EEVblog #437 - Removing SMD Parts with ChipQuick  - Page 1
Forum section: electronics / general

author: robbak
author_rank: Contributor
timestamp: March 11, 2013, 05:56:16 am
content: The Canonical thread seems to be missing, so I'll put one in. Feel Free to remove it to put the right one in.The Video:http://youtu.be/UmD7F0--7LcI wanted to add to this thread, with the following:The users over at YouTube consider this a variant of Field's Metal, or perhaps Cerrosafe with some indium. Low melting point metals are really interesting. Cast a teaspoon out of one of them, and hand it to an unsuspecting guest!Secondly, used ChipQuick would have some extra solder contamination, but it should still be useable. But using it as a ball would be difficult, so how would you go about getting it back into wire or strips for reuse?

author: LoyalServant
author_rank: Regular Contributor
timestamp: March 11, 2013, 06:03:21 am
content: I have used this stuff for many years and it works a treat.Dave used too much of it and he lifted a passive when he did the second flat packYou really only need a small amount of this stuff for it to work.I use it in conjunction with a hot air gun and it works better for me that way.You also reduce the risk of lifting pads and bending pins if you want to reuse the chip.Good product I highly recommend it.

author: Kiwi_frog
author_rank: Contributor
timestamp: March 11, 2013, 06:28:11 am
content: I also have used this for years, I prefer it to hot air. It's crucial that the pcb is cleaned properly after.The flux is some of the best I've used for re-flow also...Mike.

author: justanothercanuck
author_rank: Frequent Contributor
timestamp: March 11, 2013, 11:52:10 am
content: I laughed when I saw the patent sticker pasted on the packet of alcohol wipes. I see boxes of those wipes at work on a weekly basis.

author: notsob
author_rank: Frequent Contributor
timestamp: March 11, 2013, 12:33:45 pm
content: The main ingredient in chipquik is bismuth (approx50%), similar product to zephtronics 'lowmelt' product.

author: G7PSK
author_rank: Super Contributor
timestamp: March 11, 2013, 12:42:07 pm
content: There is a whole host of low melting point alloys, at one time you could buy spoons made from such metals which would melt when stirring your tea or coffee. The link is to wikipedia woods metal which then gives a list of other alloys which I have also put below.http://en.wikipedia.org/wiki/Wood's_metalAlloy Melting point Eutectic? Bismuth Lead Tin Indium Cadmium ThalliumRose's metal 98 °C (208 °F) no 50% 25% 25% – – –Cerrosafe 74 °C (165 °F) no 42.5% 37.7% 11.3% – 8.5% –Wood's metal 70 °C (158 °F) yes 50% 26.7% 13.3% – 10% –Field's metal 62 °C (144 °F) yes 32.5% – 16.5% 51% – –Cerrolow 136 58 °C (136 °F) yes 49% 18% 12% 21% – –Cerrolow 117 47.2 °C (117 °F) yes 44.7% 22.6% 8.3% 19.1% 5.3% –Bi-Pb-Sn-Cd-In-Tl 41.5 °C (107 °F) yes 40.3% 22.2% 10.7% 17.7% 8.1% 1.1%

author: ktulu
author_rank: Regular Contributor
timestamp: March 11, 2013, 12:48:36 pm
content: If you don't have a hot air gun, it is still possible to salvage IC's (or any parts) from a PCB by heating it from underneath with a lighter or torch, or even your regular gas cooking plate.The board will be demaged of course, and you need good ventilation.

author: Winston
author_rank: Regular Contributor
timestamp: March 11, 2013, 02:00:34 pm
content: With its 58C melting point, it looks like Bolton 136 (Cerro Low 136) is it:http://shop.boltonmetalproducts.com/Bolton-136-formerly-sold-as-Cerro-Low-136-LB220002.htm"Alloy is used in anchoring parts for machining (jet blades); testing, inspection, block lenses in optical manufacturing, proof casting; fusible element in safety devices (sprinkler heads); fusible cores in compound cores; low temperature solder; sealing adjustment screws and many craft applications."$100.43/lb

author: robrenz
author_rank: Super Contributor
timestamp: March 11, 2013, 02:18:58 pm
content: Idealy you want to anticipate the addition of the tin and lead from the solder you are blending with. So you would want the Cerro Low 136 alloywith the tin and lead removed. Then when you add it to the solder you end up with aproximately the Cerro Low 136 alloy with a 58C melting point.

