Working With SMDS - Prototyping
Adam Horden, Sun Aug 06 2006, 05:09PMHi All,
I want to start working on my new projects but all the parts I want to use are now all SMD only so its a little hard to build a rats nest prototype without making a pcb.
Farnell sell these
Will these work for most of the new smds like DPacks and the small SOT223 SOT23 I-pak and d-pak? I am guessing the will work with SOIC ICS as well.
Whats the best way to solder them using a fine tip a decent light and gluing them in place while soldering them in place? I think there is a glue designed for doing this.
Any one got any tips?
This is the first time I will be working with SMDs.
Adam
Re: Working With SMDS - Prototyping
Electroholic, Sun Aug 06 2006, 07:02PM
its really not that hard, a very clean fine iron tip, and a steady hand will do. you can also practice on old electronix stuff first. like broken laptop mobo and junk like that.
Electroholic, Sun Aug 06 2006, 07:02PM
its really not that hard, a very clean fine iron tip, and a steady hand will do. you can also practice on old electronix stuff first. like broken laptop mobo and junk like that.
Re: Working With SMDS - Prototyping
Pete, Sun Aug 06 2006, 08:05PM
Try this if you have the time.
These guys are using their toaster oven to do all at once soldering. I've never tried it, but have heard it's a nice way to go.
Pete
Pete, Sun Aug 06 2006, 08:05PM
Try this if you have the time.
These guys are using their toaster oven to do all at once soldering. I've never tried it, but have heard it's a nice way to go.
Pete
Re: Working With SMDS - Prototyping
..., Sun Aug 06 2006, 11:06PM
Well, as long as you don't want to use any parts smaller than sioc, you should be fine with just a fine tipped soldering iron (preferably temp controlled) and plenty of flux. I cannot stress the importance of flux enough, it makes soldering much easier.
I wouldn't worry about to glue too much, seems to work fine to just hold them in place with a tweser, but it might make life easier for you. I would recommend something that is more just a sticky goo than a glue, so you don't have to wait for it to dry.
As to prototyping, the correct device to use is called a 'surf board' and can be bought from places like digikey or sparkfun for about $1/board that will handle a single chip. This does get expensive tho... They have a set of pads for the chip, and then either pins on the side, or just pads to build the circuit on the board.
If you would be willing to draw up a layout for your converters for whatever pinouts of chips you need (sioc-8 and 16, to-23, and 8035 packages come to mind) I would be happy to etch a board of them for you. I could do a 2x5" of you design board shipped for $20.
I also have tons of smd parts if you need anything, just see my assorted components thread.
Overall I would recommend that you use a hybird approach to prototyping, using smd components of the 'big' components like the ic's, and using normal leaded resistors/caps/led/etc all on a bread board; because no matter how hard you try you are going to end up with a major rats nest of wires running around after the first few revisions which makes it very hard to use a soldering iron on the board (thus being able to plug the stuff in is a good idea).
Have fun!
..., Sun Aug 06 2006, 11:06PM
Well, as long as you don't want to use any parts smaller than sioc, you should be fine with just a fine tipped soldering iron (preferably temp controlled) and plenty of flux. I cannot stress the importance of flux enough, it makes soldering much easier.
I wouldn't worry about to glue too much, seems to work fine to just hold them in place with a tweser, but it might make life easier for you. I would recommend something that is more just a sticky goo than a glue, so you don't have to wait for it to dry.
As to prototyping, the correct device to use is called a 'surf board' and can be bought from places like digikey or sparkfun for about $1/board that will handle a single chip. This does get expensive tho... They have a set of pads for the chip, and then either pins on the side, or just pads to build the circuit on the board.
If you would be willing to draw up a layout for your converters for whatever pinouts of chips you need (sioc-8 and 16, to-23, and 8035 packages come to mind) I would be happy to etch a board of them for you. I could do a 2x5" of you design board shipped for $20.
I also have tons of smd parts if you need anything, just see my assorted components thread.
Overall I would recommend that you use a hybird approach to prototyping, using smd components of the 'big' components like the ic's, and using normal leaded resistors/caps/led/etc all on a bread board; because no matter how hard you try you are going to end up with a major rats nest of wires running around after the first few revisions which makes it very hard to use a soldering iron on the board (thus being able to plug the stuff in is a good idea).
Have fun!
Re: Working With SMDS - Prototyping
williamn, Mon Aug 07 2006, 12:48AM
I use through hole components and a breadboard or perf board for proto work, then design a PCB using SMD.
williamn, Mon Aug 07 2006, 12:48AM
I use through hole components and a breadboard or perf board for proto work, then design a PCB using SMD.
