QS-5100 Reflow oven, any tips, warnings etc ? - Page 1
Forum section: electronics / general

author: cgroen
author_rank: Unknown
timestamp: April 21, 2016, 01:51:26 pm
content: I pulled myself together and just ordered a QS-5100 reflow oven (based on the positive comments on the forum).I ordered it from here:http://www.aliexpress.com/snapshot/7592749862.html?orderId=74706341677918Are there any of you that has some experience they want to share, and especially any tips, warnings, precautions etc ?Or is it just "working right out of the box" ?(it seems from the video from Dangerous Prototypes that the temperature is quite a "bit" off, is that so with all the units, or was that just this particular unit Ian tested ?)

author: wraper
author_rank: Unknown
timestamp: April 21, 2016, 02:36:17 pm
content: Uneven heating guaranteed, and no possibility to visually inspect solder melting process.

author: harry4516
author_rank: Regular Contributor
timestamp: April 21, 2016, 11:24:24 pm
content: all these ovens are off-temperature.It needs a couple of test boards to find the right temperature and see if there are any hot/cold spots

author: uncle_bob
author_rank: Unknown
timestamp: April 22, 2016, 01:21:04 am
content: HiIt needs the masking tape replaced with Kapton. If you don't it will be a mess when you fire it up.The time calibration on the profiles is likely off by 2:1. A firmware update will take care of this.Like all ovens, it has temperature gradients. Don't plan on packing any of them wall to wall with parts.It is an IR based system so flat black low temp parts right next to gold plated shiny high temp parts ... not going to workDepending on the fan in your particular example, it may (or may not) be a bit noisy.It gets the table under is a bit warm. Be a bit careful what you set it up on.It's a "top heating" device. If you have parts on both sides of the board ... not going to work well.Lots of fun !!Bob

author: ar__systems
author_rank: Frequent Contributor
timestamp: April 22, 2016, 03:20:58 am
content: Yeah, I have a similar one, and it barely passable. Ok for small boards, but leave at least 1.5" on all sides.

author: cgroen
author_rank: Unknown
timestamp: April 24, 2016, 07:21:40 pm
content: Thanks for the info, especially from those that actually have the same oven. I'm not planning on using every square inch for PCBs, as long as I can make maybe 4 PCBs (each 2 x 2") at a time I'm happy.I will do some measurements on it (one of my boards can log and measure temperatures from up to 8 K sensors)The oven should be with me in a couple of days, then we will see

author: uncle_bob
author_rank: Unknown
timestamp: April 24, 2016, 07:59:50 pm
content: HiMix of parts and board design are at least as significant variables as board size. A 16 layer board with 10 full layer planes will be a challenge on a lot of machines. Parts with a lot of thermal mass are a challenge to many machines. If you stick with double sided boards and minimal planes, they will work better on any reflow gizmo. If your parts mix is all ~0805 resistors and caps plus "normal" IC's, that will go through any reflow system easier.Solder type matters on these ovens. If you are ok with lead solder, it will make using one a much easier task.All of the IR systems I have used (not just this one) have been better with "parts soldering only on one side" processes. Running double side boards through a single pass reflow is *not* something I recommend. That makes the "one side soldering" a minor issue to me. The risk with this machine is getting cold (frosty) joints on the back side.Lots of things to watch.Bob

author: ar__systems
author_rank: Frequent Contributor
timestamp: April 24, 2016, 08:30:53 pm
content: Quote from: uncle_bob on April 24, 2016, 07:59:50 pmLet's be realistic here. Nobody will build 16 layer boards and put them into the bottom of the barrel oven.

author: uncle_bob
author_rank: Unknown
timestamp: April 24, 2016, 10:20:05 pm
content: Quote from: ar__systems on April 24, 2016, 08:30:53 pmHiThat board might be a challenge for a number of reflow systems. Since this is a "who knows what" sort of dialog ... it's not that bad a "outside the limits" target.Bob

author: coppice
author_rank: Super Contributor
timestamp: April 25, 2016, 03:26:05 am
content: Quote from: uncle_bob on April 22, 2016, 01:21:04 amAre you confusing this with the T-962?

author: uncle_bob
author_rank: Unknown
timestamp: April 25, 2016, 11:12:09 am
content: Quote from: coppice on April 25, 2016, 03:26:05 amHiMy guess was that it had the same issue. The two ovens are very similar.Bob

author: cgroen
author_rank: Unknown
timestamp: April 25, 2016, 11:15:49 am
content: But, according to the video from Dangerous Prototypes they are in fact NOT the same ?It would be really cool (no pun intended) if some of the users that actually have thisparticular ovenhad some input/experience etc)Video:

author: zapta
author_rank: Super Contributor
timestamp: April 25, 2016, 11:27:18 am
content: An advice from the iantube video, don't place your boards directly on the metal shelf, raise them with small pieces of unused PCB.

