The present invention relates generally to semiconductor devices, and more specifically, to a universal carrier tape for transporting semiconductor devices.
Semiconductor integrated circuits (IC""s) are typically fabricated in wafer form. After fabrication, the individual chips are scribed from the wafer and then undergo numerous processing and handling steps before they are tested and packaged. One type of common chip package, known as a xe2x80x9cflip chip,xe2x80x9d is a package having electrical contacts extending outwardly from the bottom surface of the package. Flip chip packages are manufactured in many different sizes. However, flip chips can be grouped into a number of families wherein each family has electrical contacts formed in a standardized pattern.
A carrier tape and reel assembly is typically used to transport the flip chips to the individual manufacturing stations for processing and testing. The carrier tape and reel assembly includes a carrier tape having a plurality of cavities designed to hold flip chips. Generally, there is nothing in the cavity to secure the chip. As a result, the chip may rotate or physically move within the cavity. If the chip rotates, an automated machine may pick up and place the device in the wrong orientation on a test machine or on a printed circuit board. A severe physical disturbance may damage the chip, thereby causing it to be unfit for use or causing a system utilizing the chip to malfunction.
To avoid these problems, the size of the cavity is customized for each flip chip package size. This tends to be expensive, particularly for semiconductor manufacturers which produce flip chips having many different package sizes. Sometimes, semiconductor manufacturers seal the chips within the cavities using a cover tape. Utilizing the cover tape material and implementing the extra steps to attach and remove the cover tape, however, increases the cost and complexity of transporting and handling the chips. Another method of securing the flip chips is through adhering the chip to adhesive tape placed on the bottom surface of the cavity. However, the adhesive substance may cause contamination of the electrical contacts on the chip as well as increase the cost and complexity of handling the devices.
In view of the foregoing, a low cost carrier tape that securely holds and protects flip chips, but that does not require the use of either cover tape or adhesive tape would be desired.
The present invention provides a low cost carrier tape designed to store chips during transportation. The invention comprises a carrier tape which contains receptacle holes designed to secure chips onto the carrier tape by clasping onto the chip""s electrical contacts. The receptacle holes are formed in patterns to match the standardized electrical contact patterns of each flip chip family.
The receptacle holes prevent the flip chip from rotating and physically moving. Preventing rotation ensures proper orientation of the flip chip in the testing and manufacturing processes. Preventing physical movement reduces the chance of damage occurring to the flip chip. Preventing rotation and physical movement makes the use of cover tape or adhesive tape unnecessary. This reduces the cost and complexity of the transportation process, as well as avoids possible contamination of the electrical contacts on the flip chips. Additionally, cavity sizes do not need to be customized to chip package sizes within each family of flip chips since the receptacle hole patterns are created to match the contact patterns of specific flip chip families. This further reduces the cost of transporting flip chips. In sum, this invention provides a more cost effective, more secure and contamination-free method for transporting flip chips.
USPTO Backgrounds
USPTO Backgrounds