hybridfree/eevblog-posts huggingface dataset:
QFN and QFP, what service to use ? HASL or ENIG - Page 1
Forum section: electronics / general

author: mwilliams03
author_rank: Newbie
timestamp: January 22, 2018, 05:51:51 am
content: I am using fine pitch QFN and QFP components and i have read that it is better to use immersion gold finish instead of HASL... why is this so?In my prototyping, I have never had any issue hand soldering the components to a HASL PCB.

author: AndyC_772
author_rank: Super Contributor
timestamp: January 22, 2018, 08:35:22 am
content: HASL isn't guaranteed to be flat, so with a component like a QFN, there's a chance that it'll sit at an angle to the PCB, and the pads along one or two edges won't solder when the board is reflowed.Gold, silver or OSP finishes are perfectly flat, so coplanarity isn't a problem.If you're hand soldering, then you should be OK either way. Personally I prefer gold finish for hand soldered PCBs because, if nothing else, the difference in colour makes it obvious which joints have been soldered and which haven't.

author: jpanhalt
author_rank: Super Contributor
timestamp: January 22, 2018, 10:50:22 am
content: The immersion finishes are flat. However, note that immersion silver was found to have its own problems with creeping corrosion:https://www.dfrsolutions.com/hubfs/DfR_Solutions_Website/Resources-Archived/Publications/2005-2007/2007_08_creep_corrosion_on_lead-free_pcb_in_high_sulfur_environments.pdfImmersion gold is apparently less susceptible.Of course, for a short-lived prototype that shouldn't make a difference.
Help!  Can't Open mysterious .sch and .pcb files - Page 1
Forum section: electronics / general

author: guitarjoe91
author_rank: Newbie
timestamp: January 04, 2018, 06:34:19 pm
content: I'm struggling to open some old .sch and .pcb files from out PCBA supplier in Altium17 or Altium18. Our supplier says the files were probably created in Protel 99. No combination of opening the files or importers in Altium have worked thus far. What should I do?

author: AndersJ
author_rank: Frequent Contributor
timestamp: January 04, 2018, 07:11:01 pm
content: PADS from Mentor Graphics uses those file extensions.sch: Schematicspcb: Layout

author: frozenfrogz
author_rank: Frequent Contributor
timestamp: January 04, 2018, 07:14:03 pm
content: Can you open the files with a text editor and post the header? (or upload files to have someone else take a look at these mysterious files).

author: guitarjoe91
author_rank: Newbie
timestamp: January 04, 2018, 11:04:31 pm
content: Here is the header of one of the files when opened in Notepad. Looks like a garbled mess to me:þ7  L  L ðŒv  ! ! Hv    A A h»R   À  0 X›v 0  Ø ° `[w    d  hcw   ‘ ˜ew   þ ø ÍS   X U 8 w “'  XD P }w @   z z P“v    (îw @ ˜F û ˜F 0õw H ” $ @S Ð;x @ P @  $ ØÏx  $ À @ž(   Òx @ À  (  C  (Ùx   $  $ @¸b  $ FieldDrawn By FieldChecked By FieldQC By FieldReleased By FieldDrawn Date FieldChecked Date FieldQC Date FieldRelease Date Field

author: tautech
author_rank: Super Contributor
timestamp: January 04, 2018, 11:19:09 pm
content: Quote from: guitarjoe91 on January 04, 2018, 06:34:19 pmYep, sch and pcb file extensions go way back to Protel days.Earlier versions of Altium will import and open them.

author: Chris56000
author_rank: Frequent Contributor
timestamp: January 11, 2018, 08:01:51 pm
content: Hi!Have you tried using the AutoTrax Altium Freeware to open them?NB! Please do NOT confuse this with AutoTraxDEX (Kov's) software - this is NOT the one you need!Another possibility is they might be P-Cad 2004 files - I don't know wether trial versions are still available as P-Cad was retired years ago!Chris Williams

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: January 15, 2018, 11:14:30 pm
content: Almost every PCB package uses .pcb and .sch extensions, so unless there are clues in text in the file,it's trial & error on importers/viewers

author: apurvdate
author_rank: Contributor
timestamp: January 16, 2018, 05:24:32 am
content: There is also ExpressPCB (https://www.expresspcb.com/)I havn't used it for ages..used it in college days actually... but it has .sch & .pcb file extensions..I see they've updated version.. classic version also available..

author: Jeroen3
author_rank: Super Contributor
timestamp: January 16, 2018, 07:26:33 am
content: Open the file in a hex viewer, look at the magic bytes.https://en.wikipedia.org/wiki/List_of_file_signatures

author: Nusa
author_rank: Super Contributor
timestamp: January 16, 2018, 10:42:29 am
content: Quote from: Jeroen3 on January 16, 2018, 07:26:33 amValid idea, bad source of data for this problem. There are no pcb or sch software packages on that list, not even the mainstream ones.
Distance of bottom layer SMD pad to thru-hole pads - Page 1
Forum section: electronics / general

author: ocset
author_rank: Super Contributor
timestamp: March 21, 2018, 03:45:26 pm
content: Hello,Please can you confirm that for a offline power supply board (50w) with surface mount components on the bottom, and thru-hole on the top,the SMD pads must be at least 3mm away from the thru-hole pads.I just wiondered if Wave and reflow soldering techniques have changed so that they can be closer?

