hybridfree/eevblog-posts huggingface dataset:
How to make a splitable pcb joint with signals for fabtests? - Page 1
Forum section: electronics / general

author: picatostas
author_rank: Newbie
timestamp: October 20, 2021, 08:03:59 am
content: I am not sure if I named it correctly but basically I need to split my pcb due to mechanical-space constrains. But I would like to leavethe signals through for factory testing. I would use mouse bites in a normal scenario if there where no tracks but I don't knowwhat arebest practices for doing it when you need tracks through.For the time being my approach has been placing vias across the desired breakline. The signals are Power, gnd and some enable signals.And routed the interconnected signals in the inner layer. I am using KiCAD, for reference.

author: Kasper
author_rank: Frequent Contributor
timestamp: October 23, 2021, 07:15:18 am
content: Yes you can route traces between mousebites. Dave shows it inEEVblog #552 - DFM Automated PCB Panel TestingI tried it once with cheap PCBs from JLC and it worked well.You probably don't want to route different nets on different layers ontop of eachother due to risk of shorting.I think another option is to route traces on internal layers and v-score the outer layers but I'm not really familiar with that.

author: Styno
author_rank: Regular Contributor
timestamp: October 26, 2021, 09:27:31 am
content: Quote from: Kasper on October 23, 2021, 07:15:18 amOn a generic 4-layer board there is a thick core and the inner copper layers are very close to the outer, just separated by thin prepreg. V-scoring would probably score the inner copper layers as well.

author: Gribo
author_rank: Frequent Contributor
timestamp: October 26, 2021, 11:41:45 am
content: Don't use normal plated vias, use non-plated drill holes (obviously, don't drill the traces), you will get a cleaner break this way. Also, try to use traces either on top or bottom layer and not on the internal layers, as others said, you don't want internal shorts.
JLCPCB Part equivalent to VN5160STR-E - Page 1
Forum section: electronics / general

author: roboteux
author_rank: Contributor
timestamp: August 11, 2021, 02:31:30 pm
content: Hi,I would like to use the VN5160STR-E, on board soldered by JLCPB. But fortunately this part is out of stock. And it also out of stock in a lot of distributor, so I'm sure that it won"t come back in stock in JLCPCB.I'm trying to find something equivalent, but without any success.I'm looking for any high side switch that can handle 30V Vin.If anyone is better than me, to find elusive part in their catalog, that would be very helpful.https://yaqwsx.github.io/jlcparts/#/, I've used this site for my search but without any success.

author: DIYGUY Chris
author_rank: Contributor
timestamp: August 15, 2021, 10:14:58 pm
content: Since you are looking for the part elsewhere then I can assume that you have the ability to assemble it by yourself! if you are willing to do this then maybe you need to check the stocks of LCSC, the part is available out there :https://lcsc.com/product-detail/Power-Distribution-Switches_STMicroelectronics-VN5160STR-E_C155580.htmlLow stock quantity but you still can pre-order it anyway for whatever quantity you need.Maybe you can check with JLCPCB team by Emailing henry@jlcpcb.com he is in charge of assembly so if the part is already in LCSC stocks then it could be assembled by JLCPCBIf you don't have any open path out there then we can work together to find alternative to your part
How to insert/extract wire ends to /from connector - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: August 12, 2021, 11:48:47 am
content: Hi,Hello, we are using these connectors (below) for up to 32Arms wiring to go in them.Do you know the proper way to insert/extract ferrule ends from the terminals?At the moment i am jamming a screwdriver in the hole above the terminal port and pressing ruinously hard till the ferrule eventually releases.I must be doing this wrong?TLB008V-1000-03BEhttps://www.cuidevices.com/product/resource/tbl008v-1000.pdf

author: langwadt
author_rank: Super Contributor
timestamp: August 12, 2021, 12:39:38 pm
content: I assume they work like these,https://youtu.be/CZB0tsT5hNEwith the right size of screw driver and right technique they work just fine

author: jmelson
author_rank: Super Contributor
timestamp: August 13, 2021, 04:44:07 pm
content: Are these connectors designed for ferrules? I'm guessing, from the spring-cage design, they are desigend for stripped, stranded wire, WITHOUT ferrules!Jon

author: langwadt
author_rank: Super Contributor
timestamp: August 13, 2021, 04:52:30 pm
content: Quote from: jmelson on August 13, 2021, 04:44:07 pmthey are for for both solid and stranded wire, ferrules are not needed but neater
RayPCB review please? - Page 1
Forum section: electronics / general

author: Nrkb
author_rank: Contributor
timestamp: September 09, 2021, 04:49:39 am
content: Hello, i posted on this forum a few days ago looking for a pcb manufactuer for my project, now i just found ray pcb and they seem better but i'm looking for some people that use Ray PCB to give their opinion about the quality of pcb made, i'm mainly interested in the visual appearance because i plan to use them as art, they don't have circuits in them, so no scratches at all, with smooth nice black matte soldermask using enig for the gold color.Anyone here using them and can tell if they are able to do this, visually very very close to perfect looking?They say to me by email that they will try their best and usualy is smooth soldermask but i can't seem to get a clear answer from them to guarantee it.I know pcb are not usualy made to be visualy perfect, functionnal is important usualy, i get that, but in my case i have so much advantages using pcb, it makes a lot of sense.Thanks!http://www.raypcb.com/
Need cheap CT for test jig - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: August 12, 2021, 11:39:44 am
content: Hi, I need to order a CT for a test jig so that it roughly measures mains current 16Arms, 50Hz. The voltage output of this should go into a mini meter display device so that it can be chassis mounted to the test jig so we can see the current thats being drawnThis is the only CT that i can find in stock in UK...but its £22 including P&P...do you knwo of any cheaper in stockk.....nothing seems to be in stock in farnell or anywhereCurrent transformer for 16Arms, 50Hzhttps://uk.farnell.com/acme-electric/ac-1020/current-sense-transformer/dp/1707839

