SMD soldering

[Dave Dixon]

Our company got the short end of the stick. We are Lead-free exempt. For years now, our Purchasing dept and I warned engineers in my company that it would affect us regardless, and our warnings went unheeded. NOW, I spend a great percentage of my day trying to find parts that are no longer readily available in the leaded(Pb) version, or else making sure that the Pb free part is acceptable in our application. We may be exempt, and use leaded solder, but it has had a deep imact on our BOM's and cost of inventory/paperwork all around.
I have yet to be convinced that I have helped the environment in any way, by being forced into this situation!
Happy Thanksgiving
Dave

[philba]

Hi guy's

Well since your all looking at ways to hold, and solder down SMD's.
I thought you should consider this SMD Holder,
that I came a cross in an old issue of Nut&Volts.

This is my own design, and feel free to make any changes.
The only problem with this design is it doesn't take into account double sided SMD Boards.


Signed: Janitor Tzap

I hate to be negative but this seems like more work than it's worth. Set up time alone has to be 30 seconds. Holding a component with tweezers or hemos is easy as pie. Tin the pad, pickup the chip, solder the lead, finish the rest, resolder the first pad and you're done. 1206s take around 20 seconds. SOIC18s, about 30-40 secs. I'd say every 5th chip takes a little extra fussing because of my low skill level.

By the way, I really love my curved tip hemostats. It's so easy to pick up a chip and hold it to the board. Even bigger ones like 28 pin devices. There are also vacuum chip placement tools that are supposedly really great, especially for bigger chips.

One other thing. Get a fan or vent. The flux vapors are nasty. I got asthma from breathing them.

[Janitor Tzap]

Hi guy's

Well since your all looking at ways to hold, and solder down SMD's.
I thought you should consider this SMD Holder,
that I came a cross in an old issue of Nut&Volts.

This is my own design, and feel free to make any changes.
The only problem with this design is it doesn't take into account double sided SMD Boards.


Signed: Janitor Tzap

I hate to be negative but this seems like more work than it's worth. Set up time alone has to be 30 seconds. Holding a component with tweezers or hemos is easy as pie. Tin the pad, pickup the chip, solder the lead, finish the rest, resolder the first pad and you're done. 1206s take around 20 seconds. SOIC18s, about 30-40 secs. I'd say every 5th chip takes a little extra fussing because of my low skill level.

By the way, I really love my curved tip hemostats. It's so easy to pick up a chip and hold it to the board. Even bigger ones like 28 pin devices. There are also vacuum chip placement tools that are supposedly really great, especially for bigger chips.

One other thing. Get a fan or vent. The flux vapors are nasty. I got asthma from breathing them.

Hemostats and tweezers work great on the small components like individual diodes, capacitors, or resistors.
But chips that have more than 28 pins,
and have them coming out all four sides.
Can be a real pain to get lined up before soldering.
Thus, this third hand would be helpful in those cases.

But, as I stated.
This is a design I came up with, that is based on an earlier one.
I saw in an old Nuts&Volts Article.

I already see I could improve the Base part.
By adding jaws that could hold the PC board in place.
And design the arm so it can be repositioned to different spots on the PC Board.


Signed: Janitor Tzap

[Mike6158]

Speaking of lead free solder- In my real job I've run into computer (PC) failures related to lead free solder ]. At least I think it was related to lead free solder. I programmed a control system that uses PC's for the HMI. The control room has problems with H2S in the air (too long to explain) and over the course of about 6 months something is happening to the motherboards in the PC's. The vendor (Dell) says solder joints are failing due to stress cracking cause by H2S.

I used CadSoft Eagle to do the board layout.

I use EAGLE. Would you be willing to share your
SCH and BRD files? I'd like to see your circuit.

I guess I'm not sure what the point would be? It's not a very complicated design...

[Bigglez]

I used CadSoft Eagle to do the board layout.

I use EAGLE. Would you be willing to share your
SCH and BRD files? I'd like to see your circuit.

I guess I'm not sure what the point would be? It's not a very complicated design...

It has less to do with the complexity and more to help
us inderstand your OP. Also, other members of this
forum use the same tools and would be willing to review
your design (the power of "many eyes"), and probably
learn something for themselves.

As you know, the tool is very powerful, and a lot of
potential problems with a design can only be revealed
by manipulation of the tool's options (turning off layers
for inspection, running ERC and DRC routines).

Better to send a good PCB package to the PCB house,
than create another "green coaster"!

[Mike6158]

I use EAGLE. Would you be willing to share your
SCH and BRD files? I'd like to see your circuit.

I guess I'm not sure what the point would be? It's not a very complicated design...

It has less to do with the complexity and more to help
us inderstand your OP. Also, other members of this
forum use the same tools and would be willing to review
your design (the power of "many eyes"), and probably
learn something for themselves.

As you know, the tool is very powerful, and a lot of
potential problems with a design can only be revealed
by manipulation of the tool's options (turning off layers
for inspection, running ERC and DRC routines).

Better to send a good PCB package to the PCB house,
than create another "green coaster"![/quote

well... I may indeed have 3 green coasters (I already have boards but you might save me some smoke). Since it's a prototype only I won't be too bothered if I missed a size (think my resistor package selection was wrong) and have to use wire to connect the dots. I wouldn't mind sending it to you. I'm going to be out of pocket (other hobby / would be vocation) clcik the Bosque Link for recent work until late Sunday and I'm not getting reply emails but if I hear from you I'll reply with files attached. Honestly there isn't much to it...

[email protected]

Shoot me an email ^^^ and I'll reply with the files attached.