hybridfree/eevblog-posts huggingface dataset:
Regulation temperature peaks in reflow temperature (at least at the probe) - Page 1
Forum section: electronics / general

author: babysitter
author_rank: Frequent Contributor
timestamp: October 15, 2018, 12:27:29 pm
content: Hey everybody,employing a induction cooker and a tall asparagus cooking pot I made a setup to solder prototypes.I am trying to approximate the VPS process as recommended by the solder paste maker, leaning towards using JEDEC J-STD-020 as guideline a bit now. The vapour medium used is Galden LS 230 and I realize the profile basically by observing a stop watch and thermometer to change the power setting of the induction cooker.Attached you find the temperatures I logged with a K-type probe "sitting" on top of a bare PCB during one trial, the other records look similar. (Dont care for the cooling, I am not there yet.)During the ramp-up phase you see that I got large temperature swings which I explain to myself by on-off-regulator action. These swings are much more than the JEDEC recommendation of 3 K/second.Do they look dangerous or will these be low pass filtered by the parts on the PCB? The K-Type probe has a low mass to heat and is sitting on top of the board dry while the parts will already swim in a mix of flux and metal balls, coupled to the PCB and its "thermal inertia."Does anyone have experience with this or how to measure better? I want to prevent the need to immerse the probe in paste with preparation, desoldering and cleaning each time, and with boards to populate there is not a lot of space for it besides a "touchdown area". (Actually I would like to have the probe "flying" over the board and consider that I first verify that the profile will be reproduced each time at board+part level and then I can go to measure the temp of the flying probe only to confirm that the board is exposed to the right profile.)Best regards

author: babysitter
author_rank: Frequent Contributor
timestamp: October 15, 2018, 12:34:03 pm
content: Forgotten attachment syndrome
Heatsink is solderable? - Page 1
Forum section: electronics / general

author: ocset
author_rank: Super Contributor
timestamp: October 11, 2018, 04:53:53 am
content: Do you think it will be possible to easily solder the solder tab on the SK 469 35 STS heatsink?.....https://www.fischerelektronik.de/web_fischer/en_GB/heatsinks/A04/Extruded%20heatsinks%20for%20PCB%20mounting/VA/SK46935STS/$productCard/parameters/index.xhtml...surely the soldering iron's heat will just get absorbed up into the heatsink itself?

author: Berni
author_rank: Super Contributor
timestamp: October 11, 2018, 06:05:08 am
content: Heat is not a problem, you can get 300W soldering irons that will heat up the little thing in an instant.The problem is that it is aluminium. Not only that, it is anodized aluminium. The anodizing is basically alumina glass and its really tough.The only thing you can do is grind the coating off and then TIG weld the aluminum heatsink to another aluminum object.

author: ivaylo
author_rank: Frequent Contributor
timestamp: October 11, 2018, 06:37:05 am
content: This works -https://www.ebay.com/itm/Flux-for-low-temperature-soldering-of-aluminum-Made-in-Russia/253517448373?hash=item3b06d144b5:g:xPoAAOSwoFZatru2It’s aggressive though, don’t use with expensive soldering gun tips. Remove the anodized layer of course...

author: Berni
author_rank: Super Contributor
timestamp: October 11, 2018, 06:45:18 am
content: Oh wait i just realized. Did you mean the little PCB mounting pin on the bottom? Those are not a problem because they are tin plated and designed to be soldered, but yes you will probably want a 100W soldering iron to get it hot enough in a reasonable time since heat will want to flow to the heatsink (But such a small rod has limited heat transfer capacity so its not that difficult). If you have trouble with a little under powered soldering iron you could still use a tiny flame to heat the heatsink body to 100°C before soldering.

author: 2N3055
author_rank: Super Contributor
timestamp: October 11, 2018, 06:54:16 am
content: Those get easily soldered with my 80W Weller.

author: Nusa
author_rank: Super Contributor
timestamp: October 11, 2018, 11:32:34 am
content: It's even a hollow pin in the picture. You should have no trouble soldering it with any decent iron.
Stencil printer project - Page 1
Forum section: electronics / general

author: PartialDischarge
author_rank: Super Contributor
timestamp: September 23, 2018, 11:24:08 am
content: So last month I decided to build my own tensioned stencil printer. My constraints were to build it with the materials I have around+work from my lathe/mill. The weirdest boards I have are around 5cmx38cm so I aimed for a rectangular area. I got some design ideas from a stencil printer I saw in another post too.I took a plastic sheet (I believe it is delrin) and added some handles, feet and attached a aluminum plate:

author: Pinkus
author_rank: Frequent Contributor
timestamp: September 23, 2018, 12:03:01 pm
content: Interesting and nice use of scrap parts. I wish I would have such a XY table laying around.Side note: If somebody wants to sell one, please PM me.Please keep us informed about how it finally works.

author: PartialDischarge
author_rank: Super Contributor
timestamp: September 23, 2018, 12:11:27 pm
content: Quote from: Pinkus on September 23, 2018, 12:03:01 pmThanks, I believe profile projectors are not used much today and u may find an old one for a decent price. The nice thing about these tables is that they use ball bearing guides and they have absolutely no play.