author: free_electron
author_rank: Super Contributor
timestamp: March 11, 2013, 03:57:18 pm
content: This is a high bismuth alloy. Even though bismuth itself only melts at 270 degree c it lowers the melting point of other metals drastically.The reason this stuff works is because of two things:You put on quite bit of mass. That mass , combined with the heat retention capability of the qfp and the board you are heating up ( remeber you need to heat the whole thing ) gives you a long tome where the alloy remains in liquiod state.Always remeber to thoroughly clean the pads of this stuff ! You don't want to contaminate you solder withe bit of bismuth.

author: EExtrom
author_rank: Contributor
timestamp: March 11, 2013, 04:49:47 pm
content: Didnt know this stuff exist ... quite expensive though ... anyway, THANKS!

author: kodai
author_rank: Contributor
timestamp: March 11, 2013, 04:53:02 pm
content: Its just plain old woods metal. Those of use that play with crystal radios know it very well as its been a part of crystal sets for about a hundred years now. When you place down your gelana crystal for your cats whisker you put it in a little metal cup that is filled with woods metal. You can use hot water to melt it and you prevent damage to the crystal by using low heat. Lots of beginners try to solder their crystal in place but find out the hard way that it kills the crystal. So woods metal is the only real way to get a full connection to the crystal. I've often wondered if solder and woods metal would mix and what the outcome would be. Now I know. Now I also know of a good source to get some more for my radio builds when my limited supply of woods metal runs out (got about 3-4 more uses left), so thanks for the vid. ^_^

author: KuchateK
author_rank: Regular Contributor
timestamp: March 11, 2013, 04:54:51 pm
content: Dave, it probably took you so long to remove that big chip because although you melted ChipQuick on the pins soldering iron temperature was too low for existing solder underneath.

author: Arp
author_rank: Unknown
timestamp: March 11, 2013, 07:10:50 pm
content: I bought a few packs of 70% medical iso-propanol pads some time ago. They contained skin lotion to prevent drying of the skin. Left a nasty residue on the mirror. I thought this lotion was common with medical pads?

author: justanothercanuck
author_rank: Frequent Contributor
timestamp: March 11, 2013, 07:38:29 pm
content: Quote from: Arp on March 11, 2013, 07:10:50 pmI don't think I've come across any of the lotion ones at work, people actually bring in their own moisturizers because of the alcohol... It used to be worse before they changed the hand wash stations... they also were a high-percent alcohol, and it would make your hands all chapped. The wipes shown in the video are just 70% isopropyl.

author: m0r
author_rank: Newbie
timestamp: March 11, 2013, 08:58:45 pm
content: Seeing the nice blobs of alloy it forms, have any of you tried to be cheap and reused this kind of material?

author: shashwatratan
author_rank: Newbie
timestamp: March 11, 2013, 09:02:57 pm
content: Cool Stuff! Never Used it.Shashwat

author: LaurenceW
author_rank: Frequent Contributor
timestamp: March 11, 2013, 11:22:01 pm
content: OOPS! Watch for C08 just to the south of the small chip which is desoldered as part of the second demonstration.Now ya see it, then ya don't...

author: JoannaK
author_rank: Frequent Contributor
timestamp: March 11, 2013, 11:28:06 pm
content: Nice video. I used this in 2000 or so when I needed to replace qfp-chip (SMC ethernet) on one of our boards. Back then the hot air gun's were not as easy to find as these days (china clones) so this ChipQuick was really a treat.Expensive, yes. But on a day you need it, it's totally worth the money.

