The ic packages are getting rediculous, end of hobbie? - Page 1
Forum section: electronics / general

author: Kjelt
author_rank: Super Contributor
timestamp: May 21, 2015, 08:56:31 am
content: Just saw a new motorcontroller ic from ST, everything integrated incl. 8 mosfets resulting in this rediculous vfqfpn package with a lot of hidden pads beneath for cooling.If I see this packages I get nightmares, a bit too little paste and it will die overheating, a bit too much paste and you might have shorts.Am I the only one thinking that these kind of packages are the end of the hobbie?

author: tom66
author_rank: Super Contributor
timestamp: May 21, 2015, 09:00:45 am
content: Such devices are intended for highly specialised and integrated controller modules that are going to be made in large quantities - especially common in automotive markets.SOIC, QFP, QFN, MSOP and TSSOP+EP will still be around in 15-20 years, I guarantee it.

author: Tandy
author_rank: Frequent Contributor
timestamp: May 21, 2015, 10:29:25 am
content: Also components that are most useful for hobbyists will be mounted on little breakout boards and sold by hobby friendly suppliers. It might mean that hobbyists miss out on some of the more exotic ICs but solutions will be found to most obstacles I'm sure.

author: daqq
author_rank: Super Contributor
timestamp: May 21, 2015, 10:36:45 am
content: To be honest I'm amazed that parts in hobbyist friendly packages like DIP are still available. I mean, who (in bulk) uses say, a 74HC00 in a classic 2.54mm DIP?

author: krivx
author_rank: Frequent Contributor
timestamp: May 21, 2015, 10:43:27 am
content: Quote from: daqq on May 21, 2015, 10:36:45 amIf I buy a 74 series DIP today, am I likely to get new stock? With a '15 data code? I would guess there are vast quantities of old parts sitting in distributor inventories. If no one buys them in bulk then it makes sense that hobbyists can get them in small quantities for a long time...

author: rsjsouza
author_rank: Super Contributor
timestamp: May 21, 2015, 10:47:36 am
content: Quote from: krivx on May 21, 2015, 10:43:27 amYes, you will. These parts are still being actively manufactured in decent quantities and distributors move parts as they arrive: they don't keep stale inventory on their warehouses.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 21, 2015, 10:52:25 am
content: Hidden pads aren't a problem if you use a stencil.

author: bktemp
author_rank: Super Contributor
timestamp: May 21, 2015, 11:26:29 am
content: I once asked Microchip why they make 16 and 32bit microcontrollers in DIP packages. The answer was simple: Because is it easier for prototypes.If you do not need any special PCB for the microcontroller then people simply start using them, because it is cheaper and faster than making or buying a PCB.This is probably not longer the case due to Arduino and cheap PCBs from China, but it was until a few years ago.

author: Kjelt
author_rank: Super Contributor
timestamp: May 21, 2015, 11:28:57 am
content: Quote from: mikeselectricstuff on May 21, 2015, 10:52:25 amIf you have a pro stencilprinter you are right. If you do it like a hobbieist by taping it to a board and placing the pcb under it and squashing the paste with human pressure under aprox. the right angle it varies. Sometimes you have too much and sometimes you have too little paste, at least my experiences, but it is workable.But look at this package with all its tiny pins on the side , just asking for a short with too much paste from the pads nearby.

author: c4757p
author_rank: Super Contributor
timestamp: May 21, 2015, 11:33:47 am
content: Am I the only hobbyist who'sexcitedby cool new stuff and wants to try using parts that look a bit tricky, maybe even because they look a bit tricky? That's half the fun...

author: Kjelt
author_rank: Super Contributor
timestamp: May 21, 2015, 11:41:31 am
content: Quote from: c4757p on May 21, 2015, 11:33:47 amWait till half your creations die after a few months unless you have an xray machine to check the padbonding

author: daqq
author_rank: Super Contributor
timestamp: May 21, 2015, 11:45:40 am
content: QuoteWell, I'm all for great new stuff, but the moment a simple technology disapears, the learning curve gets steeper, the cost to enter the game gets higher, possibly discouraging potential players.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 21, 2015, 12:04:03 pm
content: Quote from: krivx on May 21, 2015, 10:43:27 amYes.The oldest lines have lapsed (RTL, DTL, 7400 TTL), except for special application ones that have remained in production (e.g., 7406 high voltage open collector inverter). The "good enough to be worthwhile" ones like 74LS are still either current production (if obsolecent) or nearing close. 74HC and CD4000 are still current production. I think ECL (10k series) too? Though if you need ECL, there are new and better available (100k series, PECL, etc.) too.Tim

author: krivx
author_rank: Frequent Contributor
timestamp: May 21, 2015, 12:05:23 pm
content: Quote from: rsjsouza on May 21, 2015, 10:47:36 amI get that hanging onto parts is bad business, but Digikey have 10k+ 74HC00 in stock in DIP packages. That seems like a huge amount to just cover orders "on demand", and seems like it could be sitting there for some time.I'll be totally honest though, I have no idea. I haven't ordered parts like that in a while.

