CN100446977C - Fluid ejection device - Google Patents

Abstract

The invention is a fluid ejection device and a method of manufacturing the same, wherein the fluid ejection device includes: a substrate; a structural layer formed on the substrate; a manifold disposed in the substrate to supply a fluid; a plurality of fluid chambers having the same length formed between the substrate and the structural layer and communicating with the manifold to accommodate a fluid to be ejected; and a plurality of nozzles penetrating the structural layer and communicating with the plurality of fluid chambers to eject fluid, wherein distances between the plurality of nozzles and the manifold are substantially different. The invention also includes a method of manufacturing a fluid ejection device.

Description

fluid ejection device

technical field

The present invention relates to a semiconductor device, in particular to a fluid ejection device and a manufacturing method thereof.

Background technique

At present, the fluid injection technology has been widely used in various technical fields, such as printer inkjet heads, fuel injection devices, or biomedical systems such as pharmaceutical injection mechanisms and other technical products.

A known fluid ejection device is illustrated with reference to FIG. 1 . Fig. 1 shows the fluid injection device disclosed in U.S. Patent No. 6,102,530. This fluid injection device includes a silicon substrate 38, a manifold 26 to deliver fluid, and a fluid chamber 14 located on one side of the manifold 26 for use in To accommodate the fluid, a nozzle hole 18 is provided on the surface of the fluid cavity 14 for the fluid to be sprayed out, and injection components 20 , 22 are arranged around the nozzle hole 18 .

The method for manufacturing the fluid chamber 14 in the above-mentioned fluid ejection device will be described below, referring to FIGS. 2 a to 2 c. As shown in FIG. 2a, a substrate 38 comprising upper and lower protective layers 42, 44 is provided. Next, as shown in FIG. 2b, the backside of the substrate 38 is etched by an anisotropic wet etching method to form a manifold 26 and expose the replacement layer 40, and then the replacement layer 40 is removed by etching with a hydrofluoric acid (HF) solution. layer 40, and again use KOH to etch the substrate 38 to complete the fabrication of a fluid chamber 14, as shown in FIG. 2c.

However, as shown in FIGS. 3a and 3b, wherein FIG. 3a is a photomask pattern of a fluid chamber, and FIG. 3b is a schematic diagram after etching the fluid chamber. Anisotropic etching has different etching rates for different lattice planes, so the etching effect is bound to occur on the substrate portion 30 separating the fluid chambers during the process, resulting in differences in the length and design of the fluid chambers, resulting in gaps between the fluid chambers. Mutual interference (cross talk), at the same time, when the etching cusp 31 appears, there will also be a stress concentration effect, which will also have a serious impact on the structural strength and service life, and the smaller the structure size, the more serious this phenomenon .

Contents of the invention

In view of this, the object of the present invention is to disclose a fluid injection device, which is intended to be designed with the same length of the fluid chamber to improve the phenomenon of cross talk during the refill process.

In order to achieve the above object, the present invention provides a fluid ejection device, comprising: a base; a structural layer formed on the base; a manifold, the manifold is arranged in the base to supply fluid; A fluid cavity with the same length is formed between the substrate and the structural layer and communicates with the manifold to accommodate the fluid to be injected; a plurality of channels is formed in the Between the fluid chambers and the manifold, where two ends of each channel are respectively connected to a fluid chamber and the manifold; and a plurality of nozzle holes, the plurality of nozzle holes pass through the structural layer and communicate with the fluids The cavity communicates to inject fluid. The orifices are at substantially different distances from the manifold.

According to the design of the fluid injection device of the present invention, when the fluid is backfilled, due to the narrow and long channel formed between the fluid chamber and the manifold, adjacent fluid chambers will no longer interfere with each other due to excessive fluid disturbance.

The present invention also provides a method for manufacturing a fluid ejection device. The plurality of nozzle holes includes the following steps: providing a substrate; forming a patterned substitution layer on the substrate, and the patterned substitution layer is used as a predetermined formation of a plurality of channels and a plurality of areas with the same length of the fluid cavity; forming a patterned structural layer on the substrate, and covering the patterned replacement layer; forming a manifold through the substrate, and exposing the patterned replacement layer; removing the substitute layer to complete the fabrication of the channels and the fluid cavities through which the fluid cavity communicates with the manifold; and etch the structural layer to form a plurality of nozzles in communication with the fluid cavities orifices, wherein the orifices are substantially at different distances from the manifold.