author: PartialDischarge
author_rank: Super Contributor
timestamp: November 01, 2018, 09:08:31 am
content: An update. Basically I noted that the front side of the tensioner was a bit flimsy, so I made a couple of improvements. I moved both frontal supports to the front side (they were a bit behind before) made them stiff and with a brass gear as height adjustment.But most importantly I made a couple of guides for the lateral bars so that the stencil always falls in the same place, which was the main drawback I saw before. Now the repeatability is excellentI've tested it only with simple boards, my final test with a small QFN is coming in a few weeks.
What flux bio cleaner for ultrasonic baths in Oz? - Page 1
Forum section: electronics / general

author: Fleetz
author_rank: Regular Contributor
timestamp: September 30, 2018, 12:38:40 am
content: Any recommendations for a good bio clean product that can be added to distilled water for cleaning flux residue off PCBs in an ultrasonic bath here in Australia?I have tried locating Branson EC here in Oz but doesn't look like its available. I am heading off to the US next week and probably could pick some up there but not too sure on if bringing this solution back is going to cause issues on both USA and Oz customs?Anyway I really am looking for an ongoing Australian supply solution?Any thoughts?
Which PCB prototype service for 0.5mm BGA (max via incl. ring = 0.35mm dia.) - Page 1
Forum section: electronics / general

author: AloyseTech
author_rank: Regular Contributor
timestamp: September 25, 2018, 02:00:32 pm
content: Hi,I have a board which includes a BGA package with 0.5mm ball pitch, 0.2mm ball land pattern diameter. I need a 4 layers board. Without via-in-pad I can route the BGA if the finished via diameter of 350µm (external diameter of the annular ring). Most of the cheapest PCB prototype manufacturer offer only down to 0.45mm finished diameter... Do you guys know of a fab house which can go down to 0.35 without exploding costs? The trace/clearance minimum requirement is 0.1mm trace width / 0.1mm copper clearance (to route between the BGA pads).Thanks

author: asmi
author_rank: Super Contributor
timestamp: September 25, 2018, 05:41:49 pm
content: Send an email to OurPCB/WellPCB and ask them. These guys can go down to 3/3 mil traces and 0.15 mm drills, so they should be able to do what you want. They are fairly affordable too.

author: Dubbie
author_rank: Unknown
timestamp: September 25, 2018, 06:49:59 pm
content: I had this done recently by allpcb. It wasn’t that cheap but was a good job. The main cost contributor was filled vias

author: AloyseTech
author_rank: Regular Contributor
timestamp: September 25, 2018, 06:55:07 pm
content: Quote from: Dubbie on September 25, 2018, 06:49:59 pmDo I need filled vias if I use the dog bones technic for the BGA?

author: Dubbie
author_rank: Unknown
timestamp: September 25, 2018, 06:56:11 pm
content: No. Not for 0.5mm. I did 0.4 which has no room for dog bones.

author: asmi
author_rank: Super Contributor
timestamp: September 25, 2018, 06:57:43 pm
content: Forgot to mention - I've done 0.2/0.4 mm vias on 6 layer controlled impedance boards with custom stackup with OurPCB/WellPCB, and they all came at about $160-$200 per 10 boards 10x10cm each. I consider this price a bargain as PCBWay's online quote was showing me over twice that price. So if you down to 0.15/0.35 or 0.2/0.35 - they should be able to do it.

author: Dubbie
author_rank: Unknown
timestamp: September 25, 2018, 06:58:57 pm
content: That is a very good price. Better than allpcb.
Chinese Fabs with LPI or DLP? - Page 1
Forum section: electronics / general

author: 1276-2449-1-ND
author_rank: Regular Contributor
timestamp: October 18, 2018, 07:58:50 pm
content: Anyone recently run across any Chinese fabs able to use LPI or DLP for the silkscreen?

author: 1276-2449-1-ND
author_rank: Regular Contributor
timestamp: October 19, 2018, 09:39:50 pm
content: It turns out that Elecrow's "Premium PCB" service uses DLP. I had PCBs done using this service, but although the printing was sharp it wasn't very opaque. From what images I can find online it looks like DLP might not lay on as thick a coat of ink as silkscreening so that might be perfectly normal for DLP -- but I don't know.

author: mrpackethead
author_rank: Super Contributor
timestamp: October 20, 2018, 05:13:13 am
content: Why is there such a desire for high quality Silk Screens. I've never seen the need.
Glue for securing JST and other connectors to a board - Page 1
Forum section: electronics / general

author: ziplock9000
author_rank: Regular Contributor
timestamp: September 24, 2018, 09:13:04 pm
content: I've made some boards with a lot of JST and pin headers/connectors and other elements that I want to glue down tight to the board as they will be used quite a lot. What sort of glue would be best for this?I know some sort of epoxy would work well, but they are quite expensive, especially the named brands from the US when over here in the UK. Maybe some off-brand names that work just as well?I've tried UV cured adhesive and it's garbage.. It sets far too soft and leaves a Vicks Vaporub smelling greasy residue.. or at least the chineasium one I've just tried.Thanks.

author: maginnovision
author_rank: Super Contributor
timestamp: September 25, 2018, 06:03:34 am
content: I usually just solder headers down. If they're surface mount I'd recommend large pads where the mask covers some. Glue probably won't work as well as you want, just make it harder to fix faulty connections. Worst I'd try is solderable conformal coat.

author: ziplock9000
author_rank: Regular Contributor
timestamp: September 25, 2018, 07:41:31 am
content: All my stuff is still through hole, but I'll be plugging and unplugging a lot on the connectors and I wanted to offer them more support than just the solder if possible.

author: AndyC_772
author_rank: Super Contributor
timestamp: September 25, 2018, 08:40:31 am
content: A soldered through-hole pin will rip the PCB apart before the solder joint breaks. They're incredibly strong in shear.In any case, on something like a plastic body JST connector, the connector housing is only attached to the pins by friction. Gluing down the plastic won't have any significant effect on the stress experienced by the pins; they're free to slide.

