Dai Nippon Printing Co., Ltd. (DNP, TOKYO: 7912) has developed a highly reliable manufacturing technology that configures a high definition silver plated area for lead frames that fix semiconductor chips and connects them externally. In addition, the new technology improves adhesiveness with a surface roughening technology of the highest industry standard that seals the copper surface to the mold compound. 

By providing this high definition, highly reliable lead frame we aim to expand the use of semiconductor Quad Flat Non-leaded package (QFN) for vehicles. 

Background

QFN, unlike other semiconductor packages has no extended lead, which as a result makes it possible to reduce the overall area, and have developed a firm reputation based on the fact that they exhibit high heat dissipating characteristics, which are not possible to replicate with other package formats such as the die pad that fixes the semiconductor chip is sealed with mold compound, making it more difficult for the heat to disperse. With lead frames used with QFN it is necessary to configure a high definition silver plated area that can accommodate the miniaturization and high-pin count associated with improved chip performance. At the same time, the in-vehicle package demands high level reliability in suppressing the ingress of water. 

In order to overcome these challenges, DNP has taken advantage of our microfabrication technology developed over many years to successfully achieve the configuration of lead frame silver plated area of ±25um. It has also been possible to maintain high level reliability by improving the adhesion of the mold compound and the lead frame. 

Diagram 1: QFN Package Image. For expanded view of highlighted portion please see diagram 2

Diagram 2: Structure of DNP developed product (at left)

DNP Developed Lead Frame Features

The newly developed DNP lead frame utilizes roughening technology of the highest industry standard on the surface of the lead flame to improve the adhesion of the mold compound. In addition, by realizing a high definition silver plated area, which works to maintain an appropriate distance between the tip of the lead frame and the silver plating, and by also expanding the contact area between the roughened lead flame and the mold compound, it has also been made possible to achieve high level reliability by suppressing the ingress of water into the package.

The Joint Electron Device Engineering Council (JEDEC) has established Moisture Sensitivity Levels (MSL) with the objective of preventing a variety of phenomena from volume expansion due to the absorption and vaporization of air-borne moisture in the mold compound. And DNP is pleased to announce that our newly developed product has been verified the highest MSL 1 (≤30 °C/85% RH unlimited) ranking.

Going Forward

DNP will propose the newly developed high definition, highly reliable lead frame to post-processing manufacturers and expand this business. We will also strengthen our facilities to meet increasing demand, and plan to double our production capacity by FY 2023 compared to FY 2020. 

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*Product information and service details described in this release are accurate as of the date of issue. They are subject to change without notice.