author: Kean
author_rank: Unknown
timestamp: August 12, 2021, 12:18:03 pm
content: OMG, you are working on a commercial project and you waste the time of engineers worldwide to save a few bucks on a one-off test jig?Based on the OPs recent posting history, I think everyone should refuse to answer this on principle. (Maybe I'm just in a grumpy mood)

author: geggi1
author_rank: Frequent Contributor
timestamp: August 12, 2021, 12:37:59 pm
content: If time is not important get one from Ebay or Alibaba.Normally a current transformer is not a amperage to voltage transformer. To get that you would have to use a converter cuircuit, but you can get away with a carefully calculated resistor and a high ohm voltmeter.Another way to get around the whole test jig is to buy a current clamp meter and just modify it to run of a DC power supply. You might have to find a way to get around the power time-out on the unit.Look at the information about UNI-T UT210E its hackable to remove the auto power of.https://goughlui.com/2020/06/05/project-testing-uni-t-ut210e-clamp-meter-eeprom-hacks/https://thearduinoshed.wordpress.com/2020/04/13/uni-t-ut210e-current-clamp-hacking/
Jak Electronics? - Page 1
Forum section: electronics / general

author: cburgess
author_rank: Contributor
timestamp: July 14, 2021, 04:19:33 pm
content: I'm guessing a lot of folks are in the same position we are - having to cast the net outside of Europe and the USA for components that used to be ex-stock everywhere last year, and are now on silly lead times.We've managed to locate stock of one IC we need with Jak Electronics in Hong KongAny one here had a good or bad experience with this outfit?~ Carl

author: johnboxall
author_rank: Unknown
timestamp: July 21, 2021, 01:30:29 am
content: They're just a trading platform/sourcing agent with a nice website, they don't hold any stock. No warranty whatsoever. Domiciled in a serviced office complex up in Mong Kok.

author: blundar
author_rank: Contributor
timestamp: August 12, 2021, 02:52:09 am
content: Broker or not, I've had good luck with them.I've bought several thousand CSTCE oscillators and several thousand infineon H bridges. Good communication and service. Definitely not on my preferred vendor list but they seem to be a semi-reliable way to tap the Shenzhen supply markets from the web.

author: Clif
author_rank: Newbie
timestamp: August 12, 2021, 11:20:40 am
content: I guess the location is Huaqiangbei
CHMT48VB vacuum pump not working - Page 1
Forum section: electronics / general

author: kraftdinners
author_rank: Newbie
timestamp: August 09, 2021, 07:32:21 pm
content: My CHMT48VB's vacuum pump is not working. It's not a blockage as its effecting both nozzles. The pump itself seems to not be running. charmhigh have not been very helpful, has anyone had any experience with this?

author: james_s
author_rank: Super Contributor
timestamp: August 09, 2021, 07:39:15 pm
content: What is a CHMT48VB? What does "not working" mean? Is the motor not running? Is it running but no pumping is taking place?

author: lutkeveld
author_rank: Regular Contributor
timestamp: August 10, 2021, 11:35:22 am
content: Is it not making noise at all or just not working correctly? I had a problem with my zb3245t where the air filter in the reel holder bay was blocking the pressure. I do not know where the pump is located in your machine but otherwise you can test it by temporarily bypassing it (attaching the pump directly to the pick and place).
Chip on board manufacturer recommendations - Page 1
Forum section: electronics / general

author: mattbrockuk
author_rank: Contributor
timestamp: August 04, 2021, 07:54:38 am
content: HiWe've got a high volume product and we are looking for a good pcb assembly house (far east) that can handle chip on board - has anyone used someone in the past they can recommend?A western based (ideal UK) low volume assembly house for future prototypes would also be good if anyone has any prior experience?Many thanks in advanceMatt

author: mon2
author_rank: Frequent Contributor
timestamp: August 07, 2021, 05:29:10 pm
content: Try the following PCB / PCBA shop whom we have used for a number of projects with excellent results for bare PCBs and PCBAs for key house accounts including medical. They build for some large OEMs and the quality has been close to perfect. Had only one issue with a PCB where the connector was slightly off on the through hole mount - nothing serious.We have not done COB but you can always ask them. I think they are more capable than most shops. Also consider them to do a few pieces of build for your validation of the prototypes.Just be very clear on your specs; share pictures (if applicable) and be patient on the dialog - otherwise this shop is very competitive with positive results.Quote
insulating pcbs from the back of a tft lcd  - Page 1
Forum section: electronics / general

author: franksterb92
author_rank: Contributor
timestamp: August 02, 2021, 06:10:03 am
content: hi sorry if there is a relevant topic but I'm building this project that has a tft lcd and i was wondering what i could use to insulate the back of the screen to prevent short circuits that's also anti static if u could leave a link that would be most apricated
Connector Question - Page 1
Forum section: electronics / general

author: DDCE88
author_rank: Newbie
timestamp: July 28, 2021, 07:57:55 pm
content: Who makes the battery contacts inside cordless drills.See attached image for reference.

author: thm_w
author_rank: Super Contributor
timestamp: July 28, 2021, 09:40:42 pm
content: Its going to be a custom stamped part:https://www.alibaba.com/product-detail/Customized-phosphor-bronze-electrical-stamping-metal_60747929574.htmlhttps://www.fourslide.com/fourslide-parts/battery-contacts.phpWhy do you need to know though?