In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and understandable, a preferred embodiment is specifically cited below, and in conjunction with the accompanying drawings, the detailed description is as follows:

Description of drawings

FIG. 1 is a schematic diagram of a fluid ejection device in US Pat. No. 6,102,530.

2a to 2c are schematic cross-sectional views of the fluid ejection device in US Pat. No. 6,102,530.

3a and 3b are schematic diagrams of conventional photomask patterns and anisotropic etching.

4a to 4d are schematic diagrams made for a fluid ejection device according to a first embodiment of the present invention.

5a and 5b are schematic diagrams of photomask patterning and etching of a fluid ejection device according to a second embodiment of the present invention.

6a and 6b are schematic diagrams of photomask patterning and etching of a fluid ejection device according to a third embodiment of the present invention.

7a and 7b are schematic diagrams of photomask patterning and etching of a fluid ejection device according to a fourth embodiment of the present invention.

Explanation of reference symbols:

Known parts (Fig. 1, Fig. 2a to Fig. 2c and Fig. 3a and 3b)

14 ~ fluid cavity;

18 ~ spray hole;

20, 22～jet assembly;

26 ~ manifold;

30, 38 ~ substrate;

31～etching sharp point;

40～replacement layer;

42, 44 ~ protective layer.

Part of the embodiment of the present invention (Figure 4a to Figure 4c, Figure 5a and Figure 5b, Figure 6a and Figure 6b and Figure 7a and Figure 7b)

Lc～fluid chamber length;

Ln～neck structure length;

Wch～joint width;

Wn～neck structure width;

400～base;

405～replacement layer;

410, 510, 610, 710～manifold;

420, 520, 620, 720 ~ fluid cavity;

430 ~ channel;

525, 625, 725～neck structure;

530～connection;

440～structural layer;

450～resistive layer;

460～isolation layer;

470～conductive layer;

480～protective layer;

490～Signal transmission line contact window;

495～nozzle hole;

θ～angle;

Detailed ways

Example 1

The structural feature of the fluid injection device in this embodiment is that, as shown in FIG. 4 d , a long and narrow channel 430 is formed between the fluid chamber 420 and the manifold 410 , so that the lengths (Lc) of the fluid chambers 420 remain the same.

Referring to FIG. 4b (schematic cross-sectional view) and FIG. 4d (schematic top view), the composition of the fluid ejection device of this embodiment is illustrated, wherein FIG. 4b is a cross-sectional view along the cutting line 4b-4b of FIG. 4d. As shown in Figure 4b, the fluid ejection device includes a substrate 400, a manifold 410, a fluid chamber 420, a channel 430, a structural layer 440, a resistive layer 450, an isolation layer 460, a conductive layer 470, a protective layer 480 , a plurality of signal transmission line contact windows 490 and a plurality of injection holes 495 . The manifold 410 is formed in the substrate 400, the fluid cavity 420 and the channel 430 are formed between the substrate 400 and the structural layer 440, and the length of the fluid cavity 420 is uniform due to the design of the channel 430, as shown in FIG. 4d.

The structural layer 440 covers the substrate 400 , the channel 430 and the fluid cavity 420 . The resistive layer 450 is disposed on the structural layer 440 and located on both sides of the nozzle hole 495 , which represents a plurality of fluid ejection actuators such as heaters, so that the fluid is ejected from the nozzle hole 495 after being driven by the ejection actuator. The isolation layer 460 covers the substrate 400 , the structure layer 440 and the resistance layer 450 , but exposes a part of the resistance layer 450 to form a heater contact window. The conductive layer 470 covers the isolation layer 460 and fills the contact window of the heater as a signal transmission line.

