<title>Machine vision inspection of component footprints in PCB artwork</title>

Abstract

Abstt'act. A new iiiiited circuit boaicI (PCB) inspection scheme designed to peifoim automated iIlSI)eCtiofl of C0fl11)Ofleflt sites is pi'eseiitecl. A digitized illiage of the artwork for a board is stored after digitization via a scanner (300 dots per inch) in a TIFF (Tag Image File Format) file. At inspection time, after reading in the compressed foiiiiat TIFF file and decoding the compressed ilnage, the PCB is gra)11ica11y displayed oh a PC SCFCCfl t()ge(hcr vitIi a coinnianci menu. The user is then taken though a stlies of incnu-d ii yen coin naiid t .) ul t inately check t he dimensions of centerto-cent er distan(2c l)et ween holes and Ikls f:i e1t nic c()lIIpolleLlts on the PCB. The significance of this research i in lw aclapt.atioit of the LIN1(.)N-FINJ) I)1oce(1u1e to develop a robust algorithm t 1) segineilt an i iilage i u t o 111j)C)LCt1t cI)Jce t S hi (1 liaclgiouncL t 0 facili tat e dimensional analysis and inspection of t lie ut voik * Mechanical lngi neering, Urn versit v f Nlai'y laud Halt inure Counts', Cat unsville, MD 21228. Mechanical Engineeting. Peimnsvlvaiiia State tiiiiveisitv.