Hello community, I have designed a PCB which has a little proto area. This area has ~15*20 holes similar to [THIS](https://goo.gl/images/ibwrVm). The distance between the holes are 100mil, the diameters are 40mil with 40mil pad (so both the width and the height are 80mil each). My design is rejected by JLCPCB claiming that the "holes are too close to each other and there will be a scratch during manufacturing". I'm surprised as 100mil is standard, each thruhole IC has the same drill distance. Was it because the pads are too wide? What is JLCPCB limitation here, I couldnt locate anything on their website. Unfortunately no further explanation were given except that I should try ENIG (which I'd like to avoid due to the costs). Please help me out. Thanks.