author: krivx
author_rank: Frequent Contributor
timestamp: May 21, 2015, 12:06:33 pm
content: Quote from: T3sl4co1l on May 21, 2015, 12:04:03 pmInteresting. I would have assumed that these lines are still in production, just not in DIP.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 21, 2015, 12:30:38 pm
content: Also, you'd be surprised just how much industrial hardware is out there, still in current production since the early 80s, and probably plenty even older than that. If they're lucky, they can drop in 74LS or 74HC for 7400, and production stays happy for another three decades.So DIP and discrete logic aren't going anywhere.CD4000 has the added feature that it's blissfully integrable with analog circuits, for those odd times when you need, like, a sequential selector switch function, with analog mux. Saves the trouble of a 5V rail (or 3.3V or less!) and interface logic!Tim

author: djQUAN
author_rank: Frequent Contributor
timestamp: May 21, 2015, 12:33:29 pm
content: I just recently bought a 74C series chip around last month........with a '91 date code.

author: Asmyldof
author_rank: Regular Contributor
timestamp: May 21, 2015, 12:53:59 pm
content: Instead of buying your 74xxxxx chips, you can always ask me.I'm again in a little 2 minute break at work, so no photos elas, but I have a cabinet that's been nearly untouched for many years now with a vast array of DIPs. :-) If you don't care about a '9* date code.To be honest, I'm not going to go through the hassle of packing and shipping them, so it's moot as an offer, but to make the point the other way... I have the stock but no desire to ever use them again.I'm a ... probbyist ...? (pro-hobbyist) I do still make many PCBs myself, and solder them myself, often without the use of paste. Not because I don't want to, but because it's more of a craft left over from the very early '90s where I had only the reel of klunky 1mm tin/lead wire (with flux, luckily), a jar of smelly resin and some alcohol to thin that for application.But packages like these aren't that big a problem for me, to be fair I have added SMD-pre-heaters and SMD-rework guns to my collection and have put in several days of destructive fooling around with them to tune my craft so to speak.But, yes, I do try to avoid them in any fully hand-made design, since the PCB tolerances and manual placement tolerances do add up and the risks become quite large.By the way, "a bit too little paste" isn't as dangerous as you put it, since there's always some electrically insulating matter between the top copper and whatever thing is beneath that and the vias needed to transport that heat away aren't going to win from a thin layer of paste which may only cover 70% of the possible connection.Usually those pad sizes are over dimensioned for the transport required or attainable on the current technologies in matters of PCB materials and processes.Not for your hobby, but because industry also doesn't really like things that come down to the single percent.If I ask a fab to place something (whether chip or paste) with an infinitesimal accuracy they will sometimes agree, but you should see the bill they send at the end, nobody would use the chip if a fab placing it had to send a bill that has a +fee for that one chip that's the same as the chip cost (or double that).All that said, I do agree with the general consensus that no hobbyist should want to use a chip like this. I don't want to either, I just do sometimes, because.... eh... reasons. (staying up to date with developments and tech mostly)

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 21, 2015, 01:16:02 pm
content: Quote from: Kjelt on May 21, 2015, 11:28:57 amThe stencil thickness gives a reasonably consistent thickness. The amount of paste isn't really that critical.

author: jlmoon
author_rank: Unknown
timestamp: May 21, 2015, 02:31:27 pm
content: Quote from: c4757p on May 21, 2015, 11:33:47 amNope, the trickier the better. Nothing like a late night challenge both fabricating and diagnosing. It can be quite the rewarding experience!

author: free_electron
author_rank: Super Contributor
timestamp: May 21, 2015, 02:46:24 pm
content: Quote from: c4757p on May 21, 2015, 11:33:47 amit ain;t fun if all you need is a hammer to build something.