The protective layer 480 covers the isolation layer 460 and the conductive layer 470 , and exposes a part of the conductive layer 470 , forming a plurality of signal transmission circuit contact windows 490 to facilitate subsequent packaging operations. Another plurality of injection holes 495 pass through each layer of the protective layer 480 , the conductive layer 470 , the resistive layer 450 and the structural layer 440 , and communicate with the fluid cavity 420 .

Next, referring to FIG. 4a to FIG. 4c , the fabrication of the fluid ejection device according to an embodiment of the present invention will be described. First, as shown in FIG. 4a, a substrate 400, such as a silicon substrate, is provided, and the thickness of the substrate 400 is generally between 625-675 microns. Next, carry out a characteristic step of this embodiment, the fabrication of the patterned replacement layer 405, first, form a replacement layer on a first surface 4001 of the substrate 400, and then, use a photomask with a pattern layout of channels and fluid chambers As shown in FIG. 4c, the replacement layer is exposed, and after development, a patterned replacement layer 405 including a channel pattern and a fluid cavity pattern is formed, wherein the lengths of the formed fluid cavity patterns are all the same.

The replacement layer 405 is made of borophosphosilicate glass (BPSG), phosphosilicate glass (PSG) or silicon oxide material, among which phosphosilicate glass is a better choice, and the thickness of the replacement layer 405 is generally between 1-2 microns.

Then form a patterned structural layer 440 on the substrate 400, and cover the patterned replacement layer 405. The structural layer 440 can be a silicon oxynitride layer formed by chemical vapor deposition (CVD). The thickness of the structural layer 440 is approximately between Between 1.5 and 2 microns. In addition, the structure layer 440 is a low-stress material, and its stress value is generally between 100-200 megapascal (MPa) tensile stress.

Next, a patterned resistive layer 450 is formed on the structural layer 440 to be used as a fluid ejection actuator, such as a heater, so that the fluid is driven by the ejection actuator and ejected from the subsequent nozzle holes. The resistive layer 450 It is composed of HfB ₂ , TaAl, TaN or TiN, among which TaAl is a better choice.

A patterned isolation layer 460 is then formed to cover the substrate 400, the structural layer 440 and the resistance layer 450, and after the heater contact window is formed, a patterned conductive layer 470 is formed on the isolation layer 460 to fill the heater contact window, To form a signal transmission line. Finally, a protection layer 480 is formed on the isolation layer 460 and the conductive layer 470 , and a signal transmission line contact window 490 is formed to expose the conductive layer 470 to facilitate subsequent packaging operations.

Next, referring to Figure 4b, a series of etchs are initiated to form the final fluid ejection device. First, by anisotropic wet etching method, the etchant is, for example, potassium hydroxide (KOH) solution, etch the back side of the substrate 400, that is, a second surface 4002, to form a manifold 410, and expose the patterned replacement layer 405.

The width of the narrow opening of the manifold 410 is approximately 160-200 microns, and the width of the wide opening is approximately 1100-1200 microns. The angle θ between the inner wall and the horizontal line is approximately 54.74 degrees, so the manifold 410 after etching is wide at the bottom and narrow at the top. The shape structure, and the manifold 410 communicates with a fluid storage tank downward.

Then use a wet etching method containing hydrofluoric acid (HF) solution to etch the patterned replacement layer 405, and then etch the substrate 400 again with an etching solution such as a potassium hydroxide (KOH) solution to expand the patterned replacement layer. Areas of layer 405 are hollowed out to form fluid chambers 420 and channels 430 . The channels 430 are formed between the fluid chambers 420 and the manifold 410, and due to the special design of the channels 430, the lengths (Lc) of these fluid chambers 420 are all the same, as shown in FIG. 4d.

Finally, the protection layer 480 , the isolation layer 460 and the structure layer 440 are sequentially etched to form the nozzle holes 495 communicating with the fluid cavity 420 , wherein the distances between the nozzle holes 495 and the manifold 410 are substantially different. Etching utilizes plasma etching, chemical gas etching, reactive ion etching, or laser etching. So far, the fabrication of a fluid ejection device is completed.

This embodiment utilizes the special connection layout of the manifold-channel-fluid cavity on the photomask to compensate in the direction of faster etching rate, thereby maintaining the consistency of the length between the fluid cavities and significantly improving the time when the fluid is backfilled into a certain fluid cavity. A phenomenon that tends to interfere with the inkjet effect of adjacent fluid chambers.

