Kenichiroh Mukai

A New Reliable Adhesion Enhancement Process for Directly Plating on Molding Compounds for Package Level EMI Shielding

Plating on molding compound is a relatively new field which could open up new package designs. One major application is conformal self EMI shielding (package level shielding) of ICs. Generally, EMI shielding is done mainly by metallic cans, however, this technique increases the space requirements and reduces flexibility of component layout on the PCB, that would not be suitable to handset products.

VitroCoat GI - Ultra-thin adhesive layer for metallization of glass interposer

In this paper a glass-copper interface adhesion promoting thin film is described that forms chemical bonds with glass, and mechanically and possibly chemically anchors to copper to create strong, reliable adhesion between the glass substrate and the deposited metal. Wet chemical deposition of a low volatile organic content (VOC), emissions free, cost-effective, water based coating solution was used to create a thin, transparent metal oxide film that then enables electroless, and electrolytic copper plating directly onto glass. With this approach, a copper film thickness of 30μm can be applied without delamination from the smooth glass. Adhesion at 15μm Cu thickness as measured by 90° peel strength tests can achieve values of ≥4 N/cm. Thermal and stress tests using lead free reflow conditions and Highly Accelerated Stress Testing (HAST) were carried out with manageable to minimal adhesion loss. Through hole plating of aspect ratios up to 5:1 are also demonstrated. Photolithography of fine-lines as small as 5/5 μm was feasible, with very small undercut observed.

Metal Plating on Mold Compound for EMI Shielding with Industrial Test Compliance

The need for EMI shielding is becoming more pronounced as it is driven by miniaturization of devices, higher bandwidth of market needs, multiple applications on the same device, and heightened safety concerns with regard to the threat of electromagnetism to the health of users. In this paper, we present a reliable method for thin film coating on the surface of a molding compound by nickel and copper plating for EMI shielding applications. The correct adhesion promoter is carefully selected before proceeding into the plating process. After that, the plated samples were subjected to a series of aging processes following standard industrial compliance, and were found to have passed all the required criteria. The new approach has several advantages, such as excellent distribution of three-dimensional conformal coating and ease of mass production, which ultimately lowers the cost of production.

EMI shielding performance by metal plating on mold compound

Conformal plating on mold compound is a new fabrication process technology, it offers new possibility for IC package design to improve features such as rigidization of the flexible core, heat sinking, 3D circuit patterning and EMI shielding. This fabrication technology had successfully demostrated a process which is able to achieve high reliable performance, as being proven to have high peeling strength and electrical consistency after sample had gone through the critical moisture and temperature cycle test. Following after the reliability test, this paper studies the shielding effectiveness of varying coating thickness with respect to laboratory simulated EMI condition using radio frequency from 10MHz to 5.8 GHz. Different metal namely pure nickel, nickel-phosphorous and pure plated copper are also being studies for their performance in the effectively of EMI sheilding.

Adhesion enhancement for electroless plating on mold compound for EMI shielding with industrial test compliance

In the manufacturing process, metal capping for EMI shielding is done during the integrated circuit (IC) assembly process, which hinders the attempt of reducing the size of electronic device and also incurs higher cost of assembly. Therefore direct deposition of metal on IC mold compound is desirable. Conventional metal plating techniques, however fail tape test. This paper studies the condition of plating metal directly onto surface of mold compound with the enhancement of novel non-etching adhesion promoter CovaBond MR™. By plating direct onto mold compound, the shielding capping task can be done in array form before the die saw process in IC manufacturing (before IC assembly), which reduce the thickness and dimension of chip and improves design flexibility of circuit board as well as reduce the manufacturing cost. The industrial test results in this paper have proven the performance of the enhanced metal plating technique.

Adhesive enabling technology for directly plating metal on molding resin

This paper aims to introduce a new wet chemical process for adhesion enhancement of plated metal to epoxy molding compounds (EMC). The approach is based on an innovative combination of mechanical anchoring and chemical adhesion. The new approach broadens possible application ranges and replaces more limited processes such as sandblasting and sputtering, which have cost and technical drawbacks.