author: ocset
author_rank: Super Contributor
timestamp: March 23, 2018, 06:28:34 pm
content: Thanks, i am not talking about regulations...i am speaking about the manufacture of the board in the cheapest way.For a board with smd bottm, and thru hole top, it is difficult to wave solder the thru-hole pins if they are too near to the smd pads.....i was wondering how far do the smd pads have to be away from the protruding thru-hole pins in order to make the wave soldering easy and cheap.I am assuming that the smd bottom components get mounted first....in the manufacture (pcb assembly) process

author: tautech
author_rank: Super Contributor
timestamp: March 23, 2018, 06:45:13 pm
content: As you can make your own custom pads I see no reason why you can't make the design very compact (same net) however the possibility of doing rework should be given high priority in any layout and sadly these days it isn't.

author: PCB.Wiz
author_rank: Super Contributor
timestamp: March 23, 2018, 08:28:04 pm
content: Quote from: treez on March 23, 2018, 06:28:34 pmSurely the one to ask is those actually doing the PCB assembly ?!Wave soldering clearances I would expect to vary,depending on the direction of solder wave travel.Typically they would place the SMD parts with glue-dots, then wave-flow the fully stuffed board last.

author: katy201607
author_rank: Contributor
timestamp: March 24, 2018, 02:17:25 am
content: depending on the direction of solder wave travel is correct
Math Function in Altium - Page 1
Forum section: electronics / general

author: xzswq21
author_rank: Frequent Contributor
timestamp: January 09, 2018, 08:35:26 pm
content: HelloI'm designing a PCB with Altium.how should I extract a length of a net using an expression?for example I want to put the expression (like length (net31)) in the properties of a components to calculate something automatically.Thanks
How to rout xSignals in Altium - Page 1
Forum section: electronics / general

author: xzswq21
author_rank: Frequent Contributor
timestamp: January 06, 2018, 12:45:40 pm
content: Hellomy circuit is like below:IC1====>(20 differential pairs)=====IC2===(20 differential pairs)===>Female HeaderI have usedxSignals wizardin Altium. I have chosen the source (IC1), destination(Female Header) and ... within 10mils mismatch.now some rules have been created to tune the length.my question is:now how should I start routing it? using ActiveRoute?..Thanks
PCB-RE: Tools & Techniques - Page 1
Forum section: electronics / general

author: Singapura
author_rank: Regular Contributor
timestamp: January 03, 2018, 07:59:18 am
content: Hi Everybody!I'm happy to announce that after almost three years from my first book,The Art of PCB Reverse Engineering, and seven months in the works, this sequel book,PCB-RE: Tools & Techniques, is now available online for order on Amazon.This new book covers various industry practices on PCB reverse engineering and there are a number of contributors to the chapters, some of whom you may be familiar or perhaps heard of. One of them is Fraser, a frequent contributor to this forum and an experienced engineer in many fields of interest.You can go over to my blog to find out more:visio-for-engineers.blogspot.comThere is a link to Amazon by clicking on the book cover there, and you can get to view more sample pages.Have a great new year. Cheers!Singapura (KT)

author: capt bullshot
author_rank: Super Contributor
timestamp: January 03, 2018, 08:20:09 am
content: Quote from: blueskull on January 03, 2018, 08:06:55 amNot too difficult to google:http://visio-for-engineers.blogspot.de/

author: Singapura
author_rank: Regular Contributor
timestamp: January 03, 2018, 08:32:49 am
content: My apologies. The link is below my avatar - just click on the globe icon.But I guess it's not too obvious, so I've included it in my earlier post.Sorry about that...

author: capt bullshot
author_rank: Super Contributor
timestamp: January 03, 2018, 08:47:55 am
content: Quote from: Singapura on January 03, 2018, 08:32:49 amYes, there's the link indeed. But I simply don't notice these icons anymore ...Better just include it in your signature.
pcb-rnd & cschem - Page 1
Forum section: electronics / general

author: ScribblesOnNapkins
author_rank: Regular Contributor
timestamp: December 14, 2017, 06:19:14 pm
content: Hi I am officially requesting a child board in "General PCB/EDA/CAD Discussions" for pcb-rnd and it's sister project cschem (EDA).

author: donotdespisethesnake
author_rank: Super Contributor
timestamp: December 21, 2017, 11:14:13 pm
content: Why don't you set up your own forum? Then you won't need to go spamming other unrelated forums all the time.

author: hermit
author_rank: Frequent Contributor
timestamp: December 22, 2017, 05:10:38 am
content: Well, the mods don't read every post so this probably isn't the best way to ask. I believe these are all mods. You might try a PM.EEVbloggniffSimon

author: ebastler
author_rank: Super Contributor
timestamp: December 22, 2017, 06:52:13 pm
content: Quote from: ScribblesOnNapkins on December 14, 2017, 06:19:14 pmWhat's wrong with using the gEDA child board, as you have done in the past? I understand that pcb-rnd is a branch of gEDA. And the gEDA board is the one with the smallest number of posts in the PCB/CAD section, so I'm not sure why another board would need to be spun off?

author: ScribblesOnNapkins
author_rank: Regular Contributor
timestamp: January 01, 2018, 07:33:09 am
content: hermit thanks.ebastler At this point over 2/3 of our code is different from the mainline of pcb and we are starting our own tool to replace geda. At the start of that process we most likely won't be compatible with gEDA in terms of schematic or symbol format. Rather than spam their communications channels with our stuff we want to do have our own space.donotdespisethesnake I have no idea what your problem is.

author: ebastler
author_rank: Super Contributor
timestamp: January 01, 2018, 09:42:11 am
content: Hmm... Looking at the response times in this thread (8 days for a first response, and then another 10 days before the OP returned), I am not sure how vibrant that pcb-rnd child board would be.

