Silver-bonded quartz crystal
AssigneeStatek Corporation
InventorsYue Fang, Thomas Pham
Life of this patent
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Abstract
The disclosed technology generally relates to packaging a quartz crystal, and more particularly to bonding a quartz crystal using sintering silver paste. In one aspect, a method of packaging a quartz crystal comprises attaching a quartz crystal to a package substrate using one or more silver paste layers comprising silver particles. The method additionally comprises sintering the silver paste in a substantially oxygen-free atmosphere and at a sintering temperature sufficient to cause sintering of the silver particles. The sintering is such that the quartz crystal exhibits a positive drift in resonance frequency of the quartz crystal over time. The method further comprises hermetically sealing the quartz crystal in the package substrate.
Claims30
A quartz crystal oscillator, comprising:
- a package substrate;
- a quartz crystal bonded to the package substrate by one or more bonding layers at a first end in a lengthwise direction of the quartz crystal;
- and
- an integrated (IC) die electrically connected to the quartz crystal and bonded to the package substrate by an additional bonding layer;
- and
- the additional bonding layer having a different silver content relative to a silver content of the one or more bonding layers,
- wherein one of the one or more bonding layers and the additional bonding layer comprises a sintered silver paste, and the other of the one or more bonding layers and the additional bonding layer comprises an epoxy, a silicon-based elastomer or a polyimide-based material.
A quartz crystal oscillator, comprising:
- a package substrate comprising a cavity;
- a mounting pedestal disposed in the cavity of the package substrate;
- a quartz crystal bonded to the mounting pedestal by one or more bonding layers at a first end in a lengthwise direction of the quartz crystal;
- an integrated (IC) die electrically connected to the quartz crystal and bonded to the package substrate by an additional bonding layer,
- wherein the IC die is disposed in the cavity of the package substrate below the quartz crystal in a depth direction of the cavity;
- and
- the additional bonding layer having a different silver content relative to a silver content of the one or more bonding layers,
- wherein one of the one or more bonding layers and the additional bonding layer comprises a sintered silver paste, and the other of the one or more bonding layers and the additional bonding layer comprises an epoxy, a silicon-based elastomer or a polyimide-based material.
A method of packaging a quartz crystal oscillator, the method comprising:
- forming one or more bonding layers to bond a quartz crystal to a package substrate at a first location in a lengthwise direction of the quartz crystal;
- and
- forming an additional bonding layer to bond an integrated circuit (IC) die to the package substrate at a second location, the additional bonding layer having a different silver content relative to a silver content of the one or more bonding layers,
- wherein one of the one or more bonding layers and the additional bonding layer comprises a sintered silver paste, and the other of the one or more bonding layers and the additional bonding layer comprises an epoxy, a silicon-based elastomer or a polyimide-based material.
Dependencies are inferred from the claim text.