1. A method of measuring a free air ball size during a wire bonding process of a wire bonder, the wire bonder having a position sensor and a bonding tool for forming an electrical connection between a semiconductor device and a substrate using a bonding wire, the method comprising the steps of:
forming a free air ball from a wire tail of the bonding wire;
using the position sensor to determine a positional difference between a first and a second position of the bonding tool with respect to a reference position, wherein the first position of the bonding tool is a position of the bonding tool with respect to the reference position when the free air ball contacts a conductive surface; and
measuring the free air ball size based on the positional difference of the bonding tool as determined by the position sensor.
2. The method of claim 1, wherein the second position of the bonding tool is a position of the bonding tool with respect to the reference position when the wire tail contacts the conductive surface.
3. The method of claim 2, wherein the second position of the bonding tool is a position of the bonding tool with respect to the reference position when the wire tail contacts a bonding surface of the semiconductor device.
4. The method of claim 2, wherein the step of measuring the free air ball size is based on the conservation of mass between the wire tail and the free air ball.
5. The method of claim 1, wherein the second position of the bonding tool is a position of the bonding tool with respect to the reference position when a base of the bonding tool contacts the conductive surface.
6. The method of claim 5, wherein the second position of the bonding tool is a position of the bonding tool with respect to the reference position when a base of the bonding tool contacts a bonding surface of the substrate.
7. The method of claim 5, wherein the step of measuring the free air ball size is based on a chamfered diameter of the bonding tool and a chamfered angle between the free air ball and the bonding tool.
8. The method of claim 1, wherein the step of using the position sensor to determine the positional difference of the bonding tool comprises using an encoder to measure respective heights of the bonding tool with respect to a reference height.
9. The method of claim 1, wherein the free air ball size is measured in relation to a radius of the free air ball.
10. The method of claim 1, wherein the first and second positions of the bonding tool with respect to the reference position are the respective positions of a base of the bonding tool.
11. A wire bonder, comprising:
a bonding tool operative to form an electrical connection between a semiconductor device and a substrate using a bonding wire;
a position sensor operative to determine a positional difference between a first and a second position of the bonding tool with respect to a reference position, wherein the first position of the bonding tool is a position of the bonding tool with respect to the reference position when a free air ball contacts a conductive surface, the free air ball being formed from a wire tail of the bonding wire; and
a processor configured to measure a size of the free air ball based on the positional difference of the bonding tool as determined by the position sensor.
12. The wire bonder of claim 11, wherein the second position of the bonding tool is a position of the bonding tool with respect to the reference position when the wire tail contacts the conductive surface.
13. The wire bonder of claim 12, wherein the second position of the bonding tool is a position of the bonding tool with respect to the reference position when the wire tail contacts a bonding surface of the semiconductor device.
14. The wire bonder of claim 12, wherein the processor is configured to measure the free air ball size based on the conservation of mass between the wire tail and the free air ball.
15. The wire bonder of claim 11, wherein the second position of the bonding tool is a position of the bonding tool with respect to the reference position when a base of the bonding tool contacts the conductive surface.
16. The wire bonder of claim 15, wherein the second position of the bonding tool is a position of the bonding tool with respect to the reference position when a base of the bonding tool contacts a bonding surface of the substrate.
17. The wire bonder of claim 15, wherein the processor is configured to measure the free air ball size based on a chamfered diameter of the bonding tool and a chamfered angle between the free air ball and the bonding tool.
18. The wire bonder of claim 11, wherein the position sensor is an encoder configured to measure respective heights of the bonding tool with respect to a reference height.
19. The wire bonder of claim 11, wherein the free air ball size is measured in relation to a radius of the free air ball.
20. The wire bonder of claim 11, wherein the first and second positions of the bonding tool with respect to the reference position are the respective positions of a base of the bonding tool.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A digital scanning device for decoding a digitally encoded symbol comprising:
a light source comprising individually-controllable lighting elements for providing low angle dark field illumination to an encoded data symbol;
an image sensor for detecting image data reflected from the encoded data symbol when illuminated by the light source; and
a controller connected to each of the individually-controllable lighting elements, the controller being programmed to selectively activate a subset of individually-controllable lighting elements, wherein when the subset of the individually-controllable lighting elements are activated the light source illuminates the data encoded symbol in a desired direction.
2. The digital scanning device of claim 1 wherein the controller is configured to selectively activate the lighting elements such that all of the individually-controllable lighting elements are activated.
3. The digital scanning device of claim 1 wherein the controller is configured to process the image data collected by the image sensor to decode the symbol.
4. The digital scanning device of claim 1, wherein the individually-controllable lighting elements comprise portions of at least one of a circular ring, an oval ring, or an elliptical ring.
5. The digital scanning device of claim 4, wherein the portions of the circular ring comprise quadrants.
6. The digital scanning device of claim 1, wherein the individually-controllable lighting elements comprise a plurality of electrically-connected individual light elements.
7. The digital scanning device of claim 1, wherein the individually-controllable lighting elements provide at least one of a rectangular ring, an oval ring or an elliptical ring.
8. The digital scanning device of claim 1, wherein the controller is programmed to evaluate the data acquired by the image sensor and to vary the light applied to the data symbol from the individually-controllable lighting elements to optimize symbol decoding.
9. The digital scanning device of claim 1, wherein the light source comprises a passive illumination pipe.
10. The digital scanning device of in claim 1, wherein the light source comprises an active light pipe.
11. The digital scanning device of claim 1 wherein the individually-controllable lighting elements comprise portions of a ring light source.
12. The digital scanning device of claim 11 wherein the portions of the ring light source comprise quadrants.
13. The digital scanning device of claim 1 further comprising a bright field light source for providing bright field illumination to the encoded data symbol.
14. A digital scanning device for decoding a digitally encoded symbol comprising:
a dark field light source comprising individually-controllable lighting elements for providing low angle dark field illumination to an encoded data symbol;
a bright field light source for providing bright field illumination to the encoded data symbol;
an image sensor for detecting image data reflected from the encoded data symbol when illuminated by the light source; and
a controller connected to each of the individually-controllable lighting elements and the bright filed light source, the controller being programmed to selectively activate a subset of the individually-controllable lighting elements and to selectively activate the bright field light source, wherein when a subset of the individually-controllable lighting elements are activated the light source illuminates the data encoded symbol in a desired direction.
15. A digital scanning device, comprising:
a ring light source comprising individually-controllable lighting elements providing low angle dark field illumination to an adjacent surface including a symbol to be decoded;
a controller connected to the ring light source for selectively activating a subset of the individually-controllable lighting elements, wherein when a subset of the individually-controllable lighting elements are activated the light source illuminates the data encoded symbol in a desired direction; and
an image sensor connected to the controller for acquiring image data of the symbol, wherein the controller is programmed to evaluate the image data to determine whether the image data is sufficient to decode the symbol and to vary the light projected from the light source until the image data is sufficient to decode the symbol.
16. The digital scanning device of claim 15, further comprising a bright field light source for providing bright field illumination to the adjacent surface, wherein the controller is further programmed to selectively activate the bright field light source to illuminate the symbol.
17. The digital scanning device of claim 15, wherein the ring light source comprises a passive light pipe.
18. The digital scanning device of claim 15, wherein the ring light source comprises an active light pipe.
19. The digital scanning device of claim 15, wherein the ring light source comprises a plurality of individually-controllable lighting segments.
20. The digital scanning device of claim 15, further comprising a memory component connected to the controller for storing light conditions.