author: ziplock9000
author_rank: Regular Contributor
timestamp: September 25, 2018, 08:52:46 am
content: I'm using perfboard and I've found it's not as strong as I'd hoped. I also have bending and twisting toques too that I'd like to ease. Yep it's the stress on the plastic socket not the pins that I want to alleviate for the most part anyway.
PCB copper weight (thickness) and thermal relief - Page 1
Forum section: electronics / general

author: SiliconWizard
author_rank: Super Contributor
timestamp: September 19, 2018, 08:42:16 pm
content: Do you typically adjust your thermal relief parameters when designing a PCB with a greater copper weight than standard (eg. 2 oz instead of 1 oz)?My latest board has 2 oz copper weight and I didn't think of changing anything regarding thermal relief. Pads that are connected to a copper plane (with thermal relief) are *very* hard to solder onto compared to what I'm used to. I even managed to "tombstone" one cap while hand-soldering it, something that has very rarely happened to me.

author: KL27x
author_rank: Super Contributor
timestamp: September 19, 2018, 08:51:32 pm
content: i havent found a a good way to do that in Eagle.What i have done thus far is to remove the thermal and route a trace into the ground plane, then rename the net of the stub trace to ground. it js a pain to rework, so I try to leave this to the end. honestly i k ow i am missing a step here but i cant remember how i disconnect the pad from the plane.

author: ConKbot
author_rank: Super Contributor
timestamp: September 20, 2018, 06:06:10 pm
content: Yep. You need software that supports rule based definition of thermal reliefs, rather than one generic one for a pour/plane and all the components on it. I.e. with 2 Oz copper you can set 0402's to have a 6 mil wide connection, 0805s can have wider, MOSFETs that youre trying to sink the the plane can be no relief. The copper pour gets generated appropriately and no having muck around with manually adding traces.
Solder mask working too well? (on protoboards) - Page 1
Forum section: electronics / general

author: llkiwi2006
author_rank: Regular Contributor
timestamp: September 14, 2018, 02:36:13 am
content: I find it rather difficult to bridge solder between the holes on a protoboard, often I resort to using wire to connect pins up. I wonder if there's an easy solution or should I get protoboards without solder mask?

author: ogden
author_rank: Super Contributor
timestamp: September 14, 2018, 04:02:22 am
content: Brown (paper/bakelite) boards usually does not have mask, but does not have through-hole plating as well.https://www.aliexpress.com/store/product/2Pcs-5-7cm-pcb-Prototype-Paper-Copper-PCB-5-7-Universal-Experiment-Matrix-Circuit-Board-5x7cm/1970323_32851437126.htmlThere are specialized prototyping boards with smaller clearances. One I just found for example:https://www.aliexpress.com/store/product/Double-Side-Prototype-PCB-Universal-Breadboard-PCB-Test-Board-95mm-95mm/1829717_32705109940.html
P&p components placement video - Page 1
Forum section: electronics / general

author: Kjelt
author_rank: Super Contributor
timestamp: August 31, 2018, 11:43:57 pm
content: Impressive demo IMO Seeing the vision speed of this machinehttps://youtu.be/tiQLS34A7LU

author: jmelson
author_rank: Super Contributor
timestamp: September 09, 2018, 04:12:26 am
content: Quote from: Kjelt on August 31, 2018, 11:43:57 pmNote, this is NOT really a pick and place machine. (Well, maybe it is, but I didn't see any feeders.) It seems to be moving glass beads or something around, and only moving each one a couple cm at most. So, it is a trade show demo to look cool, and it may be quite good for SOME job in the factory, but probably not SMT P&P.Jon

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 09, 2018, 12:14:12 pm
content: Looks like more aimed at placing mechanical parts than components
SD memory UHS-II contact footprint - Page 1
Forum section: electronics / general

author: peteb2
author_rank: Regular Contributor
timestamp: September 02, 2018, 12:45:34 am
content: Faintly ridiculous question possibly but i just can't seem to find a footprint dimensional drawing of the standard specification for the contact pads etc of a Secure Digital device 32mm x 24mm in the UHS-II version.I've drilled down on the SD website and all the usual places but it must be one of those cases of me using the completely wrong search words/phrases...Such an item must exist.... Anyone who can enlighten me, a massiveto you....
OpenPNP + CHMT36VA becomes reality!!  - Page 1
Forum section: electronics / general

author: TJ232
author_rank: Frequent Contributor
timestamp: July 24, 2018, 06:40:08 am
content: Now that can be a game changer on the hobby/low volume/prototype market !!Jason von Nieda, the founder of the OpenPnP project is fully committed to port OpenPNP to the CHMT36VA PNP machine.Original Jason message:https://groups.google.com/forum/#!topic/openpnp/pHEsz118180If I would be Charmhight I would give him asap a PNP machine for free!! To be the first low cost Chinese PNP machine working with a decent software package, now that's something to talk about.If you want to give a help with the OpenPNP project, can be done here:https://www.gofundme.com/help-openpnp-grow/Happy breadboarding,TJ.

author: Gary.M
author_rank: Regular Contributor
timestamp: August 07, 2018, 10:35:53 pm
content: I see his machine just arrived in the USA, and being from China it incurred a 25% Trump tax.

author: vonnieda
author_rank: Regular Contributor
timestamp: August 07, 2018, 10:37:06 pm
content: Quote from: Gary.M on August 07, 2018, 10:35:53 pmIndeed! I was a bit shocked to get the text message last night that I owed $752 in fees! Looks like the tariffs went into effect on July 6th. Prior to that, people were paying about $68 in fees

author: Gary.M
author_rank: Regular Contributor
timestamp: August 08, 2018, 12:33:39 am
content: Following your project with interest.