author: uncle_bob
author_rank: Unknown
timestamp: April 25, 2016, 11:32:15 am
content: Quote from: cgroen on April 25, 2016, 11:15:49 amHiInterestingly the forum software does not pop that video link up in the normal message listing. No idea why. It's there when I quote your message, so you did indeed link it.I promise I will never ever give you any more input on any of your questions ...Bob

author: coppice
author_rank: Super Contributor
timestamp: April 25, 2016, 11:41:27 am
content: Quote from: uncle_bob on April 25, 2016, 11:12:09 amThe T-962 and the QS-5100 clearly have some common ancestry, but the QS-5100 appears to be a T-962 with most of the serious shortcomings cleaned up. There are videos like, where someone familiar with the T-962 tears down a QS-5100 and finds it a considerable improvement.

author: cgroen
author_rank: Unknown
timestamp: April 25, 2016, 11:49:11 am
content: Thanks for input! It seems that the temperature is way off on the test shown, maybe it is because of the position of the sensor in the oven? I will try and do some measurements once I get the oven (hopefully the nice DHL guy will show up here in not too long)

author: ar__systems
author_rank: Frequent Contributor
timestamp: April 25, 2016, 12:52:14 pm
content: the temperature will always be off for IR oven. Unless you place thermo-couple on the PCB.

author: cgroen
author_rank: Unknown
timestamp: April 25, 2016, 12:55:20 pm
content: Quote from: ar__systems on April 25, 2016, 12:52:14 pmAre there any possibilities to relocate the sensor in the oven so it can be attached to a PCB on the tray or will one just have to adjust the profiles in the oven so that it follows more correctly (when measuring with a probe on the PCB) ?Or is this not possible and/or not needed ?

author: zapta
author_rank: Super Contributor
timestamp: April 25, 2016, 07:56:08 pm
content: Quote from: uncle_bob I promise I will never ever give you any more input on any of your questions ...Bob[/quote

author: ar__systems
author_rank: Frequent Contributor
timestamp: April 25, 2016, 11:03:31 pm
content: Quote from: cgroen on April 25, 2016, 12:55:20 pmYou can leave with temperature being off... Stay far from the sides. use simple boards. It can work kind of ok. But it is not very consistent. So it is really only ok for prototypes.

author: legacy
author_rank: Super Contributor
timestamp: October 27, 2016, 11:16:25 am
content: interesting topics

author: engineer@iotexpert.com
author_rank: Newbie
timestamp: November 29, 2016, 02:28:02 pm
content: I bought and use this oven. Like some of you above Mr. Lesnets Dangerous Prototypes review was helpful.This weekend I put a temperature recording system into mine and made a bunch of runs to see about the temperature.... which turned out very close to correct... and was also very repeatable.I used the profile from the YT video..preheat 150/60sheat 180/58ssolder 210/30skeep 180cool 150Here is one of the plots:I believe that the oven is does pretty damn close to what it says that it will do. I don't know that the +6 degrees during the heat phase matters... maybe?Certainly, I think that some of the commentary in this thread seems like it is 2nd hand.Anyway. You can read about it if you like on my bloghttps://iotexpert.com/2016/11/28/qinsi-qs5100-sn63pb37-solder-profile/Alan Hawse@askiotexperthttp://www.iotexpert.com

author: cgroen
author_rank: Unknown
timestamp: November 29, 2016, 05:21:57 pm
content: Brilliant Alan !!Thanks for the very nice report, very well done!