author: Gribo
author_rank: Frequent Contributor
timestamp: July 30, 2021, 03:53:44 pm
content: This one looks like a custom job, but you can also check Wurth, AVX or Samtec - They have similar power connectors.
Official Semiconductor Distributor on Asia - Page 1
Forum section: electronics / general

author: GFTCTP
author_rank: Newbie
timestamp: July 22, 2021, 12:42:06 pm
content: Hello,Nowadays my company have been bought components on big distributors on America, as Digikey, Mouser, Future and etc, but because of pandemic of COVID-19 we are have been got problems to found some partnumbers.Have anyone a tip of big distributor on Asia? A unique requeriment that its need to be official distributor (to I going to have garantee of quality of them).Thank you,B.R.

author: MR
author_rank: Regular Contributor
timestamp: July 25, 2021, 12:14:28 am
content: There are many distributors in Asia, some of them only carry particular components.And you are right, if you buy from the grey market (overstock) you might get something unexpected for high volume production it's a risk.
Why so few convenient screened cables? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: July 20, 2021, 10:21:50 am
content: Hi,Why are there so few screened cables with the screen connection coming out as a convenient wire so it can be easily connected into a connector?We only want up to 1A or even signal level, but little exists offtheshelf

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 20, 2021, 10:33:52 am
content: Because they do..? -- What kind of screened cable are you looking at?Usually "screened" (as in, foil shield with "drain" wire) has a bare wire just for that.Any shielded (e.g. braid) cable will necessarily take more effort to do up.Tim

author: Jeroen3
author_rank: Super Contributor
timestamp: July 20, 2021, 10:45:37 am
content: Farnell has lots in stock, what do you need?

author: dmills
author_rank: Super Contributor
timestamp: July 22, 2021, 08:47:46 pm
content: Note that some foil shield with drain wire constructions can cause a disturbing amount of common mode to differential mode conversion simply because of the geometry.Also, usually the pig tail you wind up with in that sort of cable winds up acting as a way to radiate all sorts of hash inside your can (or to pick it up), braided screen cables with a 360 degree termination of the braid are generally far superior (But a pain in the arse to terminate).What the hell are you doing that a fucking power supply needs this sort of tweakery? I can generally get a pass with just a filtered IEC, and some modest filtering on all the signal lines to take the edge off the edge rate so to speak, my biggest pain point is generally HDMI IO and the 850mumble MHz clock harmonic), but there are ways to skin that.

author: Faringdon
author_rank: Super Contributor
timestamp: July 23, 2021, 04:36:07 am
content: QuoteThanks, i think i heard you saying that most of what you do is class I?....ie, inside a metal enclosure?

author: dmills
author_rank: Super Contributor
timestamp: July 23, 2021, 09:23:58 am
content: Yea, we don't touch class II, generally no point in industrial doings, and convincing yourself (And the test house) that **Everything** is really correct is a bit of a 'mare.

author: Neomys Sapiens
author_rank: Super Contributor
timestamp: July 23, 2021, 06:58:03 pm
content: There is actually a very simple solution to connect a wire to a cable screen. they are called SolderSleeve Shield Terminators.
Putting offline SMPS module into earthed metal enclosure - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: July 17, 2021, 10:48:36 pm
content: Hi,We have the "stood up" version of this 15W offline Flyback power module mounted on a PCB...(Page 6)https://www.mornsun-power.com/html/pdf/LS15-13B12SS.htmlWhats the easiest way to put a totally enclosing metal shield (enclosure) around it?(bearing in mind that the PCB copper cannot be used to shield the bottom side bit, as the isolation barrier is to be clear of copper.)

author: AJ3G
author_rank: Regular Contributor
timestamp: July 22, 2021, 12:44:20 pm
content: Faringdon:I have used small Hammond Die cast boxes for applications like this. It looks like there are some mounting holes (at least on the picture to the left), on the PCB. You could stand it off in the center of the box and then drill through the die cast aluminum to place the interfaces to the outside world.Rich
Common mode choke with no polarity? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: July 20, 2021, 09:27:36 am
content: Hi, this ACM4520 common mode choke says "no polarity" at the schem symbol.https://product.tdk.com/system/files/dam/doc/product/emc/emc/cmf_cmc/catalog/cmf_commercial_power_acm4520_en.pdfdo you know what they mean by this. We wish to see a symbol with the usual two dots.

author: Bassman59
author_rank: Super Contributor
timestamp: July 20, 2021, 07:07:21 pm
content: Quote from: Faringdon on July 20, 2021, 09:27:36 amWhen used in the circuit as a choke, it doesn't matter whether your input is on pins 1 and 2, or on pins 3 and 4. This means, for example, when you install the part on the board, it can be rotated 180 degrees or not rotated, and it performs exactly the same.Draw a simple schematic that shows how a choke is used and it should be clear.

author: Faringdon
author_rank: Super Contributor
timestamp: July 20, 2021, 07:34:47 pm
content: Thanks, i guess i was just being paranoid, i just was worrying that they may not be meaning people to connect them in the "obvious" way...i still like to see the dots either way.Quite a few CM chokes do have the dots.

author: Bassman59
author_rank: Super Contributor
timestamp: July 21, 2021, 09:19:10 pm
content: Quote from: Faringdon on July 20, 2021, 07:34:47 pmWhat do the dots indicate?

