You basically get what you pay for. If your chip is not too expensive you might take a chance in a regular envelope. Don't bet your life it will get there in one piece. Watch this USPS video. Most chips don't bend very well.

https://www.youtube.com/watch?v=gB7QOK1bd3U

I've had many bad experiences with some trying to save money with the mail. Use a padded envelope and avoid the machinery whipping envelopes around in circles. Just saying.