hybridfree/eevblog-posts huggingface dataset:
Sprint Layout, fiducials - Page 1
Forum section: electronics / general

author: SMdude
author_rank: Frequent Contributor
timestamp: October 24, 2020, 06:34:57 am
content: Hi everybody,I'm trying to help a friend out with board assembly.The design has been done in Sprint Layout. We have figured out how to panelise it, but creating a fiducial seems to be difficult. I am not using Sprint, I can't stand it!I really need a clear way to make a fiducial component in/for Sprint Layout.Could somebody who uses sprint please chime in, your help with this would be greatly appreciated.All I need is a 1mm round pad with a 0.5mm soldermask clearance around it. Preferably as a component so when it exports the pick and place file the location is correct.Thanks in advance.

author: nisma
author_rank: Regular Contributor
timestamp: October 25, 2020, 07:44:08 pm
content: Draw a reference mark on the copper layer, then switch to mask editing mode ("O" key) and remove the mask over the drawn circle. Next, when exporting Gerber files, you should set the gap for the solder mask to the required size (This will not affect the gap between the mask and the contacts, since such a gap is adjusted separately, but it will affect the gaps between other PCB elements that are forcedly open from the mask).Clearly you could use macros instead of boards in order to insert it as component.

author: SMdude
author_rank: Frequent Contributor
timestamp: October 27, 2020, 10:02:05 pm
content: Thanks! Will give that a try.
SurLok 0/1 guage crimper part number? - Page 1
Forum section: electronics / general

author: MarkMoses
author_rank: Newbie
timestamp: October 27, 2020, 06:33:18 pm
content: I'm having a heck of a time trying to find the crimper for these parts: SLPIPB50BNR2 & SLPIRBBPNR2Digi-Key Part Number - 965-SLPIRBBPNR2-NDManufacturer - Amphenol Industrial OperationsManufacturer Product Number - SLPIRBBPNR2This is for 1/0awg or 50mm2 wireI have some crimpers that are about the right size, but they are obviously not right when they crimp the part.I have some e-mails out but I'm not getting much from the manufacurer.Thanks in advance,Mark

author: Monkeh
author_rank: Super Contributor
timestamp: October 27, 2020, 06:54:22 pm
content: A little searching suggests the right tool for that is the TE0500 crimper + TE0500-011 die.Bend over:https://www.digikey.com/en/products/detail/amphenol-sine-systems-corp/TE0500/3918470https://www.digikey.com/en/products/detail/amphenol-sine-systems-corp/TE0500-011/3918163Obviously I'd get someone to confirm that's correct before splashing that sort of money on my guesswork..
Custom plug power supplies - Page 1
Forum section: electronics / general

author: artag
author_rank: Super Contributor
timestamp: October 26, 2020, 04:12:20 pm
content: I'm looking for a manufacturer of reasonable quality wallplug power supplies.I need some options not often available in the very generic suppliers : notably white plastic casing and 3.5mm barrel jack output. The electrical spec is pretty generic but I probably need a semi-custom manufacturer to get the aesthetics right.Can anyone recommend a manufacturer ? I need at least a UK connector so probably a UK or Chinese manufacturer willing to ship pilot-run quantities (eg 50, 100).

author: fcb
author_rank: Super Contributor
timestamp: October 26, 2020, 06:03:38 pm
content: Friwo stuff is very well made and they are approchable but expensive.For the volumes you are looking at, I would defo repaint a suitable supply and fit your own connector.

author: Monkeh
author_rank: Super Contributor
timestamp: October 26, 2020, 06:20:06 pm
content: Maybe speak to these guys:https://www.ttelectronics.comThey make about half what places like CPC sell, they might be willing to get a different bag of pellets dumped in the hopper. The connector shouldn't be an issue.

author: ANTALIFE
author_rank: Frequent Contributor
timestamp: October 27, 2020, 01:45:22 am
content: I made a list of medical grade PSU suppliers a while back, might be a good starting point:https://www.eevblog.com/forum/projects/list-of-medical-grade-power-supply-manufacturers/msg2928316/
Where to get small amounts of 'high tack' pressure sensitive adhesive? - Page 1
Forum section: electronics / general

author: e100
author_rank: Frequent Contributor
timestamp: October 22, 2020, 01:31:47 pm
content: I think this is the stuff they use for sticking things like solar panels to the tops of polyethylene garden lights to give a flexible watertight seal. It might also be similar to what they use for making the sticky side of sticky tape.It seems that to buy this stuff you need to know exactly what you are looking for, and I don't. Easily understandable information for those who work outside the adhesives industry doesn't seem to exist.

author: jfiresto
author_rank: Frequent Contributor
timestamp: October 22, 2020, 05:08:48 pm
content: Polyethelene? I find PE, PP and PTFE are hard to bond to. I lined a mold this evening with PE cling film because the adhesives and potting compounds I favor do not stick to it. It would be cool if that stuff works.
PCB Guillotine's - Page 1
Forum section: electronics / general

author: Davy
author_rank: Regular Contributor
timestamp: November 21, 2020, 06:00:07 pm
content: I've read elsewhere the Mega Electronics PCB Guillotine isn't all the great..... I'm wondering if Fortex guillotine is the same one?http://www.fortex.co.uk/product/pcb-guillotine-shear/I did get a Proxxon KS230 mini table saw...... the darn thing I had was a joke, the splitter blad was forevr jamming..... 12 months down the line the motor squealed - no jams or nothing and a smell of burning after 1 minute if use when cutting a paper resin pcb - opened the motor up and a capacitor had exploded... taking a very small 22uH miniature axle choke with it..... No more Proxxons for me, I do have the drill and that uses the same motor.Dave
Has Anyone tried VAFL PCB? - Page 1
Forum section: electronics / general

