Strained Encapsulation Layer for IC Tamper Protection

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Solution Overview

Problem

Current integrated circuits face challenges in protecting against invasive and semi-invasive attacks, as existing tamper resistance methods are inadequate in preventing physical tampering and data retrieval by hackers.

Innovation Solution

The integrated circuit employs a strained encapsulation layer that induces stress on the substrate, with strain detectors and disabling circuits to prevent access when tampering occurs, either by directly disabling the circuit or causing mechanical disintegration, such as cracking or delamination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional encapsulation is used without strain, then the device structure is simple and easy to manufacture, but the device is vulnerable to invasive attacks and tampering

Engineering Contradiction:
Improvetamper protectionVSAvoidencapsulation structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The encapsulation layer is pre-strained during manufacturing to store mechanical energy. This preliminary action creates a latent protective mechanism that activates only when tampering occurs, resolving the contradiction by adding protection without requiring complex active monitoring systems during normal operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The strained encapsulation layer acts as a pre-prepared protective barrier that releases stored stress to damage the substrate upon tampering. This beforehand cushioning provides automatic protection without requiring real-time detection systems, maintaining simplicity while enhancing reliability.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Reliability

If the encapsulation layer is made thicker to improve protection, then tamper resistance increases, but manufacturing complexity and cost increase

Engineering Contradiction:
Improvetamper resistanceVSAvoidmanufacturing process
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

Instead of increasing thickness, the invention changes the mechanical parameter of the encapsulation layer by introducing strain. This parameter change allows thin layers to provide protection equivalent to much thicker unstrained layers, resolving the contradiction by achieving high tamper resistance without increasing manufacturing complexity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite structure where a thin encapsulation layer with stored strain energy provides protection equivalent to thick material. The strain-energy-dense composite resolves the contradiction by achieving high protection with minimal material thickness, simplifying manufacturing.

Inventive Principle:
Principle #40Composite materials

3Reliability

If strain detectors and disabling circuits are added, then data protection against invasive attacks improves, but device complexity increases

Engineering Contradiction:
Improvedata protectionVSAvoidcircuit structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention replaces complex electronic detection and disabling circuits with a passive mechanical system. The strained encapsulation layer automatically translates mechanical tampering into substrate damage through stress release, eliminating the need for active electronic protection circuits and resolving the contradiction between data protection and circuit complexity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The encapsulation layer performs the protective function autonomously without requiring external control circuits. The stored strain energy self-activates upon tampering to damage the substrate, providing data protection through self-service mechanics rather than complex controlled systems.

Inventive Principle:
Principle #25Self-service

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

This approach provides enhanced tamper protection by detecting strain changes and triggering disabling mechanisms, effectively preventing data access even when physical tampering attempts are made, thereby offering a robust security solution against invasive and semi-invasive attacks.

Implementation Method 1

a first strained encapsulation layer being provided on a first side of the substrate, wherein the first strained encapsulation layer has a strain in a direction parallel to a surface of the substrate

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2300953B1Intrusion protection using stress changes
Publication Date: 2013.01.23 NXP BV
  • EP2300953B1 patent drawingFigure 1(a)~1(c)
  • EP2300953B1 patent drawingFigure 2(a)~2(c)
  • EP2300953B1 patent drawingFigure 3(a)~4(c)

AI summary

The invention relates to a integrated circuit comprising an electronic circuit integrated on a substrate (5), and further comprising protections means for protection of the electronic circuit (25). The protection means comprise: i) a first strained encapsulation layer (10) being provided on a first side of the substrate (5), wherein the first strained encapsulation layer (10) has a strain (Sl) in a direction parallel to the substrate (5), and ii) disabling means (20) arranged for at least partially disabling the electronic circuit (25) under control of a strain change in the substrate (5). The invention further relates to a method of manufacturing such integrated circuit, and to a system comprising such integrated circuit. Such system is selected from a group comprising: a bank-card, a smart-card, a contact-less card and an RFID. All embodiments of the integrated circuit in accordance with the invention provide essentially an alternative tamper protection to the data stored or present in the electronic circuit therein. A first main group of embodiments concerns an integrated circuit wherein tamper protection is obtained by detecting a strain change during tampering and subsequently disabling the electronic circuit. A second main group of embodiments concerns an integrated circuit wherein tamper protection is obtained by designing a stack of strained encapsulation layers, such that tampering causes releasing of strain and thereby mechanical disintegrate (break, delaminate, etc) of the integrated circuit, and thus disabling the electronic circuit.