QFN IC Chip Will Not Desolder - Page 1
Forum section: electronics / repair

author: Snecho
author_rank: Newbie
timestamp: June 26, 2021, 08:07:37 am
content: Hello allI'm here because I was looking for advice on desoldering a QFN IC Chip. It has about 40 pins and a thermal pad/viasI'm trying to replace the TDP158 Retimer Chip on an Xbox One X motherboard. I've watched at least a half dozen videos on how to replace it, where they use a hot air rework station to apply heat to the chip and remove it. They never use a preheater or anything like that, they just apply hot air over the whole chip and have it removed in about 15-30 seconds. Seems simple enoughThe other day I attempted to do this myself. I tried 350C, 400C, 450C, and 500C with my hot air station, and after two minutes, the chip still would not budge. And now it's starting to break apart from the heatAm I doing something wrong?One video of what I'm talking about for reference:https://youtu.be/EaTw_2qQUg8?t=60

author: ataradov
author_rank: Super Contributor
timestamp: June 26, 2021, 08:43:10 am
content: It is hard to tell if you are doing something wrong without seeing what you are doing. 500 C is definitely overkill.When I need to remove a chip like this with a lot of thermal mass on the board, I set 350-400 C and lower air flow. Then basically do what they do in the video. Hold the nozzle close to the IC. Temperature drops very fast with the distance.You don't need to hold the IC with the tweezers. It is enough to just poke it on the side. Once the solder is melted, it will just move to the solder mask around.I would also try to find some scrap boards and train on them first. If you have issues removing the chip, then soldering it back is likely to not go smoothly either.

author: Microdoser
author_rank: Frequent Contributor
timestamp: June 26, 2021, 09:14:16 am
content: I agree, low flow, 350C, keep the nozzle on the chip, plenty of flux.What air gun station do you have? They are not all made equal after all.

author: ambrosia heart
author_rank: Regular Contributor
timestamp: June 26, 2021, 10:30:51 am
content: See what he did may help you.500°C did more harm than good than in motherboard.This temperature damaged pads; lift off pads.Heat board in both sides.

author: aqibi2000
author_rank: Regular Contributor
timestamp: June 26, 2021, 12:00:44 pm
content: You need to use some form of preheater, the thermal mass of the board is far too great

author: PA4TIM
author_rank: Super Contributor
timestamp: June 26, 2021, 12:15:03 pm
content: I think he needs a better hot air station. I never crank up mine that high and I only once needed a preheater but that was an extreme situation. I have seen videos of people unboxing and trying cheap (under 200 dollar) Chinese hot air stations and they were struggling with things my old OKI does in less then 10 seconds.A good station measures the air so you have the set temp un-depended of the airflow. Cheap stations cool down a lot if you increase the airflow and you have to crank them up by hand to compensate. If so, leave the airflow low, use a IR or TC tempmeter to check what happens on a chip while practicing/experimenting. .Besides that, you need some experience so practice on some old pcbs first.

author: Microdoser
author_rank: Frequent Contributor
timestamp: June 26, 2021, 01:14:29 pm
content: After looking at the video, that chip has a big pad. I have never had a problem with my Atten, no matter the size of pad on a chip.What hot air station are you using?

author: Bud
author_rank: Super Contributor
timestamp: June 26, 2021, 02:00:47 pm
content: If it is a multilayer board with ground plane(s), desoldering may be difficult. I would preheat the board from below to 100-120 C, then hit the chip with hot air.

author: madires
author_rank: Super Contributor
timestamp: June 26, 2021, 02:35:54 pm
content: Yep, in case of a thermal pad I preheat the other side first with hot air, flip the board, and then desolder the IC. Usually I set the hot air station to around 320 - 350 °C for desoldering. For preheating I use the same temperature setting (too lazy to change) but increase the distance to the board.

author: Mario87
author_rank: Frequent Contributor
timestamp: June 26, 2021, 10:05:54 pm
content: Agree with what others have said and also want to add use lots of good quality flux!! Makes a world of difference.

author: narkeleptk
author_rank: Contributor
timestamp: June 27, 2021, 12:33:22 am
content: When things dont like to come off for me I use 2 hot air guns @ 450C. I work a lot on things still attached to aluminum cases tho. Normal things 350C is good enough.

