Most likely, you were not engaged in welding but simply soldering parts to each other. In this case, you need to monitor the temperature and soldering time carefully.
Make sure that the chips are evenly distributed along with the place of adhesion. Thus, the voltage should equalize.
If you want to do welding, you should buy a suitable quality device. I advise you to choose a model on this site —
https://www.cherokeeobserver.org/best-welding-respirator-reviews/. I have recently updated my welding device myself.
If you have any questions, please get in touch with me. With pleasure, I will help.