author: Faringdon
author_rank: Super Contributor
timestamp: July 22, 2021, 04:33:43 am
content: when dot is positive on one coil, then dot is also positive on the other coil

author: Gyro
author_rank: Super Contributor
timestamp: July 22, 2021, 09:37:47 am
content: The dots are irrelevant. A CM choke will have it's winding directions correct at manufacture for the two winding anyway.The only important thing is that the footprint pin spacing doesn't allow it to be accidentally fitted at 90', this shorting the input. A 180' rotation makes no difference. I've never seen one that could be fitted wrongly.
Minimum Solder Dam and Part Assembly - Page 1
Forum section: electronics / general

author: SteamingGizmo
author_rank: Newbie
timestamp: July 20, 2021, 09:37:17 pm
content: I have the a PCB laid out with the ADS1115 ADC from Texas instruments.For this PCB I used the 10 pin "RUG" package.Following TI's recommended layout , the solder mask opening are set to only 0.05mm.However this results in a thin solder dam of only 83 microns between the vertical and horizontal pins.This is smaller then the Board houses minimum of 100 microns.Removal of the mask in this area has been highly recommended against by the assembler due to risk of shorts.I am not sure what is typically done in situations like this.Decreasing the solder mask opening is probably not the best option, as being at only 50 microns, its liable for registration issues.Those of you with more experience, how is this typically handled?I was thinking of decreasing the width of the vertical pads by 50 microns as this would allow for a 100 micron solder dam.Or maybe decreasing both the vertical pad width and horizontal pad length?I have typically only used manufacturer recommended layouts, so a change like this is new to me.I am not sure what effects this would have on the reflow of the chip.Would this be an instance where SMD pads would be used, despite their drawbacks?

author: kylehunter
author_rank: Regular Contributor
timestamp: July 20, 2021, 09:50:02 pm
content: Quote from: SteamingGizmo on July 20, 2021, 09:37:17 pmUhm, your assembly house shouldn't be relying on mask to prevent shorts.. Without going into too much depth with your specifics, I would typically follow the datasheet, and if the fab can't handle that dam (100 micron min seems normal), just live without solder mask.

author: ANTALIFE
author_rank: Frequent Contributor
timestamp: July 20, 2021, 11:58:22 pm
content: Like kylehunter said, 0.1mm seems to be reasonable for most PCB fab houses. The other question is, why can't you use the bigger VSSOP package for ADS1115?

author: Cerebus
author_rank: Super Contributor
timestamp: July 21, 2021, 01:03:36 am
content: There is a Texas' Application Report "Quad Flatpack No-Lead Logic Packages" document number scba017d. It details all Texas' recommendations for footprints for a similar range pf packages. It's a bit hard going. I know, because I had to slog though it the other day to figure out a footprint for a very similar, but not identical, package from TI (an MO-241 which uses the same basic geometry but has a centre pad). Given that document exists then I'm sure they have one specific to the MO-288 package you're looking at. But even if they don't the guidance in that document is useful for finding where you can shrink or stretch pads.The reason I mention it is that looking at your footprint it looks a little 'fat' in places compared to what I ended up with from following Texas' recommendations and you might get yourself a bit more wiggle room to work with by carefully following what Texas have to say. Then again, you might not.
Hot air gun to solder micro crystal? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: July 19, 2021, 04:09:24 pm
content: Hi,Is it acceptable to solder this micro crystal on with a hot air gun?https://www.microcrystal.com/fileadmin/Media/Products/RTC/Datasheet/RV-3028-C7.pdf

author: thm_w
author_rank: Super Contributor
timestamp: July 19, 2021, 09:13:26 pm
content: Yes, if by hot air gun you mean hot air station with temperature control.From the datasheet:Quote
Standard ubiquitous footprint for common mode choke? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: July 14, 2021, 07:11:39 am
content: Hi,We need a ~1.5ASMD common mode choke for a 12V power rail.This one does the job....but if it goes obselete/nil-sock, we've had it...https://product.tdk.com/en/system/files?file=dam/doc/product/emc/emc/cmf_cmc/catalog/cmf_commercial_power_acp3225_en.pdf...is there a particular range of these which has a standard, common, ubiquitous , ~1.5A, SMD footprint so we can replace if necessary, without a board respin?Is there a standard footprint for these type of SMD common mode chokes....or does every manufacturer have their own custom one?..it seems like it

author: awallin
author_rank: Frequent Contributor
timestamp: July 14, 2021, 09:13:13 am
content: I used a TDK ZJYS-series part which also went obsolete, replaced with Bourns SRF 0905 serieshttps://www.bourns.com/docs/Product-Datasheets/SRF0905.pdfthere's probably no universal footprint for cm-chokes..

author: SMTech
author_rank: Frequent Contributor
timestamp: July 14, 2021, 11:09:34 am
content: There seems to be an endless number of footprints for chokes and inductors. I have seen a few clients create a footprint mashup of a few similar ones so they have the option to chop and change a bit if required, typically they have footprints that let you get away with that kind of thing.

author: Kean
author_rank: Unknown
timestamp: July 14, 2021, 04:40:15 pm
content: You'll find a bunch in very similar larger footprints like the 9x6mm Bourns one linked above, but at 3.2x2.5mm (1210) and that rating there doesn't seem to be much available apart from the TDK ACP3225.You don't mention the filtering specs you need, but Wurth have one that might suit in 4.5x3.2mm (1812).https://www.we-online.com/catalog/en/WE-CNSWMurata had some similar small ones but I recall they went NRND. Yeah, the DLW44 series - 4.0x4.0mm. Looks like some new ones are coming to replace them.So, I think the answer is no. If you have the space then try go for a larger part or place multiple alternative footprints. Or buy up big in advance.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 14, 2021, 09:29:42 pm
content: Or buy custom. Parts of that shape aren't too uncommon, good luck getting the attention of a big OEM like TDK or Murata of course but Coilcraft might do that.Unfortunately their closest standard part doesn't offer quite the current rating,https://www.coilcraft.com/getmedia/5619fb0a-2a49-4855-889a-768b243e7115/pfd3215_cm.pdfso you may have to see what they're capable of, or choose a different part.Looks like choosing a somewhat bigger part may be a good idea anyway, just for availability. The smaller size may be pushing capability, and thus costing more than a relaxed design would.Tim
OK to rest PCB on hot plate mesh? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: July 13, 2021, 07:24:53 am
content: Hi, supposing you want to heat a single sided PCB on this hot plate, is it ok to rest the pcb down on the metal mesh (instead of holding it above the mesh with those metal "arms"?https://www.pcb-soldering.co.uk/aoyue-863-infrared-preheater-with-variable-temperature-for-reworking-pcb-s

