Using sockets instead of components - Page 1
Forum section: electronics / general

author: JSanders
author_rank: Contributor
timestamp: January 21, 2023, 02:39:01 pm
content: New here to the forum and to EDA software and have a basic question when wanting to use sockets instead of actual components.When designing the circuit the actual component is used in order to see / reference pin assignments, but then how does one switch over to using a socket for laying out the board?I'm using EasyEdaThanks.Update: The component in question is D1A050000 8 pin through hole Reed Relay which has fewer pins then the corresponding socket. So I need to somehow swap out the relay for the socket during the board layout for proper hole placement and need to update things accordingly for the BOM.

author: themadhippy
author_rank: Super Contributor
timestamp: January 21, 2023, 03:44:22 pm
content: you change the footprint of the relay

author: jpanhalt
author_rank: Super Contributor
timestamp: January 21, 2023, 03:57:25 pm
content: It's best to start building your own library of components and hardware (e.g., sockets). In the program I use, one draws a symbol and package separately, then associates the two to get a device.As for your immediate question, you can add pins to the relay and mark them NC for not connected or subtract pins from the DIP socket and rename that the appropriate socket. Pulling pins from a standard socket before assembly is really quite easy. I would probably go the latter route as having extra space on a PCB may be helpful. I am not aware of any instance in which it was a disadvantage.

author: JSanders
author_rank: Contributor
timestamp: January 21, 2023, 04:42:26 pm
content: Took a quick look and found a Footprint Manager in EasyEDA but yet to find a way to edit or modify it, have to keep looking.Once I manage to create or modify the Footprint adding in the required pins so the board will have the correct hole placement, still not sure how to configure things so the BOM will reference the socket rather then the relay for the assembly process. Ideally would like to have both the Relay and Socket included in the BOM while somehow indicating that only the socket be soldered not the relay.

author: themadhippy
author_rank: Super Contributor
timestamp: January 21, 2023, 04:50:19 pm
content: Quotehttps://docs.easyeda.com/en/PCBLib/PCBLib-Edit/index.htmlor to create your ownhttps://docs.easyeda.com/en/PCBLib/PCBLib-Create/index.htmlHowever in this instance if its a standard ic socket add a chip that uses the base your after to the circuit diagram,hit tools-footprint manager ,you'll see your components listed,click on the chip you added and the footprint it uses should appear in the search box,copy the contents of the search box ,select your relay and paste the copied text into the search box,find it on the drop down list ,double click and it should then be associated to the relay,next up change the component pin assignment in the same window so the pins on the relay go to the right socket pins.go back to the circuit diagram,delete the chip you added,job done.

author: langwadt
author_rank: Super Contributor
timestamp: January 21, 2023, 04:57:31 pm
content: why not pull the extra pins out off the socket?

author: JSanders
author_rank: Contributor
timestamp: January 21, 2023, 05:01:07 pm
content: themadhippy, thanks for the links, already started playing around with editing both the symbol and footprint.

author: themadhippy
author_rank: Super Contributor
timestamp: January 21, 2023, 05:04:21 pm
content: see my edit for a simpler way

author: JSanders
author_rank: Contributor
timestamp: January 21, 2023, 05:06:46 pm
content: langwadt - plans are to have the boards pre-assembled so wouldn't have the ability to modify things such as removing pins.

author: JSanders
author_rank: Contributor
timestamp: January 21, 2023, 05:21:25 pm
content: themadhippy - If I'm understanding things correctly here it sounds like your saying I can link two components together, coupling a standard IC socket with the Relay?That actually sounds like the solution I'm looking for, when designing the circuit it would show the correct pin assignments and then when laying out the board it should have all of the proper through holes. Also sounds like it might take care of the BOM situation by having both components included.

author: themadhippy
author_rank: Super Contributor
timestamp: January 21, 2023, 05:29:40 pm
content: Quoteno ,all its doing is swapping the footprint of the relay

author: JSanders
author_rank: Contributor
timestamp: January 21, 2023, 05:42:23 pm
content: Oh, gotcha - bummer was hoping I could somehow build a symbol & footprint combining the two components as it would have solved both the design and BOM issues.