author: PA4TIM
author_rank: Super Contributor
timestamp: June 27, 2021, 12:47:02 am
content: Sometimes parts are glued to the PCB, but you can see that (red stuff peeping out under resistors and caps)

author: Snecho
author_rank: Newbie
timestamp: June 27, 2021, 04:02:53 am
content: Thanks for all the feedback thus farQuote from: ataradov on June 26, 2021, 08:43:10 amYeah, I agree with you it's hard to tell what exactly I'm doing from the original post alone. Allow me to elaborateI do pretty much what you stated, and what they do in all the videos. I set my temperature to 350C at first, and 50% airflow. Then I started applying hot air from a few inches away to the chip area to warm up the board, and then moved the nozzle a few millimeters from the chip and applied heat directly to the chip while moving the nozzle in small circular motions. As you said, I did not hold the chip with tweezers. I held them close by and poked the chip every 10 seconds or so. After about 45 seconds, the chip still would not budge. That's when I started increasing the temperature and kept applying heat a few millimeters away from the IC and moving the nozzle in small circular motionsAs for practicing on scrap boards, I have a few that I've been desoldering and soldering various chips on for a week. I've never had an issue removing a chip from them. Quite oddAlso, Я видел ваш сайт и говорю по-русски, если вы тоже. У вас довольно впечатляющая и интересная история. Мой тоже похож на моего отцаQuote from: Microdoser on June 26, 2021, 09:14:16 amYep, that's what I've been doing. One thing to note though is I used white generic flux paste and applied it to the chip with a cotton swab. Reference:https://www.amazon.com/Delcast-Rosin-Soldering-Flux-Paste/dp/B00SVESNTC/ref=sr_1_2?dchild=1&keywords=delcast+flux&qid=1624762597&sr=8-2However, today I got a soldering shipment in, and now have Chip-Quik Tack Flux. The kind that comes in a syringe. Reference:https://www.amazon.com/gp/product/B08KJPG3NZ/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1Admittedly, understanding flux is one of my weaker points in soldering knowledge, but I've been getting along until this point by using common sense, and the way my father taught me to solder many years ago. And outside of that, using whatever kind of flux they use in whatever instructions or video I'm attempting to followQuote from: Microdoser on June 26, 2021, 09:14:16 amQuote from: Microdoser on June 26, 2021, 01:14:29 pmQuote from: PA4TIM on June 26, 2021, 12:15:03 pmThe hot air rework station I'm using is the X-Tronic 6020-PRO-X. Link:https://xtronicusa.com/products/hot-air-rework-stations-parts/X-Tronic-6020-PRO-X-%E2%80%A2-Platinum-Series-%E2%80%A2-750-Watt-%E2%80%A2-Hot-Air-Rework-Station-%E2%80%A2-3-Temp-Presets-Temp-Calibration-Func-C-F-Func-Auto-Cool-Down-Standby-Mode-Mute-Unmute-Sound-&-Patented-Nozzle-Holder-p278541017I got it because I didn't want to get a cheap no-name $50 one from Amazon, and I love my X-Tronic soldering iron so I thought it would pair nicely with itQuote from: ambrosia heart on June 26, 2021, 10:30:51 amThanks for the feedback. Yes, I agree, 500C seems a bit excessiveQuote from: PA4TIM on June 26, 2021, 12:15:03 pmAgreed, that's why I have a few that I've been desoldering and soldering various chips on for a week. I've never had an issue removing a chip from them. Quite oddQuote from: Bud on June 26, 2021, 02:00:47 pmI'm sure it could work, just seems odd that not one person in the half dozen videos I've seen uses a preheater or something to heat the board from below, and yet they always successfully remove the chip 🤔Quote from: madires on June 26, 2021, 02:35:54 pmYes that could work, again just seems odd no one else doing this repair has used a form of preheatingQuote from: Mario87 on June 26, 2021, 10:05:54 pmAs with my reply to Microdoser, I used white generic flux paste and applied it to the chip with a cotton swab. Reference:https://www.amazon.com/Delcast-Rosin-Soldering-Flux-Paste/dp/B00SVESNTC/ref=sr_1_2?dchild=1&keywords=delcast+flux&qid=1624762597&sr=8-2However, today I got a soldering shipment in, and now have Chip-Quik Tack Flux. The kind that comes in a syringe. Reference:https://www.amazon.com/gp/product/B08KJPG3NZ/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1Admittedly, understanding flux is one of my weaker points in soldering knowledge, but I've been getting along until this point by using common sense, and the way my father taught me to solder many years ago. And outside of that, using whatever kind of flux they use in whatever instructions or video I'm attempting to followQuote from: narkeleptk on June 27, 2021, 12:33:22 amUnfortunately, I do not have two hot air stations, but that would seem rather excessive in this situationQuote from: PA4TIM on June 27, 2021, 12:47:02 amI definitely don't think it's glued on, as it's never been seen or mentioned in any of the videos

author: dc101
author_rank: Regular Contributor
timestamp: June 27, 2021, 08:01:15 am
content: Might be worth taking some regular solder and trying to mix it in with the existing solder using a regular soldering iron. Just put a blob on your iron and run it thoroughly over the exposed pads. And yes definitely need to be using flux. I would highly recommend the YouTube channel NorthridgeFix if you're interested in electronics repair.He did a video where he replaced that exact IC you're trying to replace:Cheers