author: funbags
author_rank: Contributor
timestamp: August 08, 2018, 05:32:15 pm
content: Quote from: vonnieda on August 07, 2018, 10:37:06 pmI'm curious is that's the only way you were informed of the tariff? I got my 36VA yesterday morning. But it had been in the states since 5th. Maybe I dodged a bullet?Thanks!EDIT: Oh *July 6th* .... awe crap does that mean someone is going to be sending me a text message insisting I owe Trump some money?

author: vonnieda
author_rank: Regular Contributor
timestamp: August 08, 2018, 05:35:00 pm
content: It was via the DHL notification process, so I got a text message and an email, since I had signed up for both. I'm assuming that if I hadn't received it, and then paid it, I would have had to pay when the driver arrived.I believe that if you've taken possession of the machine from the delivery agent the process is complete and you did indeed dodge a bullet by the machine entering the country before July 6th.Jason

author: mrpackethead
author_rank: Super Contributor
timestamp: August 09, 2018, 10:10:57 am
content: tarrif wars never help anyone.

author: Merlysys
author_rank: Regular Contributor
timestamp: August 16, 2018, 03:27:12 am
content: To Canada, how much would taxes+duties come to?Will they ship by surface, if so how much is the savings over air?I know it takes longer but I am seeking a machine to start using in 3-4 months.

author: 1276-2449-1-ND
author_rank: Regular Contributor
timestamp: September 01, 2018, 11:57:23 am
content: I had it shipped to Ontario, and there were no duties, just PST (5% I think). Shipping was DHL for around $300 and it took just a few days.
Use of Mechanical Barriers with Potting - Page 1
Forum section: electronics / general

author: Munsterfield
author_rank: Newbie
timestamp: August 29, 2018, 05:16:50 pm
content: I need to be able to encapsulate a PCB in a production environment, but I need to be able to restrict where the potting material goes.Typically, you see potting being done where the PCB is placed within its enclosure and the PCB is effectively 'drowned' at the bottom as the enclosure is filled with epoxy.I need to create a setup which allows me to pour a- specific amount of epoxy onto a- very specific zone of a PCB to a- specific thicknessThis will require a mechanical barrier of some kind, and I would like to hear about others experiences with this.- Has anyone had experience with barriers which are glue in permanently when the epoxy cures? What about temporary/removable barriers?- Have you had issues with the potting material wicking under barrier?- Has anyone ever used reusable masks, such as a silicon mold, which would allow for the PCB to be inserted, epoxy cured, and then the potted PCB removed from the silicon mold?Any thoughts on this?Thanks!
Proteus VSM flip relay to TOP top copper - Page 1
Forum section: electronics / general

author: BFX
author_rank: Frequent Contributor
timestamp: August 27, 2018, 08:26:17 pm
content: Hello guys,I have small problem in Proteus.I made new package for relay which is not in standard library but when I put this relay to PCB it's on the bottom in 3d view.How to flip it to top side where is my smd stuff?
JLCPCB Factory Tour - Page 1
Forum section: electronics / general

author: Gary350z
author_rank: Regular Contributor
timestamp: August 23, 2018, 09:08:37 pm
content: Here's a tour of the JLCPCB factory. The guy is a bit hyper but it's still interesting.https://youtu.be/ljOoGyCso8sHere's a list of more JLCPCB factory tours if your interested.https://www.youtube.com/results?search_query=jlcpcb+factory

author: harry4516
author_rank: Regular Contributor
timestamp: August 23, 2018, 11:24:38 pm
content: very interesting video. Nice to see how my boards are madeThis guy is on drugs, better to watch the video without audio.
ESD damaged components more likely to blow up when dv/dt is high?  - Page 1
Forum section: electronics / general

author: ocset
author_rank: Super Contributor
timestamp: August 19, 2018, 01:57:31 pm
content: We suspect ESD damage to some of our components….possibly the damage being caused before the components got put on the PCB.To ensure that PCB’s with ESD damaged components don’t get out to our customers…we want to instigate the ESD failure in our production test facility.The products are offline LED drivers. They have no electrolytic capacitors, and basically the components suffer a higher dv/dt at switch-on if the switch-on happens at the instant of mains peak.So we want to subject the products to an “on-at-mains-peak” tester, which turns them on repeatedly at mains peak.But anyway, do you believe that an ESD damaged component is more likely to blow up when its rail voltage rises with higher dv/dt?

author: TJ232
author_rank: Frequent Contributor
timestamp: August 19, 2018, 02:38:05 pm
content: This must be for sure another treez trolling day, it's raining outside, it's raining here with treez-style questionsWhen you talk about a commercial product that will be released on the market you are not allowed to even think to start any product related sentence with something like : "We SUSPECT ESD damage to some of our components...".Usually you are are just suspecting something about something out there or you are searching to have a solid proof or what? Are you using proper engineering testing methods out there or just using prays, voodoo or any whatever other esoteric method of testing?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 19, 2018, 07:07:41 pm
content: Perform an IEC 61000-4-5 surge test.Tim
Screwing PCB to heatsink may cause flexion and damage to ceramic capacitors? - Page 1
Forum section: electronics / general

author: ocset
author_rank: Super Contributor
timestamp: August 19, 2018, 11:50:58 am
content: HelloWe have a SMD_only SMPS PCB of 10W which we screw to a flat heatsink surface. There is a rubbery thermal pad between PCB and heatsink.The PCB is 6cm x 15cm x 1.6mm thick. There are five screws which screw the PCB to the heatsink….one in each corner, and one in the middle.There are multiple SMD ceramic capacitors on the PCB. Do you think that as the screws are tightened up one by one, that there is a risk of PCB flexion causing some of the ceramic capacitors to break.?

