Base Package System With Knuckle Region For IC Stacking

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Solution Overview

Problem

Current integrated circuit packaging technologies face challenges in reducing package dimensions, improving manufacturing yields, and minimizing assembly defects such as contamination and delamination, which hinder cost-effective and efficient package stacking.

Innovation Solution

A base package system is developed with a substrate having ball lands and a molded package body featuring a knuckle region, which redirects and reduces stress during the singulation process, preventing flash and delamination, and includes a finger mold chase design to manage pressure and temperature during molding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If package molding compound is applied during manufacturing, then integrated circuits are protected and encapsulated, but the molding compound may become extruded onto the substrate surface causing contamination of electrical contacts

Engineering Contradiction:

Improveencapsulation protectionVSAvoidcontamination of electrical contacts

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary anti-action by designing a molding process that prevents extrusion of molding compound onto the substrate surface before contamination can occur. The molding compound is contained within defined boundaries during the molding process, and excess material is prevented from reaching the electrical contacts area, thus eliminating the harmful effect before it can manifest.

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The patent extracts or removes the harmful aspect by separating the molding compound application from the electrical contact areas. The molding process is designed to apply compound only to specific regions that do not overlap with electrical contacts, effectively taking out the contamination risk from the manufacturing process.

Inventive Principle:

Principle #2Taking out (Extraction)

2Productivity

If singulation is performed to separate individual devices from a larger strip, then manufacturing efficiency is improved, but delamination of package molding compound from die surface can occur causing broken electrical connections

Engineering Contradiction:

Improvemanufacturing efficiencyVSAvoidelectrical connections

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent applies beforehand cushioning by designing the package structure with enhanced adhesion between the molding compound and die surface prior to the singulation process. The molding compound is formulated or applied in a way that creates strong bonding that can withstand the mechanical stresses of subsequent singulation, thus cushioning against the potential delamination harm.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The patent employs parameter changes by modifying the physical or chemical properties of the molding compound or the bonding interface to enhance adhesion strength. This could involve changing temperature, pressure, or material composition parameters during molding to ensure the bonding is strong enough to prevent delamination during the mechanical singulation process.

Inventive Principle:

Principle #35Parameter changes

3Area of stationary object

If multiple packages are stacked to reduce board space, then area utilization is improved, but assembly process difficulties increase due to contamination and broken connections

Engineering Contradiction:

Improveboard space utilizationVSAvoidassembly process difficulties

Core Design Contradiction:

Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by ensuring that all potential contamination and delamination issues are resolved during the individual package manufacturing process, before the packages are stacked. By preventing defects upfront during molding and singulation, the packages are ready for clean assembly into stacks, reducing assembly complexity.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent converts the potential harm of molding compound extrusion and delamination into benefit by designing processes that transform these risks into opportunities for improved package integrity. The controlled molding and enhanced adhesion techniques that prevent defects also create more reliable packages suitable for stacking, thus converting what could be harmful manufacturing challenges into benefits for multi-package assembly.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Data Source

PatentUS8022538B2Base package system for integrated circuit package stacking and method of manufacture thereof

Publication Date: 2011.09.20 STATS CHIPPAC MANAGEMENT PTE LTD

AI summary

A method of manufacture of a base package system includes: forming a substrate strip assembly including: providing a substrate strip having ball lands, mounting an integrated circuit on the substrate strip, and molding a finger structure, having a knuckle region, on the integrated circuit; and singulating a substrate from the substrate strip assembly.