author: PA4TIM
author_rank: Super Contributor
timestamp: June 27, 2021, 10:49:01 am
content: 50 dollar hot air stations are toys, under 200 they are usable for easy jobs done by a skilled person, good stations that can handle everything, also difficult jobs like this one, cost over 500 dollar upto 1500 dollar. Louis Rossmann has some videos over this. In one he tells people who ask if they can have a cheap one instead of the "expensive" Hakko., "the Hakko is the cheap one"(i saw a video about your station, it was really struggling to remove a smd resistor. That is very badIf you do exactly the same as in the videos then the only thing left is your station. They are usable for removing easy to remove parts. Multilayer, heat-tabs, older solder, dirt etc makes it much more difficult. Adding fresh solder, flux etc (all the tips already stated in this topic) can help but if a station just does not has enough power even a pro can not get the parts off.Be careful with flux paste, never use the plumber stuff, it will eat away traces and vias. Use a good solder that has flux inside. (that Chip Quick from your link looks a lot different from the stuff I have, are you sure it is no fake ? )But have you thought about the next step, removing is often the easy part, cleaning can be done by wick or a desolder station, but resoldering a new one is often more difficult as removing. The pads must be 100% flat and clean, then the tin must melt everywhere at the same time and stays that so the part can "float" to centre. Flux !!An other option is to use a paintstripper to preheat (When I did not have a hotair station I used a paintstripper. I made a nozzle for it from welding a cone from sheetmetal. Worked great but a bit dangerous, that thing was 2200W. My desolder station is only 900W(heatpower) but thanks to the good regulation and element design it is in normal use pretty powerful. It is like audio, you have audio Watts and "ohms law based" real watts. And sometimes the whole device pulls X watt, not stating how much is lost between mains plug and the tip of the handpiece. And how efficient the heater is. A1000W nail as element will not be as succesful as a optimal designed 500W heater and airflow path.

author: dc101
author_rank: Regular Contributor
timestamp: June 27, 2021, 04:45:43 pm
content: Chip Quick is legit, I've used their flux before and I use their low-melt solder at work. Their market is more focused on rework/repair as opposed to companies like Amtech.

author: narkeleptk
author_rank: Contributor
timestamp: June 27, 2021, 07:01:00 pm
content: Quote from: Snecho on June 27, 2021, 04:02:53 amSays the guy who has not been able to remove the IC.... Personally, I have no problem removing a 40-Pin WQFN or any other IC. I have a few rework stations but I use the same 6040-pro-x your trying to use most of the time. Its plenty capable.The problem is simple. You do not have enough heat getting to the thermal pad. You can achieve this many different ways.A few idea'sPre-heater,Another hot air gun (from bottom is best, top if no access to bottom)Large tip soldering iron placed on bottom of PCB if thermal pad goes all the way through.Use a scalpel type razor to gently lift at the chip and scratch around the pins while heating.Side note about extra air, if your desperate. It doesn't need to be a fancy rework station. A cheap paint stripper like this:https://www.harborfreight.com/1500-watt-11-amp-dual-temperature-heat-gun-56434.htmlWill work just fine for the extra heating needed. Your basically just using it as a pre-heater while your real rework gun is your main tool.

author: Snecho
author_rank: Newbie
timestamp: June 28, 2021, 05:15:50 am
content: Quote from: dc101 on June 27, 2021, 08:01:15 amHahaha, I've been binge watching NorthridgeFix for the past two weeks. In fact, the video example I linked in the original post of a retimer IC getting replaced was by NorthridgeFixBut yeah, I've thought about carefully adding more solder to the pads. Might be worth a shotQuote from: PA4TIM on June 27, 2021, 10:49:01 amHmmm, you make pretty valid points. Is it ok if I ask what makes a good hot air station in your opinion then? Like for example you mentioned "power." Because $50-$1500 is a really huge variance. Especially since they all seem to do the same basic thing, i.e. temp control, air flow control, and all have a temperature range of around 100C-500C. Or perhaps I'm overlooking somethingI realize most people on this forum are electrical vets that do this for a living. However despite my background of always being in and around electrical engineering, I've always been more of a tinkerer/hacker/hobbyist. That's probably why an $800-$1500 hot air station just didn't seem feasible for me, as that's more of a professional market. Also perhaps a reason I went with the mid-tier $150 X-Tronic oneYep, my solder is rosin core leaded solder. And if you're asking if the flux is a fake Chip-Quik, I doubt it, as it came with all the official Chip-Quik paperworkAnd yes I have thought about next step of resoldering quite a bit. In all the videos, each person does it a bit differently. As with many things with soldering, there is not really one definitive way. I have to take all the methods into consideration and do it my own wayQuote from: dc101 on June 27, 2021, 04:45:43 pmi went with the Chip-Quik syringe as my first flux syringe because it looked similar to the type of flux used in the videos and had a good price. I do hope it works in the same fashion. My other choice was the MG Chemicals flux syringe, as I do love MG Chemicals, but it was more expensive, and I had already settled on the Chip-Quik fluxQuote from: narkeleptk on June 27, 2021, 07:01:00 pmSorry, I didn't mean to offend. I thought you meant aim two hot air guns at the chip @450C, in which case, I made the assumption that that seemed excessive, as ataradov and ambrosia heart pointed out to me that just one hot air gun @500C is overkillMany thanks for reassuring me about the hot air station I'm using though. And you seem to have a good point about the extra pre-heating that may be needed. i may have to try that