author: nctnico
author_rank: Super Contributor
timestamp: January 03, 2018, 01:01:43 am
content: Quote from: ScribblesOnNapkins on January 01, 2018, 07:33:09 amIf you are going to create your own schematics software then please don't make the mistake by making a symbol the center of a component! That is completely wrong. What would be ideal is to have the components in a database (sqlite for example) and each component record connects a symbol with a footprint, a value, manufacturer part number, manufacturer, etc. Then that component record can easely be extended to have an internal part number, order code, etc. Look for Orcad Capture CIS videos for further details. IMHO one of the biggest problems with the low end CAD packages is that you have to create a bill-of-materials by hand (which is prone to errors) because the component management system has been setup wrong. If you have the components in a database it is very easy to create a BOM with the right part number, order codes with one mouse click.
PCB spacing of TO220 FET legs in offline Flyback SMPS PCB - Page 1
Forum section: electronics / general

author: ocset
author_rank: Super Contributor
timestamp: December 28, 2017, 12:37:04 am
content: As you know, it is illegal to have an offline 230VAC flyback SMPS which uses a TO220 FET in the PCB without legs bent to get the clearance above 1.5mm from drain to source.…But I have taken apart an offline flyback SMPS, which is sold throughout the EU. It comprises a TO220 FET which is soldered into the PCB with legs not bent. There is just 1.09mm clearance (also creepage) between the bare metal of the drain and source pins along the PCB. This is illegal.It is sold by a huge European corporation, throughout the EU, though the SMPS was designed in China.How is this allowed? The volume sales of these product are enormous.

author: ocset
author_rank: Super Contributor
timestamp: December 28, 2017, 11:47:02 am
content: Thanks, there is no con coat.Also, this is a consmer product.

author: Circlotron
author_rank: Super Contributor
timestamp: December 28, 2017, 12:34:19 pm
content: Post a picture.

author: floobydust
author_rank: Super Contributor
timestamp: December 28, 2017, 07:08:00 pm
content: Ultimately it's the pin space on the package that is the limiting factor, so TO-220 and D2PAK same issue.App note has good info:AN-4179.pdf

author: ebastler
author_rank: Super Contributor
timestamp: December 28, 2017, 08:52:27 pm
content: Quote from: floobydust on December 28, 2017, 07:08:00 pmThanks for that reference. It is enlightening, although (or because?) I find it to be suprisingly hand-waving: "From various sources on the internet ... this can be defined as following." "The entire industry sells optoisolators with 320 mil spacing..." "This seems to agree with the industry rule of thumb..."I had expected the manufacturers to consistently refer to ISO/EN standards, if only to cover their behinds. Apparently this is a less well-defined area than I had thought.

author: floobydust
author_rank: Super Contributor
timestamp: December 28, 2017, 11:00:39 pm
content: It's the safety issue arising from having a creepage/clearance breakdown.If the TO-220 and PCB do not meet regulatory spacings requirements, it is assumed to breakdown and short.On a flyback converter, this just arcs and hopefully blows the mains fuse.It does not endanger anyone as would an arc between hazardous live and ground/or the secondary, breakdown between the D-S pins.

author: Mattylad
author_rank: Regular Contributor
timestamp: December 29, 2017, 02:27:03 pm
content: Quote from: treez on December 28, 2017, 12:37:04 amWhat law makes it illegal?Very poor design practise maybe, but what law are you referring to that makes it illegal?
solder mask free area in Altium? - Page 1
Forum section: electronics / general

author: xzswq21
author_rank: Frequent Contributor
timestamp: December 17, 2017, 12:59:54 pm
content: HelloI want to define a solder mask free area on a PCB.how should I define?I couldn't find anything

author: Deni
author_rank: Regular Contributor
timestamp: December 17, 2017, 01:06:28 pm
content: Just draw on the solder mask layer whatever you want. Altium will correctly generate negative gerber images

author: ncoonrod14
author_rank: Contributor
timestamp: December 26, 2017, 02:03:59 am
content: First select the top solder layer and then use any of the shape options in the place menu. Alternatively, if you need something that isn't a line, rectangle, or arc. You can make the outline of what you want filled using the above tools, select those objects, and got to Tools/Convert/Create Polygon from selected primitives.
LVDS pairs routing in Altium - Page 1
Forum section: electronics / general

author: xzswq21
author_rank: Frequent Contributor
timestamp: January 04, 2018, 05:08:23 pm
content: HelloI have some length matched LVDS pairs.How should I route them at the same time?Thanks

author: Mattylad
author_rank: Regular Contributor
timestamp: January 05, 2018, 01:32:47 pm
content: If you do not have a diff pair routing function then you will have to manually route them individually, measure the longest and reroute the shortest until it is within the correct skew. If they all have to be within a certain skew then you will have to figure out which will be the longest and get them to match it.Looking at those unrouted nets, for the ones on the left you will not be able to match the length to the ones on the right unless you move the chips further away.What does the spec say your routing perimeters should be?Just matched lenght per pair (thats the easy one) or matched length for a group?Moving the larger resistor/capacitor that's there would also help you.

