Canada's federal government has put its very useful Termium French-English dictionary on the web for free. It is great for technical expressions that you would not find in a regular dictionary.
Another way to find translations for technical expressions in English or French is to go to Google and type: "site:gc.ca" and then the expression. This will make Google show you all the pages on the Government of Canada website that use the expression. Almost everything the government publishes on the internet is translated, so once you have found your expression somewhere on a government website, click "Francais" at the top of the page to find out how the government translated it.