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Method for fabricated single-use supportive carriers for flexible tape-based substrates

IP.com Disclosure Number: IPCOM000019522D
Publication Date: 2003-Sep-17
Document File: 5 page(s) / 2M

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for fabricated single-use supportive carriers for flexible tape-based substrates. Benefits include improved reliability and improved process simplicity.

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Method for fabricated single-use supportive carriers for flexible tape-based substrates

Disclosed is a method for fabricated single-use supportive carriers for flexible tape-based substrates. Benefits include improved reliability and improved process simplicity.

Background

         Flexible tape-based package substrates have very thin core materials, approximately 25 µm. They lack the mechanical stiffness to resist warpage due to the slight differences in the amount of metal layers on the top and bottom of the core material. The tapes physically stretch during shipment and reel handling. The mounting of wavy tape substrate strips onto preformed metal or organic frames is a difficult challenge. The alignment of the tape to the frame carrier is critical for accurate precision molding, which aligns to the frame carrier and not to the substrate. The frame must hold the tape flat for increased die-attach bond line thickness (BLT) control (see Figure 1).

         The conventional method for flexible tape substrate preparation includes the following steps: 1.         Cut a section of the strip from the reel.

2.         Lay down the frame on the vacuum jig with alignment pins.
3.         Position the tape strip over the alignment pins.

4.         Apply a vacuum to hold the tape strip on the pins.
5.         Apply pieces of thin high-temperature adhesive tape on all sides to hold the substrate onto the frame.

         The alignment of the tape substrate to the frame is only as accurate as the tension created by the alignment pins holding the frame and substrates. The warpage in the tape substrates is not eliminated because the application of the tape substrates to the frames occurs after the tape substrates are manufactured.

General description

         The disclosed method is low-cost rigid substrate frames that are laminated to tape-based flexible substrates at the substrate manufacturer. The frames are single use. The alignment tolerance between the frame and substrate is increased. Tape warpage is reduced due to handling in shipping and assembly.

Advantages

         The disclosed method provides advantages, including:

•         Improved reliability due to the improved ease of de...