author: gregorious
author_rank: Newbie
timestamp: October 21, 2020, 01:49:40 am
content: I saw some spam post on reddit that they were having a sale and their prices seem pretty good, but I've never heard of them before. I don't want to waste my money, so has anyone heard of this company before and what's their quality like.
SMD equivalent for this possibly obsolete transistor - Page 1
Forum section: electronics / general

author: taser8612
author_rank: Newbie
timestamp: October 11, 2020, 07:28:06 pm
content: I'm trying to reverse engineer a small board from a proximity sensor. The only thru-hole component on it is a 2SC2655 transistor. While there are many versions out there, I haven't found any with the "WH-Y" marking on them.Any help deciphering the meaning of that marking and what smd equivalent could be used would be hugely appreciated!Much thanks!

author: phil from seattle
author_rank: Super Contributor
timestamp: October 11, 2020, 08:12:10 pm
content: I'd go to a disti and use their search criteria to match the key characteristics. My guess it's not too critical as that looks like a switching application. Anyway, here's what Mouser gave mehttps://www.mouser.com/Semiconductors/Discrete-Semiconductors/Transistors/Bipolar-Transistors-BJT/_/N-ax1sh?P=1z0z7ptZ1z0y4diZ1y95l6hZ1z0wa4fZ1z0wajc&Rl=ax1shZgjdh6cZ1z0w6i4Z1y9nhcjSGgjdhp0Z1yw7z6yZ1yw7ztcSGT
SMD alignment question - Page 1
Forum section: electronics / general

author: phil from seattle
author_rank: Super Contributor
timestamp: October 19, 2020, 08:37:57 pm
content: I have had a number of PCBs made and assembled in China and have been seeing some slight misalignment of 2 pin packages after reflow. As I understand reflow, the surface tension of the solder should center the part on the pads. None of these misalignments resulted in actual board failures but I wonder if there is something I should be changing.As you can see, the 1K resistor is fairly misaligned. I get 1 or 2 out of 50 resistors per board that do this.

author: ANTALIFE
author_rank: Frequent Contributor
timestamp: October 19, 2020, 11:07:11 pm
content: It's all about pad geometry (as well as how tracks come into those pads), if you want components to be pulled straight by the solder tension then your pads will need to be tighter (https://www.eevblog.com/forum/altium/l-m-and-n/)Also you only worry about these sort of things when you are working with a tight board, so in your case I would just leave pads as is

author: jmelson
author_rank: Super Contributor
timestamp: October 20, 2020, 01:28:25 am
content: Note that both traces to R13 come in from opposite sides. These draw heat away from the pads and cause the wave of melting solder to go sideways across the component. So, that may be the cause. Note the capacitor shows no such effect.Jon

author: phil from seattle
author_rank: Super Contributor
timestamp: October 20, 2020, 02:25:35 am
content: I'm no expert but it is not consistent and is pretty randomly distributed over all the 805 resistors on the boards. Here's a photo of the same resistor on another board from that batch. Note the very slight misalignment in the opposite direction. I took a look at 10 other boards from that batch and R13 was pretty close to perfect on them. Not saying you are wrong but there must be more to it than that. I wonder if the reflow oven conveyor is being cranked up and not giving enough time for surface tension to fully work its magic. The solder doesn't look super shiny to me.The footprint size point makes sense to me. It is a standard Eagle 805 footprint. I agree it's probably not worth messing with. I haven't had any customer complaints.

author: phil from seattle
author_rank: Super Contributor
timestamp: October 20, 2020, 02:50:01 am
content: OK, thanks. So, in this case there is absolutely nothing to worry about.
Juki Nozzle Spring - Page 1
Forum section: electronics / general

author: Mangozac
author_rank: Frequent Contributor
timestamp: October 01, 2020, 11:44:13 am
content: As I'm sure many of you are aware, Juki nozzles are spring loaded. We have been setting things up so as to avoid the spring compressing but I'm curious how necessary that is. We have tried having the spring compress a little when placing the component and it doesn't seem to have had any adverse effect. What's the general recommendation?

author: SMdude
author_rank: Frequent Contributor
timestamp: October 01, 2020, 10:11:02 pm
content: You want the spring to compress a little as it then accounts for the part to be a little lower in the strip and it presses it slightly into the paste on placement.If you make it just touch, you get mis-picks galore.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: October 01, 2020, 10:57:29 pm
content: Spring loading is done to make a reliable connection in spite of always existing tolerances.Mechanical things move, they always do.If you put in a roll of new resistors from another manufacturer there may be slight differences in thickness of the tape or even the resistors themselves. The feeder may be slightly moved after you put it back etc.

author: Mangozac
author_rank: Frequent Contributor
timestamp: October 02, 2020, 03:02:06 am
content: Thanks guys, that's what I was thinking. For parts less than say 1.5mm height can we just set the placement Z-height to be where the nozzle just touches the top of the PCB and let the spring compress? Obviously for taller components we need to provide some offset.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: October 07, 2020, 10:54:14 am
content: The nozzles are designed to be compressed a bit.Why would you even consider it would have "adverse affects"?

