Patent Application
20050140751
1. Field of the Invention
The invention relates to an inkjet dispensing apparatus with a multi-channel cartridge, and in particular, the invention relates to an inkjet dispensing apparatus able to detect leakage between channels thereof.
2. Description of the Related Art
Advances in industries employing chemical and biological processes have created a need for devices that accurately and automatically dispense small quantities of liquids containing chemically or biologically active substances for commercial or experimental use. Accuracy and precision in the amount of liquid dispensed is important both from the standpoint of generating a desired reaction and minimizing the amount of material used. An example of a device with an array of reagents disposed thereupon is a biochip.
From the standpoint of reliability, it is important to prevent different reagents from intermixing during dispensing. In view of this, a multi-channel inkjet cartridge has been disclosed, preventing intermixing of different reagents during dispensing.
As well as during dispensing, intermixing of different reagents may occur due to the leakage in the inkjet printhead. For example, the leakage between different reagents may occur between the cartridge and the chip, between the chip and the barrier layer, or between the barrier layer and the nozzle plate. However, there is no leakage detection apparatus and method for an inkjet dispensing apparatus with a multi-channel inkjet cartridge.
U.S. Pat. No. 6,431,678 discloses an ink leakage detection apparatus. Referring to
Although the apparatus disclosed in U.S. Pat. No. 6,431,678 can detect leakage in some inkjet print heads, it is not applicable to an inkjet dispensing apparatus with a multi-channel inkjet cartridge. Specifically, the detection apparatus shown in
In view of this, the invention provides an inkjet dispensing apparatus with the capability to detect leakage between channels therein. Another purpose of the invention is to provide a method for manufacturing a structure for an inkjet printhead that can conveniently detect leakage.
Accordingly, the invention provides an inkjet dispensing apparatus including a cartridge, a chip, and a sensor controller. The cartridge includes a first channel and a second channel. The first channel has a first kind of liquid therein, and the second channel has a second kind of liquid therein. The chip is disposed on the cartridge, and includes a first conductor and a second conductor. The first conductor is in contact with the first kind of liquid, and the second conductor is in contact with the second kind of liquid. The sensor controller is coupled to the first conductor and the second conductor to detect leakage between the first channel and the second channel.
In a preferred embodiment, the inkjet dispensing apparatus includes a first terminal and a second terminal. The first terminal is coupled to the first conductor such that the sensor controller is, in turn, coupled to the first conductor via the first terminal.
The second terminal is coupled to the second conductor such that the sensor controller is, in turn, coupled to the second conductor via the second terminal.
In another preferred embodiment, the chip further includes an isolation layer and a conductive layer. The isolation layer includes a plurality of contact holes, the first conductor and the second conductor are disposed on the isolation layer. The isolation layer is disposed on the conductive layer. The first conductor and the second conductor are in contact with the conductive layer via the contact holes.
It is noted that the isolation layer may include SiN and SiC, the conductive layer may be Al, and the first s conductor and the second conductor may be Ta. Additionally, the conductive layer is coupled to the sensor controller such that the first conductor and the second conductor are, in turn, coupled to the sensor controller via the conductive layer.
Furthermore, the chip further includes an actuator. The actuator may be a heating layer made of TaAl.
In another preferred embodiment, the inkjet dispensing apparatus further includes a barrier layer and a nozzle plate. The barrier layer is disposed on the chip. The nozzle plate is disposed on the barrier layer, and includes a plurality of orifices communicating with the first channel and the second channel respectively.
It is noted that the nozzle plate may be polyimide, and the chip may be glass. Alternatively, the chip may be silicon, and includes an electric-isolating layer therein.
In another preferred embodiment, the sensor controller includes a voltage supply device providing voltage to the first conductor and the second conductor. Alternatively, the sensor controller may be a multimeter. In the invention, a method for manufacturing a structure for an inkjet printhead is provided. The method includes the following steps. A substrate is provided. An actuating layer is formed on the substrate. A conductive layer is formed on the actuating layer. An isolation layer is formed on the conductive layer, and includes a plurality of contact holes therein. A plurality of conductors are formed on the isolation layer, and coupled to the conductive layer via the contact holes.