author: divelectservices
author_rank: Contributor
timestamp: March 12, 2013, 12:40:45 am
content: Good stuff...worth every penny when you have a "must-salvage" board or chip. Very messy to clean up though, too thin for the desoldering station to suck up. Solder wick and a nylon brush work good on the board and hot air works on the chip.

author: tom66
author_rank: Super Contributor
timestamp: March 12, 2013, 12:54:59 am
content: Someone suggested this was regular solder mixed with bismuth.I found some bismuth to confirm, but unfortunately, it did not work when trying to solder with it (not entirely unexpected.) I'm guessing it needs to be "melted in" with the solder then re-drawn out into a wire. And I'd guess the concentration is important. But I'm not a metallurgist.So for now I'll use plenty of flux, wick and hot air... and I have no problem. May not be as fast though, but I'm rarely in a rush.

author: Excavatoree
author_rank: Frequent Contributor
timestamp: March 12, 2013, 02:25:21 am
content: Quote from: LaurenceW on March 11, 2013, 11:22:01 pmYou can still see it. (for a bit) It ended up in the large blob on the right. Dave cut to a shot after he removed the blob and the poor, lost C8.Seriously, it has to be a result of the strange soldering iron angle needed to work under the camera.

author: EEVblog
author_rank: Unknown
timestamp: March 12, 2013, 03:21:02 am
content: Quote from: Excavatoree on March 12, 2013, 02:25:21 amYes, the angles are limited when you have an inverted tripod hanging overhead, and not wanting to move the board to keep the shot consistent etc.It's a lot different to when I'd just ordinarily do it.Dave.

author: amyk
author_rank: Super Contributor
timestamp: March 12, 2013, 06:59:40 am
content: Quote from: tom66 on March 12, 2013, 12:54:59 amAccording to theMSDSit's Sn 12% Pb 18% Bi 49% In 21%

author: Moshly
author_rank: Regular Contributor
timestamp: March 12, 2013, 08:17:49 am
content: I've used this stuff a bit at work and home. Just a few points to add.You can reuse it, it works fine for around 6 - 8 uses.More if you add more fresh ChipQuick & always use lots of flux.Works best on small to medium size gull wing & all J lead parts.You need to use a washing / squelching type motion to mix the alloy & the solder.Just putting it on top of the joins is insufficient as it needs to mix.Use a circular motion as you add solder, that causes the solder to pulse in & out between the pins a few times.You still need to bring the part and the PCB up to soldering like temperatures before you remove the part, its just that when you do, you have around 10 seconds or more to remove the part.

author: tom66
author_rank: Super Contributor
timestamp: March 12, 2013, 12:45:57 pm
content: I found the patent for ChipQuik:http://www.google.com/patents/US5326016?pg=PA2&dq=5326016&hl=en&sa=X&ei=aiI_UZOWPIyf7AaPhYHQCQ&ved=0CDMQ6AEwAA#v=onepage&q=5326016&f=falseInterestingly they patented the method (mixing low temperature solder to lower the melting point) instead of the actual product. This presumably means it isn't a violation of the patent to make low temperature solder (which would be hard to patent -- so many possible alloys) but itwouldbe a violation to use it without permission/license (which I guess is included when you buy/sample the product??) So by trying to use my own low temperature solder (because I'm a cheapskate) I violated the patent. Making it is fine. Yay for patent law on stupid stuff like that.Looks like it might have about a month left... so look out for clones in a short while.

author: Maister
author_rank: Contributor
timestamp: March 12, 2013, 01:44:24 pm
content: Any suggestions about the alloy ? Maybe there is not any tin at all in it. I would not be surprised.

author: tom66
author_rank: Super Contributor
timestamp: March 12, 2013, 01:46:46 pm
content: amyk reports:Quote from: amyk on March 12, 2013, 06:59:40 am

author: nitro2k01
author_rank: Frequent Contributor
timestamp: March 12, 2013, 03:49:15 pm
content: From the video comments:Quote from: KevtrisAnd as the comment implies, this is a pre-RoHS composition. Posting it here in case someone might be interested of the old composition.