author: Mangozac
author_rank: Frequent Contributor
timestamp: October 07, 2020, 09:33:53 pm
content: Quote from: Doctorandus_P on October 07, 2020, 10:54:14 amBecause I do not know how much they are intended to be depressed and I want to ensure that it does not disturb the part during placement. I am pleased to hear that they can be compressed considerably though
Fixing ground pad opening for QFN on a stencil - Page 1
Forum section: electronics / general

author: radar_macgyver
author_rank: Frequent Contributor
timestamp: September 30, 2020, 11:11:27 pm
content: I tried using my very first stencil today to put a few parts on a board. Two of them are QFNs, a16-pinand a24-pin. I made the rookie mistake of leaving the center pad's stencil opening the same size as the pad (with a 1 mil pullback). On the first test boad, all the parts reflowed fine, except the two QFNs which basically rode on a pillow of solder.The stencil is from OSHStencils, 4mil stainless steel. Instead of using spare boards to form a level surface, I milled out a pocket in some aluminum plate (this board is 20 mil RO4350, and I didn't have any extras lying about). Taped the stencil to the aluminum and used a plastic squeegee.I was able to rework the board and get them to work (both parts require grounding of the center pad), but I was wondering if anyone could share some tricks to removing some paste before placing the parts (I have more boards to populate). Thanks in advance.

author: Styno
author_rank: Regular Contributor
timestamp: October 01, 2020, 08:14:22 am
content: I divide the gnd pad in 4 smaller individual stencil openings. An example of this can be found on page 30 ofthis TI document.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 01, 2020, 06:27:00 pm
content: They didn't divide it down for you? Even PCBCart does...Tim

author: radar_macgyver
author_rank: Frequent Contributor
timestamp: October 03, 2020, 03:17:10 pm
content: Thanks for the link, Styno. It seems like at least for the QFN-16 one doesn't need to divide the pad. Doesn't look like OSHStencils has an option to auto-divide large pads.I did find some pre-made stencils on Digikey forQFN-16andQFN-24, which I could as references when making stencils in future.For now I suppose I could use a toothpick to remove some of the paste from the large pad by scoring a cross shape.

author: Mangozac
author_rank: Frequent Contributor
timestamp: October 03, 2020, 09:19:20 pm
content: I find that most modern data sheets (especially those from TI) provide paste aperture details like this.Indeed, the immediate solution to your problem is as you say, to use a toothpick or perhaps a small, flat head jewellers screwdriver to scrape away some excess.
App note: Stencils and Fiducials - Page 1
Forum section: electronics / general

author: GreggD
author_rank: Regular Contributor
timestamp: October 05, 2020, 06:56:39 pm
content: When I layout a pcb I always include fiducials.I just got three board designs and a stencil from JLC.No stencil producer will include fiducials which would make alignment much more accurate.So I put 0603 footprints in the pcb corners and connected one pad to a via to ground plane and success.One of the parts is a 0.65mm pitch SO-28 and on five copies the paste was perfect.

author: wilhe_jo
author_rank: Regular Contributor
timestamp: October 05, 2020, 08:33:04 pm
content: I made a component for this... 1mm non plated hole with a matching area on the past layer.I print by hand. So I just put 2 of these components o the pcb. After aligning everything sloppyly, I put 2 1mm drills in the holes. This makes everything bulletproof.I got this idea form some other post...73
Home-based (skillet / toaster) reflow of FMC connectors with "solder charge" - Page 1
Forum section: electronics / general

author: gsmecher
author_rank: Newbie
timestamp: October 02, 2020, 04:30:39 pm
content: I've been trying to reflow FMC connectors (Samtec ASP-134488-01) with mixed success on a skillet.These connectors have a solder charge (), a little like a BGA: they come with pre-formed solder caps on the terminals, but rely on the flux in your solder paste to wet them during reflow.These connectors are thorny for a few reasons:They're nearly un-inspectable and totally un-reworkable, since they're underneath the connector bodyThere are 160 pins per (LPC) connector, and "most" of them need to workThey're physically large, so any bowing or twisting of the underlying board will ruin my workI've played with the soldering profile ("twiddling the dial on the skillet while holding a stopwatch") and dabbing flux on the part before putting it on the prepared board. I am still not getting reliable results. I am going to look at the PCB footprint today to see if it's a problem with pad sizes.Before I throw up my hands and have the part reflowed elsewhere, I figured I'd ask here for suggestions. Please?Moreover, should I expect the bargain assembly houses (pcbway) I'm considering to do a 100% reliable job on connectors like this? Or, am I trading my own dubious reflow for someone better-but-still-not-good-enough?

author: Rat_Patrol
author_rank: Frequent Contributor
timestamp: October 02, 2020, 05:47:12 pm
content: My thoughts, but keep in mind I have not ever tried this solder charge technique:This process will most likely need a very controlled, repeatable, precisely timed reflow profile. If you are using a hot plate/skillet method, I doubt you will have reliable success.The solder paste application likely has to be perfect, with the proper solder paste. What you have for solder paste may just not play well with this process. I'm sure solder paste consistency also needs to be perfect.I would expect a shop even like PCBWay would have reasonable success, as they use proper reflow ovens, though I think there may be issues if this process is not compatible with their established profiles. They won't be modifying their oven profiles just for you...IMHO, if this were my project, I would look long and hard for an easier solution that is more conventional. You will have higher success rate with your own work AND discount assembly companies.

