query regarding article marketing and gaining backlinks

i am planning to make several micro niche sites over the span of next few months. if i am following article marketing route to gain backlinks
for a brand new is it okay submit an article in 500-600 directories in the first month only (in span of 7 days)?
or can google sandbox my website for building links too fast? wt should be the right strategy?

It all depends on how fast your articles get indexed in Google. If you don't ping the article URLs, you would be safe. Let Google find out your backlinks naturally