author: Psi
author_rank: Super Contributor
timestamp: July 13, 2021, 07:34:36 am
content: If it was me, and I owned one, I would give it a try.One risk is that you don't know how the heating element works, it might have hot spots on the plate and require that gap to even things out.But I guess you can turn the temp down until any hot spots are an acceptable temp.It's only a preheater, so isn't all that critical.You could mount your own metal mesh on top using those arms, then you can put your PCB anywhere on the new mesh.

author: pisoiu
author_rank: Regular Contributor
timestamp: July 13, 2021, 03:06:15 pm
content: This is how I reflow small batches of single side designs, usually with GC10 paste. PCB is directly on the mesh, but I make sure it is clean, to avoid sticking something on the other side.Above there is a sheet of borosilicate glass (from 3d printer), to keep heat inside, otherwise, convection currents will cool your board and keep it with uneven temperature.Playing with the heater control allows you to follow a good approximation of the soldering profile, it takes a little practice.

author: Faringdon
author_rank: Super Contributor
timestamp: July 13, 2021, 05:26:14 pm
content: Thanks, it looks indeed like the PCB can be rested on the mesh. And as kindly described, one can always put a sheet of aluminium on there and rest the PCB on that.
Looking for JST PH 2.0 crimp tool - Page 1
Forum section: electronics / general

author: KrudyZ
author_rank: Frequent Contributor
timestamp: July 10, 2021, 03:27:47 am
content: I bought a crimp tool For around $20 which was supposed to work for these common crimp pins, but makes a big mess of them.There is the official tool which is > $1k which I'm sure works a charm.What are you guys using and are you happy with the results?Links to where to buy and pictures of the resulting crimps would be awesome...Thanks,Rudy

author: thm_w
author_rank: Super Contributor
timestamp: July 12, 2021, 09:13:44 pm
content: I got the TZ-4228B which works well, mentioned in this thread:https://www.eevblog.com/forum/reviews/affordable-crimp-tools-for-small-connectors-(dupont-etc-)/
Soldering MSP with underside GND pad. - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: July 06, 2021, 04:21:37 pm
content: Hi,The LT3650-8.4 (12MSOP) has a centre GND pad (no GND on the pins).The centre GND pad has two thermal viasto bottom copper pour.(edit:..oops sorry, the two "thermal" vias in the centre gnd pad dont go to a bottom copper pour, they just open out into the FR4.Do you reckon we could solder it with hot air to the top-of-body and a hot plate to heat the under side simultaneously?https://www.analog.com/media/en/technical-documentation/data-sheets/36508284fd.pdf

author: thm_w
author_rank: Super Contributor
timestamp: July 06, 2021, 09:05:03 pm
content: Yes, or just hot air only on the top would work too. Or skillet method, bottom only.With a ton of thermal vias you have to look out for the solder getting wicked out, with just two its not that big of a deal.

author: m98
author_rank: Frequent Contributor
timestamp: July 06, 2021, 09:39:50 pm
content: Just ramping up a temperature controlled hot plate works excellently, no need for additional hot air.

author: ANTALIFE
author_rank: Frequent Contributor
timestamp: July 07, 2021, 12:50:36 am
content: When assembling at home I find that hotplate + hot air gun works bestWhat I do is place the board on the hotplate and bring it up to temperature so that flux evaporates (~200C for leaded solder), then I use the hot air gun (set at ~230C for leaded solder) to reflow the solderhttps://www.antalife.com/2018/10/project-hot-plate-mod.html

author: Siwastaja
author_rank: Super Contributor
timestamp: July 07, 2021, 05:01:15 pm
content: I also prefer the combination of hotplate + hot air but either one works alone as well. Hot plate focuses on heating the PCB, but the component heats up secondarily as well. With hot air from the top, it's the opposite, components tend to heat up first and getting the heat into the ground plane below the component takes longer but it will eventually do the job.For me, "hotplate" is more like a low-temperature (i.e., 140 degC) pre-heat so it can't alone cause any issues no matter the timing, even if the PCB sits on it half an hour, so after the whole PCB is clearly above some 110-120 degC I let the hot air to do the actual job, but it's much easier now thanks to the ground plane being already much closer to the melting point of solder.

author: SteveyG
author_rank: Unknown
timestamp: July 12, 2021, 09:36:26 am
content: The hotplate plus hot air gun is probably the most preferred method. The hotplate is also more likely to reduce the effects of thermal shock, something to be aware of if the package is likely to absorb moisture during storage.
JLCPCB now do Aluminium PCBs! - Page 1
Forum section: electronics / general

author: SteveyG
author_rank: Unknown
timestamp: June 30, 2021, 10:17:10 am
content: I just saw today JLCPCB are now offering low cost MCPCBs! I need to get a few orders in to compare against PCBWay, but this seems really good value.https://jlcpcb.com/cytSadly at the moment, no ENIG finish or higher thermal conductivity options but this makes high power PCBs a bit more accessible to hobbyists.

author: SteveyG
author_rank: Unknown
timestamp: June 30, 2021, 10:19:51 am
content: Looks like even a large PCB comes in at a reasonable price. Shipping obviously increases the cost significantly though

author: xavier60
author_rank: Super Contributor
timestamp: July 07, 2021, 02:34:47 am
content: To do any thermal calculation, the 1W/mK spec is meaningless without knowing the dielectric's thickness.Does anyone know?

author: xavier60
author_rank: Super Contributor
timestamp: July 07, 2021, 03:01:12 am
content: So far this is the only discussion that I have found that acknowledges the significance of the dielectric's thickness.https://forum.seeedstudio.com/t/aluminum-pcb-thermal-conductivity/5758/6

author: lordium
author_rank: Regular Contributor
timestamp: July 07, 2021, 03:52:01 am
content: Quick search gave some results. Run through your favorite translation program/plugin.https://order.jlc.com/portal/server_guide_27793.html

author: xavier60
author_rank: Super Contributor
timestamp: July 07, 2021, 08:28:45 am
content: From that order.jlc.com/ link." thermal insulation: is a layer of low thermal resistance thermal insulation material, thickness of 2-8mil"PCBway say 120um for their 2W/mK material. Who really knows?Next thing to deal with is how much heat spreading the copper contributes.

author: SteveyG
author_rank: Unknown
timestamp: July 10, 2021, 07:42:57 pm
content: This is apparently what they're using

author: SteveyG
author_rank: Unknown
timestamp: July 10, 2021, 07:47:00 pm
content: Dielectric material thickness is 100um for this PCB material
Are dead/stuck/laggy pixels common or acceptable on low resolution e-paper? - Page 1
Forum section: electronics / general

author: Bradlez
author_rank: Contributor
timestamp: July 08, 2021, 11:05:30 am
content: Hi. Recently I've ordered 3 low resolution 296x128 (~40,000 pixels) e-paper displays from China. Unfortunately every single one of them had faulty pixels whether it be specific pixels that lag behind or pixels that are just simply stuck. Is this generally normal or common? I have a 9 year old Kindle touch that has a much higher resolution display with no faulty pixels, so it doesn't seem reasonable for something at much lower resolution to have faulty pixels. I talked with the manufacturer and they said up to 5 faulty pixels are within spec (the QC does say that is the case). Any thoughts?

author: Gribo
author_rank: Frequent Contributor
timestamp: July 08, 2021, 12:51:38 pm
content: I had a product which used the Pervasive Displays 1.44" module. We never had stuck pixels, ~20,000 units.We never had an RMA with a display issue, over 10 years of the product's life time, and this was in a very harsh environment (45C ambient, physical abuse).
Chemtronic flux-off spray brush is ESD safe? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: July 07, 2021, 11:44:16 am
content: HiThis Chemtronix “Flux-off” spray has a brush on its nozzle….do you think its ESD non-generative to brush over components after spraying them with the “flux-off”?Chemtronix “Flux-off”http://www.farnell.com/datasheets/2692996.pdf

author: thm_w
author_rank: Super Contributor
timestamp: July 07, 2021, 09:14:13 pm
content: Visually it does look like it:https://tmelectronics.ru/product/CH-ES830BE/but they don't tell you.If you are working on something super sensitive to ESD I would get a proper esd safe brush and then add a wrist strap. For normal electronics that thing will be fine.

author: Faringdon
author_rank: Super Contributor
timestamp: July 08, 2021, 06:06:41 am
content: Thanks i just brushed over a 12MSOP pwm controller IC with it...i hope it will be OK
How to work the FT-02 Reflow oven? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: July 07, 2021, 11:43:25 am
content: Hi,Does anyone know how to set the FT-02 (by C.I.T) reflow oven?You have to setpre-wait timePre-heat timeReflow timeCooling time.You also have to set an aiming temperature for each of the above.But you only have three buttons (A,B,C) to play with, and the manual doesn’t seem to help much.FT-02 Reflow ovenhttp://www.farnell.com/datasheets/2157390.pdf

author: wraper
author_rank: Unknown
timestamp: July 07, 2021, 12:08:26 pm
content: The best you can do is get rid of it. It's a complete trash, worse than cheap Chinese ovens. No proper temperature increase curve control, no reasonable temperature uniformity. Unless all you want is reflowing small boards, parts of the PCB will be overheated while the rest barely above solder melting point. Also there is no consistency between the runs whatsoever.

author: wraper
author_rank: Unknown
timestamp: July 07, 2021, 12:16:09 pm
content: IIRC you just cycle between 4 parameters with one button and set final temp and time of 2 segments by 2 other buttons. The problem is that it reaches that temp in unspecified time which varies between the runs and stays there until the segment ends. Controller is incredibly dumb overall and not even electrically safe in older ovens.https://www.eevblog.com/forum/reviews/deadly-insane-design-(cif-ft-02-reflow-oven)-teardown-rant-safety-fix/
Tronstol MR30 min-reflow oven - Page 1
Forum section: electronics / general

author: Jemma.zhang
author_rank: Contributor
timestamp: July 01, 2021, 08:25:49 am
content: Small size:It has a small size which looks like a microwave.The size is 45CM×45CM×29CM.Easy to use:Just select the type of solder paste you use, press “RUN/STOP” button to working, no need for extra settings.Save you time:It only takes about 8 minutes to solder a PCB after preheating.Use the touch screen:Easy for you to change the parameters.High-quality soldering results:Greatly improve the yield of products.Industrialized appearance design and user-friendly UI design:This is really a good assistant for welding.You can check this video about Tronstol MR30:https://youtu.be/WLyG7sThj4c
Fastener - Page 1
Forum section: electronics / general

author: roboteux
author_rank: Contributor
timestamp: August 08, 2021, 06:15:30 pm
content: Hi, I'm trying to find a good way to fix 2 PCBs together on top of each other.Ideally I'm looking for a nut that I could solder on the bottom pcb. Then I could use a screw to fix the top pcb and the bottom one.Or an insert that could work with the a 1.6mm pcb.I wand my TOP and BOTTOM pcb to touch each other.Thanks for any help.