author: gsmecher
author_rank: Newbie
timestamp: October 02, 2020, 08:20:30 pm
content: Your guidance here (work towards a more controlled conventional reflow, rather than heading off into the weeds) makes sense to me. I have a few obvious gaps to plug before I run out of un-creative ideas.Thanks.

author: Rat_Patrol
author_rank: Frequent Contributor
timestamp: October 05, 2020, 04:39:09 pm
content: The results from a Controleo converted toaster oven are honestly great. I have reflowed hundreds of PCBs perfectly every time with one. Total investment is about $350, and a reflow takes about 20 minutes from start to cool-down enough to remove with bare hands with leaded solder.
Macro Lens for JVC camcorder - Page 1
Forum section: electronics / general

author: pitfermi
author_rank: Contributor
timestamp: October 04, 2020, 12:07:02 pm
content: i have a JVC Everio GZ-E100SE from 2012 which i used to record classes with, which I want to turn into a soldering microscope or at least try to. I've seen Dave's video on a diy soldering microscope so i figured it might be possible with my camcorder as well. the outer aperture dia on the front is 45mm wide and there is not much room to mount a macro lens, unless someone has a suggestion on how to do so.what kind of lens do I need exactly? i have no experience with camera lenses whatsoever. i am not willing to spend more than 20€ on one

author: Kleinstein
author_rank: Super Contributor
timestamp: October 04, 2020, 12:30:45 pm
content: I can not see a thread for mounting a standard filter or the usual extra lenses for macro photography. So one would have to improvise on this, probably with some glue. My best bet would be getting an adapter ring / reduction for filters that could be glued to the camera and than some extra lens(es) for that thread. There are some relatively cheap sets available for photography. 45 mm is more on the small size. The cheap ones should be OK, but with chromatic aberrations. Achromatic lenses are likely beyond the $20 range unless lucky on a used one.The lens strength needed depends on the magnification / working distance needed. As the camera has a large zoom range one has likely a relatively large range to adjust. With the camera set to infinite one would get a working distance = focal length. With the camera close focus to some 1 m this would add 1 dp to the lens. So for a 20 cm working distance one would need some 5 dp with the camera at infinite focus and some 4 dp with the camera set to 1 m. Depending on the magnification I would consider some 5-20 dp a useful range.A possible problem would be if the front lens moves when focusing - this can confuse the auto focus control.I have done my first macro experiments with the front lens from binoculars and it was a reasonable match for a compact camera.
Looking for CNC milling of prototype chassis, advice please! - Page 1
Forum section: electronics / general

author: bsodmike
author_rank: Regular Contributor
timestamp: October 02, 2020, 12:29:04 pm
content: Hi all,I'm looking for a company or someone talented enough to turn my Fusion 360 model into the final Aluminium chassis (Aluminum of US friends!) which has a base thickness of 3mm.I've attached an example of the CAD drawings I've compiled, so far it is 10-pages long and details all aspects.First, I planned to have this locally done but I'm having trouble finding talent to assist. Therefore, the solid sections will need to be separated so that this can be flat-packed for shipping to keep volume to a minimum.Also, all 4mm holes should be tapped for machine screw threading; other final details have been left out.Appreciate any advice and thanks again!Cheers, Mike.
SHORTS IN QFN PACAkge - Page 1
Forum section: electronics / general

author: robin@ganmartechnologies.
author_rank: Newbie
timestamp: September 22, 2020, 07:21:07 am
content: Hello: We have found it very difficult to solder successfuly 16 pin QFN pkg. Most disturbing has bee in 2 occasions, 1 pad was found shorted internally to the IC GND. Internally, not to anything external.Vendor pointed out the possibility of ESD. We have used hot air whenever we have to replace a device. In the proto level, we have had such shorts twice so far.Any ideas?Hard to beleive it is ESD. Could hot air generate ESD & not blow all or a few but just one random?For now, we are stuck : got to know why & whow to avoid repetition.Any help will be highly appreciated.r

author: ar__systems
author_rank: Frequent Contributor
timestamp: September 22, 2020, 10:58:26 am
content: Stencil & hot air works, very easy. Reworking could be tricky, cause the small part is easily blown away.Internal shorts are almost 100% ESD. Air obviously does not cause it, but the handling of the parts/boards.

author: free_electron
author_rank: Super Contributor
timestamp: September 22, 2020, 12:31:44 pm
content: first of all : is your footprint correct and do you have correct soldermask between the pads ?

author: Kasper
author_rank: Frequent Contributor
timestamp: September 23, 2020, 02:29:01 am
content: If you intentionally zap a good one with ESD that could give you an idea how susceptible it is to ESD.

author: GerardG
author_rank: Regular Contributor
timestamp: September 23, 2020, 10:32:00 am
content: Hello Robin,ESD is a pain in the ****You can not see it and it can make shorts or intermittent problems. They will not show at first. So you think it is OK and you get the board back with a problem from the customer.In the datasheet of the component it can show the ESD Voltage that can damage the part.I would recommend to always use an ESD mat, and connect it properly to ground. Wear a wrist strap connected to the table mat with a 1Meg resistance.https://bit.ly/2G27UaZThink also about the ESD discharge in the other direction. (The nozzle of the hot air tool is grounded, mostly without 1Meg)

author: Doctorandus_P
author_rank: Super Contributor
timestamp: October 01, 2020, 11:01:41 pm
content: QFN may have extra "pins" in the corners that are not shown on the datasheet.Have a look at this:https://hackaday.com/2015/10/13/fail-of-the-week-marginally-documented-pad-shorts-to-maskless-pcb/

author: ANTALIFE
author_rank: Frequent Contributor
timestamp: October 01, 2020, 11:44:43 pm
content: OP post pics of PCB footprint and package footprint from datasheetESD is definitely a possibility, are you guys taking all the proper precautions (ESD wrist/foot straps, ESD safe floors, ESD trays/safe bags...)? Also where are you finding the fault, in testing?
Cost to program EEPROM - Page 1
Forum section: electronics / general

author: knick
author_rank: Newbie
timestamp: October 01, 2020, 06:20:24 am
content: Does anyone have a figure? My run size would be 100 boards.Would programming typically be done via test pads on the board?I would ask my PCB assembly house, but they in China and currently on holidays.

author: ebclr
author_rank: Super Contributor
timestamp: October 01, 2020, 08:18:46 am
content: This service in China will be something like 30USD setup charge plus peniies for each unit

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: October 01, 2020, 08:56:21 am
content: Microchipdirect offer a programming service for their parts, which IME is way cheaper than third parties.

author: JoeyG
author_rank: Regular Contributor
timestamp: October 01, 2020, 10:08:51 am
content: cost lookup fpr programming herehttps://www.microchipdirect.com/programming/price-lookup
on-line printing for PCB toner transfer - Page 1
Forum section: electronics / general

author: freda
author_rank: Regular Contributor
timestamp: September 30, 2020, 02:09:29 pm
content: My printers fuser has failed...i don't actually do much printing and instead of replacing it and saving some space thought I mighttry Officeworks.The result print has great Black but dimensionally not so good, 3.7% less in X and 4.2%less in Y.....I guess could adjust for that.I'm not sure which of gloss or trace paper will work best atm.there is some wording in the submit process" A4 - 287mm x 200mmDimensions represent printable area of your document. All documents are printed with a 5mm outer margin. All bound documents should also include an additional 5mm left margin."I don't know atm whether that might be triggering some scaling,....thought it would be within that anyway, submitted as a A4 pdf.Maybe there's some other artifact I need to understand......Anyone had success ?

author: SilverSolder
author_rank: Super Contributor
timestamp: September 30, 2020, 02:25:26 pm
content: The problem with outsourcing this, is that you have no control of how it is printed (driver settings), or what paper it gets printed on - and it might be different the next time you place an order.Do you still have an inkjet printer? It can be used for PCB work too...

author: freda
author_rank: Regular Contributor
timestamp: September 30, 2020, 02:47:32 pm
content: with Officeworks the choice of paper is well defined, different papers cost different. theres quite a few different choices,but magazine paper seems to be missingthe actual printer settings yeah thats a possible problem vector.I do have a inkjet printer gathering dust, doubt it works anymore.......used to use it to print transparencies, I have the UV box setup and all that (not used in years) but I may getback to it after finding out about some special stick on film so i ordered some.

author: SilverSolder
author_rank: Super Contributor
timestamp: September 30, 2020, 05:35:05 pm
content: I've found a big improvement in recent years, you can now buy special transparencies that really soak up the ink and allows you to make high quality masters with the inkjet. Needs the dye based toner, not the pigment based stuff, to work.
Hot-Plate Reflow in commercial volume manufacturing? - Page 1
Forum section: electronics / general

author: Dave8266
author_rank: Contributor
timestamp: September 22, 2020, 03:25:04 pm
content: Quick question:Is hot-plate reflow soldering, for SMD components, used at all in medium or large-scale or commercial contract PCB manufacturing? Or is it strictly a hobbyist shortcut?My searches and reading so far seems to say "no", that the thermal mass makes hitting the desired solder temperature profiles difficult, and that bottom-up heating and the resulting uneven expansion, with the associated flexing on cool-down, puts long-term mechanical stresses on the board and larger components, so reflow ovens are the method of choice. As an outsider, it's hard to see if those issues are truly insurmountable, or if instead the efficiency and workflow benefits of the conveyor ovens simply makes it the dominant preference for non-technical reasons.(And yes, I'm aware of Spark Fun's articles on the subject, using hot-plate soldering to get by while launching a small company. That technically does constitute "commercial production"... but I'm more interested in real, proper production - following temp profiles, relevant quality specifications, etc.)This is just a curiosity question - I'm scaling up some hobby work, and wondering if there was a parallel path in the big companies or not.Thanks!

author: SMTech
author_rank: Frequent Contributor
timestamp: September 22, 2020, 07:19:59 pm
content: Not even in a lab, strictly hobbyist only.

author: kylehunter
author_rank: Regular Contributor
timestamp: September 22, 2020, 08:23:46 pm
content: Agree with SMTech that it isn't common. Though we are a mix of a design shop and small CM, we use the heck out of a custom hot-plate for "one-offs" and prototypes. It's hard to justify the time and energy expense for us to fire up our big reflow oven's when a small <15A hotplate can reflow even lead-free boards from a cold start in less than 5 minutes. It is able to roughly follow a linear profile, just a bit slow of a ramp rate, but we've never had a board that it can't reflow.