author: Bored@Work
author_rank: Super Contributor
timestamp: March 12, 2013, 06:43:23 pm
content: Quote from: tom66 on March 12, 2013, 12:45:57 pmThis is not how it works. A patent is limited to a jurisdication. You have to be in that juristication, otherwise it doesn't apply. E.g. a US patent is useless in the UK (I didn't check if the patent you pointed to was a US patent, just explaining the principle).Second, in many juristications the usage of a patent must be commercial before it might be an infringement. What you do in the privacy of your lab is typical no patent holder's business. Even commercial entities often experiment in the lab with patented techology they don't own, to understand it, improve it or circumvent it. As long as they don't sell stuff without a license it is usually no problem, and if they manage to find a circumvention it is anyhow not a problem.

author: SeanB
author_rank: Super Contributor
timestamp: March 12, 2013, 07:22:21 pm
content: Wonder how mercury would work....... [ Looks around for a hatter]. I know it does dissolve solder and copper. Very cool to place a drop on an aluminium alloy block and scratch through it then leave in a warm spot for a week, it turns into white flakes.

author: Electr0nicus
author_rank: Regular Contributor
timestamp: March 12, 2013, 08:20:48 pm
content: Hi Dave!Interesting video, I liked it.If you don't want to buy a complete kit, only because you've run out of Chip Quik solder, farnell has the solder on its own in 1.3m packaging. Search for article 2128169 .Referring to the MSDS it consists of 17% Tin 57% Bismuth and 26% Indium

author: tom66
author_rank: Super Contributor
timestamp: March 12, 2013, 09:29:46 pm
content: Quote from: Bored@Work on March 12, 2013, 06:43:23 pmOK, yeah, assuming I am in the US, I violated it.I was informed that commercial use does not matter? For example, MPEG is patented. You need to pay a fee to use it on your device if it doesn't already include it (legally.) No-one bothers, but it's still patent infringement. And say I publish this fact on the internet and MPEG-LA found out, and decided to sue me. A judge would almost certainly throw out the case, but it's still illegal.Now let's say a company does this. Boom, they infringed this totally over-reaching patent. Mixing solder to remove parts is not new. I hardly see how using a lower temperature solder qualifies as a unique and innovate discovery.

author: chickenHeadKnob
author_rank: Super Contributor
timestamp: March 13, 2013, 12:02:12 am
content: Quote from: SeanB on March 12, 2013, 07:22:21 pmI know you have a repository of aircraft maintenance stories of your own but you might like this true one from my youth:It is 1970 and I have just moved to the remote small community of Gillam in northern Manitoba. My father is at the time an electrical engineer working for Manitoba Hydro, his job the construction and commissioning the AC/DC converter stations of a high capacity DC transmission line to carry the power from dams on the nelson river south. The early design of the station used mercury valves from english electric. They were later replaced by solid state devices from ASEA Brown-Boveri. I am recalling all this from childhood memory so some of the details maybe a little wrong. The mercury valves had large tanks possibly 2 -3 meters long. Father pointed one out when he took me on a tour of the radisson station. "There is mercury in there, (points to tank), guys need to wear special suit to work on them. These things have been nothing but trouble, the whole project is being delayed by them. One sank en route on a ship in the english channel another one some how broke and leaked in an airplane, a flying boxcar, on the last leg up to Gillam. The airplane is a write-off. "I can imagine all those little blobs of mercury dancing their way into every nook and cranny of an aluminum stressed skin plane.

author: SeanB
author_rank: Super Contributor
timestamp: March 13, 2013, 04:42:25 am
content: Corrosion in aircraft is a killer. Engines can blow up no problem but most pilots are very afraid if the wings fall off or the bottom falls out.

