Coreless Substrate Package Layout With Stiffener Ring Warpage Control

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Solution Overview

Problem

Conventional semiconductor packaging with a core substrate material increases package thickness, leading to longer routing distances and profile issues, and challenges in warpage control for coreless substrates.

Innovation Solution

A coreless substrate package design featuring a silicon die mounted on a substrate without a permanent core, using insulating and conductive layers, underfill and gap fill materials, and a stiffener ring for warpage control, with C4 bumps and BGA balls for electrical connections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a core substrate material is used, then the package substrate provides structural support and routing capability, but the package thickness increases and routing distance becomes longer

Engineering Contradiction:
Improvestructural supportVSAvoidpackage thickness
Core Design Contradiction:
StrengthVSLength of stationary object

Solution Approach 1:

The patent removes the core substrate material from the package structure, extracting only the essential functions (structural support and routing) and implementing them through alternative means: a substrate without core material, with conductive traces formed directly on the substrate surface and insulating layers providing necessary support, thereby reducing thickness while maintaining functionality

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent segments the substrate structure into distinct functional layers: insulating layers, conductive trace layers, and optional reinforcement elements, allowing each layer to perform its specific function independently without requiring a thick core material, thus achieving thin profile with adequate structural support

Inventive Principle:
Principle #1Segmentation

2Ease of operation

If a core substrate material is used, then the package substrate provides routing capability, but the routing distance between upper layers and lower signal layers becomes longer

Engineering Contradiction:
Improverouting capabilityVSAvoidrouting distance
Core Design Contradiction:
Ease of operationVSLength of stationary object

Solution Approach 1:

The patent extracts the routing function from the core substrate and implements it through surface-level conductive traces and vias, eliminating the need for signals to traverse through the thickness of a core material, thereby significantly reducing routing distance while maintaining full routing capability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent transitions routing from a three-dimensional path through core layers to a primarily two-dimensional path on the substrate surface, using conductive traces and vias that minimize vertical traversal, thus reducing routing distance while preserving connectivity between layers

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Length of stationary object

If a coreless substrate is used, then the package thickness is reduced and profile is thinner, but warpage control becomes challenging

Engineering Contradiction:
Improvepackage thicknessVSAvoidwarpage control
Core Design Contradiction:
Length of stationary objectVSStability of the object's composition

Solution Approach 1:

The patent employs composite material structures combining substrate material with insulating layers and conductive traces, where the combination of materials with different mechanical properties provides both thin profile and warpage resistance through material composition rather than core thickness

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent segments the substrate into multiple thin functional layers (insulating layers, conductive trace layers) that can be independently optimized, allowing the overall structure to achieve thin profile while the distributed layer structure provides warpage control through balanced stress distribution

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4379791A1Coreless substrate package and fabrication method thereof
Publication Date: 2024.06.05 MEDIATEK INC
  • EP4379791A1 patent drawingFigure 1
  • EP4379791A1 patent drawingFigure 2
  • EP4379791A1 patent drawingFigure 3

AI summary

A coreless substrate package (1) includes a coreless substrate (20); a package device (10) mounted on the coreless substrate (20); an underfill material (310) filling into a space between the package device (10) and the coreless substrate (20); a stiffener ring (40) disposed on a top surface (20a) of the coreless substrate (20) along perimeter of the coreless substrate (20); and a gap fill material (50) disposed in a gap between the stiffener ring (40) and the package device (10).