author: perieanuo
author_rank: Frequent Contributor
timestamp: June 28, 2021, 09:15:57 am
content: hi,even with 80usd hotair station for chips with some big gnd pad, your chances are multiplied by 10 if you use a heating plate below the pcb (first, you reduce overheat, you reduce curbe radius and component stressing for pcb caused by one-side only heating)what everyone says, quality flux is a must, but someone who works with bga soldering, heating up AND bottom pcb is also a mustwatch pro soldering stations like metcal 5000 hotair series, they heat on both sides.btw, i saw mobos with more than 1cm flexing even with that method, for big pcb's you need to stabilise mechanically the board even better than a 25 000 euros reworking machineor like the cheap chinese reworking machines, with quartz bottom heater, they were like 300-400 euros some years ago, i bet they work fine enough for the money, at least for small boardsbut, you cab manage to do yourself something similar, maybe a little more $$$ but more reliable (me personal bottom heater board witk 2x800w heating resistances incorporated in Aluminium aviation plates was less than 100 euros, of course with some spare parts from my drawer (temperature controller, threaded temperature sensor into ALU plate etc)the secret for pro soldering bga workshop, BOTTOM HEATING, don't need to buy 600 euros equipment, i work sometimes with atten 8502d, 200 euros, plus 100 euros heating plate or why not, a second 80 euros hotair rework station as bottom heater (it was a project on r&d company i never finished, i changed job)

author: Ian.M
author_rank: Super Contributor
timestamp: June 28, 2021, 09:56:46 am
content: Its possible to use a 50W 12V MR16 halogen bulb as an improvised local area board preheater. If you can still get hold of halogen bulbs, and can scrounge the rest of the parts (i.e. are a serious skip-rat, as many halogen installations are being scrapped and replaced with LED fixtures) you can probably put something together with change from $10. If you have to order in parts and materials, it gets more expensive. Seehttps://www.eevblog.com/forum/manufacture/small-bottom-heater-for-rework-and-reflow/msg3427730/#msg3427730for details.I believe the Xbox One X board has decoupling caps and a few other components on the underside. Mask them off with aluminum foil with a window cut under the offending chip location (3x to 4x the width of the chip) and Kapton tape round the window and strategically at the board edges, so you don't knock off other parts while orbiting the board over the heater lamp, and don't turn the heat all the way up, as you don't want it to get quite hot enough to melt solder on its own without the localized hot air from the top side. Practice on a scrap board with similar package ICs is essential.

author: Snecho
author_rank: Newbie
timestamp: June 28, 2021, 11:55:21 pm
content: Quote from: perieanuo on June 28, 2021, 09:15:57 amQuote from: Ian.M on June 28, 2021, 09:56:46 amOkay, definitely looks like using a form of pre-heater is becoming a running theme. Definitely seems like a good suggestion, and I think I will have to use this methodThanks for the suggestions 🙂

author: Rasz
author_rank: Super Contributor
timestamp: June 29, 2021, 03:16:04 am
content: Quote from: PA4TIM on June 26, 2021, 12:15:03 pmnowadays $200 is the realm of 1KW Quick 861DW, even HCT-1000 is half the power at 10x the priceQuote from: Snecho on June 27, 2021, 04:02:53 amwell, you didnt want it, yet thats precisely what you gotYour "station" is just a fancy digital triac controller regulating power to the same heater hand piece used in all those $30 hotairs, with integrated pissant fan.Quote from: Snecho on June 27, 2021, 04:02:53 amthermal mass - your station is pushing less hot airtechnique - nozzle size and shape, distance, angle, airflow - those are as important as the temperature setStop looking at all the temperature figures thrown around, or the one on your station, those numbers are allmeaningless. The only thing that matters is the temperature at the component you are trying to desolder and surrounding PCB, and nobody is measuring that.

