How many companies do you know that have established for electronic manufacturing in Mexico?

Cisco, Dell, HP, and Siemens all have major fabrication operations in Mexico. There are certainly many more than just those 4.

I am sure that there is a ministry in Mexico City that keeps track of this. I don't personally know any such companies. Many or even most multi-national electronics outfits probably have such subsidiaries because Mexico has free trade agreements with 50 something nations and thus is an excellent place for export oriented production.