author: Dave8266
author_rank: Contributor
timestamp: September 28, 2020, 07:03:18 pm
content: Thanks, appreciate the replies.I had a feeling that this was the case. The marketing for some of the equipment sure doesn't read that way, but the lack of any high-end equipment coming up in my searches was suspicious.
Metcal MFR-1110 short tip life? (Metcal SFP/SxP type) - Page 1
Forum section: electronics / general

author: philpem
author_rank: Frequent Contributor
timestamp: September 25, 2020, 09:54:35 pm
content: I'm curious if anyone's seen a drop in the lifetime of Metcal SFP series tips...My daily driver is an MFR-1110 station with an SFP-CH25 tip. The first tip I bought with the station lasted a couple of years, then failed completely. Red light on power on, no heat.The last two tips have lasted a couple of months with similar usage to the first (an hour or so a week). Both have failed with the same failure mode.The tip heats up fine, no errors from the MFR base station. Two green lights. I can leave the iron in the stand (on auto set-back) until the timer trips.But if I try to solder with it, the station will red-light part way through the job. Inevitably I'll notice when the solder isn't melting any more...Often the thing which triggers a shutdown is touching the brass shavings to clean the tip. This led me to believe the handpiece (either the tip connector or the cable) had failed. The new handpiece worked for a while - then predictably I got the red-light again. New tip, problem solved.Fair enough these things have a finite life, they are after all a consumable. But a couple of months seems rather short, given only evenings-and-weekends hobby use.Has anyone had similar issues with the MFR / SFP / SxP series stations and parts -- or recent-manufacture Metcal stuff in general?CheersPhil.

author: thm_w
author_rank: Super Contributor
timestamp: September 25, 2020, 10:34:21 pm
content: Contact Metcal and let them know the coil in the tip failed after a month of light use. Measure the tip and let them/us know if its open circuit.https://www.eevblog.com/forum/chat/metcal-soldering-tip-pathology/

author: philpem
author_rank: Frequent Contributor
timestamp: September 26, 2020, 02:01:57 am
content: It doesn't seem to be O/C - I measured about half an Ohm. But the resistance shot up when I touched the meter probe against the side of the inner pin.I've cleaned the tip connector with a foam swab and acetone, then cleaned the tip storage bays in the stand with a dry foam swab. Who knows, that might fix something... it can't make it any worse...
IC re-taping machine or service  - Page 1
Forum section: electronics / general

author: schmitt trigger
author_rank: Super Contributor
timestamp: September 25, 2020, 03:43:39 am
content: We have to take some SOIC-8 and 14 devices from its plastic tape carrier, test them and re-tape them again for the pick and place machine.Required quantity is about 1000 or 2000 pcs a week, thus the machine needs not be high speed.We can also consider an external, US-based contractor to do it for us.The reason? An embarrassing error committed by someone else and which I have to correct.

author: Mangozac
author_rank: Frequent Contributor
timestamp: September 25, 2020, 11:21:31 am
content: Why not just transfer them into tubes and use a tube feeder?

author: schmitt trigger
author_rank: Super Contributor
timestamp: September 25, 2020, 03:44:44 pm
content: Excellent idea, sometimes the best solution is the simplest.I will check and see if our pick and place machines accept feeder tubes.

author: electrolust
author_rank: Unknown
timestamp: September 25, 2020, 07:44:19 pm
content: i wonder if you can share the error, or hint at it. it is hard for me to imagine an error where this is the solution. did the taped parts get sent through the washing machine or something?

author: schmitt trigger
author_rank: Super Contributor
timestamp: September 25, 2020, 10:43:36 pm
content: Someone who did not read or understand the datasheet, and chose a plain vainilla opamp for use on a critical application.Because of various “pencils down” clauses with the customer, no changes are allowed at all, until the next product iteration.I didn’t choose the opamp nor did I sign the contract. I only have to deal with the yield fallout.

author: schmitt trigger
author_rank: Super Contributor
timestamp: September 25, 2020, 10:45:58 pm
content: I have checked our pick and place equipment, it can use tube feeders.

author: electrolust
author_rank: Unknown
timestamp: September 26, 2020, 12:27:08 am
content: might be cheaper to apply a new laser mark to the correct partskinda like how we would change our report cards in grade school!!
Philips CSM84 will be available in a few months - Page 1
Forum section: electronics / general

author: jmelson
author_rank: Super Contributor
timestamp: July 20, 2020, 03:28:39 am
content: I have a 1995 Philips CSM84 which I've been using for the last 12 years. It is not accurate enough for some of the parts I am placing, so I just bought a Quad QSA-30A to replace it. I will have to keep the CSM84 around until the Quad is at least mostly up and running.I have about 50 feeders with the CSM, several versions of the manuals, an on-line service manual, a few small parts. It is a great machine if you are not doing fine-pitch parts. I do 0603 just fine, and SOIC and some SSOP parts. But, 0.5mm lead pitch is just asking too much. With 3 nozzles, it can do over 3000 PPH. It has an adjustable conveyor, teach camera and "beam sensor" for fiducial pickup.It does not have nozzle exchange or vision. I have a program to convert my CAD system's placement file to the CSM format and download over a serial port. The machine is now configured for 240 V single phase, but can be set up for 120 V if you need it.This is in the St. Louis, MO area (USA). Is anybody interested?Jon

author: 48X24X48X
author_rank: Frequent Contributor
timestamp: July 20, 2020, 04:13:27 am
content: Please put this post in the buy sell section. Sold my machine there.