author: NF6X
author_rank: Unknown
timestamp: November 30, 2016, 03:48:40 pm
content: I would have joined this thread much earlier if I had noticed it, but I just discovered it after Ianposted a linktoAlan's blog poston Twitter. I just don't spend as much time in the EEVBlog forums as I should.I have both a T-962 and a QS-5100 which have been gathering dust for quite some time. By a funny coincidence, I am also finally getting around to trying to tame the wild temperature profile of my QS-5100, so I was very interested in Alan's recent work. I may not bother to do the same with the T-962, which has dramatically inferior construction to the QS-5100. The T-962 is wrapped with masking tape as many of you know, and its oven drawer window is held in place with hot melt glue!The QS-5100 has no such dangerously brain-dead construction features (but it sadly has no oven drawer window at all). I have made tear-down videos of both ovens, which I'll link to at the end of this post. While the two ovens are similar in concept and they can easily be confused with each other at first glance, they're clearly different designs once you take a close look at their innards.I have aPax Instruments 4-channel temperature logger, and I'm waiting for some thermocouples to arrive from Digi-Key which are rated for the temperatures they will encounter in the oven. The probes which came with the logger were having trouble in the oven heat. Their cloth jackets char, and one of them became intermittent at high temperature. I'm using multiple probes so I can get a better look at the temperature distribution at different points in the oven. I expect that there are hot and cold spots that I'll need to work around.I don't have a plot handy, but my first attempt to plot the temperature profile showed that my actual board temperatures were MUCH higher than the oven's profile settings. I was surprised to see Alan's plot showing temperatures much closer to a proper soldering profile. I'll gather more data and share my results once I get my new probes.I suppose that the easiest fix would be to monkey around with the profile settings until my measured profile is reasonably close to what I want, but I have doubts about the repeatability of such an open-loop approach. I think that I will probably want to replace the oven's thermocouple with one in contact with the board being soldered, rather than hanging in the air right between the two heater tubes. I had an idea about placing a contact thermocouple in the drawer to contact the bottom of the board, but a quick experiment with thermocouples on both sides of a test board showed that would not work much better than the oven's dangling air probe due to the temperature differential between the two sides of the board. That's a shame, because it would have been so convenient to just set boards on top of a sensor mounted in the drawer. I have the beginnings of an idea of how to mechanically mount a thermocouple to make it easy to have it contact the top of the board while making it easy to swap out boards without knocking components off.Here are my T-962 and QS-5100 teardown videos:

author: engineer@iotexpert.com
author_rank: Newbie
timestamp: December 01, 2016, 01:44:57 pm
content: QuoteDont do that...My data was very stable... I ran it something like 20 times and had basically the same thing going on every time.I guess that if I were you I would run exactly the same profile that I did... then we can start looking for the differences.. firmware version, thermocouple, cold junction... board version... I guess Id like to see a plot of your data. Im not sure what you mean by "wild temperature profile"I think that if you are using a leaded solder... then it would be much better not to re-engineer the temperature measurement profile.I would be open to working on an open source oven controller to retrofit into that oven....Do you think that the design of the IR tubes is correct? i.e. is the platform sound sans temp measurement.

author: NF6X
author_rank: Unknown
timestamp: December 01, 2016, 03:49:05 pm
content: Quote from: engineer@iotexpert.com on December 01, 2016, 01:44:57 pmI still had some test data left on the logger's memory card. Here is a plot with the thermocouple taped to the top of the board, using the oven's default temperature profile:I just plotted one channel there, but the measurements were pretty consistent at the other three locations I probed. Measured temperatures were a lot higher than the profile settings, with big overshoots at each step. Next time I work with the oven, I'll take better data, including logging the actual profile settings. If I recall correctly, the setting for that first shelf, just under 200ºC, had a 150ºC setpoint. The soak stage ended up well above reflow temperature.Quote from: engineer@iotexpert.com on December 01, 2016, 01:44:57 pmUnless we identify a serious problem with the controller card design, I would be more inclined to want open source firmware for the original controller. We could clean up the user interface for English-speaking users, and maybe add options such as running the fan slowly during soldering to even out hot spots in the oven?Quote from: engineer@iotexpert.com on December 01, 2016, 01:44:57 pmI don't have enough experience with these things yet to form much of an opinion on that. I certainly like the QS-5100 platform more than the T-962 platform, but even the inferior (in my opinion) T-962 platform appears to be giving many people good results after being modified and upgraded.

author: engineer@iotexpert.com
author_rank: Newbie
timestamp: December 03, 2016, 04:20:50 pm
content: Default? I notice that the oven kept the last profile it was on... presumably in flash...That is considerably hot for sure... I wonder if you oven was on profile 4 or 5?If that is true I wonder if the oven has problems with the hotter temperatures...I guess I love to see what your oven does with the same profile that I used.As far as open source firmware... sure... that would be better.I guess that I am looking to forward to seeing some data where you are for sure about the profile... because if the graph you have is really profile 1 then this thing is way far away.Alan

