solder paste for manual stencil printing - Page 1
Forum section: electronics / general

author: EEVaditya
author_rank: Regular Contributor
timestamp: June 30, 2018, 03:39:52 am
content: Hello,I need solder paste for my manual stencil printing purpose.The solder paste should have good shelf life after the seal is broken.It should not get dry immediately during its application.should have good consistency.my usage would be one jar per month or 45 days.also, In my circuit I will have one or two fine pitch smd componentsand rest are normal smd components, so which type should i go for Type 3 or Type 4

author: jmelson
author_rank: Super Contributor
timestamp: June 30, 2018, 04:50:13 pm
content: There are so many variables! I went to extreme difficulty to buy some Warton Metals paste directly from England, after a glowing recommendation.It was great stuff, didn't need any special handling like refrigeration, and I was able to use it right down to the end. But, they have no distributor in the US. You don't indicate where you are.Right now I am using some Indium Corp. paste, and while it works fairly well, it does not stay in neat little bricks like some other pastes. A few minutes after printing, it turns into a "lake" of solder beads and clear fluid. I think this is causing solder bridging on the fine-pitch components. So, I am going to have to try something different. I do keep the Indium stuff in the refrigerator as instructed.Jon

author: RobK_NL
author_rank: Frequent Contributor
timestamp: June 30, 2018, 06:01:30 pm
content: Loctite GC10

author: Doctorandus_P
author_rank: Super Contributor
timestamp: June 30, 2018, 06:37:51 pm
content: Store your paste in a refrigerator when not in use.Shelf life of > 1 year is not uncommon when paste is stored cold.My guess is that it can be stored in a freezer for even longer (no water content) but I have no experience with this.

author: Kean
author_rank: Unknown
timestamp: June 30, 2018, 09:01:09 pm
content: Quote from: RobK_NL on June 30, 2018, 06:01:30 pmAgreed - it is great stuff. But don't store it in the fridge.

author: TJ232
author_rank: Frequent Contributor
timestamp: July 01, 2018, 03:51:41 am
content: One simple answer : Loctite GC10

author: Doctorandus_P
author_rank: Super Contributor
timestamp: July 01, 2018, 07:53:41 pm
content: So I was curious about this GC10 stuff.Optimal storage: 5 to 25ºC (± 1.5°C)I'm not quite sure what to make of this.The one year shelf life decreases to a month @ 40 Celcius though, so it is not such a revolution at temperature stability as they claim.But don't listen to me, I've never used the stuff.

author: funbags
author_rank: Contributor
timestamp: July 01, 2018, 08:24:11 pm
content: and likely never will... it's out of stock everywhere. hahaI've been looking. lolIs there a paste available to US customers that's nearly as good?

author: EEVaditya
author_rank: Regular Contributor
timestamp: July 02, 2018, 04:08:03 am
content: Loctite GC10 is lead free and way too costly for me.any other alternative, which is Leaded with ratio 63Sn/37Pb and a lot more cheaper

author: TJ232
author_rank: Frequent Contributor
timestamp: July 02, 2018, 04:16:59 am
content: Quote from: Doctorandus_P on July 01, 2018, 07:53:41 pmDo you have 35-40C in your office or house? In most places that I know people are working and living at about 19-24C all around the year.After you use it and compare with other types of solder paste you can see what's the difference, not only in shelf life but also other important stuff like wettability, process time, etc.

author: EEVaditya
author_rank: Regular Contributor
timestamp: July 02, 2018, 06:51:41 am
content: The temperature in which I'll be using it would be anywhere between 27-31C

author: RobK_NL
author_rank: Frequent Contributor
timestamp: July 02, 2018, 08:29:45 am
content: Quote from: EEVaditya on July 02, 2018, 04:08:03 amYou specified neither the required composition nor a price range.

author: wraper
author_rank: Unknown
timestamp: July 02, 2018, 09:47:52 am
content: Quote from: Doctorandus_P on July 01, 2018, 07:53:41 pmThose are old figures. New batches have 8-28OC storage temperature printed on them. How it's not a revolution, usual solder pastes are not allowed to be stored at temperatures higher than approximately 8oC. When you buy such, you should pray that it was properly stored which is sometimes not the case IME. Not to say it almost certainly will be transported without cooling.

author: luiHS
author_rank: Frequent Contributor
timestamp: July 02, 2018, 11:31:13 am
content: I use this Loctite of the image, with very good results, I buy it directly from the distributor and it costs me only 36€ for the 500 Gr bottle. They send it refrigerated, and as I read it expires after 1 year if it is stored in the refrigerator and half the time at room temperature.

author: Cliff Matthews
author_rank: Unknown
timestamp: July 02, 2018, 11:54:03 am
content: Recent video (good timing for this thread IMO)

author: wraper
author_rank: Unknown
timestamp: July 02, 2018, 11:58:30 am
content: Quote from: EEVaditya on July 02, 2018, 04:08:03 am1 jar per month mentioned suggests commercial use. Do you realize it's illegal to sell such devices in many countries.

author: wraper
author_rank: Unknown
timestamp: July 02, 2018, 12:15:20 pm
content: Quote from: Cliff Matthews on July 02, 2018, 11:54:03 amThat guy does not know how to apply solder paste. Using both pastes result in a mess, yet he tells which one is easier to work with.

author: IconicPCB
author_rank: Super Contributor
timestamp: July 02, 2018, 01:32:01 pm
content: I had been using SN100C paste in the past.Decided to try Locktite GC10. Got a jar of it from a distributor in Sydney at cost of 130 something dollars.he jar was into its seventh month post manufacture date.I sent the supplier a note asking for a prorata refund for the remainder of shelf life barely five months of it. Let me say I do not consumemuch solder paste. Presently i have three jars in the fridge which are way out of date and barely touched.I needed to use the solder paste over a weekend in order to finish a job.On monday the sales manager responded to my email saying no prorata refund but if the jar is not opened he will refund moneys.I am screwed... but at the same time the supplier had no qualms in returning the jar to stock.I hope Loctite get to weed out these kinds of onsellers from their distribution network.