author: Kleinstein
author_rank: Super Contributor
timestamp: January 21, 2023, 08:08:48 pm
content: One would keep the original symbol (relays) and add (if not already present) an extra footprint that can be used with the relay. In the BOM the power would show as relay - possibly as the variant socketed (depends on the EDA package).In many cases I would just keep the normal relay and add the socket only an assembly, as the DIP style THT sockets fit the same footprint on the PCB and only change the hight. There are however also sockets that have a different pinout on the PCB than the part they take (e.g. some PLCC, some relay sockets)

author: nctnico
author_rank: Super Contributor
timestamp: January 21, 2023, 09:29:33 pm
content: How about buying sockets that match the relay?https://www.mill-max.com/products/new/new-relay-and-oscillator-socketsPut the socket in the BOM and put the relay in a seperate parts list with things that need to be added to the PCB later on (like screws, stickers, heatsinks, jumpers, etc). In some CAD software you can add mechanical parts to the BOM which are not placed on the board but are included in the BOM for assembly.

author: JSanders
author_rank: Contributor
timestamp: January 23, 2023, 08:18:17 am
content: nctnico - Had no idea they made specialized sockets just for the relay I’m looking to use and the link you provided shows the exact one needed right there on the home page.Okay so mentioned above that I’m new to EastEDA and not sure if I’m doing things wrong or missing something but having trouble locating the odd component. Chips, diodes, caps & resistors no problem but others like connectors and well the Mill-Max relay sockets not going so well.Found the Mill-Max relay socket (110-43-316-10-005000) at Mouser and Digikey as well as the 5.5 x 2.1 DC Power Connector but can’t locate either within EasyEDA. Not sure if LCSC just doesn’t carry the components or if they’re under a different part number.Sort of understand not being able to find the Mill-Max socket as its probably not a part used all that often, but surprised in not finding the 5.5 x 2.1 DC Power Connector as I thought it was fairly common.

author: nctnico
author_rank: Super Contributor
timestamp: January 23, 2023, 09:44:23 am
content: You will likely need to create the components (symbol, footprint, part information) that are missing from the standard database, by yourself. That is normal for every CAD package you use.

author: JSanders
author_rank: Contributor
timestamp: January 23, 2023, 11:18:42 am
content: Got a taste of creating / modifying symbols & footprints from an earlier post above but was planing on having the boards both manufactured and assembled. Not quite sure how that process can take place if components aren’t available. Should I be modifying my design to only use components in JLCPCB’s inventory?

author: langwadt
author_rank: Super Contributor
timestamp: January 23, 2023, 11:30:18 am
content: Quote from: JSanders on January 23, 2023, 11:18:42 amys, if you want it assembled you have to use components in JLCPCB’s inventory

author: JSanders
author_rank: Contributor
timestamp: January 23, 2023, 12:08:08 pm
content: Sorry for all the questions, this is all new to me and wasn’t sure if perhaps odd components could be supplied for the assembly process. Would prefer to have the entire board assembled but adding one or two components post production could be an option.If through hole components aren’t available and excluded from the BOM, can they be easily added after assembly or would there be a concern that holes could get soldered over / closed in the process?

author: nctnico
author_rank: Super Contributor
timestamp: January 23, 2023, 12:46:54 pm
content: Quote from: JSanders on January 23, 2023, 12:08:08 pmIf there are no other through hole components on the board, then the holes should stay open because there is no reason to use wave soldering. In a rare occasion it might possible bottom SMT parts are soldered using wave soldering but I think the chances for this are super small. What is a concern though that the open holes may become less solderable due to getting heated so an oxide layer may form. This also depends on the finish. For hand soldering, I like tin finish much better compared to gold. Then again, gold finish is better for solder paste / reflow process. You'd have to ask JLCPCB to make sure...

author: langwadt
author_rank: Super Contributor
timestamp: January 23, 2023, 01:17:16 pm
content: Quote from: JSanders on January 23, 2023, 12:08:08 pmadding parts later is not a problem, afaict they only put paste on the pads for components they actually mount and through hole they solder manually

author: JSanders
author_rank: Contributor
timestamp: January 23, 2023, 01:29:29 pm
content: The only through hole components on the board would be the relay socket and the power connector. Since JLCPCB doesn’t carry the Mill-Max relay socket, was going to switch back to using a standard through hole 14 pin dip socket. But just to be safe probably going to swap that out for an SMT socket to avoid the wave soldering process all together, well that’s if LCSC carries them in there inventory.That would leave only the DC power connector and I’d want to keep that as a through hole component for the secure physical connection to the board it would provide.The only post production work to be done would be to solder the DC power connector and that seems like a doable solution.

