KR20070116023A - Method of bonding substrates - Google Patents

Abstract

A method of bonding a first substrate to a second substrate is provided. The method comprises the steps of: (a) providing a first substrate having a plurality of etched trenches defined in a first bonding surface; (b) providing a second substrate having a second bonding surface; and (c) bonding the first bonding surface and the second bonding surface together using an adhesive. During bonding, the adhesive is received, at least partially, in the plurality of etched trenches, thereby increasing the adhesive bond strength whilst avoiding surface roughening. The method is particularly suitable for bonding semiconductor chips using liquid adhesives.

Description

Substrate bonding method {METHOD OF BONDING SUBSTRATES}

The present invention relates to a method of adhering substrates together, and to a substrate so applied. While circumventing existing surface friction techniques, it has been developed primarily for optimizing microscale substrates to other substrates.

The following patents or patent applications filed by the applicant or the assignee of the present invention are incorporated herein by reference.

Some applications are listed under filing number. This clearance number is replaced by the application number once the application number is known.

It is well known that once the surface is roughened, it is better to use a liquid adhesive as the surface bond. Surface roughness increases the surface area effective for adhesion with a liquid adhesive, which significantly increases the adhesion by adhesion.

Generally, the roughness of the surface is obtained by abrading one or both of the surfaces to be bonded. For example, by simply rubbing one of the surfaces with an emery cloth, a significant improvement in adhesive strength can be achieved over non-rubbing surfaces.

However, it is generally not desirable to rub the substrate surface when adhering microscale substrates such as semiconductor integrated circuits (“chips”). In fact, it is highly desirable that semiconductor chips have a very smooth surface. Any defects on the integrated circuit surface cause crack propagation and severely degrade the instrument. There is a need for corresponding surface roughness reduction in order for the drive to make integrated circuits (eg 200 micron ICs) thinner while maintaining acceptable mechanical strength in the instruments.

Silicon wafers are usually processed thinly in a two-step process, since surface roughness is of primary importance. After the front-end processing of the wafer, the wafer is generally thinly processed first by backgrinding using a mechanical grinding tool. Examples of wafer grinding tools are Strasbaugh 7 AF and Disco DFG-841. Mechanical grinding is a quick and inexpensive way to grind silicon. However, this method also has a relatively high surface roughness on the back side after processing. Moreover, mechanical grinding results in defects (eg, cracks or dislocations) of about 20 micrometers (μm) on the backside of the wafer.

In terms of mechanical strength, surface roughness and surface defects are unacceptable in integrated circuits. Thus, back-end thinning is typically technically completed to eliminate these defects and provide low surface finish. Plasma thinning is one method that has been used to complete wafer thinning. Typically, plasma thinning has been used to remove the last 20 micrometers of silicon to achieve the desired wafer thickness. While plasma thinning is relatively slow, it is possible to obtain extremely smooth backsides that are substantially free of surface bonds. Typically, plasma thinning provides a maximum surface roughness (R _max ) of less than 1 nanometer (nm). Therefore, plasma thinning is an optional method for post-processing in integrated circuit construction.

Integrated circuits, such as MEMS devices, often need to be bonded to other substrates. In the configuration of the Applicant's MEMS printhead, for example, printhead integrated circuits bonded face-to-face onto the molded ink are copied to form a printhead assembly (more specific description of Applicant's printhead construction process And the contents of US patent application no. 10 / 728,970, which is incorporated herein by reference and cross-references below).

However, it will be appreciated that integrated circuits have contradictory requirements behind them. On the other hand, the backside of the integrated circuit should have a low surface roughness and any cracks should be excluded in order to increase the mechanical strength of the backside. This is particularly important for thinning (eg integrated circuits of 250 μm or less). On the other hand, the back side of an integrated circuit often needs to be suitable for bonding to another substrate using adhesive or adhesive tape. As mentioned above, the adhesive strength is generally increased as the surface roughness of the surface to be bonded is increased, thereby expanding the contact with the intervening adhesive.