author: xzswq21
author_rank: Frequent Contributor
timestamp: January 06, 2018, 05:26:18 pm
content: Quote from: Mattylad on January 05, 2018, 01:32:47 pmeach pairs should be matched within 10mils. for example 1_P & 1_N should be matched within 10 mils.but when I tried to tune them, the mismatch was 20 mils.
Solder Mask free Area advantages and recommendations - Page 1
Forum section: electronics / general

author: xzswq21
author_rank: Frequent Contributor
timestamp: December 23, 2017, 08:16:47 am
content: HelloI'm designing a 4-layers PCB for a high speed ADC/ FPGA.there are many 0.8mm pitch connectors/LFCSP/0201/0402/0603/0805/1206/..... packages on the board.the surface finish is ENIG.I have seen some people set a solder mask free area around the pads.what's the advantage of solder mask free area around a pad?how much the suitable size should I set for such a PCB?Thanks

author: DerekG
author_rank: Frequent Contributor
timestamp: December 23, 2017, 12:26:27 pm
content: Quote from: xzswq21 on December 23, 2017, 08:16:47 amThe solder mask adds some height above the board. Whilst 0.8mm is not fine pitch, when the pads get small & the associated clearances between them small, the solder paste stencil needs to be quite thin to avoid laying down too much solder which may lead to bridges between the pads. Under these conditions, the solder mask height may lead to a degradation in both the solder pad adhesion area & the associated mechanical strength of the joint.

author: vzoole
author_rank: Regular Contributor
timestamp: December 26, 2017, 12:53:56 am
content: Solder mask size has to be bigger than the PAD because of manufacturing tolerances.If they are the same size and the layer align is not perfect there could be solder mask on the PAD.There is some nice info:https://www.eurocircuits.com/pcb-design-guidelines/#soldermask
OTA and Norton amp library for EAGLE available - Page 1
Forum section: electronics / general

author: DrGonzoDK
author_rank: Regular Contributor
timestamp: December 21, 2017, 12:18:48 pm
content: Hey guys.I've been needing some Operational Transconductance and Norton amplifier symbols/footprints for EAGLE for some time. So I've just gone and done it.They are not flawless, but they work just fine in schematic and board.They're available athttps://github.com/dhkris/EAGLE-OTAand can be modified and so on to your heart's content.The included devices are:OTAsCA3080LM13600 / NJM13600LM13700 / NJM13700NE5517OPA861Norton AmplifiersLM2900LM3900LM359in the usual footprints (DIP, SOIC, SOT23). I am aware that there are more RCA OTAs out there - but they are pretty hard to dig up. Please let me know which ones I've missed - as well as the Norton amps.I hope it will find use somewhere out there!Symbol examples
Best printer/setup for bar label stickers? - Page 1
Forum section: electronics / general

author: Martin F
author_rank: Regular Contributor
timestamp: December 15, 2017, 07:39:11 am
content: Hi there,We've been asked by a customer to print bar label stickers and attach to our product, according to a set of specifications they provide.The labels have to be incl. a unique serial no for each product and all info is to be encrypted into a 2D bar code data matrix.Two questions:1) Do you have a good suggestion for a printer for bar labels? (46 mm x 21 mm)2) Do any of you have suggestions for how to best manage the production of unique labels ala this at scale - do you script it, do it via Excel or something else?Thanks a lot,Martin

author: woody
author_rank: Frequent Contributor
timestamp: December 15, 2017, 08:32:46 am
content: I use a Brother PT-9700PC to generate labels with a QR code containing an URL and a serial number. That serial number is generated automatically when the labels are printed. This is scripted in the P-touch software.It does barcodes in a lot of formats but I never used that. The P-touch software has a lot of nifty features to get data out of files into labels. Look at their website for an example:http://support.brother.com/g/b/faqend.aspx?c=us&lang=en&prod=3600eus&faqid=faqp00001040_003AFAIK the maximum label height (tape width) is 36 mm, don't know if that is enough for your purposes.

author: fcb
author_rank: Super Contributor
timestamp: December 15, 2017, 09:41:15 am
content: I use a Brother QL-500 and P750W for labels. Mainly because they've never failed me and the editor software is fairly powerful (generates labels from spreadsheets and databases) and seems easy to use. But then I haven't used anything else in the last 10 years, so no idea what the competition is like.When the QL-500 eventually fails (I bought it in 2008) then i'll just replace it with a new one - there seems to be about a half-dozen models to choose from.And like woody, I use barcodes no problem. Just tried the QR, MicroQR and Maxicode (for shipping) - all work fine. There are 18 and 24mm TZe tapes available for the P750W, but no 21mm wide.Avery make great labels, but I haven't tried their latest software (Design&Print) - but this might be do the 2D barcodes etc.. This will certainly be the cheapest way to mass produce these labels.

author: Gribo
author_rank: Frequent Contributor
timestamp: December 15, 2017, 05:23:53 pm
content: What is the daily volume?
0.3mm thermal vias in DPAK pads have failed badly - Page 1
Forum section: electronics / general

author: ocset
author_rank: Super Contributor
timestamp: December 23, 2017, 11:15:14 am
content: Hello, This thread speaks of using 0.3mm thermal vias in the pads of DPAK power FETs…We have 12 vias equally spaced under the drain pad of the DPAK…we have now tried this, and unfortunately some (not all) of our PCBs come back from the PCB assembly factory with sharp “shards” of solder protruding out of the bottom of the thermal vias.This is disastrous, as it pierces the thermal rubber pad that the PCB sits on, and contacts with the earthed heatsink.Some organisations speak of putting solder resist on the bottom copper layer, with an opening just wider than the thermal via opening. I wonder if this will solve our problem?Alternatively, I wonder if we should just add solder resist over the entire bottom copper, so that the bottom of the thermal vias is covered up, and might stop solder from leaking out?I wonder if using leaded solder would also help solve the problem?I also wonder whether the solder bath of the reflow oven was too hot?Also, I deeply suspect that just maybe the DPAK FETs were actually hand soldered on, because of the difficulty in getting the reflow solder bath the right temperature for all the 0402 resistors, and also the big DPAK FETs. As such, the hand solderers (if they were hand soldered, we don’t know) might have been responsible for the protruding solder?-Maybe its just impossible to get the reflow solder bath the right temperature for a board which contains both ‘teeny’ tiny 0402 resistors, and also ‘big’ DPAK FETs?