author: TJ232
author_rank: Frequent Contributor
timestamp: August 19, 2018, 12:35:31 pm
content: about 48%

author: ocset
author_rank: Super Contributor
timestamp: August 19, 2018, 01:42:02 pm
content: Thanks, thats what i was worried about, so i wonder how people get round this?I mean, as you know, its very handy to have a power PCB sat on, and afixed to, a heatsink.

author: TJ232
author_rank: Frequent Contributor
timestamp: August 19, 2018, 02:30:22 pm
content: Quote from: treez on August 19, 2018, 01:42:02 pmProper design & stuff like that?I would suggest you to look at Dave DPS5020 Power supply module repair video, he was quite badly hit by a SMD cap crack:

author: ocset
author_rank: Super Contributor
timestamp: August 19, 2018, 04:55:30 pm
content: Thanks, good video...we're not quite as bad as that.....our screws arent right over the caps....but board flexion could result with us......i suppose our rubbery thermal pad kind of lessens the flexion of the PCB...but still, it would be nice if there was a cheap way to get round this and avoid any board flexion.Doing the screws up alternately and bit by bit solves it, but you cant expect production staff to be so careful and painstaking like that

author: ogden
author_rank: Super Contributor
timestamp: August 19, 2018, 05:22:12 pm
content: Quote from: treez on August 19, 2018, 04:55:30 pmTorque limiting screwdrivers/wrenches is a must in factory where overtightening by staff can cause fault. This is in addition to properly designed PCB layout that does not put mechanical stress on sensitive SMD components.
Experiences soldering with low-temp SnBi paste? - Page 1
Forum section: electronics / general

author: magpie_lark
author_rank: Newbie
timestamp: August 18, 2018, 04:00:24 am
content: Hi folks! What experience do folks have using low-temp lead-free paste? Anyone have good advice for going down this road? Bonus points for reflow on FR-1 boards!!I'm doing some hobby boards using low-temp lead-free paste on milled FR-1 circuit boards. My goal is to reflow some neopixels and assorted components on a small panel of boards (maybe 30 x 55 mm, each board is about 5 x 55 mm). I'm going to start with just a stock toaster oven and hand-dispensed paste, but I'll eventually fit a DIY reflow controller into the oven, and I'll make some stencils once that shim stock comes in.My rationale is that low-temp lead-free paste will let me reflow on FR-1 without delaminating or otherwise cooking the board. I did a quick test with a small board, some paste and no components on a pre-heated 12 mm thick aluminum block. The board didn't burn or delam, and the solder flowed beautifully, so I'm hopeful. Advice, cheap equipment recommendations, and numbers would be awesome.Main questions:1. After reflowing and cooling, can I solder with standard lead-free on the other side without melting joints on the side I reflowed with low-temp? For this one board, I'd be reflowing neopixels and 0402 caps, then soldering an ATTiny85 directly on the other side.2. Anyone know an easy way to make it so I can get a temperature reading on an aluminum block with an IR thermometer? I'm trying out placing the board on a preheated aluminum block in the oven in the hope that I can heat it somewhat evenly, but the thing is too reflective in IR to get a reading.3. How do you deal with SnBi paste's tendency to run all over the place as it heats up?4. Will smaller joints (under 0402 passives) oxidize or otherwise go screwy in the time it takes to flow larger joints (under neopixels, inductors, regulators, etc)?(Before anyone says it, Yes, I know I can go the JLC route and have nice things like FR-4, masks, pro stencils and whatnot, but I'm more in it for fun than ease.)
Automatic Solder Joint Validation - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: August 14, 2018, 02:20:33 pm
content: It's a thing now apparently:http://info.okinternational.com/metcal-connection-validationSounds just like having some bastard standing over your shoulder watching you solder and nagging on each joint

author: Neilm
author_rank: Super Contributor
timestamp: August 14, 2018, 06:48:16 pm
content: Given how bad some solder joints I have seen are - good.I got called to production where the manager was telling me the transformer primary (wire about 12 A.W.G)would not solder to the power plane on the PCB. Turned out they were using the smallest bit on the iron they had - cos that was what was fitted when the operator picked up the iron. Neither she nor her manager had spotted this. Put in the largest bit and it soldered with no problem. I hate to think how many of those have gone out with poor / dry joints.

author: floobydust
author_rank: Super Contributor
timestamp: August 14, 2018, 08:12:05 pm
content: Same idea in the welding industry. Measure current and voltage, integrate and you'll know how much heat energy was in the weld. This was for an automated butt-joint welder.This wouldn't know the amount of solder, flux adhesion etc. it only can guess the thermal mass of the connection.It will only prevent factory workers who are too quick and do not use enough heat, which we all see in stuff from china where through-hole parts are barely soldered in.