There is a need to provide an improved substrate bonding method using an adhesive without increasing the surface roughness of the substrate. There is also a need to provide a thin substrate (eg, a substrate having a thickness of less than 1000 microns) having a surface suitable for adhesion with an adhesive and maintaining acceptable mechanical strength.

In the first form,

(a) a first substrate having a plurality of etched trenches defined in a first bonding surface,

(b) a second substrate having a second bonding surface,

(c) joining the first bonding surface and the second bonding surface together using an adhesive;

A method of joining a first substrate to a second substrate, at least partially contained, is provided in the plurality of etched trenches during which the adhesive is joined.

In a second form, the first substrate has a plurality of etched trenches defined in the first joining surface, the etched trenches being formed to receive an adhesive during bonding, so that the first substrate is formed using the adhesive. It is provided to be suitable to be combined.

In a third form,

(a) a first substrate having a plurality of etched trenches defined in a first bonding surface;

(b) a second substrate having a second bonding surface; And

(c) an adhesive for joining the first coupling surface and the second coupling surface together,

A bonded assembly is provided wherein the adhesive is sandwiched between the first and second substrates and is also received in the plurality of etched trenches.

In the fourth form,

(a) a plurality of nozzles formed on the front side of the integrated circuit of the printhead;

A plurality of ink supply channels for supplying ink to the nozzles from the backside of the print head; And

A plurality of printhead integrated circuits each including a plurality of etched trenches defined on the backside; And

(b) an ink manifold having a mounting surface to which the backside of each printhead integrated circuit is bonded by an adhesive;

A printhead assembly is provided in which the adhesive is at least partially received in the plurality of etched trenches.

In a fifth aspect, a plurality of nozzles formed on the front surface of the printhead integrated circuit;

A plurality of ink supply channels for supplying ink to the nozzles from the back of the printhead integrated circuit; And

Provided is a printhead integrated circuit defined on the back, comprising a plurality of etched trenches formed to receive an adhesive during bonding, and suitable for bonding to the mounting surface of the ink manifold using the adhesive.

Until now, the only method used to improve the surface properties of the substrates to be bonded has been surface roughening. However, as mentioned above, surface roughening is not desirable for very thin substrates, such as silicon chips having a thickness of less than 1000 μm, optionally less than 500 μm or less than 250 μm. Therefore, the present invention provides a method for improving adhesive bonding in a controlled manner, and is particularly suitable for bonding silicon chips (eg MEMS chips) to other substrates for use. However, the present invention is not limited to application to semiconductor chips, and any etchable substrate (e.g., metal substrate, silicon oxide substrate, silicon nitride substrate, etc.) where surface roughening is undesirable. The same applies to the combination of.

The present invention is particularly preferably applied to the processing of printhead chips, since typically printhead chips have ink supply channels etched into the back joining the surface.

The property of the second substrate is not particularly limited, and is made of, for example, plastic, metal, silicon, glass, or the like. The second substrate is optionally provided with the trenches described above in connection with the first substrate.

The trenches are dimensioned such that the adhesive is attracted by capillary action. The exact dimensions required depend on the surface tension of the adhesive. The required trench dimensions can be readily determined by one skilled in the art using known capillary equations. Alternatively, the trenches are simply dimensioned for accepting the adhesive when the second substrate and the adhesive are pressed against the first engagement surface. Typically, the trenches have a diameter (for cylindrical trenches) or a width (for non-cylindrical trenches) of about 10 μm or less, optionally about 5 μm or less or about 3 μm or less.

The trenches have a depth suitable for improving adhesion without compromising the overall firmness of the first substrate. Optionally, the trenches are etched to a depth of at least 10 μm, optionally at least 20 μm, optionally at least 30 μm, or optionally at least 50 μm. Typically, the trenches have an aspect ratio of at least 3: 1, at least 5: 1 or at least 10: 1. High aspect ratio trenches are easily etched with known anisotropic etching techniques (eg, the Bosch process described in US Pat. No. 5,501,893). High aspect ratios are desirable to maximize the effective surface area for the adhesive without compromising the overall mechanical strength.