Example 2

The compositional feature of the fluid injection device in this embodiment is that, as shown in FIG. The width (Wch) of the joint 530 between the internal structure 525 and the manifold 510 is also kept the same. In addition to the same length of the fluid chambers 520 , the additional neck structure 525 has the same width (Wch) inwardly of the joint 530 of the manifold 510 .

The manufacturing steps of the fluid ejection device in this embodiment are substantially the same as those in Embodiment 1, except for the pattern formation of the patterned replacement layer. The differences between this embodiment and Embodiment 1 will be described below. After forming a replacement layer on a first surface of the substrate, use a photomask with a neck structure and a fluid cavity pattern layout, as shown in Figure 5a, to expose the replacement layer, and form a It includes a patterned replacement layer of a neck structure pattern and a fluid chamber pattern, wherein the lengths of the fluid chamber patterns are consistent.

After each semiconductor layer is deposited, a series of etching processes are performed to form the final fluid ejection device. The fluid cavity 520 and the neck structure 525 are formed after etching. The neck structure 525 is formed between the fluid chamber 520 and the manifold 510. Due to the special design of the neck structure 525, the lengths (Lc) of these fluid chambers 520 are all the same, and the neck structure 525 is inwardly connected to the manifold 510. The widths (Wch) of the joints 530 are also the same, as shown in FIG. 5b.

In this embodiment, the manifold-neck structure-fluid cavity special connection layout of the photomask has a rectangular, narrow and long neck structure to maintain a fixed size of the fluid cavity, and the neck structure is inwardly connected to the manifold With the same width, the interference phenomenon of adjacent chambers is also significantly improved. In addition, the appearance of etching sharp corners is effectively slowed down because the area of the front end of the spacer 30 is increased in the photomask as shown in FIG. 3b.

Example 3

The compositional feature of the fluid injection device in this embodiment is that, as shown in FIG. The length (Ln) of the neck structure 625 is also all the same. The difference between this embodiment and Embodiment 2 is that the length of the neck structure 525 is not set in Embodiment 2, but the length (Ln) of the neck structure 625 is designed in this embodiment. ) are the same.

The manufacturing steps of the fluid ejection device in this embodiment are substantially the same as those in Embodiment 2, except for the pattern formation of the patterned replacement layer. The difference between this embodiment and Embodiment 2 will be described below. After forming a replacement layer on a first surface of the substrate, use a photomask with a neck structure and a fluid chamber pattern layout, as shown in Figure 6a, to expose the replacement layer, and form a It includes a patterned replacement layer of a neck structure pattern and a fluid chamber pattern, wherein the lengths of the fluid chamber patterns formed are the same, and the lengths of the neck structure patterns are also the same.

After each semiconductor layer is deposited, a series of etching processes are performed to form the final fluid ejection device. Fluid cavity 620 and neck structure 625 are formed after etching. The neck structure 625 is formed between the fluid chamber 620 and the manifold 610. Due to the special design of the neck structure 625, the lengths (Lc) of these fluid chambers 620 are all the same, and the length of the neck structure 625 is also kept the same. As shown in Figure 6b.

In this embodiment, the manifold-neck structure-fluid cavity special connection layout of the photomask, the neck structure is designed to maintain a fixed size of the fluid cavity, and the neck structure of the same length, in addition to improving the phenomenon of interference , It also helps a lot in controlling flow resistance.

Example 4

The compositional feature of the fluid injection device in this embodiment is that, as shown in FIG. The length (Ln) of the internal structure 725 is also the same, and its width (Wn) increases with the distance between the fluid cavity 720 and the manifold 710. The difference between this embodiment and Embodiment 3 is that Embodiment 3 does not set a neck The width of the structure 625 is narrow, while the width (Wn) of the neck structure 725 in this embodiment increases with the distance of the fluid cavity 720 from the manifold 710 .