author: Orpheus
author_rank: Regular Contributor
timestamp: March 13, 2013, 06:00:38 am
content: For physical patents, you are free to make your own device for personal use.Software patents have philosophical issues that I don't want to tackle (Dammit Jim, I'm a doctor, not a lawyer), but if you wrote your own coder and decoder, and coded only your own data for playback by only yourself, Frauhofer wouldn't have had a claim against you (until recent judicial and political swings that vastly favored corporate "rights") then again, it wasn't so long ago that they wouldn't have been able to patent an algorithm at all (and you still can't patent software methods in much of the world -- Europe, until fairly recently, if not today-- but Europe will now *enforce* patents issued elsewhere, even if they wouldn't have issued them locally)I did quite a bit of dallying with low-melt alloys in my youth (I frequently encountered a hobbyist writeup on SMT tricks that I posted to a mailing list under my real name, as well as my early (1996? 97? Within about a year of them marketing online, anyway) Chipquik circulating on the web 10 years later). I mention this because I still have the remainder of my very first sample from their original recipe (tossed it in a general toolkit when I bought more, but never needed to use it in "general" work) and can confirm it was quite different from the brittle stuff Dave showed (which is more like Woods, Cerro-Low, etc.) It was only moderately less flexible than 63/37Woods metal *will* work as a low melt desolderer. and is relatively cheap in the quantities used by plumbers, AC workers, etc. for pipe-bending, heat-activated sprinklers, etc. You'll sometimes see Woods Metal sold in 100-2000g lots on eBay, crude unmarked "ingots" that were very likely just cast from scraps/blocks of old plumber's material (I once got one where I could read the embossing of the kitchen bowl they'd cast it in) IIRC, not so long ago, a 3lb block could be had for $20-30 plus s/h if you were patient. I took a quick look and found plenty of sales of "Woods Alloy", but few real bargains -- but those offers were erratic when I used to buy it.There are a number of such low-melting alloy to experiment with: French's metal, Field's metal, Rose's metal ... it's been a long time since I was into this, so the exact details elude me. Cerrometals, on the other hand are typically sold in small quantities for specific uses (e.g. cerro-Low is used for revolver pistol chamber measurements, because it shrinks very slightly on cooling for easy separation), and tend to be much pricier (and undoubtedly purer) than their technical grade equivalents. I don't know of any cheap source for the Cerro-metals, but if I were *counting* on them, I'd go for the brand-name; chipQuik likewise can't patent an alloy that has been known and used for over a century, but it can patent a use, so no one else can sell it.If I correctly recall the date of my review of the original ChipQuik, a 20-year patent would be running out very soon.I would steer you clear of the (near) liquid metals. Mercury will suck gold off contacts so fast that you won't even be sure if it was ever there. Gallium (liquid at body temperature, but not *quite* at room temp, IIRC) will dissolve aluminum -- and some metal/liquid metal combos can be quite exothermic during dissolution, become exothermic on exposure to water, etc. Such metal/metal solutions are used in advanced organic chemistry to perform surprising reactions. I don't remember what Gallium does when it hits magnesium, for example, but you wouldn't want a flung droplet to hit your bike frame in the corner and start a fire that night.Stick to low-melting solid alloys. You have to add heat, but by controlling the heat, you have more control over the physical materialIt's dense, and they need to temporarily fill a fixed volume of often 100s/100cs of cc) - and they I never worried much about how to cast it into a wire, because it will stick to many materials (like the polyethylene containers I used in a water bath to melt it) creating thin "flashing" sheets that can easily be flexed off the poly and used almost as conveniently as wire. As you can see with the new Chipquik in the video, though,