Typically, the first bonding surface has a maximum surface roughness R _{max of} 20 nm or less, optionally 5 nm or less, or optionally 1 nm or less. The present invention is particularly preferred when such surfaces are used, in which bonds with adhesives are generally poor due to the exceptionally good smoothness of the surface. Alternatively, the first bonding surface has an average surface roughness (R _a ) of 20 nm or less, optionally 5 nm or less, or optionally 1 nm or less.

The adhesive is typically a liquid adhesive, or an adhesive that becomes liquid when heated upon bonding. Optionally, the adhesive may be an adhesive tape having an adhesive applied to one side or both sides. Double-sided adhesives or tapes are known in the semiconductor art.

Optionally, the first substrate is cooled during the bonding process. This is generally accomplished by heating the first substrate (which also dissolves the adhesive) and then allowing it to cool while bonding to the second substrate. The advantage of this choice is that a partial vacuum is formed in the trenches over the adhesive, which helps to hold the substrates together during bonding. In another aspect, a method suitable for joining a first substrate to a second substrate using an adhesive, wherein the first substrate has a plurality of etched trenches defined in a first joining surface, the etched trenches being A method is provided that is configured to receive an adhesive during bonding.

In another form,

(a) a first substrate having a plurality of etched trenches defined in a first bonding surface; And

(b) a second substrate having a second bonding surface joined to the first bonding surface with an adhesive;

A bonded assembly is provided wherein the adhesive is at least partially received in a plurality of etched trenches.

In another form,

(a) a plurality of nozzles formed on the front side of the printhead integrated circuit;

A plurality of ink supply channels for supplying ink to the nozzles from the back of the print head; And

A plurality of printhead integrated circuits each including a plurality of etched trenches defined on the backside; And

(b) an ink manifold having a mounting surface to which the backside of each printhead integrated circuit is bonded by an adhesive;

A printhead assembly is provided in which the adhesive is at least partially received in the plurality of etched trenches.

In other ways,

A plurality of nozzles formed on the front side of the printhead integrated circuit;

A plurality of ink supply channels for supplying ink to the nozzles from the back of the printhead integrated circuit; And

Provided is a printhead integrated circuit defined on the back, comprising a plurality of etched trenches formed to receive an adhesive during bonding, and suitable for joining to the mounting surface of the ink manifold using the adhesive.

In another form,

(a) having a first substrate having a plurality of etched trenches defined in the first bonding surface;

(b) a second substrate having a second bonding surface; And

(c) joining the first bonding surface and the second bonding surface together using an adhesive;

A method of joining a first substrate to a second substrate, at least partially contained, is provided in the plurality of etched trenches during which the adhesive is joined.

In another form,

(a) a first substrate having a plurality of etched trenches defined in a first bonding surface; And

(b) a second substrate having a second bonding surface bonded to the first bonding surface as an adhesive;

A bonded assembly is provided wherein the adhesive is at least partially received in a plurality of etched trenches.

In other ways,

(a) having a first substrate having a plurality of etched trenches defined in the first bonding surface;

(b) a second substrate having a second bonding surface; And

(c) joining the first bonding surface and the second bonding surface together using an adhesive;

A method of joining a first substrate to a second substrate, at least partially contained, is provided in the plurality of etched trenches during which the adhesive is joined.

In another form, the first substrate has a plurality of etched trenches defined on the first mating surface, and the etched trench is formed to receive an adhesive during bonding, so that the first substrate is formed using the adhesive to form the second substrate. It is provided to be suitable to be combined.

In other ways,

(a) having a first substrate having a plurality of etched trenches defined in the first bonding surface;

(b) a second substrate having a second bonding surface; And

(c) joining the first bonding surface and the second bonding surface together using an adhesive;

A method of joining a first substrate to a second substrate, at least partially contained, is provided in the plurality of etched trenches during which the adhesive is joined.

