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US 6,530,653 B2Granted
Ultrasonic bonding of ink-jet print head components
AssigneePicoJet, Inc.
InventorsHue P. Le, Hoi P. Le, Thanh P. Le, Linh B. Tran
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Abstract
A piezoelectric ceramic ink-jet print head is made by ultrasonic bonding processes. Several improved features of ink jet print heads include more cost-effective bonding processes using an ultrasonic bonding technique, an improved piezoelectric ceramic structural element pattern, and improved print head piezoelectric electrical contacts. There is also disclosed an ultrasonic bonding process for joining ceramic and metallic objects.
Claims25
A process for ultrasonic bonding of ceramic and metallic surfaces, comprising:
- applying a coating of bonding material to the ceramic and metallic surfaces to be bonded;
- assembling on a bonding fixture ceramic and metallic objects having the ceramic and metallic surfaces to form an assembled stack in which confronting surfaces coated with bonding material form a bonding material interface;
- heating the assembled stack to a temperature that softens but is below a melting temperature of the bonding material at the bonding material interface;
- and
- applying an ultrasonic force at a bonding pressure and at an ultrasonic vibration frequency for a bonding time sufficient for the bonding material at the bonding material interface to wet and thereby promote completion of bonding of the ceramic and metallic surfaces in the absence of the ultrasonic force.
2 more elements
An ink jet print head, comprising:
- multiple metallic inner plates assembled in a stack of contiguous layers and positioned between first and second metallic outer plates, the metallic inner plates having openings aligned to form an internal ink cavity communicating with an internal ink channel;
- a piezoelectric ceramic plate assembled to the stack adjacent to the first metallic outer
- plate and positioned to effect ink flow in the internal ink channel, and the second metallic outer plate having an aperture aligned with the internal ink channel to form an ink nozzle from which ink delivered from the internal ink cavity and flowing in the internal ink channel is ejected;
- different pairs of the multiple metallic inner plates and the piezoelectric ceramic plate having confronting surfaces joined by an ultrasonic bond between each pair, the first outer metallic plate having a first interface formed by an ultrasonic bond joining opposed surfaces of the first outer metallic plate and one of the inner plates, the second outer metallic plate having a second interface formed by an ultrasonic bond joining opposed surfaces of the second outer metallic plate and a different one of the inner plates, and the first outer metallic plate and the piezoelectric ceramic plate having a third interface formed by an ultrasonic joining opposed surfaces of the first outer metallic plate and the piezoelectric ceramic plate;
- and
- each of the interior, first, second, and third interfaces including a bonding material comprised of a metallic formulation including tin or a tin alloy.
3 more elements
Dependencies are inferred from the claim text.