author: ataradov
author_rank: Super Contributor
timestamp: August 08, 2021, 06:33:29 pm
content: It sounds like you want PCB solderable threaded standoffs.Here is a thing to start your searchhttps://www.digikey.com/en/product-highlight/k/keystone/surface-mount-threaded-standoffsThere are quite a few options in length, diameter, thread type.As far as I know, there is nothing like this that would be flush with the PCB (1.6 mm tall), so there will be some part sticking on top of the PCB, but if you want PCBs to touch, you can mount one of the those things on the reverse of the PCB.

author: roboteux
author_rank: Contributor
timestamp: August 08, 2021, 07:28:58 pm
content: Thanks a lot guys.That's very helpful. I'll look into those links. But from a first glance, that's exactly what I was looking for.

author: roboteux
author_rank: Contributor
timestamp: August 11, 2021, 02:26:19 pm
content: Hi,so I've used the 153-SMTSO-M3-3EThttps://www.mouser.fr/ProductDetail/153-SMTSO-M3-3ETIt's small, easy to solder and quite strong. So perfect for what I wanted

author: tooki
author_rank: Super Contributor
timestamp: August 18, 2021, 04:48:17 pm
content: Excellent!I just wanted to add that for metric sizes, Würth also sells them.
Solder running on parts - Page 1
Forum section: electronics / general

author: Marsupilami
author_rank: Frequent Contributor
timestamp: June 25, 2021, 04:45:09 am
content: Hi Folks,Anybody could tell me what's the proper name of this phenomenon?Solder is running up and away on parts. What concerns me on this particular one is how it goes around the lip and gets inside the connector body.Is there a property of solder to look for regarding how viscous it is or something that's related to this? I can't seem to find any related info but I might be using incorrect terms.Another suspicion I have is that the solder might spend to much time above liquidus as I happened to notice it towards the end of the cycle. I obviously need to do my experiments but if there's some common knowledge I'd start tuning my parameters accordingly.Thanks!

author: ANTALIFE
author_rank: Frequent Contributor
timestamp: June 25, 2021, 06:02:40 am
content: surface tension + adhesive forces = capillary actionhttps://en.wikipedia.org/wiki/Capillary_actionEDIT:One quick experiment you could do is adjust the paste shape & volume. Like rather than having a big "square" blob of solder paste you could adjust the shape to be a 2 or 4 small squares. As for what solder chemistry to be considerate of, flux would probably be a key one. But I think easiest thing to do would be to contact some solder manufacturers (chipquick, kester, MG...) and see what they recommend, as I am sure they would have run into this "issue" before

author: AmnevaR
author_rank: Contributor
timestamp: June 25, 2021, 06:26:20 am
content: I had experience with such phenomenon when assembling some prototypes on my previous job. Adjusting solder paste shape and plug in those holes with high temperature silicone did a trick.

author: Marsupilami
author_rank: Frequent Contributor
timestamp: June 25, 2021, 04:36:55 pm
content: Quote from: ANTALIFE on June 25, 2021, 06:02:40 amI'll try a different paste. That's a easy experiment. The paste shape... I'm not sure, it seems to me that there's no abundance of solder there so if I remove it I starve the joint. I might try something though.

author: Marsupilami
author_rank: Frequent Contributor
timestamp: June 25, 2021, 04:38:30 pm
content: Quote from: AmnevaR on June 25, 2021, 06:26:20 amYeah the via plugging is ongoing but there are no vias on the right side where I'm concerned. I might mask off the stancil farther from the board edge.

author: Cerebus
author_rank: Super Contributor
timestamp: June 25, 2021, 09:14:34 pm
content: "Wicking" is the term I'd probably use.You can probably alleviate this problem by reducing the amount of solder paste on the pad. You might even want to consider/investigate modified solder mask shapes in the same vein as these:i.e. You might want to consider not putting paste onto the pads in areas where it's flowing away and around corners from.
Recommended SMPS transformer manufacturer - Page 1
Forum section: electronics / general

author: Dexter23
author_rank: Newbie
timestamp: June 22, 2021, 09:48:25 am
content: Hello fellow engineers,For my latest product i need a custom designed low voltage isolation SMPS transformer (50W) manufactured in low volume (<500 per year).Do any of you have suggestions for manufacturers in Europe that can also supply me with of few test samples to finalize prototype testing?With kind regards.

