Through Hole vs. Surface Mount
in [Design]
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From: Hammy on 29 Mar 2010 10:00 On Mon, 29 Mar 2010 08:10:39 -0500, Jim Yanik <jyanik(a)abuse.gov> wrote: >Robert Baer <robertbaer(a)localnet.com> wrote in >news:xLqdnSAtgJGa0S3WnZ2dnUVZ_oQwAAAA(a)posted.localnet: > >> Chris wrote: >>> I have just completed a designing a board that has 5 16 pin ICs. I >>> was planing on etching and drilling myself, but after my last project >>> took for ever to drill far fewer holes, I was considering going >>> surface mount. I am only planing to make three at first. Should I >>> stick to through hole for the ease of hand soldering, or should I >>> switch to decaf and wait a month and try my hand at surface mount. >>> >>> Comments Welcome, >>> Chris Maness >> If you are young (good eyes), the smallest parts to use would be >> 0402. That said, fine pitch QFPs are not a big problem if pads are >> pre-tinned. >> > >making a one-off PCB to use fine pitch ICs is the real problem. > >I have a project on hold until I can figure out how to make a PCB for a 8 >pin eMSOP package,LM3410XMY. the entire IC is about the size of a pencil >eraser. :-( > >(It's a boost LED driver-regulator,1 IC and 7 other parts,all 0603 size) I use the TPS40210-11 Boost controller in 10 pin MSOP with powerpad. They aren't that bad. Drill one or two holes under the IC put light solder under the IC, and a dab of solder on the power pad. The parts are so tiny you can heat the exposed copper pore on either side of the IC causing the solder on the power pad to reflow. The other way is heat the wires you use for vias under the IC to reflow the solder.Just dont go crazy with the solder under The IC or when it settles it will push the solder on the pads; short phhsst! The only thing about those parts if you suspect it's damaged there's no easy way to swap it out without damaging all the pads and traces.
From: Tim Williams on 29 Mar 2010 10:10 "mpm" <mpmillard(a)aol.com> wrote in message news:3c2cb2d5-5c26-496d-8de8-abc5392f8269(a)z4g2000yqa.googlegroups.com... > One mis-step, and you've potentially ruined hours worth of work, only > to start all over again. > Plus, after you're purchased the bare copper boards, the checmials, > the drills, and include your time -- it costs way more than the cheap > PCB houses. > With the latter giving you near perfect boards most of the time, on 2 > or 3 day turns, for $50 or so, and some even include the > silkscreening. The chemicals are practically free. Muriatic acid $5 at the hardware store. Acetone $5. You could get about a hundred boards from each, the cost per board doesn't even count. You'll spend more on the transfer paper. As a student, I don't have $50 to spare, nor is my time worth more than $50 for the same. It makes sense to make my own boards. There is one more advantage you missed. I also get them same day, a service you'd be charged many times the list price from a commercial supplier. Tim -- Deep Friar: a very philosophical monk. Website: http://webpages.charter.net/dawill/tmoranwms
From: Joerg on 29 Mar 2010 10:49 Robert Baer wrote: > Joerg wrote: >> Martin Riddle wrote: >>> "Chris" <christopher.maness(a)gmail.com> wrote in message >>> news:fbd910e4-f10e-42d8-a193-bb9c7a1cd19f(a)c2g2000pre.googlegroups.com... >>>> I have just completed a designing a board that has 5 16 pin ICs. I >>>> was planing on etching and drilling myself, but after my last project >>>> took for ever to drill far fewer holes, I was considering going >>>> surface mount. I am only planing to make three at first. Should I >>>> stick to through hole for the ease of hand soldering, or should I >>>> switch to decaf and wait a month and try my hand at surface mount. >>>> >> >> A glass of Guinness works much better :-) >> >> >>>> Comments Welcome, >>>> Chris Maness >>> >>> I second the SMT try. It's not as difficult as it seems. Get a good >>> magnifier , headband type. >>> A good pair of tweezers, fine tips for your iron, and fine 0.015" >>> solder helps too. >>> >> >> I like 0.015" Kester No-Clean best. No mess. >> >> >>> There are some good parts out there that only come in SMT. >>> >> >> Yep, like tons of great RF transistors or fast opamps. >> > "No-Clean"? GACK! avoid that junk like the plague it is... I've had no issues at all with it. Very clean solder joints, and they stay clean. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: mpm on 29 Mar 2010 11:22 On Mar 29, 9:10 am, "Tim Williams" <tmoran...(a)charter.net> wrote: > "mpm" <mpmill...(a)aol.com> wrote in message > > news:3c2cb2d5-5c26-496d-8de8-abc5392f8269(a)z4g2000yqa.googlegroups.com... > > > One mis-step, and you've potentially ruined hours worth of work, only > > to start all over again. > > Plus, after you're purchased the bare copper boards, the checmials, > > the drills, and include your time -- it costs way more than the cheap > > PCB houses. > > With the latter giving you near perfect boards most of the time, on 2 > > or 3 day turns, for $50 or so, and some even include the > > silkscreening. > > The chemicals are practically free. Muriatic acid $5 at the hardware store. > Acetone $5. You could get about a hundred boards from each, the cost per > board doesn't even count. You'll spend more on the transfer paper. > > As a student, I don't have $50 to spare, nor is my time worth more than $50 > for the same. It makes sense to make my own boards. > > There is one more advantage you missed. I also get them same day, a service > you'd be charged many times the list price from a commercial supplier. > > Tim > > -- > Deep Friar: a very philosophical monk. > Website:http://webpages.charter.net/dawill/tmoranwms That's a fair statement. Several, in fact. I was a student myself the last time I went the DIY route. Perhaps it is a rite of passage? :) Never again though.
From: Jim Yanik on 29 Mar 2010 12:17
Hammy <spam(a)spam.com> wrote in news:9fc1r5p8f21dgh6htq6lpf6ts4tf1ij0dt(a)4ax.com: > On Mon, 29 Mar 2010 08:10:39 -0500, Jim Yanik <jyanik(a)abuse.gov> > wrote: > >>Robert Baer <robertbaer(a)localnet.com> wrote in >>news:xLqdnSAtgJGa0S3WnZ2dnUVZ_oQwAAAA(a)posted.localnet: >> >>> Chris wrote: >>>> I have just completed a designing a board that has 5 16 pin ICs. I >>>> was planing on etching and drilling myself, but after my last >>>> project took for ever to drill far fewer holes, I was considering >>>> going surface mount. I am only planing to make three at first. >>>> Should I stick to through hole for the ease of hand soldering, or >>>> should I switch to decaf and wait a month and try my hand at >>>> surface mount. >>>> >>>> Comments Welcome, >>>> Chris Maness >>> If you are young (good eyes), the smallest parts to use would be >>> 0402. That said, fine pitch QFPs are not a big problem if pads are >>> pre-tinned. >>> >> >>making a one-off PCB to use fine pitch ICs is the real problem. >> >>I have a project on hold until I can figure out how to make a PCB for >>a 8 pin eMSOP package,LM3410XMY. the entire IC is about the size of a >>pencil eraser. :-( >> >>(It's a boost LED driver-regulator,1 IC and 7 other parts,all 0603 >>size) > > I use the TPS40210-11 Boost controller in 10 pin MSOP with powerpad. > They aren't that bad. Drill one or two holes under the IC put light > solder under the IC, and a dab of solder on the power pad. The parts > are so tiny you can heat the exposed copper pore on either side of the > IC causing the solder on the power pad to reflow. The other way is > heat the wires you use for vias under the IC to reflow the solder.Just > dont go crazy with the solder under The IC or when it settles it will > push the solder on the pads; short phhsst! > > The only thing about those parts if you suspect it's damaged there's > no easy way to swap it out without damaging all the pads and traces. > my problem isn't in soldering the IC,but in laying out and etching a PCB with such fine pitch leads. (I had thought the IC would be bigger...) Also,I was mistaken about the 603 size,they are 805,except for the coil and diode. -- Jim Yanik jyanik at localnet dot com |