Semiconductor Oscillator Package with Buried Conductive Paths

Solution Overview

Problem

Conventional crystal oscillator packages are large, heavy, and costly, with high manufacturing costs and significant dimensions, while still requiring hermetic isolation and protection for the resonator.

Innovation Solution

A semiconductor-based oscillator device with a package comprising a substrate, structural layer, and cap, featuring buried conductive paths and pads for electrical signal transmission, and a getter layer for pressure control, manufactured using micromachining techniques to reduce size and cost.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If ceramic or metal packages are used for crystal oscillators, then hermetic isolation and protection characteristics are improved, but device dimensions, weight, and manufacturing cost increase

Engineering Contradiction:

Improvehermetic isolation and protectionVSAvoidpackage weight

Core Design Contradiction:

ReliabilityVSWeight of stationary object

Solution Approach 1:

The patent changes the material parameter from traditional ceramic or metal to semiconductor material, achieving comparable hermetic isolation properties while significantly reducing weight and cost. The semiconductor package maintains the necessary protection characteristics through material substitution rather than structural modification.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention employs a cost-effective semiconductor package that eliminates the need for expensive ceramic or metal construction while maintaining functional equivalence. The package achieves reliable hermetic isolation at lower manufacturing cost through advanced semiconductor fabrication processes.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Reliability

If ceramic or metal packages are used for crystal oscillators, then hermetic isolation and protection characteristics are improved, but device dimensions and manufacturing cost increase

Engineering Contradiction:

Improvehermetic isolation and protectionVSAvoidpackage dimensions

Core Design Contradiction:

ReliabilityVSLength of stationary object

Solution Approach 1:

The patent changes the material parameter from traditional ceramic or metal to semiconductor material, achieving comparable hermetic isolation properties while significantly reducing weight and cost. The semiconductor package maintains the necessary protection characteristics through material substitution rather than structural modification.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention transitions from three-dimensional ceramic/metal package structures to a planar semiconductor-based package architecture. This dimensional shift enables compact integration while maintaining hermetic isolation through thin-film deposition and wafer bonding techniques.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Reliability

If ceramic or metal packages are used for crystal oscillators, then hermetic isolation and protection characteristics are improved, but manufacturing cost increases

Engineering Contradiction:

Improvehermetic isolation and protectionVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent changes the material parameter from traditional ceramic or metal to semiconductor material, achieving comparable hermetic isolation properties while significantly reducing weight and cost. The semiconductor package maintains the necessary protection characteristics through material substitution rather than structural modification.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention replaces mechanical assembly processes typical of ceramic/metal packages with semiconductor fabrication processes including thin-film deposition, photolithography, and wafer bonding. This substitution enables higher precision, better hermetic sealing, and lower manufacturing costs through standardized semiconductor manufacturing.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

The solution achieves a compact, cost-effective oscillator package with hermetic isolation and protection, enabling efficient electrical signal transmission and reduced susceptibility to environmental factors, while maintaining the stability of the resonator.

Implementation Method 1

Crystal oscillators are electronic circuits that exploit the mechanical resonance of a vibrating piezoelectric crystal to create an electrical signal characterized by a very precise frequency

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

a getter layer for pressure control

Methodology Applied

Scientific EffectGettering: Gettering

Data Source

PatentUS8988155B2Oscillator device and manufacturing process of the same

Publication Date: 2015.03.24 STMICROELECTRONICS SRL

AI summary

An oscillator device includes: a structural layer extending over a first side of a semiconductor substrate; a semiconductor cap set on the structural layer; a coupling region extending between and hermetically sealing the structural layer and the cap and forming a cavity within the oscillator device; first and second conductive paths extending between the substrate and the structural layer; first and second conductive pads housed in the cavity and electrically coupled to first terminal portions of the first and second conductive paths by first and second connection regions, respectively, which extend through and are insulated from the structural layer; a piezoelectric resonator having first and second ends electrically coupled, respectively, to the first and second conductive pads, and extending in the cavity; and third and fourth conductive pads positioned outside the cavity and electrically coupled to second terminal portions of the first and second conductive paths.