author: jmelson
author_rank: Super Contributor
timestamp: September 25, 2020, 02:53:53 pm
content: Quote from: 48X24X48X on July 20, 2020, 04:13:27 amNow that it looks like the new machine is almost ready to run boards, I have put a more informative thread in the buy/sell forum. Anybody interested?Thanks,Jon
Favorite custom rubber product manufacturers? - Page 1
Forum section: electronics / general

author: Rat_Patrol
author_rank: Frequent Contributor
timestamp: September 23, 2020, 09:22:28 pm
content: I need a custom rubber gasket (3D profile unfortunately, not die cut flat) for an enclosure, thought maybe some of you folks may have a line of a short run custom shop, as I only need about 1000 or so pieces.Can't be from China, Russia and a few other countries due to contract obligations, but can be pretty much anywhere else.Of course, I have the 3D model and the 3D printed TPU prototypes work perfectly. Push comes to shove, I guess I know what my 3D printer will be doing for a while...

author: Mangozac
author_rank: Frequent Contributor
timestamp: September 23, 2020, 09:33:59 pm
content: I have the same requirement for a project and my current plan is to source a rapid set 2-part silicone and use with a machined mould. A 2-part silicone putty would be ideal but I can't find one that isn't coloured (I need white).

author: Rat_Patrol
author_rank: Frequent Contributor
timestamp: September 23, 2020, 09:57:16 pm
content: I should mention that cast silicone for me should work just fine as well.
Solder paste on 0.5mm qfp pads creates bridges. Possible to dilute paste? - Page 1
Forum section: electronics / general

author: julian1
author_rank: Frequent Contributor
timestamp: September 18, 2020, 10:04:44 pm
content: No stencils. Using the smallest nozzle applicator I have. With the thinnest line of paste across pads I can make.I am considering reducing the solder concentration in the paste by diluting it with extra flux - perhaps 1:2 or 1:3.Has anyone tried that?Alternatively is it possible to buy paste with different solder concentrations? I am using a new paste brand (60sn/40pb) after the old lot ranout, and I don't remember it being as problematic.

author: janoc
author_rank: Super Contributor
timestamp: September 18, 2020, 10:20:51 pm
content: If you have bridges you either don't have soldermask between pins or are applying way too much paste. Likely both.Don't try to dilute the paste. Rather fix the bridges using a bit of solder wick and apply less paste next time. You really need only a tiny amount and if you aren't applying it using a stencil, bridging is almost inevitable - it is very hard to apply by hand from a syringe because all needles you are able to use are still likely too large (and anything smaller you won't be able to squeeze the paste out from by hand).

author: wraper
author_rank: Unknown
timestamp: September 18, 2020, 10:21:16 pm
content: Dumb idea, all you will get are crappy solder joints and solder balls around. And unless you use stencil there always will be solder bridges. To reduce amount of bridges you need to apply lower amount of solder paste in some other way.

author: Kasper
author_rank: Frequent Contributor
timestamp: September 19, 2020, 02:53:20 am
content: You could try using an exacto knife to remove some solder paste. Probably easier to use a stencil though, the chinese PCB fab house sell them for cheap and last I checked Polulu did too.

author: TK
author_rank: Super Contributor
timestamp: September 19, 2020, 02:57:41 am
content: If you order from JLCPCB, you can add the stencil for around $7... it makes SMD reflow soldering much easier

author: jmelson
author_rank: Super Contributor
timestamp: September 19, 2020, 04:09:30 pm
content: Quote from: TK on September 19, 2020, 02:57:41 amBut, for 0.5mm lead pitch, you need to reduce the amount of solder. So, specify your own solder mask Gerber layer, and reduce the QFP aperture to about 50 - 75% of the area of the copper pad. I've worked out the right reducion for my process, which compensates for some over-ethcing of my solder stencil, so my numbers may not exacly apply to other stencil technologies. But, reduced solder amount is really critical. There is NO WAY to do 0.5 mm QFP without a stencil!Jon
User forum specifically for Charmhigh PnP machines? - Page 1
Forum section: electronics / general

author: Rat_Patrol
author_rank: Frequent Contributor
timestamp: September 17, 2020, 10:46:45 pm
content: Yes, I bought one; a 48VB. It was about the only machine that did what I needed it to do in my price range. On the plus side, it works fine. Maybe I got luckyAnyway...Are there any specific forums for these machines? I imagine there has to be, but I have no located it.

author: 48X24X48X
author_rank: Frequent Contributor
timestamp: September 18, 2020, 07:06:22 pm
content: I think there's none here other than a mix bag of different manufacturer in a thread of someone asking for a few machine candidates to purchase. It's good to have one so owners can share experience/tips/etc and while prospective buyer can know what to expect. Other than that, as long as advertisement is not part of the discussion it should be good.
Drilled versus Plated diameter - Page 1
Forum section: electronics / general

author: neuralengineer
author_rank: Newbie
timestamp: September 14, 2020, 09:42:22 pm
content: Help!When doing PCB layout, do you specify the drilled diameter or the finished (plated) diameter for plated through holes? Here's a picture:https://www.protoexpress.com/blog/no-chilling-when-it-comes-to-pcb-drilling/The part I'm using is press-fit, so the final diameter is critical. I've been using Upverter's online EDA. It only lets me specify one diameter for holes, so is it the drilled diameter or the finished diameter?Thank you,New Circuit Designer

author: thm_w
author_rank: Super Contributor
timestamp: September 14, 2020, 09:59:21 pm
content: Finished.The manufacturer will have a tolerance range as it will vary a bit:https://jlcpcb.com/capabilities/CapabilitiesWhat is the part in question?

