Semiconductor Package Cooling Fixture for Warpage Flatness Control

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Solution Overview

Problem

Warping issues in wafer-level and strip-level semiconductor packaging complicate connections to semiconductor die, affecting yield, reliability, and handling, necessitating improved warpage control methods.

Innovation Solution

A cooling fixture with nozzles and a control system to manage fluid flow, temperature, and duration for controlled cooling of encapsulated semiconductor assemblies, ensuring desired flatness through systematic cooling processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If encapsulation process is performed on semiconductor devices, then device protection and integration are achieved, but warping occurs affecting yield and reliability

Engineering Contradiction:
Improvedevice reliabilityVSAvoidflatness control
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary cooling action by providing a cooling fixture that contacts the encapsulated semiconductor devices before warping fully develops. The cooling fixture cools specific regions (such as the center portion) to prevent warping from occurring, thereby maintaining flatness and enabling subsequent planar-sensitive processing steps.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the temperature parameter by introducing a cooling fixture that selectively cools regions of the encapsulated semiconductor devices. By controlling the temperature distribution during and after encapsulation, the thermal contraction differences are managed to prevent warping while maintaining device reliability.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If wafer-level and strip-level packaging are used, then production efficiency is improved, but connection difficulty increases due to warpage

Engineering Contradiction:
Improveproduction efficiencyVSAvoidconnection ease
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The cooling fixture is applied immediately after encapsulation to prevent warping before connection processes. This preliminary action ensures that the semiconductor devices remain flat and easy to connect, maintaining both high productivity and ease of manufacture.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The cooling fixture selectively cools specific regions of the encapsulated semiconductor devices (such as the center portion) rather than uniformly cooling the entire wafer or strip. This localized cooling approach effectively controls warping while maintaining overall production efficiency.

Inventive Principle:
Principle #3Local quality

3Temperature

If uniform cooling is applied to encapsulated assemblies, then overall temperature reduction is achieved, but controlled flatness cannot be obtained

Engineering Contradiction:
Improvetemperature reductionVSAvoidflatness control
Core Design Contradiction:
TemperatureVSManufacturing precision

Solution Approach 1:

The cooling fixture is designed to cool specific regions of the encapsulated semiconductor devices differently. For example, the center portion may be cooled more aggressively than the edges, or specific warprone areas receive targeted cooling. This non-uniform, localized cooling approach achieves both temperature reduction and precise flatness control.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The cooling fixture divides the cooling action into multiple independent cooling zones or regions. Each zone can be controlled separately to apply the appropriate cooling intensity to different parts of the encapsulated assembly, thereby achieving both overall temperature reduction and localized flatness control.

Inventive Principle:
Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Achieves improved yield, reliability, and cost-effectiveness by allowing planar-sensitive processing layers, enhancing handling and reducing warpage-related issues.

Implementation Method 1

A cooling fixture is provided which cools an encapsulated semiconductor device assembly

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

A desired flatness of the encapsulated assembly is achieved by way of the cooling fixture and controlled fluid delivery process

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP4099367B1Semiconductor device packaging warpage control
Publication Date: 2025.10.01 NXP USA INC
  • EP4099367B1 patent drawingFigure 1A
  • EP4099367B1 patent drawingFigure 1B
  • EP4099367B1 patent drawingFigure 2

AI summary

A method of manufacturing a packaged semiconductor device is provided. The method includes placing a plurality of semiconductor die on a carrier substrate. The plurality of semiconductor die and an exposed portion of the carrier substrate are encapsulated with an encapsulant. A cooling fixture includes a plurality of nozzles and is placed over the encapsulant. The encapsulant is cooled by way of air exiting the plurality of nozzles. A property of air exiting a first nozzle of the plurality of nozzles is different from that of a second nozzle of the plurality of nozzles.