Confocal 3D inspection system and process
View Patent ↗An inspection device comprises a light source, a pellicle beamsplitter for receiving light from the light source and for redirecting the light, and an aperture array for receiving light from the pellicle beamsplitter. The aperture array is a two dimensional array of pinholes having an x axis and a y axis ninety degrees apart, wherein the distance between pinholes in the x direction is greater than the distance between pinholes in the y direction. The inspection device further comprises an imaging system comprising an object imager including a plurality of lenses, a camera reimager including a plurality of lenses, and a camera for acquiring an image.
1. An inspection device comprising:
a light source;
a pellicle beamsplitter for receiving light from the light source and redirecting said light;
an aperture array for receiving light from the pellicle beamsplitter wherein the aperture array is a two dimensional array of pinholes having an x axis and a y axis ninety degrees apart, and wherein the x direction defines a scan line direction and the distance between pinholes in the x direction is greater than the distance between pinholes in the y direction; and
an imaging system including an object imager including a plurality of lenses, a camera reimager including a plurality of lenses, and a camera for acquiring an image;
wherein the pinholes in the y axis direction are axial to the y axis, while the pinholes in the x axis direction are not axial to the x axis.
2. The inspection device of claim 1 wherein the pinholes are in a rhombus pattern.
3. The inspection device of claim 2 wherein the pinholes in the x axis direction are offset from adjacent pinholes.
4. The inspection device of claim 3 wherein the offset is approximately 5 microns.
5. The inspection device of claim 4 wherein the pinholes in the y direction are approximately 51 microns apart, while the pinholes in the x direction are approximately 63 microns apart.
6. The inspection device of claim 5 wherein the diameter of each pinhole is approximately 16 microns.
7. The inspection device of claim 1 , wherein the aperture array is stationary.
8. The inspection device of claim 1 , wherein at least one of the object imager and/or camera re-imager is a dual telecentric type imager and/or re-imager.
9. The inspection device of claim 1 , wherein the pinholes are arranged in a non-radial pattern.
10. The inspection device of claim 1 , wherein the aperture array has at least one non-reflective major surface.
11. The inspection device of claim 1 , wherein a size of each of the pinholes is selected to match a diffraction of the object imager.
12. The inspection device of claim 1 , wherein the aperture array is canted to be non-perpendicular to a focal axis of the object imager.