author: neuralengineer
author_rank: Newbie
timestamp: September 14, 2020, 10:06:38 pm
content: Thank you, thank you, thm_w. I was worried I had made a big mistake. Whew!The part is a press-fit board to board connector from Samtec, SEAFP-20-05.0-L-04Here is a link to the footprint spechttp://suddendocs.samtec.com/notesandwhitepapers/samtec-compliant-pin-termination-specification.pdf

author: T3sl4co1l
author_rank: Super Contributor
timestamp: September 14, 2020, 10:30:19 pm
content: Specify it on the drill drawing or fab notes.If a fab can't provide that tolerance, they should notify you of that fact.Very cheap proto services may not bother reading notes, YMMV.Tim

author: thm_w
author_rank: Super Contributor
timestamp: September 14, 2020, 10:52:51 pm
content: Yeah JLC won't quite guarantee they meet the spec required for that connector for example:- JLC: Drill Hole Size Tolerance +0.13/-0.08mm- Samtec connector: 0.46 +/- 0.05So a higher end PCB vendor that costs at least more than the connector itself may be justified

author: phil from seattle
author_rank: Super Contributor
timestamp: September 15, 2020, 02:44:17 am
content: I've found that most vendors don't really care about small batches. I always oversize by at least a few mils - beats not being able to fit a component. Some vendors lay the plating on pretty thick.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: September 15, 2020, 04:15:25 am
content: As you can see, it may be a good idea to solder rather than press fit. The solderability may not be great, but it's better than a pin flapping loose in a hole and you can keep redoing it.Even with good fabs, press-fit connectors are hard to get right.Tim

author: ejeffrey
author_rank: Super Contributor
timestamp: September 17, 2020, 06:20:06 am
content: With press fit connectors it is good to talk to both the board house and connector manufacturer to make sure that the hole size, tolerance, and finish are appropriate for the connector. They can be really great if done correctly but solder can cover a multitude of sins.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: September 17, 2020, 11:56:31 am
content: Quote from: ejeffrey on September 17, 2020, 06:20:06 amI forget, did you use press fits in that card cage?Tim
Prototyping - BGA via in pad and missing pads - Page 1
Forum section: electronics / general

author: c64
author_rank: Frequent Contributor
timestamp: September 14, 2020, 12:55:55 am
content: Everything below is for prototyping and hand assembly. Is it a good idea to:1. Have 0.2mm vias in some of the BGA pads. In all ground and power pads, which go direct to ground and power planes. And some signals which go to bottom layer. Do i need to do anything before soldering, like tinning the pads to fill the vias with solder?2. Is it OK to remove some BGA pads from the footprint? For example, in FPGA some pads are not used, and I'd rather use this space to route a couple of extra traces. But maybe solder balls of the un-soldered pads will push the chip away from PCB?

author: asmi
author_rank: Super Contributor
timestamp: September 14, 2020, 01:48:10 am
content: Quote from: c64 on September 14, 2020, 12:55:55 am1. No, because it will lead to solder wicking inside via (unless you use via in a pad, when vias are plugged and plated over).2. No, because that solder ball will have to go somewhere, and it might just as well go and short adjacent balls.

author: pisoiu
author_rank: Regular Contributor
timestamp: September 14, 2020, 08:05:13 am
content: I used vias in pads, but only 0.1mm laser drilled, for the reason explained above.
Fixtures for flex pcb assembly - Page 1
Forum section: electronics / general

author: robint91
author_rank: Contributor
timestamp: August 24, 2020, 01:38:43 pm
content: I don't seem to find companies that provide fixtures to help to assemble flex circuits. Even the PCB fab houses don't do something like that as it would seem.Has anyone here an idea how to mount the flex panel such that we can print our solderpast, pick and place and reflow? The panel is about 150mm x 150mm.

author: SMTech
author_rank: Frequent Contributor
timestamp: August 24, 2020, 10:53:11 pm
content: The mid-low volume solution is to CNC your pallet using a material such as Durastone, in theory that's something you could do yourself. Its not something I've ever had to do but I did look it up once when someone suggested they might want it, there's a free ebook floating around the interwebs about flex circuits too. Her'se a UK company that designs that kind of thinghttps://globaldatum.co.uk/I know there were others I have come across (one had a really obvious name but my google-fu fails me)https://kaisertech.co.uk/wave-solder-palletsalso this one despite the wording I think also covers SMT as well. However the first link gives you your best search PPRC print placement reflow carrier or however that translates for local suppliers.

author: Ribster
author_rank: Frequent Contributor
timestamp: August 24, 2020, 11:10:55 pm
content: https://www.cnczone.com/forums/glass-plastic-and-stone/17802-milling-durastone-material-using-cnc.htmlDamn. Seems to be a nasty thing to cnc if you believe this guy.Quote

author: labnet
author_rank: Contributor
timestamp: September 03, 2020, 01:56:49 am
content: We have just done a trade study on this. IF you PM me, I can send you what we have found so far.

author: GerardG
author_rank: Regular Contributor
timestamp: September 03, 2020, 07:22:22 am
content: Hello Robint91,There are some solutions for it.What kind of PCB are you working on?Pure flex-pcb, flex-pcb with stiffeners or a flex-rigid PCB.Can you share a picture?

author: nisma
author_rank: Regular Contributor
timestamp: September 13, 2020, 12:03:40 am
content: I nave seen printing and assembly flex using vacuum plates and for simpler things solder paste was deposit using dispenser on Pnp. Further reflow on solder plate or proto reflow with the help of top plate. Other option is to use fixture plate and then after reflow laser cut the single circuits