The manufacturing steps of the fluid ejection device in this embodiment are substantially the same as those in Embodiment 3, except for the pattern formation of the patterned replacement layer. The differences between this embodiment and Embodiment 3 will be described below. After forming a replacement layer on a first surface of the substrate, use a photomask with a neck structure and a fluid cavity pattern layout, as shown in Figure 7a, to expose the replacement layer, and form a It includes a graphic replacement layer of a neck structure figure and a fluid cavity figure, wherein the lengths of the fluid cavity figures formed are the same, and the lengths of the neck structure figures are also the same, and the width of the neck structure figure is far from the future with the fluid cavity figure The distance that forms the manifold position increases.

After each semiconductor layer is deposited, a series of etching processes are performed to form the final fluid ejection device. Fluid cavity 720 and neck structure 725 are formed after etching. The neck structure 725 is formed between the fluid chamber 720 and the manifold 710. Due to the special design of the neck structure 725, the lengths (Lc) of these fluid chambers 720 are all the same, and the length of the neck structure 725 is also kept the same, In addition, the width of the neck structure 725 increases with the distance of the fluid chamber 720 away from the manifold 710, eg Wn3>Wn2>Wn1, as shown in FIG. 7b.

In this embodiment, the manifold-neck structure-fluid cavity special connection layout of the photomask, the design of the neck structure, makes the fluid cavity maintain a fixed size, and the change of the width of the neck structure accurately controls the size of each fluid cavity. The flow resistance greatly improves the inkjet quality of the jetting device.

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can certainly make changes and modifications without departing from the spirit and scope of the present invention. Therefore, The protection scope of the present invention should be defined by the claims.

Claims (18)

1. a fluid ejection apparatus comprises: a substrate; One manifold, this manifold are arranged in this substrate, with accommodating fluid; A plurality of fluid cavitys; And a plurality of spray orifices, it is characterized in that this fluid ejection apparatus also comprises:

One is formed at this suprabasil structure sheaf; And

One passage is formed between this manifold and each fluid cavity;

Wherein, described a plurality of fluid cavitys have equal length, and are formed between this substrate and this structure sheaf and with this manifold and are communicated with, to hold the fluid that will spray; And

Described a plurality of spray orifice passes this structure sheaf and is communicated with described these fluid cavitys, to spray fluid.

2. fluid ejection apparatus as claimed in claim 1 is characterized in that: described a plurality of spray orifices are different to the distance of this manifold.

3. fluid ejection apparatus as claimed in claim 1 is characterized in that: described passage comprises a neck structure.

4. fluid ejection apparatus as claimed in claim 3 is characterized in that: this neck structure is a rectangle.

5. fluid ejection apparatus as claimed in claim 3 is characterized in that: the length of described these neck structures is identical.

6. fluid ejection apparatus as claimed in claim 3 is characterized in that: the length difference of described these neck structures.

7. fluid ejection apparatus as claimed in claim 3 is characterized in that: the width of described these neck structures is identical.

8. fluid ejection apparatus as claimed in claim 3 is characterized in that: the width difference of described these neck structures.

9. fluid ejection apparatus as claimed in claim 3 is characterized in that: described these passages are identical with the width that this manifold engages.

10. fluid ejection apparatus as claimed in claim 3 is characterized in that: described these passages are different with the width that this manifold engages.

11. fluid ejection apparatus as claimed in claim 3 is characterized in that: described a plurality of spray orifices are different to the distance of this manifold.

12. fluid ejection apparatus as claimed in claim 3 is characterized in that: the width of described neck structure increases with the distance of described a plurality of fluid cavitys away from this manifold.

13. fluid ejection apparatus as claimed in claim 12 is characterized in that: this neck structure is a rectangle.

14. fluid ejection apparatus as claimed in claim 12 is characterized in that: the length of described these neck structures is identical.

15. fluid ejection apparatus as claimed in claim 12 is characterized in that: the length difference of described these neck structures.

16. fluid ejection apparatus as claimed in claim 12 is characterized in that: described these passages are identical with the width that this manifold engages.

17. fluid ejection apparatus as claimed in claim 12 is characterized in that: described these passages are different with the width that this manifold engages.

18. fluid ejection apparatus as claimed in claim 12 is characterized in that: described a plurality of spray orifices are different to the distance of this manifold.

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