author: thm_w
author_rank: Super Contributor
timestamp: August 14, 2018, 08:16:26 pm
content: https://www.eevblog.com/forum/reviews/new-metcal-cv-5210-the-iron-tells-you-when-the-connection-is-good/
EasyEDA Auto router  - Page 1
Forum section: electronics / general

author: bopstar
author_rank: Regular Contributor
timestamp: August 14, 2018, 06:39:22 am
content: I have been using EasyEDA for some time for making PC boards and have found it a blast to design boards. I have used Eagle and found it takes longer but has heaps of features. most of the time I route my boards myself by hand but i decided to use the auto router in EasyEDA and found it was AMAZING. I don't know if this is just my experience and would like to know what other people think about EasyEDA as a tool and its router.
Cheap 4G x16 DDR3L chips are in stock at Arrow - Page 1
Forum section: electronics / general

author: asmi
author_rank: Super Contributor
timestamp: August 13, 2018, 05:15:03 pm
content: https://www.arrow.com/en/products/mt41k256m16tw-107p/micron-technology$7.76 each for quantity of 1.I'm not affiliated with Arrow in any way, just saw these chips at a very good price and in stock, so I ordered some myself. I hope it will be helpful to somebody. If you want it - order now, as they will probably run out of stock really quickly. When I placed my order, there were 99 of them in stock, now only 71 is remaining.
Hi, i which to know 2 safety legislation applicable in this type of workplace ? - Page 1
Forum section: electronics / general

author: nyame
author_rank: Regular Contributor
timestamp: August 03, 2018, 12:41:37 pm
content: Mechanical work environment operations at the automotive manufacturing company such as jaguar identify 2 health and safety regulation that may apply to this type of working environment with key features for each of the two regulations.

author: Alesdoxc
author_rank: Newbie
timestamp: August 07, 2018, 04:55:26 am
content: Thanks for the advice from this valuable thread.
First experiments and fails with a laser-cut stencil - Page 1
Forum section: electronics / general

author: Warhawk
author_rank: Frequent Contributor
timestamp: August 03, 2018, 11:47:57 am
content: Hi Everyone,I've been always assembling my PCBs manually but now I deal with a design for friends which I need to duplicate multiple times. That's having said, I am dealing with a laser-cut stencil for the first time in my life. I don't expect that this is going to work without any practice but I would appreciate comments from somebody with more experience.I use ChipQuick SMD291AX50T3 solder paste and 0.12mm thick stencil from DirtyPCBs. I soldered the board with hot air set to 280°C.It seems to me that I have too much paste on the PCB.Do I apply too much pressure?Should I keep the paste cold (right out of the fridge)?Do I expect too much?Thanks for any tips.

author: ebclr
author_rank: Super Contributor
timestamp: August 03, 2018, 12:14:00 pm
content: Could you please a picture of a soldered one?

author: Warhawk
author_rank: Frequent Contributor
timestamp: August 03, 2018, 12:27:15 pm
content: The first picture shows PCBs after soldering. Or are you asking something else?

author: ebclr
author_rank: Super Contributor
timestamp: August 03, 2018, 12:45:24 pm
content: Sorry I mised

author: khs
author_rank: Regular Contributor
timestamp: August 03, 2018, 01:23:22 pm
content: Yes, it looks it was a little bit too much solder paste.Was there any pad size reduction?Additionally, it is important that there is no gap between the stencil and the pc board / your green pc board holder.You may take a look atAs you can see, the stencil lies flat on the board AND the board holder without any mechanical stress.If you modify your setup similar to the stencil printer shown in the video, you may get better results.

author: jmelson
author_rank: Super Contributor
timestamp: August 03, 2018, 07:04:51 pm
content: It looks like you are applying WAY too much solder paste. I use .003" thick stencils and reduce the apertures to about 60% area of the pads for ordinary parts like those, and even more reduction for fine-pitch parts. That has worked well for me. Your parts are floating on LAKES of molten solder during reflow.Jon

author: khs
author_rank: Regular Contributor
timestamp: August 03, 2018, 09:01:10 pm
content: Just for completeness:The stencil used for the video:- Thickness: 120 µm- Pad Reduction 10%(As you can see at the end of the video the pad reduction for the 0805 pads is uniform and for the 0.5 mm pitch pins is not uniform.)BTW. My first reflow soldering was a disaster. The parts swam around and it took more time for reworking as hand soldering.It took some time to optimize the stencil printing - and maybe more important - to find out the optimal pad size.So for a first reflow soldering your work looks not bad.
Identify Round Pin 2.54 72 (36x2) way header - Page 1
Forum section: electronics / general

author: Clint
author_rank: Regular Contributor
timestamp: August 01, 2018, 06:13:45 pm
content: I am strugling to find a part number for these headers, they are 2.54 pitch BUT round pin and the bottom pin has a shoulder.Anyone recognise them ?

author: Nusa
author_rank: Super Contributor
timestamp: August 01, 2018, 07:10:51 pm
content: Something like this?https://www.aliexpress.com/item/500pcs-2x40P-dual-Row-80-Pin-2-54mm-Round-Male-Machined-Pin-Header-gold-plated-through/32740302314.html

author: olkipukki
author_rank: Frequent Contributor
timestamp: August 01, 2018, 11:32:26 pm
content: What about Samtec strips?https://www.samtec.com/connectors/standard-board-to-board/screw-machine/strips
VARIAC & EARTHING - Page 1
Forum section: electronics / general

author: Nikos A.
author_rank: Regular Contributor
timestamp: August 10, 2018, 11:03:26 am
content: Dear all,I have got a Variac (Auto Transformer) rating at 1000VA. Before I start using of this, I am concerning regarding the groundAs you can see from the pictures attached the Variac has 2 prong (Line and Neutral) for input and output.There isn't any grounding point not even on the chassis.Should I earth the chassis during the installation process? There is any malfunction that earthing could cause on the Variac?I really appreciate any help you can provideNick

author: HighVoltage
author_rank: Super Contributor
timestamp: August 10, 2018, 11:17:03 am
content: Welcome to the forumThis was discussed before here on the forum:https://www.eevblog.com/forum/testgear/variac-with-ungrounded-chassis/
JDL Taiwan new guy here - Page 1
Forum section: electronics / general

author: JDL Taiwan
author_rank: Newbie
timestamp: July 22, 2018, 10:08:49 am
content: Hello everybody, I'm looking forward to a friendly cooperation.I was born in Germany, but have been living in Taiwan for 20 years.For 40 years I've been working on electronics, mostly measuring devices Grundig, and Rohde / Schwarz. Here is a picture of my hobby room.Now I have a Tek 475 and some Questions.