author: Microdoser
author_rank: Frequent Contributor
timestamp: June 29, 2021, 10:59:15 am
content: Quote from: Snecho on June 27, 2021, 04:02:53 amYes, that's the sort of flux I know, I've never used the white stuff.Regarding your hot air station, they are not made equal and generally come in two types. The sort that has the blower in the handle and the sort that has it in the main box. The handle blower type don't seem nearly as able as the other type, especially with difficult chips. Sorry to say it, but for the money, IMO you could have got a much better hot air station. The Atten ST-862D is the one I have, and I have not found any chip it cannot remove and rework.Also, as has been said, the nozzle you have on the end affects things greatly.A few years back, hot air stations were a lot of money, to the point where it was noted that the price dropped from ~$850 to $300A little while later, that price dropped againTo compare handle blower types to integrated blower types, by someone who doesn't have years of specialist experience (also with a hot air station more in the price range of your station):In the last video, he has some strong words to say about the handle blower type of hot air station...

author: narkeleptk
author_rank: Contributor
timestamp: June 29, 2021, 11:10:35 pm
content: Quote from: Microdoser on June 29, 2021, 10:59:15 amI see a lot of posts trying to say blah blah blah cheap hot air stations. How many have used the unit TS is using? I regularly use the the same hot air station he's working with it and I can say from experience its perfectly fine to do this job. @ $150 for a solid built hot air gun and iron, Its an excellent unit for any hobbyist. I highly recommend it. I never liked handle blowers before but the one in this unit is quiet and works very well. Its one of the reason I've been using this machine over some of my more expensive units. Both iron and air gun heats up quickly and accurately. My only gripe is the unit itself is a bit light on the back end and the irons cable is too short.

author: Rasz
author_rank: Super Contributor
timestamp: June 30, 2021, 05:34:16 am
content: Quote from: narkeleptk on June 29, 2021, 11:10:35 pmhttps://en.wikipedia.org/wiki/Choice-supportive_bias

author: Snecho
author_rank: Newbie
timestamp: June 30, 2021, 06:42:47 am
content: Quote from: Rasz on June 29, 2021, 03:16:04 amYeah! I was just looking at the Quick 861DW a couple days agoQuote from: Rasz on June 29, 2021, 03:16:04 amYou know, unfortunately this is pretty much what I've been thinking to myself these past few daysQuote from: Rasz on June 29, 2021, 03:16:04 amThis all makes a lot of sense. especially the thermal mass. Does that mean I should be looking at the Air Flow and Air Volume measurements on the stations? I also think this may be related to the difference between units with the blower in the handle, and units with the blower in the main box, as Microdoser is about to point outQuote from: Microdoser on June 29, 2021, 10:59:15 amYou know, I was waiting if someone was going to mention the difference between the fan in the handle type and the fan in the main box type that blows through the entire tube to the air gun. It seems like all the "proper" hot air stations are the fan-in-main-box type. Perhaps I should return the one I have and get one of those...It's a shame really. I really like the look, feel, and compactness of this one. Especially the side-mounted air gun holster. Too bad it's just lacking in performance 😔Many thanks for the informative videos on the subject. I'll take a look at themQuote from: narkeleptk on June 29, 2021, 11:10:35 pmPerhaps there was some miscommunication? Mine is the 6020 model. It doesn't have a soldering iron, only hot air______________________________________________________________________________________________________________________________UpdateI was able to desolder the IC 🙂I used a combination of various suggestions given here. I pre-heated the bottom of the board using the hot air station without a nozzle for a couple minutes. Then I flipped the board over and hit the chip with 450C with the hot air gun. It still wasn't budging, so I ran my soldering iron around across all the pads a few times, and was able to "flick" the chip off the board. It was the thermal pad, it was being a real b**** to work withThe flux worked pretty well, and similar to in the videos. Evaporated kind of quick thoughNow comes the terrifying part: soldering the new chip. I don't even know if I want to attempt it with this hot air station. Even my soldering iron has trouble with the thermal pad. The solder hardens instantly on it, and has almost no chance to flow, unless I use a huge flat tipLooks like no ripped pads though

author: wasyoungonce
author_rank: Frequent Contributor
timestamp: June 30, 2021, 07:49:07 am
content: Ok I didn't know it was thermal pad.......usually I lift all the legs using enamelled wire and iron/flux.Then dremel grind away the top of the package till I see the copper layer. Its obvious why you lift the legs. Be careful of the tool slipping off. I start at the centre work outwards. Its a copper base around 1/2 mm above the thermal pad when you see it you'll know. Then hit this with std iron......it'll lift off what's left 'easily and quicklyOld Skool stuff....works for me. I just know I'll be howled down....hahaha They are a head damn to do!But, well done to remove it no damage! There must have been thermal vias under possibly a thermal pad and vias.My Method......FWIW