author: dmills
author_rank: Super Contributor
timestamp: December 23, 2017, 12:13:31 pm
content: There is no solder bath in a reflow oven (That is wave soldering which is not normally used for smt)!I generally tent the bottom, mostly to reduce solder thieving rather then for insulation (You could even try tenting both top and bottom, but carefully consider the mask expansion value given your vendors alignment tolerances if going there).What does your stencil geometry look like?If you are having solder puncture the insulator, I would say that your insulator is probably not man enough to be reliable over time and temperature and is most certainly something that would want extensive accelerated life testing.regards, Dan.
Pmod socket footprint - Page 1
Forum section: electronics / general

author: xzswq21
author_rank: Frequent Contributor
timestamp: December 12, 2017, 07:58:57 pm
content: HelloI'm designing a board with Altium Designer.do you have any 2x6 female right angle header (Pmod) footprint with step file?Thanks

author: halexa
author_rank: Regular Contributor
timestamp: December 12, 2017, 08:58:22 pm
content: Hi,Browse over to DigiKey:https://www.digikey.se/product-detail/en/samtec-inc/SSW-103-02-G-D-RA/SAM1215-03-ND/1112401Here you have UltraLibrarian CAD models and .step file all compatible with Altium.But for this footprint I suggest you roll your own since its such a simple footprint and then just add the .step model to your footprint and Bob's your uncle.
LT-SPICE: Can't find definiton of - Page 1
Forum section: electronics / general

author: wobbert
author_rank: Newbie
timestamp: December 08, 2017, 04:28:58 pm
content: Hi guys,I'm walking into troubles with LT-SPICE. I try to define a parameter, but it seems not to work. I get the pop-up message 'Can't find definition of "RES1"', while I believe it has been defined properly. Does anybody knows the solution to this problem? I am using the latest version of LT-SPICE ("Oct 24 2017"), which I run in WINE under Ubuntu 16.04. The circuit is attached and the SPICE code is as follows:Code:Version 4SHEET 1 880 680WIRE 128 192 0 192FLAG 0 272 0FLAG 128 272 0SYMBOL voltage 0 176 R0WINDOW 3 36 68 Left 2SYMATTR InstName V1SYMATTR Value 2SYMBOL res 112 176 R0SYMATTR InstName R1SYMATTR Value Res1TEXT 32 120 Left 2 !.param Res1=1TEXT -32 296 Left 2 !.tran 10u

author: Kalvin
author_rank: Super Contributor
timestamp: December 08, 2017, 04:46:10 pm

author: wobbert
author_rank: Newbie
timestamp: December 09, 2017, 10:45:03 am
content: I'm a f*cking retard. Thanks you very muchI tried a lot of possible solution, but clearly missed the obvious details

author: Kalvin
author_rank: Super Contributor
timestamp: December 10, 2017, 05:22:27 pm
content: Don't be too hard on yourself. Been there too
OpenEMS (dfdt) simulation of RF in 3D - Page 1
Forum section: electronics / general

author: ScribblesOnNapkins
author_rank: Regular Contributor
timestamp: December 01, 2017, 05:15:23 pm
content: This isn't a coming soon. This is a HERE NOW. Also from the email list...Hi,Over the last year I started working on a library to directly exportour geometry from pcb-rnd into OpenEMS. In the course of doing thatKoen (one of the contributors to OpenEMS) decided to join our projectand he added hyperlinx format support.The following video shows my recreation of one of his demos of OpenEMSsimulating a hair pin (distributed element) filter using pcb-rndinstead of eagle which is what he was using.So yea, we already have one way to simulate RF on boards and we areworking on another.Have fun,Evan Foss

author: hagster
author_rank: Frequent Contributor
timestamp: December 02, 2017, 07:43:12 am
content: Wow. This looks really useful. Thanks

author: ScribblesOnNapkins
author_rank: Regular Contributor
timestamp: December 03, 2017, 01:08:05 am
content: Thanks!Eventually we will have more of Koen's examples reproduced and at least one pcb antenna.The idea is to add support for direct export from pcb-rnd to openems with out going through hyperlynx and to do more like display the results in pcb-rnd, provide a dedicated layer group for control of meshing, and etc. This assumes we have people who are actively using the software continuing to ask for it.Do you have much experience with EM simulation?
Identify LCD? - Page 1
Forum section: electronics / general

author: bitman
author_rank: Unknown
timestamp: December 02, 2017, 01:33:34 am
content: Apropos Dave's latest video, I have the following LCD (?) that I cannot identify. Google has by no means been any help even though the print on the unit is very clear.This is what's printed: LPH5050-1 Q1227111 JB-9026 650It has 25 pins on one side, and two sets of 4 pins on the other.What I'm looking for is a datasheet or similar to identify the pins.Thanks (and PLEASE let me know if you have a "secret" way to identify components that is better than a random google search).

author: EEVblog
author_rank: Unknown
timestamp: December 02, 2017, 01:34:41 am
content: Most a likely a fully custom part, so you'll never find the info on it.

