There was a research item to allow you to craft Tier 2 Science Packs, but there doesn't seem to be any research to enable the tier 3 science packs and some of the research items now require them.
Science Pack 3's require a good chunk of research before you hit them. They come from the Battery tech, which itself requires you to research a new resource type: Oil. From there, it just takes Sulfur, and then you can research Battery. You WILL need Plastics, as well, as Plastic Bars are in the resource chain (as part of Advanced Circuits).
Be aware, though, that the amount of resources required for Science Pack 3's are rather heavy, so having the infrastructure in place to make these things is a non-trivial effort.
As of version 0.15.7, the recipe for Science Pack 3 is:
- 1 Advanced Circuit
- 1 Electric Mining Drill
- 1 Engine Unit
Batteries (as well as the Filter Inserters) are no longer needed for making them. However, you will still need oil in order to make the Plastic Bars needed for the Advanced Circuit. The Engine Unit also requires Steel Bars, so you will now need to consider a steel bar supply in order to produce these science packs.
As stated in the other answer, you will need to put quite an effort into making these science packs. In my opinion, the current recipe makes it even more difficult to make these science packs.
There is a very handy website I found that shows the Research Tree as of 0.15.8. You can click on the "Advanced Electronics" technology and it will show you the exact things you need to research and in what order to unlock Science Pack 3. Currently, it is:
Once you research Advanced Electronics, you will be able to craft Science Pack 3's.
*Steel Processing can be researched earlier if you desire, however it is needed for Oil Processing. I put it in the most appropriate spot in the list.