Home made PCB reliability

Hi,

I made a couple of PCBs using toner transfer method. After I assembled the parts and soldered it to the pads, when i touch the components with a little force, the pads came off and the component starts shaking. Is it the problem of the copper clad board or is it because I used a 1mm bit to drill the holes so there was no friction between the component lead and the board?

Could be low quality clad material/adhesive..
could be you overheated it when soldering. <--probably

pad lifting is fairly common with boards without plated through holes as the only thing holding that pad down is the adhesive on that side.. And once you destroy the adhesive the pad will lift.

Welcome to the world of DIY PCB's..

Perhaps the annular ring (the donut of metal) was too small to support the force. It is best to mount the part flush with the board, and bend the leads a bit to snug it doen before you start soldering. Solder asghould never be used for mechanical support anyway, and this way you keep force off the pad.

Seeing a picture of the failure would also help us help you.

My soldering iron is not temperature controlled, I just put it for 5 seconds or so. Can tinning the board be any good?

The annular ring was small, Here are the images.



Please view from the image url, I uploaded on google drive and it's not popping up here.

ErnieM said:

Perhaps the annular ring (the donut of metal) was too small to support the force. It is best to mount the part flush with the board, and bend the leads a bit to snug it doen before you start soldering. Solder asghould never be used for mechanical support anyway, and this way you keep force off the pad.

Seeing a picture of the failure would also help us help you.

Click to expand...

Personally... I always shoot for a ring of 2x hole diameter..

and not having a temp controlled iron, using too much solder like you have there,etc.. all problems/contributing factors..
Not surprised at all that you lifted a pad.. "noobs" do it ALL the time.

mcgyvr said:

Personally... I always shoot for a ring of 2x hole diameter..

and not having a temp controlled iron, using too much solder like you have there,etc.. all problems/contributing factors..
Not surprised at all that you lifted a pad.. "noobs" do it ALL the time.

Click to expand...

I agree... Too much solder.

5 Seconds is too long to solder a normal through-hole pad. More like 1-2 seconds.

Bob

The components should be neat and as low as possible (touching the PCB). That way they cannot be pushed down which is what breaks the pads free from the PCB.

And PCBs were never really designed to have "force" applied to the components.

If you post a photo of your PCB we can offer suggestions for future PCBs. Don't be embrassed, we all made some shocking PCBs when we first started.

I lifted that pad by applying force on the resistor. I tried to increase the pad size while I was routing the board in Eagle. But I could not do a 2 mm pad, I am using a 1mm drill because the pads of USB B connector would overlap. Soldering Is difficult because there was hardly any pad left. A little bit of solder would make a big blob. I use wick to take out some and cut the rest with a flush cutter

mcgyvr said:

Personally... I always shoot for a ring of 2x hole diameter..

and not having a temp controlled iron, using too much solder like you have there,etc.. all problems/contributing factors..
Not surprised at all that you lifted a pad.. "noobs" do it ALL the time.

Click to expand...