author: PA4TIM
author_rank: Super Contributor
timestamp: June 30, 2021, 08:39:18 am
content: That is why they make wide flat tips. The priniple is simple, you can compare it with electronics. You have a PSU (the solder iron heater) and a load (the thing you want to solder. The trick is to optimise everything in between for the lowest resistance so your PSU can deliver the max current. That starts with the best suited connector, thick wires etc. In case of soldering you need to optimise the heat resistance for a max heat transfer from element to component/PCB.When it comes to PSUs everybody understands that the input power is not the same as the output. That is why they state something like 0 to 30V and max 10A and a max of 300W if you can draw 10A at 30V. Some PSUs can not deliver max current at max voltage so it is important to state that to in that case.Soldering is the same, only they state x degrees output and y Watt output. The problem is cheap stations often state the max input power, not the output. And that isd the trap. The heat-resistance from element to tip or from element to air must be as low as possible so all the heating power can transfer to the component/PCB. This is something you can not see. Two stations that look the same can haver a totally different resistance. If you place a nail as heating element in a hotair station it can not transfer much air and has a hard time not to cool down by the airflow. If you make a big element in such a way that a very small bit of air sees a lot of heater surface (and total the air sees a lot more surface as with the nail), the air gets hotter and the element has no hard time staying hot.For an iron there is an extra step, the tip must be optimised so the element can transfer as much heat as possible to the tip. This is upto the designer (or Chinese copier) to optimise by dimensions and types of material.Like we want our PSU to deliver a stabile precise voltage to the output, we want a stable temperature. If the PSU delivers a lot of current we need to use sense wires to compensate the voltage drop caused by the resistance of the wires to the load. In case of soldering you need to measure the temperature as close to the tip as possible. For hot air this is extra important because the amount of air cools the heater more or less. So 300 degrees at max airflow needs a lot more power to the element as when airflow is minimum. A good station controls that. No matter the amount of air, the airtemp at the nozzle will be constant. This makes the construction more complex and expensive. If your station is set at X degrees at y liter/min, this should come out of the nozzle (Often measured/defined as Z cm from the nozzle. If the design is poor the output will be lower as the display statesThe 3rd thing is the heat-resistance between tip/nozzle and component. For hot air the design, other than the nozzle shape/size it does not matter. It is the same for every station. You have X temp at Y airflow at the end of the nozzle (you hope the same as what the display shows). Only you can optimise it in this last phase by things like the right distance and nozzle size (so experience/skills)For the solder iron it is the shape and size of the tip. The tip is like the buffer caps of the powersupply, it is a sort of heat reservoirA big massive tip needs more time to heat up but also is able to bridge the time the station need to keep the tip at the set temp. And the station needs enough peak power to follow the heat loss of the tip. The thing you are soldering is trying to cool down the tip. That is why the design is important. But also skills. You need to choose a tip that is as large as possible for the situation. A big tab needs a big tip, a tiny little pin needs a tiny tip. And the right shape. A massive pencil shaped (conical) tip can not transfer much heat to a flat surface. here a big flat tip works best. A big flat tip does not do much if you want to heat up a round connector pin. It is not doable to have optimuized tips for every situation (that is why the best brands have a huge selection off tips (like 100 different shapes and sizes)The last step is solder, the function of a "blub" of solder on the tip is there to match the tip shape to the shape you are soldering. It fills the gap and so improves heat transfer from tip to component. Does solder not melt, just add solder to the tip when it is touching the componernt/pcb or old solder joint and fill the gap, and then add more to solder the part.Flux is something that is inside good solderwire and you can add some. The prime function is not a better heat transfer, it is there to clean the surfaces of dirt and oxide. The result is that the solder flows nice around the component/via/pad and so makes a good joint. No-clean flux gets activated by the heat and after that stops eating a way the metal. Other flux need to be removed because it does not stop eating away pins, vias and traces.A solderjoint made with bad solder or a to cold iron does not flow and often only attaces to the component pin but not to the via/pad. They look like a ball (convex)watching from aside. A good joint looks hollow (concave)

author: Rasz
author_rank: Super Contributor
timestamp: June 30, 2021, 09:06:45 am
content: Quote from: Snecho on June 30, 2021, 06:42:47 amsounds precariousQuote from: Snecho on June 30, 2021, 06:42:47 amlow quality flux or temp too high.With low quality equipment you end up compensating by bumping temperature all the way up, risking burning stuff.Quote from: Snecho on June 30, 2021, 06:42:47 amhuge flat tip is what you should use, even/especially when working with small smd. Small needle shaped tips are a scam shipping as the default on all cheap soldering irons for some unknown reason, great for soldering headphone wire and not much else. Bigger tip means bigger contact surface and bigger thermal mass.Quote from: Snecho on June 30, 2021, 06:42:47 amyou probably can guess what comes nextX-Tronic uses ancient Hakko 900M tip clone designshttps://www.xtronicusa.com/X-TRONIC-900M-SOLDERING-TIP-ASSORTMENT-1020-9-TIPS-p16408314https://www.xtronicusa.com/products/soldering-stations-parts/3010-XTS-Soldering-Station-&-Parts-c60141106shows they even slap that brand on unregulated mains powered garbage, not a good sign