author: ebastler
author_rank: Super Contributor
timestamp: December 02, 2017, 05:30:30 pm
content: The naming convention suggests a Philips LCD. You will find a few Philips "LPH..." displays mentioned on the web. Some of them include a controller, some are just the bare liquid crystal device; all of them are poorly documented. As Dave said, most likely a custom part, so you are out of luck finding information online.
Homemade multilayer PCB and surface finishing  - Page 1
Forum section: electronics / general

author: hv222
author_rank: Regular Contributor
timestamp: December 01, 2017, 07:30:20 pm
content: Hi,Is someone here with experience with 4+ layer PCB? I making 2-layer PCB boards for over one year with very good results. I'm using electroless copper proces from DOW Electronic Materials and galvanic copper plating solutions from Schloetter. Basically I need add only copper oxide, lamination and desmear processes. What copper oxidation process is better for home production - brown (organic) or black(inorganic) or it is not necessary and can be replaced by mechanical process (ex. sand paper)? What cheap press can be used for lamination process? I thing about buy something like this:https://www.amazon.com/Promo-Heat-Sublimation-Transfer-Machine/dp/B005Y2C8XG.Typically desmear process is most important in multilayer process due to providing best copper to copper contact while plating. Is it possible to replace it by some mechanical process (plasma desmear is to expensive) if not, maybe is it possible to make chemical process less complicated? Typically there are 3 chemical baths, 1st - epoxy softener 2nd - alkaline permanganate solution and 3rd - neutralization solution.Currently I'm manually add solder over all pads and control it height with desoldering wire or using galvanic gold (directly over copper). Both ways need lot of time. What other processes can be used in home? I heard about Sterling Silver from Mac Dermid, but it's hard to order it in small quantity and some same situation with TINPOSIT LT34. I looking for some flat surface finishing for BGA components. ENIG is too much complicated (requires about 22 baths).
looking for OrCAD tips and tricks and other ressources - Page 1
Forum section: electronics / general

author: hammy
author_rank: Unknown
timestamp: November 19, 2017, 09:23:39 pm
content: Hi,I'm looking for OrCAD Capture and PCB Designer ressources.I had already a look on yt and tried some google searches. There is a cadence support forum, some application notes for download and all such stuff.But ... is there a place for OrCAD enthusiasts? A blog or wiki with "daily tips" or something like this? Someone who demonstrates the use of the command line window or SKILL scripting?Thank you!Cheershammy

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: November 19, 2017, 11:19:37 pm
content: http://www.flowcad.de/Application_Notes.htmAnd it's in German.

author: Eternauta
author_rank: Contributor
timestamp: November 20, 2017, 11:09:56 am
content: Cadence Allegro Tutorial - How to create SKILL Script and your own Commandsby Feranec is on Youtube:

author: hammy
author_rank: Unknown
timestamp: November 21, 2017, 03:25:29 pm
content: Quote from: Eternauta on November 20, 2017, 11:09:56 amThis ist great news! Robert is preparing OrCAD courses right now.https://www.fedevel.com/academy/online-learn-orcad-and-allegro-essentials/Cheershammy

author: asmi
author_rank: Super Contributor
timestamp: November 23, 2017, 02:28:36 pm
content: My license purchase came with access to introductory e-learning courses for Capture (schematic editor) and PCB Editor. These courses (along with some YT videos from distributors) are VERY useful and got me up and running very quickly. EMA's FE was very helpful as well.Now I'm contemplating getting EMA's full course, it's pricey but I suspect it will worth it.
Help needed for component identification  - Page 1
Forum section: electronics / general

author: satyamfifa
author_rank: Regular Contributor
timestamp: November 19, 2017, 03:05:56 pm
content: Hey Guys,I was wondering if someone can identify the attached component, any help is appreciated .Thank in advance, Kind regards.Modify message

author: kayvee
author_rank: Regular Contributor
timestamp: November 19, 2017, 03:24:09 pm
content: It looks like a Liteon LTV-817-C optocoupler.https://eu.mouser.com/ProductDetail/Lite-On/LTV-817C/?qs=WAWaI72GHKzVL8VAYU18sA%3D%3DAt least the SMD version thereof.
Help needed for component identification - Page 1
Forum section: electronics / general

author: satyamfifa
author_rank: Regular Contributor
timestamp: November 19, 2017, 02:27:45 pm
content: Hey Guys,I was wondering if someone can identify the attached component, any help is appreciated .Thank in advance, Kind regards.

author: gamalot
author_rank: Super Contributor
timestamp: November 19, 2017, 02:38:04 pm
content: Looks like a feed through capacitor.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: November 19, 2017, 03:16:22 pm
content: ceramic resonator, frequency is written on it.

author: satyamfifa
author_rank: Regular Contributor
timestamp: November 19, 2017, 03:24:44 pm
content: Thanks a lot
FR408 PCB manufacturer - Page 1
Forum section: electronics / general

author: xzswq21
author_rank: Frequent Contributor
timestamp: January 31, 2018, 06:36:21 pm
content: Hellodo you know a low cost PCB manufacturer that uses FR408 material?my requirement:4 layers10mils via6 mils clearancecontrolled-impedance optionstencilsThanks
Fluke 9010A emulator Pods - Page 1
Forum section: electronics / general

author: jerryuk
author_rank: Newbie
timestamp: November 17, 2017, 06:47:41 pm
content: Does anyone have any high resolution images of a Fluke 9010A 6502 Emulator Pod?I am intending to duplicate the pcb's for this pod and make my own as it has proven impossible to find one of these pods.I would appreciate any assistance.Thanks
A Full Review of EasyEDA: A Circuit EDA Online Tool - Page 1
Forum section: electronics / general