author: Orpheus
author_rank: Regular Contributor
timestamp: March 13, 2013, 06:12:38 am
content: Historically for "physical patents" in he US, you are free to make your own device for personal use. You could even build on as a  employee for someone else. Eli Whitney pretty much went broke on the cotton gin as a result. I'm sure the corporations would beg to differ, but it hardly matters what the law actually is these day: few will contest a threat of lawsuit.I often joke that between his cotton gin [which vastly increased the market for slave-grown cotton) and his innovations in interchangeable parts (which finally made him rich building rifles), he pretty much made the US Civil War happen when/how it didSoftware patents have philosophical issues that I don't want to tackle (Dammit Jim, I'm a doctor, not a lawyer), but if you wrote your own coder and decoder, and coded only your own data for playback by only yourself .. not I promised myself I wouldn't go there. Suffice it to say that if you wrote a program to decode a legally encoded MP3, you'd have to worry more about DMCA, because you'd be circumventing an encryption (whatever rights you'd otherwise have) Besides, MP3 is part of the MPEG-2 standard (1991?), so the original patent would likely have expired by now -- or in ca 2015, at the latest, if it was an add-on. I don't recall the details.I did quite a bit of dallying with low-melt alloys in my youth (I frequently encountered a hobbyist writeup on SMT tricks that I posted to a mailing list under my real name, as well as my early (1996? 97? Within about a year of them marketing online, anyway) Chipquik circulating on the web 10 years later). I mention this because I still have the remainder of my very first sample from their original recipe (tossed it in a general toolkit when I bought more, but never needed to use it in "general" work) and can confirm it was quite different from the brittle stuff Dave showed (which is more like Woods, Cerro-Low, etc.) It was only moderately less flexible than 63/37Woods metal *will* work as a low melt desolderer. and is relatively cheap in the quantities used by plumbers, AC workers, etc. for pipe-bending, heat-activated sprinklers, etc. You'll sometimes see Woods Metal sold in 100-2000g lots on eBay, crude unmarked "ingots" that were very likely just cast from scraps/blocks of old plumber's material (I once got one where I could read the embossing of the kitchen bowl they'd cast it in) IIRC, not so long ago, a 3lb block could be had for $20-30 plus s/h if you were patient. I took a quick look and found plenty of sales of "Woods Alloy", but few real bargains -- but those offers were erratic when I used to buy it.There are a number of such low-melting alloy to experiment with: French's metal, Field's metal, Rose's metal ... it's been a long time since I was into this, so the exact details elude me. Cerrometals, on the other hand are typically sold in small quantities for specific uses (e.g. cerro-Low is used for revolver pistol chamber measurements, because it shrinks very slightly on cooling for easy separation), and tend to be much pricier (and undoubtedly purer) than their technical grade equivalents. I don't know of any cheap source for the Cerro-metals, but if I were *counting* on them, I'd go for the brand-name; chipQuik likewise can't patent an alloy that has been known and used for over a century, but it can patent a use, so no one else can sell it.If I correctly recall the date of my review of the original ChipQuik, a 20-year patent would be running out very soon.I would steer you clear of the (near) liquid metals. Mercury will suck gold off contacts so fast that you won't even be sure if it was ever there. Gallium (liquid at body temperature, but not *quite* at room temp, IIRC) will dissolve aluminum -- and some metal/liquid metal combos can be quite exothermic during dissolution, become exothermic on exposure to water, etc. Such metal/metal solutions are used in advanced organic chemistry to perform surprising reactions. I don't remember what Gallium does when it hits magnesium, for example, but you wouldn't want a flung droplet to hit your bike frame in the corner and start a fire that night.Stick to low-melting solid alloys. You have to add heat, but by controlling the heat, you have more control over the physical materialIt's dense, and they need to temporarily fill a fixed volume of often 100s/100cs of cc) - and they I never worried much about how to cast it into a wire, because it will stick to many materials (like the polyethylene containers I used in a water bath to melt it) creating thin "flashing" sheets that can easily be flexed off the poly and used almost as conveniently as wire. As you can see with the new Chipquik in the video, though,

