Pan Pacific Symposium Conference Proceedings


SAW SINGULATION OPTIMIZATION FOR THIN MOLD-LESS PACKAGE APPLICATION IN SMT ENVIRONMENT

Authors: Jusszuraini Bin Hashim, Osman Ahmad, and Teng Hoon Ng
Company: Celestica Malaysia and Celestica Thailand
Date Published: 2/12/2009   Conference: Pan Pacific Symposium


Abstract: The SIP or LGA devices in the market are typically assembled and finally molded in order to protect the internal raw parts of the package. The molding compound consists of electrometric toughening fillers, flame retardant, coupling agent to improve adhesion between the matrix and filler and also release agent to allow removal of the product from the mold die. During sawing, the mold compound may reduce debris accumulation on the blade surface and absorb the heat generated between the blade and the embedded copper. Additionally this compound may also improve the cutting quality and prevent pre-mature blade damage. Sawing through the molded packages has been proven successfully in the market especially in the semiconductor industry. However, it is a new challenge for sawing process to demonstrate its capability on thin mold-less package application.

Consumer demand for miniaturized portable wireless handhelds and personal electronic devices have become the driver for reduced manufacturing costs and smaller integrated circuit (IC) packages 1. Integrated circuit device manufacturers and subcontractors have resolved this challenge by maximizing the population density of ICs chips & components within the substrate area. Another opportunity is to minimize land estate via going moldless. Dicing methods using diamond cutting blades solve the challenge of how to singulate highly populated substrates and is a widely accepted method in the packaging industry.

Theoretically, the blade composition and the sawing process parameters are the key factors in order to deliver the best cutting quality and longer blade-life. By examination of the saw chipping & chip sizes dimension, several factors of the blade and sawing parameter can be optimized (e.g.: blade material, diamond grit size, cooling water temperature and spindle RPM). 3 different blade specifications from 3 different manufacturers are also selected in this study. Data showed that the winner is the blade with small grain size, small concentration and metal bond type. Another big challenge is how to hold down the substrate with components populated on both sides during sawing process without vacuum leak or chips flying-off. New tooling design had been proposed to handle the critical keep-out distance for the component in order to ensure all the sawing process was optimized before launching to production mode.

In this paper, the blade composition, sawing process parameter and type of handler machine will be reviewed and proposed to demonstrate the sawing process capability for singulating a thin substrate with components populated on both sides.

Key words: Mold-less package, grain size, concentration, metal bond, thin substrate



Members download articles for free:

Not a member yet?

What else do you get when you join SMTA? Read about all of the benefits that go along with membership.

Notice: Sharing of articles is restricted to just your immediate work group. Downloaded papers should not be stored on an external network or shared on the internet.


Back


SMTA Headquarters
6600 City West Parkway, Suite 300
Eden Prairie, MN 55344 USA

Phone +1 952.920.7682
Fax +1 952.926.1819