Re: Working With SMDS - Prototyping
Adam Horden, Mon Aug 07 2006, 01:07PM
Cheers for the advice. Basically I am going to use regular parts as best as I can but the inductor and mosfet / diode FETKEY package is all in SMD so I have about 4 SMD parts the rest can be regular components just rats nested to the PCB. My idea was a peace of that SMD board glued to a peace of copper clad and cut out aeras for common ground and supply and of course the power supply then use vero board (strib board) to use with the regular parts and micro. Might look a mess but it will get the prototype working as fast as possible.
http://www.irf.com/product-info/datasheets/data/irf7324d1pbf.pdf
Diode and Mosfet combined in one package. This sucker is really nice RDS on is 0.27 ohms, VDS is 20V, ID @ 25 deg is 1.8A and IDM is 22A. It’s in a SO-8 package.
It’s fu*#ing small!
http://www.farnell.com/datasheets/28593.pdf
Inductor 2200uH 1.2A.
These parts are crucial to the design so I am using them as they are in SMD form. Everything else is standard resistors, capacitors, 8 pin SOIC micro etc.
I am going to buy one of these http://www.roth-elektronik.com/MIME/datasheets/dynamic/datasheet.php?datasheet_id=RE435-LF_ENG?
The only problem I think I am going to have is with the FETKEY.
Adam
Adam Horden, Mon Aug 07 2006, 01:07PM
... wrote ...
Well, as long as you don't want to use any parts smaller than sioc, you should be fine with just a fine tipped soldering iron (preferably temp controlled) and plenty of flux. I cannot stress the importance of flux enough, it makes soldering much easier.
I wouldn't worry about to glue too much, seems to work fine to just hold them in place with a tweser, but it might make life easier for you. I would recommend something that is more just a sticky goo than a glue, so you don't have to wait for it to dry.
As to prototyping, the correct device to use is called a 'surf board' and can be bought from places like digikey or sparkfun for about $1/board that will handle a single chip. This does get expensive tho... They have a set of pads for the chip, and then either pins on the side, or just pads to build the circuit on the board.
If you would be willing to draw up a layout for your converters for whatever pinouts of chips you need (sioc-8 and 16, to-23, and 8035 packages come to mind) I would be happy to etch a board of them for you. I could do a 2x5" of you design board shipped for $20.
I also have tons of smd parts if you need anything, just see my assorted components thread.
Overall I would recommend that you use a hybird approach to prototyping, using smd components of the 'big' components like the ic's, and using normal leaded resistors/caps/led/etc all on a bread board; because no matter how hard you try you are going to end up with a major rats nest of wires running around after the first few revisions which makes it very hard to use a soldering iron on the board (thus being able to plug the stuff in is a good idea).
Have fun!
Well, as long as you don't want to use any parts smaller than sioc, you should be fine with just a fine tipped soldering iron (preferably temp controlled) and plenty of flux. I cannot stress the importance of flux enough, it makes soldering much easier.
I wouldn't worry about to glue too much, seems to work fine to just hold them in place with a tweser, but it might make life easier for you. I would recommend something that is more just a sticky goo than a glue, so you don't have to wait for it to dry.
As to prototyping, the correct device to use is called a 'surf board' and can be bought from places like digikey or sparkfun for about $1/board that will handle a single chip. This does get expensive tho... They have a set of pads for the chip, and then either pins on the side, or just pads to build the circuit on the board.
If you would be willing to draw up a layout for your converters for whatever pinouts of chips you need (sioc-8 and 16, to-23, and 8035 packages come to mind) I would be happy to etch a board of them for you. I could do a 2x5" of you design board shipped for $20.
I also have tons of smd parts if you need anything, just see my assorted components thread.
Overall I would recommend that you use a hybird approach to prototyping, using smd components of the 'big' components like the ic's, and using normal leaded resistors/caps/led/etc all on a bread board; because no matter how hard you try you are going to end up with a major rats nest of wires running around after the first few revisions which makes it very hard to use a soldering iron on the board (thus being able to plug the stuff in is a good idea).
Have fun!
Cheers for the advice. Basically I am going to use regular parts as best as I can but the inductor and mosfet / diode FETKEY package is all in SMD so I have about 4 SMD parts the rest can be regular components just rats nested to the PCB. My idea was a peace of that SMD board glued to a peace of copper clad and cut out aeras for common ground and supply and of course the power supply then use vero board (strib board) to use with the regular parts and micro. Might look a mess but it will get the prototype working as fast as possible.
http://www.irf.com/product-info/datasheets/data/irf7324d1pbf.pdf
Diode and Mosfet combined in one package. This sucker is really nice RDS on is 0.27 ohms, VDS is 20V, ID @ 25 deg is 1.8A and IDM is 22A. It’s in a SO-8 package.
