Dai Nippon Printing (DNP) is claiming to have developed a lead frame for the thinnest chip package yet.
"Using this lead frame it has become possible to achieve a semiconductor package with a thickness of 0.15mm, which is the slimmest moulded package in the world to date," said DNP.
There has been an expansion in the market for packaging which mounts semiconductors in three dimensions - either as stacked packages or stacked chips.
"In the case of multilayered chip type semiconductor packaging; while it is relatively easy to achieve a slimming down of the overall package other issues remain: including the fact that it is not easy to assure the quality of each individual multilayered chip, and also of declining yields," said DNP.
"We considered the multilayered package type, where the quality of the IC chips can be screened on an individual basis, to be the optimum type for its purposes." - hence the development of a lead frame for use with what it claims is the world's slimmest moulded semiconductor package.
The package is wire-bonded, but the lead frame does not extend below the chip. Instead the chip is suspended in a hole in the frame while it is bonded and moulded.
In cases where it is structurally necessary, the lead frame portion used for mounting the die is etched into a concave shape into which the IC chip is then embedded.
"By downsizing not only the lead frame, but also slimming down the IC chip and mould to the maximum possible extent, it has become possible to create a semiconductor package which is significantly thinner than existing products," said DNP. "The precision of the plated area has been improved by roughly three fold to +/-0.05mm, and it has also been possible to achieve improvements in humidity reliability at the same time."
Lead frame for use in new packaging
