Method and apparatus for verifying the presence or absence of a component

At apparatus for verifying the absence of a die in a cut wafer comprising:

• a wafer support;
• a visible light source positioned to direct visible light through said wafer support;
• a charge coupled device camera positioned to detect light from said light source passing through said wafer support and to generate receiver signals in response to the detected light;
• and,
• a controller attached to said camera to convert and display said receiver signals as a wafer verification map, wherein said controller accesses and compares a planned die pick pattern map with said wafer verification map, stores said comparison, and displays said comparison, said planned die pick pattern map and said wafer verification map.

An apparatus for picking dice from a cut wafer, comprising:

• a wafer support;
• a radiation source positioned to direct radiation toward said wafer support;
• a radiation detector directed toward said wafer support to detect radiation from said radiation source;
• a pick head positioned to access said wafer support and perform pick operations;
• and,
• a controller connected to and controlling said radiation detector, said radiation source and said pick head, said controller including a computer to access and compare a planned die pick pattern map with a wafer verification map generated by said computer from said detected radiation and control the movement of said pick head in accordance with said planned die pick pattern and said comparison.

A method of placing dice from a wafer onto substrates, comprising:

• producing a wafer map to identify locations of the dice in the wafer;
• testing the dice to determine whether the dice perform according to predetermined specifications;
• selecting a die to be placed on a substrate;
• identifying the location of the selected die on the wafer map;
• picking the selected die from the wafer;
• directing radiation toward the wafer;
• detecting radiation from the direction of the wafer;
• calculating the location of the picked die based on the radiation detected to determine whether the picked die is the selected die;
• and,
• placing the picked die on the substrate, when the picked die is the selected die.

A method of verifying whether a selected die was picked from a wafer, comprising:

• producing a wafer map to identify locations of the dice in the wafer;
• picking a selected die from an identified location on the wafer;
• directing radiation toward the wafer;
• detecting radiation from the direction of the wafer;
• calculating the location of the picked die based on the radiation detected;
• and,
• comparing the location of the picked die to the selected die to verify whether the picked die is the selected die.

An apparatus for picking dice from a cut wafer, comprising:

• a die attach machine having a wafer support, a pick head positioned to access said wafer support and perform pick operations, and a controller connected to and controlling pick operations performed by said pick head;
• a radiation source positioned to direct radiation toward said wafer support;
• and,
• a radiation detector attached to said controller and directed toward said wafer support to detect radiation from said radiation source, wherein said controller comprises a computer to access and compare a planned die pick pattern map with a wafer verification map generated by said computer from said detected radiation and control the movement of said pick head in accordance with said planned die pick pattern and said comparison.