Electronics > Projects, Designs, and Technical Stuff

Struggling with soldering PG-TSDSON-8

<< < (4/7) > >>

T_guttata:
Hm, is this a common design rule not to place any vias in pads? But this would rather result in too little solder than too much?

T3sl4co1l:
As you can see, you'll get a mix of information from a forum.  You're getting what you paid for... ;)

Via in pad is fine, when done right.  It's unavoidable for thermal pads on QFN, and may be necessary for SON.  It might not be required on DFNs like this, but can be used to improve thermal or electrical performance.

The standouts here are the large size of the vias, and the small size of the one pad in relation.  The, what is that, gate pin?  Don't do that.  The drain, I'd use smaller vias, and 2 or 4 of them.

I already discussed solder wicking above, so I won't reiterate that.

Tim

wraper:

--- Quote from: T_guttata on November 14, 2021, 09:55:56 pm ---Hm, is this a common design rule not to place any vias in pads? But this would rather result in too little solder than too much?

--- End quote ---
There is too little solder on 2 Q8 pads in the middle, sucked away by the via. About pad on the corner, examples where soldering is shown use a PCB different layout to bare pads shown.

EPAIII:
I am not sure a hot plate is the best way to re-flow solder. Heat from below has to penetrate the PCB substrate which, in addition to being an electrical insulator, is probably a fairly good insulator against heat. And the top, where the IC sits is exposed, at least somewhat, to the air so it is cooler than the copper traces. I can see where it is difficult to get enough heat into that large pad.

I have an old toaster oven that has one element burned out. By testing with an oven thermometer inside it, I found a heating period that approximated the recommended heating curve for re-flow soldering. And points in time to turn off the heating element and to open the door about an inch to increase the cooling effect. It provides a more uniform heat - top and bottom. I believe this, more uniform application of heat, is how the recommended re-flow temperature curves were developed.

It seems to work well with the parts I have tried it on. I have not tried it on any parts like your PG-TDSON-8 with such large pads.

T_guttata:

--- Quote from: T3sl4co1l on November 14, 2021, 10:34:17 pm ---As you can see, you'll get a mix of information from a forum.  You're getting what you paid for... ;)
Tim

--- End quote ---

While I know that phrase I don't understand it in this context?

What via diameter would you use? I just did my first PCB some months ago and regarding via diameter I just trusted easyeda. Standard diameter is 0.6mm there.


--- Quote from: wraper on November 15, 2021, 08:54:56 am ---About pad on the corner, examples where soldering is shown use a PCB different layout to bare pads shown.

--- End quote ---

Don't know what you intend to say? I have used the footprint various times and the vias are not always placed the same.


--- Quote from: EPAIII on November 15, 2021, 10:22:42 am ---I am not sure a hot plate is the best way to re-flow solder. Heat from below has to penetrate the PCB substrate which, in addition to being an electrical insulator, is probably a fairly good insulator against heat. And the top, where the IC sits is exposed, at least somewhat, to the air so it is cooler than the copper traces. I can see where it is difficult to get enough heat into that large pad.

I have an old toaster oven that has one element burned out. By testing with an oven thermometer inside it, I found a heating period that approximated the recommended heating curve for re-flow soldering. And points in time to turn off the heating element and to open the door about an inch to increase the cooling effect. It provides a more uniform heat - top and bottom. I believe this, more uniform application of heat, is how the recommended re-flow temperature curves were developed.

It seems to work well with the parts I have tried it on. I have not tried it on any parts like your PG-TDSON-8 with such large pads.

--- End quote ---

Well, yes, my method is not ideal. I'm prototyping, I'm no electronics manufacturer. I googled a lot and as far as I understand, there is no proper solution out there which is affordable, lets say <$500. Because all proposed solutions have severe drawbacks, I just tried the one which I can do for free: using my inox pan and an inductiion cooker.
SOT23 and small resistors worked perfectly fine, I just have some trouble with this PG-TSDSON-8 package.

What I have learned so far is that vias can cause errors and therefore I will try to place all vias outside of pads in the future. Maybe I have to change my PCB and reorder it.

But I repeat my two questions from the previous post:

1) Do you think error margin will increase if I use another solder paste containing lead?
2) Would another footprint such as LFPAK56 be easier to handle compared to PG-TSDSON-8?

Once I read that breadboards are bad because you are actually trouble shooting the breadboard more often than the actual circuit.
Now, I'm doing a PCB but I'm trouble shooting the PCB and not my actual circuit^^

I would have bought the PCB fully assembled, but jlcpcb does not have the mosfets I need. Is there any other supplier for prototyping?

Navigation

[0] Message Index

[#] Next page

[*] Previous page

There was an error while thanking
Thanking...
Go to full version