Inline metrology on air flotation for PCB applications

A measurement system comprising:

• a. a printed circuit board panel comprising a substrate having a first side and a second side opposing the first side, wherein the first side comprises an insulating layer with an electrically conductive surface feature positioned on the insulating layer;
• b. a light emitter and detector device comprising a light source and a sensor, wherein the light emitter and detector device is positioned relative to the printed circuit board panel such that a light beam output from the light source impinges one or more sample points on the first side of the substrate, further wherein the sensor is configured to receive a reflected light corresponding to the light beam, wherein each sample point corresponds to a pixel of the light beam impinging the first side of the printed circuit board panel, further wherein the sensor is configured to sense a light intensity value for each pixel, and the light emitter and detector device is configured to determine a light intensity measurement for each pixel;
• c. a movement and alignment apparatus coupled to the printed circuit board panel and the light emitter and detector device, wherein the movement and alignment apparatus is configured to provide relative movement between the light emitter and detector device and the printed circuit board panel and to scan the light beam over at least a portion of the first side of the printed circuit board panel;
• and
• d. a controller configured to receive data from the sensor corresponding to the received reflected light and the light intensity measurement for each pixel, to determine a distance measurement corresponding to each sample point and to determine a relative thickness of the printed circuit board panel and a height of the surface feature, wherein the controller is further configured to determine if the sample point corresponding to each pixel is a point on the first side of the printed circuit board panel that corresponds to the insulating layer or to the surface feature by comparing the light intensity measurement to light intensity measurements of known material types to determine a material type corresponding to the pixel, and to compare the determined material type corresponding to the pixel to known materials for the insulating layer and the surface feature.

A measurement system comprising:

• a. a printed circuit board panel comprising a substrate having a first side and a second side opposing the first side, wherein the first side comprises an insulating layer with an electrically conductive surface feature positioned on the insulating layer;
• b. a light emitter and detector device comprising a light source and a sensor, wherein the light emitter and detector device is positioned relative to the printed circuit board panel such that a light beam output from the light source impinges one or more sample points on the first side of the substrate, further wherein the sensor is configured to receive a reflected light corresponding to the light beam, wherein each sample point corresponds to a pixel of the light beam impinging the first side of the printed circuit board panel;
• c. a movement and alignment apparatus coupled to the printed circuit board panel and the light emitter and detector device, wherein the movement and alignment apparatus is configured to provide relative movement between the light emitter and detector device and the printed circuit board panel and to scan the light beam over at least a portion of the first side of the printed circuit board panel;
• and
• d. a controller configured to receive data from the sensor corresponding to the received reflected light and to determine a distance measurement corresponding to each sample point, and to determine a relative thickness of the printed circuit board panel and a height of the surface feature, wherein the controller is further configured to determine a transition point along the first side from insulating layer to surface feature and from surface feature to insulating layer by comparing the determined distance measurements for adjacent pixels, and to determine a number of pixels that separate subsequent transition points along a measured line of sample points, wherein the determined number of pixels that separate subsequent transition points corresponds to a surface feature dimension.