author: Orpheus
author_rank: Regular Contributor
timestamp: March 13, 2013, 06:22:06 am
content: Actually, I should've said *historically* for physical patents *in the US*, you were free to make your own device for personal use. You could even build one for someone else as a hired workman [but not as a product]. Eli Whitney pretty much went broke on the cotton gin as a result: he didn't sell it, preferring to force growers to use his mills, but they just built their own. I'm sure the corporations would beg to differ on your rights, but it hardly matters what the law actually is these day: few will contest a threat of lawsuit.I often joke that between his cotton gin [which vastly increased the market for slave-grown cotton) and his innovations in interchangeable parts (which finally made him rich building rifles), he pretty much made the US Civil War happen when/how it didSoftware patents ... I shouldn't have gone there at all. It requires a completely different venue (and more sleep than I now possess), but, MP3 is part of the MPEG-2 standard (1991?), so the original patent would likely have expired by now -- or caa 2015, at the latest, if it was an add-on. I don't recall the details, but I know I used MP3s in 1996, well before eMule, Napster and all that

author: robbak
author_rank: Contributor
timestamp: March 17, 2013, 12:37:21 pm
content: Quote from: Orpheus on March 13, 2013, 06:22:06 amWhile that would be logical, there is more to it. A patent is valid for 20(?) years from date if issue. What companies do these days is apply for the patent, and make sure that it is held up for years with edits and changes. (They will also try to edit their patent to cover things developed by others since their application, if they can get away with it). Then, sometimes 10 years later, they allow the patent to be issued, with the 'technology' now 10 years old and used literally everywhere. The can then extract rents for the next 20 years.It is a thoroughly broken system.

author: mohf
author_rank: Contributor
timestamp: March 17, 2013, 09:47:52 pm
content: LOL. Just imagine:Using ChipQuick to replace a power-hungry IC chip. Turn the device on, IC warms up, reaches 60 degrees... BOEM! IC short circuits everything.

author: Orpheus
author_rank: Regular Contributor
timestamp: March 29, 2013, 06:47:53 am
content: Actually, since 1995, "submarine patents" (patents whose application was deliberately "continued"  by the applicant) have not been allowed in the US since it signed the TRIPS agreement after the Uruguay Round of the WTO, it began counting the term of the patent from the original application, not from the grant date (unless the USPTO partially caused the delay, and even then the extension may be lessened if the applicant is seen to have participated materially in the delay of issuance). Further, since 2000, US patent applications are no longer 'secret' (previously, they were only published when granted; now they are published within 18mos and continuations are published after 6 mos)I won't say that corporations don't play a LOT of games with patent (other forms of "evergreening" remain in wide practice), but rather than say "what companies do these days", one should say "what companies used to do". Few US submarine patents remain in effect today, and the courts are even, begrudgingly, beginning to overturn evergreened and other abusive patents (so naturally the US went to "first to file" and opened a new can of abuses and tricks). A lot of the patent troll actions that catch the public eye are desperate squeeze plays in the waning years of a purchased patent portfolio.Admittedly, the patent on ChipQuik was issued in 1994, so itcouldhave been a submarine patent, but the point is: it was indeedissuedin 1994 (after being applied for in 1993), so even under the old law it would expire in 2014. "Method for removing electrical components from printed circuit boards". On MPEG-3, I have no idea. I just happened to be looking at patents for another reason today, and recalled this slightly old threadThen again, I'm not a patent lawyer, so what do I know? Heck, I wouldn't know much if I were one!

author: prasimix
author_rank: Unknown
timestamp: February 13, 2015, 10:43:11 am
content: Just to refresh this topic I'd like to say that I recently find on eBay aRose's metalin grains (50g) and tested it for desoldering some quad flat pack. It works fantastic even with higher melting point (95oC) then ChipQuik but for the much better price.

author: Ian.M
author_rank: Super Contributor
timestamp: December 02, 2021, 07:21:00 pm
content: I found the composition for ChipQuik Pb free SMD removal alloy over on the Arduino forums, where user ChrisTenone put some in a scanning electron microscope, and analysed the two grain types and the matrix by X-ray spectrography.Quote from: ChrisTenonehttps://forum.arduino.cc/t/what-is-chip-quik/412935--Deliberately Necroposting