author: NF6X
author_rank: Unknown
timestamp: January 01, 2017, 12:40:50 am
content: I finally got around to making a new test run of my QS-5100 after getting some thermocouple probes that can handle the oven temperature without their jackets burning. My oven settings were:PREH: 150 deg. C 01:00HEAT: 200 deg. C 01:30SLDR: 235 deg. C 00:30KEEP: 220 deg. CCOOL: 150 deg. CProbe 1 (blue trace) was in contact with the board, and probe 2 (green trace) was in the air just above the board. The probes shifted a bit ruing the cycles, as the Kapton tape holding them in place got hot. It looks like the board temperatures ran around 15 deg. C hotter than the oven settings.Here is the raw data, including pictures of my test setup:https://github.com/NF6X/Qinsi_QS-5100_Tests/tree/master/test01

author: NF6X
author_rank: Unknown
timestamp: January 01, 2017, 03:05:15 am
content: I ran another test with the oven's original temperature probe disconnected, and replaced with a thermocouple taped to the board surface. As I expected, the temperature profile looks much better. See the blue trace:I plan to come up with a less kludgy way to have the oven controller feedback probe in contact with the board being reflowed. I have an idea of how to accomplish that...

author: NF6X
author_rank: Unknown
timestamp: February 27, 2017, 04:20:07 am
content: After the successful experiment in which I replaced the oven's air probe with a thermocouple taped to the surface of the board being heated, I finally completed my modifications to permanently install a contact thermocouple in my oven. Unfortunately, I'm getting severe temperature overshoots, much like with the original air probe. I don't understand why yet, because my previous experiment with a contact thermocouple in the controller's feedback loop worked very nicely.I bought some K-type thermocouple elements with ceramic bead insulation which should be able to tolerate the heat inside the oven without scorching like the fabric-insulated and fiberglass-insulated probes I've been using for logging. I also got ceramic-bodied thermocouple connectors for use inside the oven chamber, and a regular plastic bulkhead thermocouple jack to reroute the controller's thermocouple input to an external connector. I installed a ceramic jack passing through the front of the drawer, built a plug-in contact probe for installation inside the drawer, and hooked it all up to the controller with an external cable:I set up a test board, with a second thermocouple also taped to the board for logging the board temperature with my Pax Instruments T400:Oven settings were:PREH: 150 deg. C 01:00HEAT: 200 deg. C 01:30SLDR: 235 deg. C 00:30KEEP: 220 deg. CCOOL: 150 deg. CResults were poor:I tried again with a different contact probe in which I removed the ceramic insulator bead near the junction, in case the bead was absorbing too much IR and throwing off the temperature reading. I also placed both the feedback and logging probes at the same location on the test board. Results were still poor:I don't understand yet why I got such poor results here. I have some additional experiments in mind. Raw data is all available at:https://github.com/NF6X/Qinsi_QS-5100_Tests

author: NF6X
author_rank: Unknown
timestamp: February 27, 2017, 05:33:24 am
content: I performed another experiment:Controller feedback via thermocouple taped to board.Temperature logging via another thermocouple taped to board. Logged on channel 1.Ceramic-insulated probe plugged into logger channel 2 to log its output.Channel 1 agreed pretty closely with temperature displayed on the oven's LCD, and its plot looked satisfactory to me. I'll be happy if I can get my oven to reliably produce temperature profiles like this without having to tape a probe to the board being soldered.Channel 2 showed that the ceramic-insulated probe was reading well below the other two probes. I think this is consistent with the temperature overshoots I saw when using this probe for the controller feedback.Maybe I just don't understand how to install thermocouples yet? I am under the impression that the ceramic-bodied connectors I bought should have contacts made with the same materials as the thermocouple probe wires, so that the connector temperature shouldn't affect the readings, and the cold junction should remain at the controller board. Is my understanding incorrect? Are the readings so far off because of the hot connector in the wall of the drawer?

author: invzim
author_rank: Contributor
timestamp: April 15, 2017, 03:11:16 pm
content: Quote from: NF6X on November 30, 2016, 03:48:40 pmNice!Got this one recently.The build quality as as far as I can tell very nice, I fired it up at home and no foul smells like I read about the T962.It is NOT as accurate as I hoped, and I too experience pretty severe overshoot. I don't have fancy measuring equipment, just a simple UNI-T UT136C with the probe that came with it. It seems to be around 5-13 degrees off at the end of a period, and 14-24 degrees off at the start of a period.I'm only going to use it for prototypes, but it WOULD be nice to be able to consistently do 4 layer boards with qfp 0.5mm and BGA parts at home.Too bad I'm not an atmel guy, as a modified firmware for the ATmega64A(?) that reads the probe a little quicker, and maybe using the fan to fix the overshoot seem very doable.I'll do dome more experiments and will post what I come up with in terms of playing with the profile.