Tatsuya Ohtaka

Manufacturing process for combination lead frame/TAB BGA

The Combination Lead Frame/TAB BGA has been studied to improve the manufacturability of TBGA LSI package. Ordinary lead frames and the TAB tape carriers have been applied to make the assembly of TBGA easier. The base technologies, the materials of the lead frame, and the TAB tape were thoroughly applied to the heat spreader and the fine routing flexible substrate. The lead frames as the heat spreader and the tape (manufactured by the line of the TAB tape for wire bonding substrate) are combined with a high thermal resistive adhesive (Tg473K). The solder or metal balls for the surface mounting were previously attached to the ball pads before assembling the die. With this improved Combination Lead Flame/TAB BGA, current assembly houses will never need any other new machines to produce the TBGA.

High performance, low-cost leadframe with a heat spreader for HQFPs

Leadframes with heat spreaders have been developed for mounting high power LSI devices, such as MPUs and MPEGs. Power dissipation of this package is from 2 to 3 W. However, there is a great need for less expensive leadframes for Heatspreader-enhanced Quad Flat Packs (HQFPs) for general use. Therefore, we modified the structure of the leadframe for the HQFP and improved the manufacturing to achieve very low-cost leadframes. The features of this new leadframe are as follows: (1) Nearly the same cost as a conventional leadframe with-out a heat spreader. (2) From 2 to 3 W thermal dissipation. (3) Easy wire bonding. (4) High reliability through solder reflow. This leadframe achieves high thermal performance and guarantees high reliability at the least cost.