The substrate 1 is formed with a relatively large hole and {TAIL ~ a plurality} of {HEAD ~ smaller holes} surrounding the large hole 
The substrate 1 is formed with a relatively large hole and { TAIL ~ a plurality } of { HEAD ~ smaller holes } surrounding the large hole
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH