There are a few different cache entries for the schema, schema:, schema:runtime, schema:runtime:1, and so on.

To clear the lot, try using a wildcard:

cache_clear_all('schema', 'cache', TRUE);


Need help clearing the schema cache
I am doing a development board for a IC with 36 WLCSP package. My PCB layout has 16 via over pads, minimum 0.1mm drill holes, 4-layers. I need to fabricate my PCB. And I could not find a exact pricing for PCBs in the required design quality. I sent sample Gerber file for some PCB manufacturers. And they replied with extreme high prices and I can't afford their pricing (eg: 200$ for 10 boards with 2.5cm * 2.5cm). And most of manufactures are not willing to share their pricing strategy to optimize my design.

My target is to deliver my demo board for the lowest price (to make it lower than 10$, while component cost around 6.5$) . So I need to keep the PCB cost lower than 2$ with the minimum area of 2cm * 2cm. 



Could I achieve that much lower PCB cost?
what are the possible PCB fabricators with lower cost with required technology?
What would be the unit PCB cost if fabricate at least 500 boards?
Feasibility of my project to make it under 10$?


Thank you