In another form, the first substrate has a plurality of etched trenches defined on the first mating surface, and the etched trench is formed to receive an adhesive during bonding, so that the first substrate is formed using the adhesive to form the second substrate. It is provided to be suitable to be combined.

In another form,

(a) a first substrate having a plurality of etched trenches defined in a first bonding surface; And

(b) a second substrate having a second bonding surface bonded to the first bonding surface as an adhesive;

A bonded assembly is provided wherein the adhesive is at least partially received in a plurality of etched trenches.

In other ways,

A plurality of nozzles formed on the front side of the printhead integrated circuit;

A plurality of ink supply channels for supplying ink to the nozzles from the back of the printhead integrated circuit; And

Provided is a printhead integrated circuit defined on the back, comprising a plurality of etched trenches formed to receive an adhesive during bonding, and suitable for joining to the mounting surface of the ink manifold using the adhesive.

In other ways,

(a) having a printhead integrated circuit according to claim 1;

(b) a second substrate having a second bonding surface; And

(c) joining the first bonding surface and the second bonding surface together using an adhesive;

A method of joining a first substrate to a second substrate, at least partially contained, is provided in the plurality of etched trenches during which the adhesive is joined.

In another form,

The first substrate has a plurality of etched trenches defined on the first joining surface, the etched trenches being formed to receive an adhesive during bonding, suitable for bonding the first substrate to the second substrate using adhesive And wherein according to claim 1, the first substrate is a printhead integrated circuit.

In other ways,

(a) a printhead integrated circuit according to claim 1; And

(b) a second substrate having a second bonding surface bonded to the first bonding surface as an adhesive;

A bonded assembly is provided in which the adhesive is received, at least in part, in a plurality of etched trenches.

In another form,

(a) a plurality of nozzles formed on the front side of the printhead integrated circuit;

A plurality of ink supply channels for supplying ink to the nozzles from the back of the print head; And

A plurality of printhead integrated circuits comprising a plurality of etched trenches defined on the back and each printhead integrated circuit according to claim 1; And

(b) an ink manifold having an installation surface on which the back side of each printhead integrated circuit is bonded by an adhesive;

A printhead assembly is provided in which the adhesive is at least partially received in the plurality of etched trenches.

1 is a front perspective view of a printer in which paper is mounted in an input tray and a collection tray extends.

FIG. 2 shows the printer unit of FIG. 1 with the casing open and the interior exposed (without paper in the input tray and the recovery tray folded back).

3 is a perspective view illustrating a cradle unit in which a cover assembly of a cradle unit is opened and a cartridge unit is separated from the cradle unit.

4 shows the cradle unit of FIG. 3 with the cover assembly closed.

5 is a front perspective view of the cartridge unit of FIG. 3.

6 is an exploded perspective view illustrating the cartridge unit of FIG. 5.

FIG. 7 is a perspective view illustrating the top of the printhead assembly shown in FIG. 6.

FIG. 8 is an exploded view of the printhead assembly shown in FIG. 7.

FIG. 9 is an exploded view inverting the printhead assembly shown in FIG. 7.

FIG. 10 is a cross-sectional view of the end of the printhead assembly of FIG. 7. FIG.

FIG. 11 is a partially enlarged perspective view illustrating the printhead integrated circuit module illustrated in FIGS. 8 to 10.

12 is a partially enlarged perspective view illustrating a coupling pattern of two printhead integrated circuit modules illustrated in FIGS. 8 to 10.

FIG. 13 is a bottom view illustrating the printhead integrated circuit of FIG. 11.

14 is a perspective view showing a cross section of the ink supply channel shown in FIG.

FIG. 15A is a top perspective view of ink trenches for supplying ink, particularly of the printhead assembly of FIG. 7, to the printhead integrated circuit. FIG.

15B is an enlarged partial view of FIG. 15A.

Figure 16 is a longitudinal sectional view showing that a single nozzle for ink ejection during use of the present invention is stationary.

