Not applicable.
The present invention relates to and apparatus and method for the placement of electronic components, and more specifically to a collet or probe used in pneumatic pick-and-place equipment to place components such as light-emitting diode (LED) chips.
The placement and arrangement of electronic components, such as semiconductor chips, is often accomplished using pick-and-place equipment. This equipment is used to transfer a chip from one location, usually a fabrication point, to a second location such as a circuit board or the like. For many components, such as LED chips, the pick-and-place equipment is often pneumatic, using suction to lift the chip off its original substrate and transfer the chip to another location.
Typical collets comprise a collet body with a single orifice at the face of the collet. The orifice is pneumatically connected to a central channel, which, in turn, is pneumatically connected to a vacuum pump or similar device. When the pump is activated, a vacuum is created, which lifts the chip up until it contacts the collet. By movement of the arm of the pick-and-place machine, the chip is the transferred to the desired location. Once the chip is in place, the vacuum pump is turned off and the chip falls into place. In current solutions, however, each collet lifts only one chip at a time. To move multiple chips, either the apparatus must repeat the process of lifting and moving the chip several times, or multiple collets are used. This can often make it difficult to achieve an acceptable chip separation without significant reduction in production rates.
This is particularly important in the case where multiple components need to be placed in close proximity to each other. For example, in order to ensure that light emitted by one LED chip blends with the light from a neighboring chip, the pick-and-place equipment must often pick-and-place each individual chip multiple times until the desired pattern is achieved.
Problems, therefore, are encountered with present pick-and-place technology spacing the individual chips without significant variation. With typical current solutions, spacing between chips of about 2 mils is the minimum that can be achieved while maintaining acceptable production rates. While smaller tolerances can be achieved, this requires slowing the pick-and-place equipment, thereby reducing production rates. Additional variations in placement are also introduced by the movement of the pick-and-place equipment and such other steps, such as the tape transfer processes.
The present invention is directed to a system and method which use a pneumatic pick-and-place machine capable of moving multiple objects simultaneously. A collet with multiple orifices permits the embodiment to pick up at least two components simultaneously while maintaining the distance and orientation of those components The example collet comprises a central channel pneumatically connected to each orifice through a path of intermediate channels. The orifices of embodiment collets can be arranged to provide the necessary spacing and placement patterns appropriate for the objects being placed.
The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention.
For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawing, in which:
In the embodiment shown in
When a vacuum is applied to either collet 10 or 12, the vacuum is transferred to the orifices allowing 2 or more chips 13 to be lifted simultaneously, while also automatically providing the appropriate separation between chips 13. In many embodiments, this spacing can be less than 2 mils (approximately 50.0 microns) depending upon the method used to dice the original wafer. While the vacuum is applied to the collet, chips 13 remain in contact with its face, and attached pick-and-place machine may maneuver chips 13 to their desired location. Once chips 13 are in place, the vacuum is released and chips 13 separate from the face of the collet.
The orifices of collets in embodiments of the present invention can be arranged in a number of different patterns. For example,
Referring to
While the present invention has been described in terms of positioning semiconductor chips such as light-emitting diodes, it will be appreciated that a system arranged according to the invention may be used to place any similar item whose placement and spacing needs to be maintained such as semiconductors, memory chips, or even non-electronic components.
Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skills in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.