Temperature distribution in IC plastic packages in the reflow soldering process.

Temperature distribution in the packages is evaluated by both experimental method and an analytical finite-element method (FEM). It is found that the FEM analysis is useful for the temperature estimation of the packages. Temperature sensors imbedded in silicon chips were used to measure the temperature distribution in the package in both the reflow soldering process and the dip-coating process. These sensor chips were encapsulated in the actual DIP (dual in-line package) type package and SOJ (small outline j-bend package) type package. Temperature distributions of these packages were measured under various soldering conditions.