author: jonpaul
author_rank: Super Contributor
timestamp: June 25, 2021, 03:19:55 pm
content: Use a stock part, try Coilcraft, Halo, Pulse, and other catalog magnetics houses.MPQ for most custom magnetics is 1000...100KJon
Recommended GC10 compatible solder for rework? - Page 1
Forum section: electronics / general

author: deanclaxton
author_rank: Regular Contributor
timestamp: June 20, 2021, 10:52:30 pm
content: Hi all,I'm wondering what solder people are using to touch up/rework boards that were reflow soldered with Loctite GC10 paste. Something that still leaves a nice shiny joint when mixed with residual GC10.I guess I need to get some SAC305 solder, but I'd like to find some with a minumum cleanup requirement as far as the flux residue goes. Something brushable would be good. Any recommendations?
DEK Horizon 03i paste inspection - Page 1
Forum section: electronics / general

author: gecdra
author_rank: Newbie
timestamp: April 29, 2021, 11:50:15 am
content: Hi,I am wondering if anyone has had some experience with DEK Horizon 03i stencil printer.Particularly I am struggling with getting 2di paste inspection functioning. I cant load any files into the machine (GBX or BMP). Actually after I open the file, nothing happens. I have tried to do a pre image, but I get no reaction. Could this be a software issue?

author: Aleksei
author_rank: Newbie
timestamp: April 30, 2021, 08:10:56 am
content: Hi, we have 2 printers. First - 2014 year manufactured. Second - 2016 year manufactured.I cant load gerber files not one printers, too.I added inspections areas manually.

author: uzbek
author_rank: Contributor
timestamp: May 21, 2021, 11:12:58 am
content: Hi gecdra and Aleksei,sorry, gecdra for hijacking thread.@Aleksei what do you use for solvent and what underside stencil cleaning system is used on your DEK?Thank you!

author: Aleksei
author_rank: Newbie
timestamp: May 31, 2021, 12:01:10 pm
content: Quote from: uzbek on May 21, 2021, 11:12:58 amHi, uzbekwe useSurCleanwe clean underside stencil withclean paper
LTB: Low volume automatic PnP for 0201 and large BGAs - Page 1
Forum section: electronics / general

author: bleedinge
author_rank: Newbie
timestamp: February 09, 2021, 12:30:44 am
content: Hi All,I know this topic makes a comeback now and then but I'm now in a position where my company needs to speed up prototyping and external assembly is really slow (around 4 weeks for each project).We are looking around to get a machine that can place boards with a couple hundred 0201 components and large BGAs (29x29). I know the chinese machines are not the best, but second hand market is non-existent in my country and I don't think we can afford a first-class PnP machine.Our budget for PnP and oven is around 20K€. Do you think we can find something in that price range that won't make us pull our hair out?Thanks!

author: ArthurRobin
author_rank: Newbie
timestamp: May 28, 2021, 02:14:42 am
content: how about this onehttps://youtu.be/2uIyyweyqmMemail qhsmt@qq.com

author: 48X24X48X
author_rank: Frequent Contributor
timestamp: May 28, 2021, 05:28:07 am
content: Quote from: bleedinge on February 09, 2021, 12:30:44 amThe machine I'm using (HW-T4-50F from HWGC) can do 0201 using the electric feeder options and can do maximum IC size of 40x40mm. I did try the 0201 on a test board I made but have never had the need to do 0201 in production. So, I don't have the statistical number to say it's 100% all good for bigger batch of 0201 placement. But, from what I see from their customer videos, there are even daring customer of theirs using normal pneumatic feeder to do 0201. I don't think there's any issue of doing 29x29mm BGA reliably. Machine cost me USD6K++ for their smallest 50 feeder slot machine without feeders and they can scale up to other bigger machine of theirs like 6 head-64 feeder, or 8 head-80 feeder. There are also other similar companies of similar capable machine like Kayo and Boreytech. Look around and you will see many forumer actually owned these machines and happy with it.

author: Kjelt
author_rank: Super Contributor
timestamp: May 28, 2021, 06:22:01 am
content: For prototyping or production?The latter you need an x-ray (or service) in order to verify the reflow process for the bga packages.

author: 48X24X48X
author_rank: Frequent Contributor
timestamp: May 28, 2021, 08:06:42 am
content: Quote from: Kjelt on May 28, 2021, 06:22:01 amI was going to mention about this, else you will be doing it blindly. Sometimes, assuming it is 100% perfect by running the test might not be enough.Even the smaller factory in China, some don't have the x-ray machine.
Wave soldering machine - Page 1
Forum section: electronics / general

author: duckie
author_rank: Contributor
timestamp: May 27, 2021, 05:25:39 pm
content: We have made ourselves a pretty basic and cheap SMT line, consisting of:Manual stencil "machine" with fine-adjustment dialsCharmhigh CHMT560P4 P&PPuhuit T960 reflow ovenI know what you might be thinking, but besides some issues with cheap feeders on the P&P, it actually works pretty damn well, for a fraction of the cost. It has allowed us to scale pretty well, from getting everything assembled to doing everything ourselves. And yes, we make pretty simple boards with large components.Ok, so I guess I mention the above because we are of course looking for a wave soldering of the same "class" (or, lack thereof, heh). Desktop or not is not so important.The largest boards are 120 x 80mm.We do have a solder bath for dip-soldering, but the results are too dependent on the operator doing things right..What have you guys tried? I do not find many reviews of these machines anywhere.

author: Mangozac
author_rank: Frequent Contributor
timestamp: May 27, 2021, 10:07:14 pm
content: Probably overkill for what you're after, but we installed a Jaguar N250 earlier this year and are very happy with it:http://www.jaguar-ele.cn/te_product_b/2015-02-04/996.chtmlI've seen benchtop wave solder machines but honestly they would be super slow and you would still get far too much process variability introduced by the operator. If volume is that low I'd rather the solder joints be done by hand by an appropriately skilled person.

author: duckie
author_rank: Contributor
timestamp: May 28, 2021, 04:30:11 am
content: Yea I agree. Could you tell me the price you paid?

author: Mangozac
author_rank: Frequent Contributor
timestamp: May 28, 2021, 06:18:22 am
content: The machine itself was USD10k. Plus freight cost and 200kg of solder.