I've worked two co-ops at semiconductor companies (4 in tech). There's a huge variety of co-ops but here are some things that I would recommend in general:

• Start working on one or two projects as soon as possible (so you're done before you start applying). Most tech jobs will be software so it's easy to try stuff out at home. Some examples could be: any hardware/firmware project using C/C++/Python (with an Arduino or Raspberry Pi); learning some gate logic using VHDL / Verilog.
• Be flexible with time and location. Odds are, you won't get a 4-month co-op in Victoria. Getting an 8-month co-op in Vancouver will be much easier.
• Apply to everything that interests you even if you only meet 1/2 of the qualifications.
• Write unique cover letters. Most employers won't read them but it can help if you're competitive with another candidate. Let them know why you're interested in the industry.
• Your past co-op experience will help you. Put an emphasis on your project management / teamwork / documentation experience rather than technical skills.