author: Tandy
author_rank: Frequent Contributor
timestamp: May 21, 2015, 03:03:02 pm
content: Quote from: daqq on May 21, 2015, 11:45:40 amThat might be true to a certain extent but in my experience young players today get started the other way round. For example my cousins daughter recently got interested in electronics and started out making projects on an Arduino. So she had little knowledge about electronics other than knowing the difference between +v and -v and how to follow the instructions for connecting things on a breadboard. She could have a fruitful hobby with this basic understanding and make many fun and interesting projects. However I showed her some electronics books that I learnt from when I was younger and she is beginning to learn about the more fundamental electronic principles. I suspect that a majority of people new to electronics will learn this way round.

author: marshallh
author_rank: Unknown
timestamp: May 21, 2015, 03:34:15 pm
content: I have seen these on WD hard disk controllers.

author: smjcuk
author_rank: Frequent Contributor
timestamp: May 21, 2015, 03:44:29 pm
content: That's just sadistic.I only do 1970s style electronics for personal use so I'm happy with through hole. I'm building a good stock of parts. If you're into this, now is a good time as it's all going cheap due to disinterest and concentration on Arduinos and the like. Can't say I've seen any stock problems either; it's still pouring out of China in vast quantities.To be honest, my last three designs have started life as a microcontroller, migrated to ICs and ended up discrete. I managed to replace a 55 line AVR-GCC program (mainly a large LUT using pointers) with 6 transistors, 3 capacitors and 11 resistors last week and it was much more fun which is why I do this

author: German_EE
author_rank: Super Contributor
timestamp: May 21, 2015, 08:52:31 pm
content: How would I deal with this package?1) The proper way, make a PCB with a layout matching that in the datasheet then get a stencil prepared and put the right amount of solder past on. Then put it through a reflow oven.However............I don't have a stencil or a reflow oven as I solder all of my surface mount parts by hand using a microscope.So....................2) The alternative method. Make a PCB with a layout matching that in the datasheet but with a single 1mm via in the middle of each pad going through to a matching pad on the other side. Holding the chip down on the PCB solder the pad on the other side and let some of the solder wick through the via until it makes contact with the chip. Solder resist around the pads should prevent any problems.

author: Sigmoid
author_rank: Frequent Contributor
timestamp: May 21, 2015, 09:00:24 pm
content: Quote from: German_EE on May 21, 2015, 08:52:31 pm3) You could dead bug it with thin insulated wires. It would be painful, but not altogether impossible.4) Design a throughhole breakout board, group up with others on-line, and order a batch of it from a workshop that does pick&place.

author: smjcuk
author_rank: Frequent Contributor
timestamp: May 21, 2015, 09:11:02 pm
content: You could dead bug it but if you blow it up, think of the pain.

author: tom66
author_rank: Super Contributor
timestamp: May 21, 2015, 09:40:02 pm
content: The pads are also there to help remove heat from the silicon inside, so dead bugging wouldn't work unless you found some other way to keep the package cool.

author: langwadt
author_rank: Super Contributor
timestamp: May 21, 2015, 10:06:54 pm
content: Quote from: Tandy on May 21, 2015, 10:29:25 amyeh, I'm sure those who did point to point wiring of tubes, thought DIP packages and PCBs wassimply impossible to do at home

author: tggzzz
author_rank: Super Contributor
timestamp: May 21, 2015, 10:09:49 pm
content: Quote from: German_EE on May 21, 2015, 08:52:31 pmStencils and ovens aren't necessary. Seehttps://entertaininghacks.wordpress.com/tag/pcb/for my experiences. Hint: easier and more successful than I expected.

author: amyk
author_rank: Super Contributor
timestamp: May 22, 2015, 02:14:04 am
content: Quote from: marshallh on May 21, 2015, 03:34:15 pmAt that point you might as well use a BGA...

author: Fsck
author_rank: Super Contributor
timestamp: May 22, 2015, 02:16:25 am
content: Quote from: amyk on May 22, 2015, 02:14:04 amit's like double the effort

author: pickle9000
author_rank: Super Contributor
timestamp: May 22, 2015, 02:27:41 am
content: The beauty of the hobbyist is they don't know you can't do things without specialized gear. They figure it out anyway.Using a frying pan to solder is crazy, but it's done and it works.Now to be honest any good EE is also and will always be a hobbyist.

author: Muxr
author_rank: Super Contributor
timestamp: May 22, 2015, 02:53:53 am
content: I've abandoned far less complex packages for being a pain to work with. I suppose it's not too bad once you decide to produce a final product and you get the proper stencil, but sometimes I just want to prototype with a part and not having a feasible way to break it out is a show stopper, for me at least.