author: nanofrog
author_rank: Super Contributor
timestamp: July 02, 2018, 04:05:18 pm
content: For those in the US,CML SupplyrepackagesKester's EP256solder paste (63/37) in hobbyist/small repair shop friendly size packages.

author: EEVaditya
author_rank: Regular Contributor
timestamp: July 04, 2018, 11:34:00 am
content: Hello,I went through all suggestions like Loctite, MG Chemicals, Kester etc.But either they are unavailable or way too costly.orthe MOQ is too high against my requirementI reside in India. I need Sn63/Pb37 type 3 solder paste for my manual stencil printing purposemy budget is 1200 INR or 17-18 USD for 1 Jar (500g)

author: nanofrog
author_rank: Super Contributor
timestamp: July 04, 2018, 12:10:45 pm
content: FWIW, I stumbled on an Indian solder manufacturer,Saru Solderthat makes 63/37 solder paste (no-clean, water soluble, and RMA flux variants, powder size = 4, and comes in jars).Definitely worth checking out.Otherwise, you'll be stuck gambling withMechanic brand pastefrom Aliexpress, Banggood, ... types of sources. It does seem to work based on user reports, but it could be old, stored under the worst possible conditions, and there's plenty of complaints about the amount being less than advertised. At least it's inexpensive.In regard to powder sizes, there's a nice chart on wiki (solder paste by size).BTW, if you go into your profile and set your country, your nation's flag will be displayed beneath your userID. Makes it so much easier to help with links, particularly in regard to availability and cost to your location.

author: EEVaditya
author_rank: Regular Contributor
timestamp: July 11, 2018, 09:45:04 am
content: Yes, I did check the brand but again the rate is on the higher side.

author: wraper
author_rank: Unknown
timestamp: July 11, 2018, 04:34:52 pm
content: Your extremely low pricing requirement is really strange. If you can consume a whole jar, solder paste will be only a tiny fraction of expenses that go into producing PCB. To the point it basically does not matter if it costs $20 or $80.

author: rx8pilot
author_rank: Super Contributor
timestamp: July 11, 2018, 05:51:06 pm
content: I have been using GC10 for about a year. It is easy to print and lasts a really long time in process - all day on the stencil is not a problem.My preferred packaging is the tube, easy to push out the volume I need and the remaining is never exposed. The leftovers go into heavy ziplock bags (left over from DigiKey deliveries). I push out the majority of the air, zip it, and store it around 41F/5C.In the end, I waste nearly zero paste and dry paste is not much of a concern as it was when I used Kester types.

author: JamesLerch
author_rank: Newbie
timestamp: July 11, 2018, 06:35:43 pm
content: I've been tinkering with this stuff from Louis Rossman's site, works a treat for me.https://store.rossmanngroup.com/index.php/amtech-syntech-solder-paste-sn63-pb3735g-syringe.htmlHere's a video of Paul re-balling a USB chip for some Apple product, something I haven't had a need to try my hand at yet thankfullyReballing USB Thunderbolt chips *Adult Language*No affiliation other than a happy customer of Louis's site.--James

author: flasonsmts
author_rank: Contributor
timestamp: July 23, 2018, 11:44:52 am
content: normally the solder paste need to store at the 5℃-10℃, and it need to be used in 24 hours. too long time don't use it will make the tin alloy be oxidated, and there will be too many water come into the solder paste. if you really need open it, then it's better save it in 5℃-10℃ and sealed it's very good and need a longer preheating time, and maybe you can add some flux into the solder paste to got better activite of the solder paste.

author: rx8pilot
author_rank: Super Contributor
timestamp: July 23, 2018, 05:01:16 pm
content: Quote from: flasonsmts on July 23, 2018, 11:44:52 amThis is true....but some paste is more durable than others. When I switched to GC10, I immediately found that its lifespan is MUCH longer than others. I purchase in tubes, push out what I need and store the leftover in a thick, small bag at 5C. So far, I have not needed to dispose of any paste even after considerable abuse.

author: D3f1ant
author_rank: Frequent Contributor
timestamp: July 23, 2018, 08:06:18 pm
content: I have a pot of GC10 that is used for hand printing and occasionally used to fill a syringe for dispensing, it is two years past it's expiry date and it seems to perform fine...it doesn't seem to have dried much, if at all. It gets very abused, I even put surplus paste straight back into the pot. I wouldn't trust it for production, but so far it hasn't given me any problems for protoype use.

author: jmelson
author_rank: Super Contributor
timestamp: August 26, 2018, 08:11:59 pm
content: Quote from: RobK_NL on June 30, 2018, 06:01:30 pmThanks to all who recommended the GC10. I had heard good recommendations before, but at that particular time it was hard to find in the US. Now, it is pretty easy to get online. I just did some boards with it, and the results look quite good. So far I have not done anything with fine lead pitch, but see a few good indications that it will do nicely. My stencil got out of alignment, and I printed a few boards with the paste going between the pads before I noticed the problem. Since the parts were already placed, I ran it through the oven, expecting some rework. But, you couldn't even tell which boards had the misaligned solder paste -- NO bridges at all.One issue, I dropped one of the boards before getting it in the oven, and most of the parts (all the chips) flew off. I have done this a couple times in the past, and usually only a few of the largest parts flew off. But, I'm not complaining at all if the soldering goes better than with other pastes.Thanks again!Jon