Light source devices for detecting hole defect of high-depth-ratio PCB (printed circuit board)

The invention provides two light source devices for detecting a hole defect of a high-depth-ratio PCB (printed circuit board). One type of the light source device comprises LED light source particles which are uniformly distributed below the PCB; and an X-direction angle selection element and a Y-direction convergence element which are arranged between the PCB and the LED light source particles. The other type of the light source device comprises LED light source particles which are uniformly distributed below the PCB; and a Fresnel lens array above the LED light source particles. The X-direction angle selection element and the Y-direction convergence element or the Fresnel lens array is arranged between the PCB and the LED light source particles, and light entering the PCB is small-angle light, so that the scattering effect of the hole wall on the large-angle light caused by the increased thickness of the PCB can be reduced, and the problem that the imaging by a large hole and a small hole in the detection of high-depth-ratio aperture is inconsistent can be solved.