It’s fu*#ing small!
http://www.farnell.com/datasheets/28593.pdf
Inductor 2200uH 1.2A.
These parts are crucial to the design so I am using them as they are in SMD form. Everything else is standard resistors, capacitors, 8 pin SOIC micro etc.
I am going to buy one of these http://www.roth-elektronik.com/MIME/datasheets/dynamic/datasheet.php?datasheet_id=RE435-LF_ENG?
The only problem I think I am going to have is with the FETKEY.
Adam
Re: Working With SMDS - Prototyping
..., Mon Aug 07 2006, 02:23PM
The so-8 package isn't all that hard to use... I have seen people that have successfully made an adapter out of perfboard (pad per hole). You take a piece 5 holes wide and 4 holes long, then use an exacto knife to remove the middle 4 pads (going the short way), then the one on either side of middle at the ends (4 more) then cut the two remaining pads in the middle in half (make the cut parallel to the short axis). Then you can solder the chip on the two cut pads, then use a little wire to jump the top/bottom half of the split pads to the 8 pads remaining on the sides, and then solder a piece of 26awg solid wire in each of the 8 holes on the side. If you have no clue what I am talking about, I can draw a pic for you.
BTW, a SO-8 is an 8 pin SOIC package.
..., Mon Aug 07 2006, 02:23PM
The so-8 package isn't all that hard to use... I have seen people that have successfully made an adapter out of perfboard (pad per hole). You take a piece 5 holes wide and 4 holes long, then use an exacto knife to remove the middle 4 pads (going the short way), then the one on either side of middle at the ends (4 more) then cut the two remaining pads in the middle in half (make the cut parallel to the short axis). Then you can solder the chip on the two cut pads, then use a little wire to jump the top/bottom half of the split pads to the 8 pads remaining on the sides, and then solder a piece of 26awg solid wire in each of the 8 holes on the side. If you have no clue what I am talking about, I can draw a pic for you.
BTW, a SO-8 is an 8 pin SOIC package.
Re: Working With SMDS - Prototyping
Adam Horden, Mon Aug 07 2006, 03:24PM
Hi,
Thanks I have seen that method. I will order the parts today and some fine wire and a peace of that board hopefully the stuff should be here tomorrow so I can build my prototype. I have some SDM adsheive on my parts list so that should help and a very fine soldering iron tip and fine solder any way.
Thanks for the tips I think I know how to go about this now. I also got a small pair of tweezers.
It will be a half and half prototype and I will post some pics. Some SMD some regular parts just to make it easier on me.
Adam
Adam Horden, Mon Aug 07 2006, 03:24PM
Hi,
Thanks I have seen that method. I will order the parts today and some fine wire and a peace of that board hopefully the stuff should be here tomorrow so I can build my prototype. I have some SDM adsheive on my parts list so that should help and a very fine soldering iron tip and fine solder any way.
Thanks for the tips I think I know how to go about this now. I also got a small pair of tweezers.
It will be a half and half prototype and I will post some pics. Some SMD some regular parts just to make it easier on me.
Adam
Re: Working With SMDS - Prototyping
Steve Conner, Mon Aug 07 2006, 03:25PM
I've managed to prototype a power electronic circuit using those SO-8 MOSFETs, switching about 2.5A at 5V. I just built it with the method I usually use, on double-sided copperclad PCB that I carved up with a Dremel. The prototype worked fine and translated well to the 4-layer PCB that I used for the production unit.
Steve Conner, Mon Aug 07 2006, 03:25PM
I've managed to prototype a power electronic circuit using those SO-8 MOSFETs, switching about 2.5A at 5V. I just built it with the method I usually use, on double-sided copperclad PCB that I carved up with a Dremel. The prototype worked fine and translated well to the 4-layer PCB that I used for the production unit.
Re: Working With SMDS - Prototyping
Conundrum, Wed Aug 09 2006, 05:43PM
Hi Adam.
If you have a use for them, I have some surplus dual FETs from old hard drive PCBs which are 8 pin SOIC, as well as some Maxim LED driver chips.
Also have SMD resistor and ceramic+tantalum capacitor kits, so if you need a specific value or 10 email me and I will send you some.
Regards, -A
"Bother" said Pooh, as he was hit in the face by a nuclear explosion...
Conundrum, Wed Aug 09 2006, 05:43PM
Hi Adam.
If you have a use for them, I have some surplus dual FETs from old hard drive PCBs which are 8 pin SOIC, as well as some Maxim LED driver chips.
Also have SMD resistor and ceramic+tantalum capacitor kits, so if you need a specific value or 10 email me and I will send you some.
Regards, -A
"Bother" said Pooh, as he was hit in the face by a nuclear explosion...
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