author: YTusername
author_rank: Regular Contributor
timestamp: November 19, 2017, 12:35:51 pm
content: HelloI've never thought that using PCB web-based editor like EasyEDA could be a real alternative to a dominated desktop application like Eagle until I wrote this review of EasyEDA. I think it has many interesting features. I hope you read my review and drop your thoughts about it here.The review:https://atadiat.com/en/articles/e-full-review-of-easyeda-circuit-eda-online-tool/I also gave Upverter tool a try in the past. What do you think? which is the best online PCB editor?
Can design rules from Altium or Eagle (Eurocircuits) be imported in gEDA pcb? - Page 1
Forum section: electronics / general

author: VinzC
author_rank: Frequent Contributor
timestamp: April 09, 2016, 08:55:18 am
content: Hi all.I'm (still) using gEDA on personal and professional ground and have my PCB fabricated byEurocircuits.com. So far I like how I manage with both but I'd like to make Eurocircuit rules the default for gEDA. Currently Eurocircuits publishes rules forAltiumorEagle. Needless to say I have neither and I run GNU/Linux (Mint on my laptop and Gentoo at home, for the record).So my question is: is there a way to import Altium or Eagle design rules into gEDA PCB?(I'm also considering switching to Kicad but it is not on topic right now.)Thanks in advance for any hint or suggestion.

author: ScribblesOnNapkins
author_rank: Regular Contributor
timestamp: April 12, 2016, 12:25:42 am
content: Look at the documentation on vendor file. It includes the design limits in the DRC area.http://pcb.geda-project.org/pcb-cvs/pcb.html#Vendor-drill-mapping

author: VinzC
author_rank: Frequent Contributor
timestamp: April 12, 2016, 05:06:49 pm
content: Quote from: ScribblesOnNapkins on April 12, 2016, 12:25:42 amThanks a lot, ScribblesOnNapkins! Can't believe after how long I sought I never came across this article. That also answers my question with a "No but..." and given how little there is to do, "manually" is a perfectly valid option.

author: ScribblesOnNapkins
author_rank: Regular Contributor
timestamp: April 14, 2016, 01:50:02 am
content: If you have documentation for vendor files for the other packages that we can legally use to write a conversion utility then I will gladly work on it.

author: VinzC
author_rank: Frequent Contributor
timestamp: April 18, 2016, 09:25:57 pm
content: Quote from: ScribblesOnNapkins on April 14, 2016, 01:50:02 amI'm not sure I follow you, do you have something specific in mind?

author: ScribblesOnNapkins
author_rank: Regular Contributor
timestamp: April 29, 2016, 03:14:06 am
content: Typically when we can find a way to automatically do something we write a utility to do it. Sadly to do that you need open documentation from the vendor about where in the configuration/project files the info we need is stored and how to decode it.

author: VinzC
author_rank: Frequent Contributor
timestamp: May 01, 2016, 03:44:33 pm
content: Quote from: ScribblesOnNapkins on April 29, 2016, 03:14:06 amAh, ok, get it now. I happen to do that, too, writing those things by hand in a repetitive manner gets somewhat boring indeed. Better have it handed to a script, that's true.

author: ScribblesOnNapkins
author_rank: Regular Contributor
timestamp: November 16, 2017, 03:14:34 am
content: Sorry for bumping an old thread but I forgot to mention this when it happened.We (pcb-rnd) can import design rules from Eagle. We can't from Altium ( yet)
What is purpose of V-shaped cutout in LED's pad? - Page 1
Forum section: electronics / general

author: ocset
author_rank: Super Contributor
timestamp: November 08, 2017, 06:19:18 am
content: Hello,What's the purpose of the V-shaped cut-out in this LED's pad? (Z8Y19 LED) Is it to help it sit centrally on the pads when its being reflow soldered?The footprint is seen on page 21 of the datasheetSeoul Semi Wicop Z8 Y19 LED:http://acrich.tw/_upload/Goods_Spec/Specification_Z8Y19_Rev5.2.pdfWe have 200 PCBs where we forgot to put the V-shape in...must we throw them in the bin?The ones we tested work well and the LEDs look perfectly central, even though we forgot the V-shape.

author: trophosphere
author_rank: Frequent Contributor
timestamp: November 08, 2017, 06:35:21 am
content: I would think it is more to help denote which pad is the cathode.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 08, 2017, 06:35:29 am
content: Probably just for polarity (assuming you don't have space to do so on silk). Outside chance it reflects the part metallization, but yeah, it isn't going to matter, not at this scale anyway.Also if it were intended, there would be dimensions.Tim

author: maukka
author_rank: Unknown
timestamp: November 08, 2017, 07:54:11 am
content: No need to include the cathode indicator on the board.
pcb-rnd 1.2.6 - Page 1
Forum section: electronics / general

author: ScribblesOnNapkins
author_rank: Regular Contributor
timestamp: October 13, 2017, 07:55:38 pm
content: This release marks an important milestone. First the original layout file (.pcb) format was replaced and now we are starting to replace the original footprint (.fp) format. With the introduction of subcircuits we would like to replace the older element data model that is used for footprints with subcircuits. The subcircuit data model can include more things that the element model can't do.* Additional flags were added to the subcircuit data model so that it could support terminals and so that those terminals can have clearance in polygons.* Openscad export has been rewritten from scratch (thanks to a donation from the private company)* Dxf export has also been rewritten from scratch* HPGL import (minimal) has been added* Changes to the HID modelThe next release will push the I/O plugins to handle the subcircuit model.