author: flasonsmts
author_rank: Contributor
timestamp: July 22, 2018, 10:36:39 am
content: Welcome , If you need any help , please post here.

author: ar__systems
author_rank: Frequent Contributor
timestamp: July 23, 2018, 04:25:41 am
content: Wow, you really need that much stuff? I'm counting like 7 scopes. What exactly are doing?

author: tautech
author_rank: Super Contributor
timestamp: July 23, 2018, 08:20:05 am
content: Welcome aboard.Post that lab pic here:https://www.eevblog.com/forum/chat/whats-your-work-benchlab-look-like-post-some-pictures-of-your-lab/For general questions on your Tek 475 ask here:https://www.eevblog.com/forum/testgear/For repair advice, here:https://www.eevblog.com/forum/repair/

author: JDL Taiwan
author_rank: Newbie
timestamp: July 23, 2018, 09:52:12 am
content: Wow you are good, but there only 6 Scopes. 1 is av Vector Monitor Pal / NTSC and 1 is a Measurement fo CB Broadcasting.Exactly I am A Service engineer for Piller UPS Systems.Or privately:I collect Measurements Grundig and Rohde & Schwarz and try to repair, I restore old tube radios and build new tube hybrid amplifiers.and sorry, my english is not so perfectly

author: Ice-Tea
author_rank: Super Contributor
timestamp: July 23, 2018, 10:26:15 am
content: It's good enoughWelcome!
Assembling smd and busbars - Page 1
Forum section: electronics / general

author: jram
author_rank: Contributor
timestamp: July 30, 2018, 09:38:43 am
content: I'm laying out a board with parallel D2PAK mosfets that require a healthy current (75A) each. Clearly I'll need to solder copper busbars to the board and have specified 5mm x 13mm for the purpose. However, I'm looking for assembly advice.The thermal mass of the busbars mean that I'll have to use an oven to solder them to the board but I'm concerned that the time to heat the busbars up may damage other components. Any thoughts please?

author: Kjelt
author_rank: Super Contributor
timestamp: July 30, 2018, 09:44:53 am
content: Just a thought:If they are only on one side perhaps you can assemble/weld/hardsolder them as a first step prior to smd components reflowing.Take a look at Frank (tatus1969) welder topic, he used post assembly with bolts but that was for 100's of Amps.https://www.eevblog.com/forum/projects/guesses-on-what-i-am-attempting-here/msg1270924/#msg1270924

author: jram
author_rank: Contributor
timestamp: July 30, 2018, 06:59:13 pm
content: Kjelt,A very good thought indeed!I need mechanical fastening anyway for the attachment of the battery power and heat sinking. It would certainly simplify matters. Thank you.I'm wondering what weight copper he had on his board? Perhaps with the proximity of the high-current parts, it may not matter too much. That said, my busbar design current is 300A (over 5 mosfets) so warrants careful consideraton.
tektronic 475  - Page 1
Forum section: electronics / general

author: JDL Taiwan
author_rank: Newbie
timestamp: July 22, 2018, 12:50:18 pm
content: Hello Evert Body,So I bought a Tektronix 475, actually it should be a gift for my friend.So it's a 475 with a DM43. Has also arrived but when switching on the first surprise came the beam, stuck at the top. With the circuit schematic I could find the vertical output IC U470 as defective.I found one IC in UK and its arrived too. Now the function is there, but all switches and pots are dirty and scratching. When measuring I noticed that my rectangle looks stringed after the input attenuator.Picture 001 shows attenuator at 5mV at 1KHz at output from attenuator andPicture 002 shows attenuator at 20mV at 1KHz at output from attenuator.But it is the same on both channels. But if I may say so, it crashes in the switches and Potis.Now to my question, I have read that one cleans the switches with IPA and a piece of paper. It makes sense to me, but how is it with the potis? I have not found anything yet.And then another things in the old radios I do, I change the Elkos is this also necessary?Thanks for your helpJohn D.LehmannTaiwan (Zhubei)
Yet another solder station question - Page 1
Forum section: electronics / general

author: rhb
author_rank: Super Contributor
timestamp: July 18, 2018, 11:07:10 pm
content: I've spent the last couple of hours reading various threads and doing searches. The results are clear as mud. I'm space constrained, so total footprint matters.I want:regular ironhot airvacuum pickuppower vacuum desoldertweezer tip ? (not so sure about this as vacuum pickup and hot air might work better)The Aoyue 2703A seems to fill the bill for a reasonable price as does the Aoyue 968A with a separate desoldering gun. I've not found anything else to match the 2703A, though I'm not considering Hakko, so they might have one, but at too stiff a price for my needs.Are there others I should look at? $300-400 is about as high as I want to go for all the above.Do the reciprocating pump desoldering guns work satisfactorily, I've got machine tools so I can build a desoldering tool with serious suction into a large chamber.