author: SoundTech-LG
author_rank: Frequent Contributor
timestamp: June 30, 2021, 02:18:36 pm
content: The next step is to remove all traces of the (likely) unleaded solder. Then, using leaded solder place the tiniest possible blob on the thermal pad. Smooth it out some without adding any more solder. If you like, touch each pad with some leaded solder (not too much). I usually hold the part in orientation with my exacto blade as I apply the heat to melt it down altogether. Good luck to you.

author: narkeleptk
author_rank: Contributor
timestamp: July 01, 2021, 01:29:17 am
content: Quote from: Rasz on June 30, 2021, 05:34:16 amNonsense. I buy so many different tools and equipment for my work I could care less about trying to spew nonsense about junk tools. The fact is the tool works good, its a decent price for what it is and imo its a great choice for a hobbyist or someone just starting out in repairs. Are there better more expensive tools? Sure, no argument there, and at some point its a smart move to invest in yourself/career but they are not required to do rework efficiently and definently not worth it for someone who only tinkers here and there.Quote from: Snecho on June 30, 2021, 06:42:47 amOh? Well, I take back what I been saying then. I thought you had the 6040-pro-x. which is a much better value. Don't think I would have supported the idea of paying 150 for just the 6020 when you could have gotten the 6040 for about the same price.

author: Rasz
author_rank: Super Contributor
timestamp: July 01, 2021, 04:50:59 am
content: Quote from: narkeleptk on June 29, 2021, 11:10:35 pmso perfect it cant dothis jobQuote from: narkeleptk on June 29, 2021, 11:10:35 pmyet here we areQuote from: narkeleptk on June 29, 2021, 11:10:35 pm6040 is same junk, just in different package. The reason why it cant touch anything with a ground plane is>Hot Air Gun Volume: 31 L/MAir works exactly as "good" as any other $30 858 clonehttps://www.amazon.com/Rework-Solder-Station-Soldering-Welding/dp/B07Y7ZCVT2/Soldering iron is of the ancient 900M tip design. 6040 is pretty much this $40https://www.amazon.com/FEITA-Station-Digital-Soldering-Nozzles/dp/B07ZJQHDJ7or $60https://www.amazon.com/CO-Z-Upgraded-Soldering-Electric-Temperature/dp/B077GS9DQMin arguably nicer looking package with blue leds to make it look more expensiveeven this $30 toyhttps://www.amazon.com/Soldering-Function-Adjustable-Temperature-Ergonomic/dp/B08NDH4Q2T/is in entirely different galactic when it comes to quality of soldering. And if you dont like hacks at $100 you can buy reputable brand producthttps://www.amazon.com/Weller-WE1010NA-Digital-Soldering-Station/dp/B077JDGY1J/tldr: not a "great choice", doesnt work all that good, and is a terrible value.

author: narkeleptk
author_rank: Contributor
timestamp: July 02, 2021, 03:04:10 pm
content: You make some good points and have a convincing opinion, If I had never used the tool I may be incline to believe you. However I have used the tool personally and I do not have any issue's with it at all. Its a solid unit as is a few of the other xtronic units I have. I do ecu repair and remove countless ic's with thermal pads large and small WHILE still attached to the aluminum cases, it should have handled the TS job no problem. I lean more to lack of experience. I have used hakko and I have used some of the cheap knock offs your comparing to. It definently performs better then the cheaper units and the QC looks to have been much better on the ones I have opened up. The iron on it works very well for me but I generally use good tips which helps quite a bit. I have never tried the quick so I cant compare with that one unfortunately.

