, so I only have a few of them (LED's are worst), so the bag trick should be manageable.I guess the only downside is, that you don't know how much floor life has already been used up when you get the components.I have never used desiccant bags myself, but I understand that you can bake them (or perhaps need to bake them regardless if they are new or not)? Are you getting new ones, and do you change into new each time you open the bag to take out some components?I do have one component that arrives in trays, that are MSL3, so I'm not sure if the bags are big enough.That also goes for the toaster oven, I assume it is a bit too small for a standard tray. But getting a normal (food) oven has crossed my mind (but they, on the other hand are unnecessary big).

author: Jackster
author_rank: Frequent Contributor
timestamp: September 20, 2023, 12:16:50 am
content: LEDs on full reels and IC trays should arrive in a moisture barrier bag from the factory they were made in.If you get partial reel or tape, they could have been left open in a warehouse for a few hours to weeks.Ideally, always buy full when you can.You might be able to find a small commercial oven on auction or surplus that will keep a good constant temperature.As for a new one. The ones "made" for the industry are quite expensive. You can go down the route but is it worth it if you can get away with not using it?That is where I am at the moment.

author: wraper
author_rank: Unknown
timestamp: September 20, 2023, 12:27:07 am
content: Quote from: Jackster on September 19, 2023, 02:23:22 pmYou actually don't need a heat sealer. I just tightly roll open end of the bag like 5-6 turns and fix with a paper clamp. It's actually air tight and keeps the moisture away just fine. And can be opened/closed as many times as you need.

author: Jackster
author_rank: Frequent Contributor
timestamp: September 20, 2023, 10:28:47 am
content: Quote from: wraper on September 20, 2023, 12:27:07 amTrue. I have a few bags of tubed components. I just fold them over and have the weight of the bag close to them. All have indicators in them and none have triggered the 5%.

author: vespaman
author_rank: Contributor
timestamp: September 20, 2023, 05:10:38 pm
content: OK, no, a commercial new oven is not worth it for me. I have also recently understood that you can't really put a reel in there, only trays and loose components, so I don't think it will really help me with the LED's anyway.Using desiccant is easily the way forward, I am convinced!But do you reload with new desiccant bags when you open, or just continue with the one(s) already in it? How quick will they "absorb themselves to death" in the open air, and what's a typical life time of such a bag?

author: Jackster
author_rank: Frequent Contributor
timestamp: September 20, 2023, 09:34:42 pm
content: The bags I have on the shelf folded over for the past year still have the same ones they were shipped with and the indicators have yet to go off.I did check to day to see if the indicators worked and they did.

author: wraper
author_rank: Unknown
timestamp: September 21, 2023, 01:39:16 am
content: How long it will last depends on type of the bag (there are poor ones which don't use aluminum foil but just thin metallization), size of the desiccant pack any punctures in the bag and outside air humidity.

author: Microdoser
author_rank: Frequent Contributor
timestamp: September 21, 2023, 02:21:31 am
content: Quote from: vespaman on September 20, 2023, 05:10:38 pmThe desiccant bags can be 'recharged' by putting them in an oven for a while, not sure of the exact temperature, the internet seems to have a few different ideas.

author: vespaman
author_rank: Contributor
timestamp: September 21, 2023, 06:25:31 am
content: Great, I think I was over thinking the "problem", but it all sound logical, and can easily be handled. Way better than purchasing small quantities like I have been.

author: wraper
author_rank: Unknown
timestamp: September 21, 2023, 08:59:58 am
content: Quote from: Microdoser on September 21, 2023, 02:21:31 amSilica gel and clay can be restored at 130oC for at least a few hours, more better. Molecular Sieve cannot be restored. Be sure that oven has at least some ventilation, you can put something in the gap to prevent the door closing completely. Otherwise all released moisture will stay in the oven thus preventing drying process.

author: jayx
author_rank: Regular Contributor
timestamp: September 21, 2023, 07:38:22 pm
content: Desiccant alone is not going to dry components (within reasonable time) which already absorbed moisture. There is JEDEC document with all the details, a bit outdated version you can find here:https://ez.analog.com/cfs-file/__key/communityserver-wikis-components-files/00-00-00-00-96/attachment.pdf. Not much changed in the latest one, apparently it can be downloaded for free, you just need to register. Baking time/temperatures is in the table 4-1.For storage, proper moisture barrier bags are not transparent. Apart from dessicant, you should put moisture indicator inside, so when you open it after some time it will show if the bag was sealed properly and low humidity was kept. Unfortunately it can't be seen through non-transparent bag.Also have a look here:https://www.eevblog.com/forum/manufacture/humidity-control-component-storage/msg4912843/#msg4912843

author: sinewave
author_rank: Unknown
timestamp: September 22, 2023, 01:14:58 pm
content: LCSC is especially bad, shipping MSL parts in either resealable ESD bags or heat sealed ESD bags (not MSD bags)

author: c64
author_rank: Frequent Contributor
timestamp: October 03, 2023, 11:13:48 pm
content: Is it possible to use vacuum instead of baking?

author: Psi
author_rank: Super Contributor
timestamp: October 03, 2023, 11:37:51 pm
content: You could also consider if you really need to care about it at all.Keep in mind the baking requirement is often just there to maximize yield at super large volumes. At ultra small volume like 100pcs it may not make any noticeable difference.Or, maybe the parts actually are super sensitive to moisture and 50% could popcorn off the PCB without baking, or maybe have a high failure rate later on. But normally if they are this bad there will be a very clear warning about it in the datasheet. Rather than just a rating with nothing else said about it.I'm not saying to ignore the rating, just saying. Make your on call, maybe after some testing.

author: Microdoser
author_rank: Frequent Contributor
timestamp: October 04, 2023, 01:00:03 pm
content: Quote from: Psi on October 03, 2023, 11:37:51 pmI use some parts that Digi-Key say are moisture sensitive and came in special moisture proof packaging with the little card that shows they weren't exposed to moisture, and had advice to bake before use, which I didn't do, and I had no issues with any of them. I test all my boards after construction and I would replace any non-functioning parts (none so far), and no parts have popcorned off the board during soldering. It's possible lifespan may have been affected, but I've had no failures in years of operation.I'm also not saying to ignore the rating, just that I have the policy to see which parts it matters for in the real world and account for that retrospectively. Currently, it's none of the parts I use.But back to your original question, if you really want to dry out components, just get a basic food dehydrator. You can get one for £30 from Amazon, set the temperature you want (usually 35c-70c), they are fairly small, won't heat up the whole house (maybe a small room will be 2 degrees warmer) and as a bonus, you can use it as a food dehydrator or 3D filament dryer.

author: Teledog
author_rank: Regular Contributor
timestamp: October 09, 2023, 04:18:10 am
content: Baking out?At what temp/how long?Plain oven, or kilns?A desiccant is relatively easy, bag the components with the desiccant for a few days/ad infinitum.And as far as desiccants go, I like to use 3A molecular sieve ("baked out" at @350F+ for a few hours).. cheap & reusable multiple times.You'll know when it's properly dried by putting a single (cooled, room temp) granule on the tongue & listen to it sizzle & get hot! ;-P..