author: JSanders
author_rank: Contributor
timestamp: January 23, 2023, 01:39:13 pm
content: langwadt – sorry didn’t get a chance to read your post before posting my last response. If through hole components are manually soldered then there shouldn’t be anything to worry about and the holes for the DC power jack should remain free of solder.

author: langwadt
author_rank: Super Contributor
timestamp: January 23, 2023, 05:11:21 pm
content: Quote from: JSanders on January 23, 2023, 01:39:13 pmfor a long time JLC only did smd so everyone did the through-hole later, there's no solder on the through-hole padsunless you have a lot of relays you might as well do the sockets yourself when you have to de the power jack anyway, and then youcan keep the relay footprint and just use regular sockets with the extra pins pushed out

author: JSanders
author_rank: Contributor
timestamp: January 23, 2023, 05:24:03 pm
content: There’s only a single relay per board, however after ordering & testing the prototype, the first planned production run will be for 34 boards so the soldering is going to add up over time.

author: james_s
author_rank: Super Contributor
timestamp: January 23, 2023, 06:49:12 pm
content: Why do you want to put the relay in a socket in the first place? Is it an optional part? Sockets add cost and potential failure points, I rarely use them unless it's something like a programmable part that needs to be removed to program it.

author: JSanders
author_rank: Contributor
timestamp: January 23, 2023, 07:08:51 pm
content: Mechanical relays don’t have the best MTBF rating, so want the ability to swap it out without having to perform major work on the board and to help eliminate any prolonged down time if a failure does occur. And the cost is negligible running $ 0.03 per socket.

author: james_s
author_rank: Super Contributor
timestamp: January 23, 2023, 08:00:35 pm
content: Relays are at least as reliable as sockets in my experience, and I wouldn't call replacing a single through-hole component as "major work" but I guess it depends on the application.

author: nctnico
author_rank: Super Contributor
timestamp: January 23, 2023, 09:45:11 pm
content: Quote from: james_s on January 23, 2023, 08:00:35 pmI agree. Well, maybe a socket is even less reliable. Unless you run a relay near the max ratings (also keep in mind the minimum current spec!), they last insanely long.The only small signal relays I recall replacing where reed relays in an old HP unit because the relays contacts got magnetised and became sticky.

author: james_s
author_rank: Super Contributor
timestamp: January 23, 2023, 11:59:44 pm
content: I replaced the relays in the attenuator modules in my TDS700 scope because contact resistance was causing SPC to fail, but that is a special case with a very sensitive circuit. Replacing those was a proper pain in the butt since they're mounted on fragile ceramic boards and you can paint yourself into a corner if you don't install them in just the right order.

author: JSanders
author_rank: Contributor
timestamp: January 24, 2023, 12:53:41 am
content: Personally I’ve never had a socket fail – ever, but have experience many relay’s that have needed replacement. As for the effort needed in replacing a soldered component vs one mounted in a socket is night and day.The boards are to be located inside an enclosure with mounting screws / standoffs and have several wired connections. In order to change out a soldered component, everything must be disconnected, the board un-screwed, removed and taken to a workbench. Heating / wicking or vacuuming the old solder to remove the relay, cleaning the pads in preparation of applying new solder, then the actual installation of the replacement relay.During this process the board could possibly be damaged, a cold solder joint could ensue and if nothing adverse takes place then the cleaning any flux residue would follow proceeding the re-installation - remounting it into the enclosure and hooking up the wired connections.With a socket mounted component one need only power down the system, pull the old relay and replace with the new. There’s minimal concern for accidental damage to nearby component and absolutely zero concerns in creating a cold solder joint. There’d be no worries in causing damage to the wired connections as they’d all stay in place as the board wouldn’t have to be removed from it’s enclosure.Also when dealing with components that have a lower then optimal MTBF, which can be easily replaced, one can justify / entertain the idea of preventative maintenance if desired or if it were deemed a critical system. While that’s not the case here it is something we’ve done in the past which simply wouldn’t be feasible with soldered components.