author: flasonsmts
author_rank: Contributor
timestamp: July 20, 2018, 09:24:08 am
content: hope the following can be helpful for you.one you need a SMT vacuum pen to pick components,can find by ebay:https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=suck+pen&_sacat=0second a hot air soldering station:https://www.ebay.com/itm/700w-Hot-Air-Gun-858d-220v-Esd-Soldering-Station-Welding-Hot-Air-Gun-Digital/273358192995?hash=item3fa56b0163%3Ag%3ABNcAAOSwZb5bS~ER&_sacat=0&_nkw=hot+air+soldering+station&_from=R40&rt=nc&LH_TitleDesc=0
Embeddedable thermal printer and QR reader module manufactorer  - Page 1
Forum section: electronics / general

author: dizgah
author_rank: Regular Contributor
timestamp: July 02, 2018, 04:05:30 am
content: HiWe are intended to use a internal thermal printer and qr reader ,embedded in our device. then do you have any recommended for most famous manufacturer of these modules?(with background in Payment/ POS devices)With best regards.

author: tooki
author_rank: Super Contributor
timestamp: July 13, 2018, 12:38:16 pm
content: Off the top of my head, both Epson and Star Micronics make thermal printer mechanisms. Entering “thermal printer mechanisms” into google (it’s an amazing tool, you should try it sometime) brought up Fujitsu and Citizen, too. All four are renowned manufacturers.I bet google can find you a bar code reader too. (Metrologic and Symbol come to mind...)

author: Gribo
author_rank: Frequent Contributor
timestamp: July 13, 2018, 02:56:59 pm
content: Symbol is now part of Zebra, which also make label printers.

author: tooki
author_rank: Super Contributor
timestamp: July 13, 2018, 03:20:54 pm
content: I’m well familiar with Zebra’s label printers, but didn’t realize they’d bought Symbol from Motorola!If Zebra made printers for paper, they’d be easy to recommend. But AFAIK they’re label only, and I assume the OP needs a receipt printer, since it’s for point of sale. The vendors I mentioned are more specialized in that.
Getting lots of small PCBs made - Page 1
Forum section: electronics / general

author: bd139
author_rank: Super Contributor
timestamp: May 17, 2018, 07:40:31 am
content: I’ve got a design I’m working on that has two different small PCBs (both 60x14mm). I need to get 100 each of these made to start with. More later if the idea works. No population required. PCBs are bog standard 2 layer 1.6mm FR4 double sided. Rectangular and no fancy cuts or anything.How should I go about organising this for production and cost efficiency? Panelising or doing that myself for example and ordering one large board with them all on?

author: Rerouter
author_rank: Super Contributor
timestamp: May 17, 2018, 08:00:46 am
content: use a few quotation tools, most of the cheap fabs rely on your designs not being panelised to keep costs downallpcb was who i used for 25x 15x300mm unpopulated boards and it came out at ~$22 AUD from memory,so based on area, I would imagine your boards to come out in the same ballpark.

author: bd139
author_rank: Super Contributor
timestamp: May 17, 2018, 08:08:50 am
content: Thanks - will look into that. Much appreciated.

author: hayatepilot
author_rank: Frequent Contributor
timestamp: May 17, 2018, 08:15:10 am
content: https://pcbshopper.com/This site compares a lot of PCB manufacturers all at once. Very handy and it saves a lot of time.Greetings

author: bd139
author_rank: Super Contributor
timestamp: May 17, 2018, 08:20:35 am
content: Thanks for the links.I'd budgeted £0.40 a board so far and they're coming up at £0.08 which is cool. £64 in my pocketEdit: last time I did any bulk stuff was around 1999 and that was EXPENSIVE. Think we were paying £7 a board in the UK then for something 2x4 inches.

author: AgileE
author_rank: Contributor
timestamp: July 20, 2018, 08:15:32 am
content: If you want automated assembly, you will most likely need to panalise the boards as most machines can't handle PCBs that small. I know mine has a Min. of 50mmx50mm (although did manage some a little smaller when I tried).

author: bd139
author_rank: Super Contributor
timestamp: July 20, 2018, 08:21:12 am
content: Thanks for the heads up on that. This first run is going to be packed as kits so non issue there. I’ve done prototype run on this but screwed something up so need to turn around another set.

author: tautech
author_rank: Super Contributor
timestamp: July 20, 2018, 08:37:50 am
content: Quote from: bd139 on July 20, 2018, 08:21:12 amDefpom did a vid on some he's not long ordered:
Parts Shortages - Page 1
Forum section: electronics / general

author: katzohki
author_rank: Frequent Contributor
timestamp: July 09, 2018, 09:09:16 pm
content: anybody else getting this? Just me?Been running into shortages on Rs and Cs all over the place like crazy and now one of our major irreplaceable ICs. Something to do with AEQ-100 parts perhaps?

author: schmitt trigger
author_rank: Super Contributor
timestamp: July 09, 2018, 09:22:04 pm
content: Precisely this morning I had opened this thread:https://www.eevblog.com/forum/chat/smt-passive-worldwide-shortage/

author: Kean
author_rank: Unknown
timestamp: July 10, 2018, 04:47:35 am
content: Also see this threadhttps://www.eevblog.com/forum/manufacture/what-is-your-longest-lead-time-wait/

author: station240
author_rank: Unknown
timestamp: July 11, 2018, 03:39:12 am
content: The SMD resistors and capacitors I understand, those are common parts and the problems lie with raw material production and not just the factories making the parts.Also a bit of greed at work, parts for automotive and cell phone usage have greater profits, but the same source materials/processes.The IC shortages have me stumped though, almost got nailed by that myself. Micro is out of stock at the moment, however I found the stash of missing parts.Problem is I have 1 microprocessor, stuff up soldering it and it's 2 weeks min to get another.

author: noras
author_rank: Contributor
timestamp: July 11, 2018, 04:03:13 am
content: Yes, you will find that the components have the appropriate adjustment markup, out of stock.