Browse Prior Art Database

ALIGNMENT OF CHANNEL BEARING CHIP AND HEATER-BEARING CHIP IN A THERMAL INK JET PRINTHEAD

IP.com Disclosure Number: IPCOM000027084D
Original Publication Date: 1995-Apr-30
Included in the Prior Art Database: 2004-Apr-07
Document File: 4 page(s) / 155K

Publishing Venue

Xerox Disclosure Journal

Abstract

A currently viable design for a thermal ink jet printhead comprises a channel chip, defining a set of narrow capillary grooves therein, and a heater chip, which is typically a silicon chip having an array of small resistance heaters formed therein. In constructing the printhead, the two chips are placed together so that each resistance element in the heater chip aligns with one capillary groove in the channel chip. In this way, a set of capillary channels are formed in the space between the chips, with each groove forming one inner surface of each channel, and the surface of the heater chip, having one resistance element defined on the surface thereof, forming the rest of the interior surface of the channel. Each channel temporarily holds liquid ink, and when the resistance element in the particular channel is activated, the liquid ink is rapidly heated within the channel and expelled through a nozzle onto a print sheet.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 54% of the total text.

Page 1 of 4

XEROX DISCLOSURE JOURNAL

ALIGNMENT OF CHANNEL- Proposed Classification BEARING CHIP AND HEATER-
BEARING CHIP IN A THERMAL
INK JET PRINTHEAD
Donald J. Drake
Almon P. Fisher

US. C1.156/633 Int. C1. B44c 1/22

I \ 16

R2 p2

 I 12

XEROX DISCLOSURE JOURNAL - Vol. 20, No. 2 MarchiApril 1995 123

[This page contains 1 picture or other non-text object]

Page 2 of 4

ALIGNMENT OF CHANNEL-BEARING CHIP AND HEATER- BEARING CHIP IN A THERMAL INK JET PRINTHEAD (Cont'd)

A currently viable design for a thermal ink jet printhead comprises a channel chip, defining a set of narrow capillary grooves therein, and a heater chip, which is typically a silicon chip having an array of small resistance heaters formed therein. In constructing the printhead, the two chips are placed together so that each resistance element in the heater chip aligns with one capillary groove in the channel chip. In this way, a set of capillary channels are formed in the space between the chips, with each groove forming one inner surface of each channel, and the surface of the heater chip, having one resistance element defined on the surface thereof, forming the rest of the interior surface of the channel. Each channel temporarily holds liquid ink, and when the resistance element in the particular channel is activated, the liquid ink is rapidly heated within the channel and expelled through a nozzle onto a print sheet.

A design challenge for a thermal ink jet printhead is proper alignment of the resistance elements in the heater chip with the corresponding grooves in the channel chip. Typically, both channel chips and heater chips are "diced" from larger wafers. In order to have proper alignment of resistance elements in the heater chips with the grooves in the channel chips, very precise tolerances are required when dicing the wafers into the chips. The Figure shows an elevational view of a channel chip 10 in contact with a heater chip 12. The channel chip 10 has defined therein a set of grooves 14, shown end-on in the Figure, which are intended to align with an equal number of resistance elements 16 in heater chip 12. For channel chip 10, the "critical measurement," upon which proper alignment is dependent, is the distance K1, and for the heater chip 12 the critical measurement is shown as K2. In either case, if the critical measurement is inaccurate, the grooves 14 will not align with the resistan...