author: beduino
author_rank: Regular Contributor
timestamp: October 29, 2017, 10:12:07 pm
content: Hello,Just recompiled and installed under Fedora Linux your latest pcb-rnd-1.2.6 software and feature I'm looking for is make array of designed pcb (marked yellow in attached screenshot) just by providing array dimensions (4x3 in attached example edited in gimp) with some spacing in vertical/horizontal direction in current selected length units (lets say 5 for 5mm between boards in gven example).Is it possible clone some how to array in this improved version of pcb ? Maybe subcircuit, but I'm ne to pcb-rnd while was unaware it exists since was looking for today for pcb array clone python scripts, but was not able find anything usefull, but I need test this board using thermal transfer, so it could be nice have plenty of them on the same A4 PDF page.I could try edit generated PDF from PS export but it could be nice to be able easy make array of selected circuit copied to buffer, etcUpdate: Never mind, 4x4 array .

author: ScribblesOnNapkins
author_rank: Regular Contributor
timestamp: October 31, 2017, 02:59:28 am
content: cool let me know if you do need help.

author: nctnico
author_rank: Super Contributor
timestamp: November 03, 2017, 08:00:29 pm
content: This sort of things are typically done at the Gerber level. There are free tools to make panels out of a Gerber file.
realistic working temperature of FR4 - Page 1
Forum section: electronics / general

author: Simon
author_rank: Unknown
timestamp: November 07, 2017, 07:10:32 pm
content: From memory FR4 has a 130 or 140C temperature rating attached to it. What does this translate into in reality? would you use it for power electronics in a 100C ambient or should i use a ore exotic type of PCB ?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 07, 2017, 08:06:27 pm
content: Tg (glass transition temperature) is where it becomes floppy, and also tends to age rapidly (turn brown -- not necessarily becoming weak or brittle in the process, but getting there). There's also a lot of expansion associated with that, which would be undesirable for temp cycling.100C ambient isn't a problem, but how much temp rise is your circuit designed for, on top of that ambient?You can also try to keep the PCB cool by blowing air over it, clamping it between thermal pads, potting, and so on.Tim

author: Simon
author_rank: Unknown
timestamp: November 07, 2017, 08:12:48 pm
content: thank you Tim, it will be potted, this is my 25A motor controller so I'm hoping to make my power tracks as wide as possible to lower any up heat and possibly glue heat-sinks to my mosfets, My other consideration is how thick can i make the copper before i have problems with track widths. Most of my small parts are on a processor board but some will be with the power electronics.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 07, 2017, 08:18:26 pm
content: Ask fab. Typically minimum width/space is 2-4 times the thickness, so you can do 7/7 rules at 2-3oz, and more relaxed rules (avoid MSOP, TSSOP parts??) for more.You may also consider a multilayer board, which gets more copper without needing individual layers being very thick. 4 layers 2oz may even be a standard proto, whereas 2 layers 4oz is usually custom.Tim

author: Simon
author_rank: Unknown
timestamp: November 07, 2017, 08:20:56 pm
content: Yes I'm hoping to go with 4 layer 2 oz on the outside, this would get me 4 oz and even 6 oz where required.
No solder resist allowed between LED pads...why? - Page 1
Forum section: electronics / general

author: ocset
author_rank: Super Contributor
timestamp: October 29, 2017, 07:43:39 pm
content: Hello,We have just found out that our LED footprint is wrong. We have had 200 LED MCPCB’s made up (100 LEDs on each one) with solder resist between the LED pads. –Now we find out that there should be no solder resist between the LED pads.Do you think we must throw all these LED MCPCBs away?The LED is the WICOP2_Z8_Y19 LED by Seoul Semiconductor.Page 8 of the Seoul Semiconductor App Note called “Wicop” says that there should be no solder resist between the pads of the LED. They say that it is because flux residue can cause short circuit between the LED pads and the flux residue more readily settles on top of solder resist.Page 8 of the following....("PSR" = Photo Solder Resist")http://www.seoulsemicon.com/_upload/Goods_Spec/WICOP_Application_Note_Rev2.0.pdfSo Since when did solder resist *cause* short circuits?

author: ataradov
author_rank: Super Contributor
timestamp: October 29, 2017, 08:21:07 pm
content: I feel like it all will work just fine, assuming your board assembly house is competent.Also, the same document "Figure 3 (b)" shows a PCB with solder resist between the pads.

author: DerekG
author_rank: Frequent Contributor
timestamp: October 29, 2017, 10:36:30 pm
content: Quote from: treez on October 29, 2017, 07:43:39 pmMost modern solder pastes leave almost most deposits behind. Pay a little more for one that is of high quality.I think there is more to this than the manufacturer is letting on. I suspect the main reason the manufacturer does not want any solder mask between the pads is because it raises up the part on the board. If the solder paste is not thick enough it is possible to get open circuits (which is our experience), not short circuits.Anyway, you can minimise the likelihood of open circuits by having a thicker solder paste stencil or minimise the likelihood of short circuits by having a thinner solder paste stencil. You can also adjust the openings in the stencil for the best reliability.Give it a try. You have nothing to lose & everything to gain.

author: donotdespisethesnake
author_rank: Super Contributor
timestamp: October 31, 2017, 01:40:39 pm
content: Quote from: ataradov on October 29, 2017, 08:21:07 pmThat is obviously demonstrating something else, doesn't mean anything.