The present invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
a is a partial cutaway isometric view of an inkjet printhead as disclosed in U.S. Pat. No. 6,431,678;
b is a top view of the inkjet print head in
a is a schematic view showing an inkjet dispensing apparatus as disclosed in the invention;
b is a plane view of an inkjet dispensing apparatus in
c is a cross section along a line c-c in
a-3d are schematic views of a method for manufacturing a structure for an inkjet printhead as disclosed in the invention.
Referring to
The cartridge 110 includes a plurality of channels 111, 112 therein. It is noted that only two channels are shown in
Different kinds of liquid are received in the different channels respectively. For example, as shown in
The chip 120 is disposed on the cartridge 110 via glue 170, and includes a plurality of conductors 121a, 121b, an isolation layer 122, a conductive layer 123, an actuating layer 124, and a substrate 125. Specifically, referring to
The conductors 121a, 121b protect the chip 120 during dispensing. It is noted that only two conductors are illustrated in
The isolation layer 122 may include SiN and SiC. The conductive layer 123 is coupled to the terminals 160, and may be Al. The actuating layer 124 is used as an actuator to generate a bubble to dispense the liquid, and may be a heating layer made of TaAl. The substrate 125 may be glass, or may be silicon and includes an electric-isolating layer therein.
As shown in
It is understood that the liquid, flowing from the cartridge 110 to the chip 120, is stored in the barrier layer 130 as shown in
The sensor controller 150 is detachably coupled to the conductors 121a, 121b via the terminals 160 to detect leakage between the channels 111, 112. For example, the sensor controller 150 may include a voltage supply device providing voltage to the conductors 121a, 121b. Alternatively, the sensor controller 150 may be a multimeter.
Each of the terminals 160 is disposed on the chip 120, and is coupled to the conductors 121a, 121b via the conductive layer 123 respectively. Additionally, each of the terminals 160 can be coupled to the sensor controller 150 so that the sensor controller 150 can provide voltage to the conductors 121a, 121b. For example, one of the terminals may be referred to as a first terminal 161, and the other one may be referred to as a second terminal 162. The first terminal 161 is coupled to the first conductor 121a such that the sensor controller 150 is, in turn, coupled to the first conductor 121a via the first terminal 161. The second terminal 162 is coupled to the second conductor 121b such that the sensor controller 150 is, in turn, coupled to the second conductor 121b via the second terminal 162.
The structure of the inkjet dispensing apparatus is described above, and the method for detecting leakage between the channels of the inkjet dispensing apparatus follows.
To detect leakage, the sensor controller 150 is coupled to any two of the terminals 160 at a time until all the terminals 160 are checked. For example, the sensor controller 150 may be coupled to the first terminal 161 and the second terminal 162. The sensor controller 150 then provides voltage to the first conductor 121a and the second conductor 121b via the first terminal 161 and the second terminal 162. In a normal situation, the detected value of the resistance between the first conductor 121a and the second conductor 121b is extremely high and cannot be measured since the first channel 111 and the second channel 112 are independent of each other. When leakage occurs between the first channel 111 and the second channel 112, the resistance value or the current value can be measured by s the sensor controller 150 since the first conductor 121a is coupled to the second conductor 121b via the liquid 11, 12.
By the apparatus and the method of the invention, leakage between the channels of the inkjet printhead can be detected, thus preventing reagents from intermixing. In addition, the leakage position can be accurately located to maintain the reliability of the inkjet printhead. Moreover, unlike conventional leakage detection apparatus, leakage between the cartridge and the chip of the inkjet dispensing apparatus can be detected.
While the invention has been described by way of example and in terms of the preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiment. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.