author: Snecho
author_rank: Newbie
timestamp: July 03, 2021, 02:14:22 am
content: Quote from: wasyoungonce on June 30, 2021, 07:49:07 amThanks!Funnily enough, the prior heat melted away part of the top of the chip, so using the soldering iron on the copper base inside is exactly what I did as wellQuote from: PA4TIM on June 30, 2021, 08:39:18 amWow, that really helps put things into perspective for me. Especially the basic physics and thermodynamics behind Power vs. Heater Element vs. Airflow, and the soldering iron tip acting as a heat reservoir. Many thanksQuote from: Rasz on June 30, 2021, 09:06:45 amIndeed it does. Is why perhaps I need a better hot sir stationQuote from: Rasz on June 30, 2021, 09:06:45 amPerhaps. I'm sure I will gain more insight as I do more work and purchase different fluxesQuote from: Rasz on June 30, 2021, 09:06:45 amI do love my soldering iron for it's simplicity and ease of use. It, with it's default conical tip has served me perfectly throughout the years up to this point for everyday household repairs, tinkering, and all of my projectsI do think however I will use a bigger tip for this job, or parts of this jobI am curious though, why do you consider the 900M tips/tip system bad?All in all, I do appreciable the feedbackQuote from: SoundTech-LG on June 30, 2021, 02:18:36 pmYup, I already cleaned all the pads with wick and alcohol. That picture was taken immediately after the chip was removed. I do plan on adding leaded solder to all the pads prior to soldering the new chipMany thanks for the best wishesQuote from: narkeleptk on July 01, 2021, 01:29:17 amI originally bought the 6020 simply because I already had an X-Tronic soldering ironQuote from: Rasz on July 01, 2021, 04:50:59 amQuote from: narkeleptk on July 02, 2021, 03:04:10 pmSo I have a question to ask the forum if I may. As has been repeatedly brought up and discussed as seen above, it seems like my X-Tronic handle type blower hot air station is less then stellarThe question is, what station should I upgrade to, as I plan on doing more of this exact repair in the near future, and am still within the return windowPersonally, it seems like the "proper" ones are ones with the blower inside the main box unit, as I had thought in the back of my mind since pretty much the beginning. Therefore, I was looking at the Quick 861DW:https://www.amazon.com/Quick-861DW-Digital-Station-Display/dp/B00EID23J6/ref=asc_df_B00EID23J6/?tag=hyprod-20&linkCode=df0&hvadid=241999416883&hvpos=&hvnetw=g&hvrand=18285797718921536960&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9014246&hvtargid=pla-571390859655&psc=1And the seemingly comparable X-Tronic 4020-PRO-X:https://xtronicusa.com/products/hot-air-rework-stations-parts/X-Tronic-4020-PRO-X-%E2%80%A2-Platinum-Series-%E2%80%A2-1000-Watt-%E2%80%A2-Hot-Air-Digital-Rework-Station-with-Patented-Nozzle-Holder-%E2%80%A2-4-Temp-Presets-Temp-Calibration-C-F-Auto-Cool-Down-&-Mute-Unmute-Sound-Features-p294696106

author: Microdoser
author_rank: Frequent Contributor
timestamp: July 03, 2021, 12:06:06 pm
content: Quote from: Snecho on July 03, 2021, 02:14:22 amIt is the same issue as with the hot air station. They both make plenty of heat, but the way that heat is delivered reduces the effectiveness of the unit.The 900M has a central heater core that the tip fits over, meaning the generated heat has to travel up the tip to the workpiece. When dealing with parts that have a high thermal mass, or which conduct heat away strongly, this can lead to the tip becoming cooler requiring the iron to be set to a very high level just to continue working.The other style of soldering iron has the heating element actually inside the tip itself, and so can deliver the heat to the workpiece far more efficiently. This allows you to have your iron set to a much lower temperature and still effectively melt the solder, which in turn reduces the chance of damaging either the components around the work area or the component you are trying to attach/remove.I would not personally call them bad, I worked with that system for many years with no real problems, it's just that the new system with the embedded heating element in the tip is far better.At around £50, the TS100 is a good entry level iron if you wanted to shift to that system. It can also fit the tips from the more expensive Hakko FX-951, although you would need to 3D print a handle extension as those tips are much longer.Dave did a video showing the difference.

author: narkeleptk
author_rank: Contributor
timestamp: July 03, 2021, 02:31:04 pm
content: Quote from: Snecho on July 03, 2021, 02:14:22 amI was looking at that one compared to the quick the other day. Its only half the air volume so I would not call it comparable. If your going pony up the dough then its looking like quick is the better choice there for sure.

author: Microdoser
author_rank: Frequent Contributor
timestamp: July 03, 2021, 03:44:25 pm
content: Quote from: narkeleptk on July 03, 2021, 02:31:04 pmAnd if you watch the video I posted above which directly compares the Quick to the Atten ST-862D then you will see the Atten is just as good as the Quick (if not better), but half the price. The money you save could be spent on getting extra nozzles and a decent soldering iron of the heating element tip style.

author: Rasz
author_rank: Super Contributor
timestamp: July 03, 2021, 06:49:38 pm
content: Quote from: Microdoser on July 03, 2021, 03:44:25 pmthat would make it $150, where?861DW is <$300

author: Microdoser
author_rank: Frequent Contributor
timestamp: July 03, 2021, 09:54:02 pm
content: Quote from: Rasz on July 03, 2021, 06:49:38 pmMy mistake, the Quick was less than half the price of the Hakko FR810 and the Atten is $50-$100 cheaper than the Quick for the same function, possibly better.