# Maszara model DCB test (The compliance of a symmetric DCB speciment)

## Description

Wafer bonds are commonly characterized by three important encapsulation parameters: bond strength, hermeticity of encapsulation and bonding induced stress. The bond strength can be evaluated using double cantilever beam or chevron respectively micro-chevron tests. Double cantilever beam test, is a method to define the strength of the bond. This is achieved by determine the energy of the bonded surfaces. A blade of a specific thickness is inserted between the bonded wafer pair. This leads to a split-up of the bond connection. The crack length equals the distance between the blade tip and the crack tip and is determined using IR transmitted light. The measured crack length determines surface energy in relation to a rectangular, beam-shaped specimen. The Maszara model neglects shear stress as well as stress in the un-cleaved part for the obtained crack lengths. The compliance of a symmetric DCB specimen is determined out of the crack length , the width and the beam thickness.

Related formulas## Variables

C | The compliance of the symmetric DCB specimen (m/N) |

L | The crack length (m) |

E* | Modulus of elasticity ( Young's modulus) (Pa) |

w | The width of the beam (m) |

t | The thikness of the beam (m) |