17 is a longitudinal sectional view showing that the nozzle of FIG. 16 is in an initial operation stage.

FIG. 18 is a longitudinal sectional view showing that the nozzle of FIG. 17 is in the late operation stage. FIG.

19 is a partial longitudinal cross-sectional perspective view of the nozzle of FIG. 16 in the operating condition shown in FIG. 18;

20 is a longitudinal sectional perspective view of the nozzle of FIG. 16 with ink removed;

21 is a longitudinal cross-sectional view of the nozzle of FIG. 20.

22 is a partial longitudinal cross-sectional perspective view of the nozzle of FIG. 16 in the operating condition shown in FIG. 17.

FIG. 23 is a plan view illustrating the nozzle of FIG. 16.

24 is a plan view of the nozzle of FIG. 16 with the lever arm and movable nozzle removed for clarity.

25 is a longitudinal sectional perspective view of a portion of a printhead chip incorporating a plurality of nozzle arrangements of the type shown in FIG.

FIG. 26 is a conceptual cross sectional view through an ink chamber of a single nozzle to eject ink in bubbles forming a heater element actuator type.

27A to 27C are conceptual diagrams showing the basic operating concept of a thermal bend actuator.

FIG. 28 is a three dimensional view showing the arrangement of a single ink jet nozzle constructed in accordance with FIG. 27. FIG.

FIG. 29 is a layout view illustrating the nozzle arrangement illustrated in FIG. 28.

Certain aspects of the present invention are described below in connection with the construction of a printhead assembly for an inkjet printer. However, it will be appreciated that the present invention may be used in connection with joining two sheets of any kind of substrate and that at least the printhead configuration is not limited to a particular embodiment.

Inkjet printer unit

1 shows a printer unit 2 having a media supply tray 3 for supporting and supplying a medium 8 printed by a print engine (hidden in a printer casing). The printed media 8 sheets are transferred from the print engine to the media output tray 4 for recovery. The user interface 5 is an LCD touch screen and allows the user to control the operation of the printer unit 2.

2 shows that the print engine 1 located in the internal cavity 6 is exposed by opening the cover 7 of the printer unit 2. A picker mechanism 9 feeds the individual paper to the print engine 1 by hanging the medium on the input tray 3 (). The print engine 1 holds the individual paper and supplies it through the printhead assembly (described below) for sequential conveyance to the print and media output tray 4 (shown folded in). It includes.

Print engine

The print engine 1 is shown in detail in FIGS. 3 and 4 and consists of two main parts: a cartridge unit 10 and a cradle unit 12.

The cartridge unit 10 is formed and made to such a size that it is housed in the cradle 12 and fixed in position by a cover assembly 11 attached to the cradle unit. The cradle unit 12 is formed to be alternately installed in the printer unit 2 to facilitate the print job as described above.

4 shows that the cartridge unit 10 fixed to the cradle unit 12 and the print engine 1 are coupled, and the cover assembly 11 is closed. The print engine 1 controls various items related to a print job corresponding to a user's input from the user interface 5 of the print unit 2. These include conveying the media past the printhead in a controlled manner and spraying controlled ink onto the media surface therethrough.

Cartridge unit

The cartridge unit 10 is shown in detail in FIGS. 5 and 6. Referring to the development of FIG. 6, the cartridge unit 10 generally includes a main body 20, an ink storage module assembly 21, a printhead assembly 22, and a maintenance assembly. (maintenance assembly) 23.

Each of these parts is joined together to form an integrated unit in which the ink storage means is joined with the ink spraying means. Such a device allows ink to be supplied directly to the printhead assembly 22 as needed for a print job, and also if either or both of the ink reservoir assembly or printhead assembly needs to be replaced, the cartridge unit 10 It is easy to complete by replacing the whole.

However, the operating life of the print head is not limited by ink supply. The top surface 42 of the cartridge unit 10 has an interface 61 for docking with a filling supply of ink to fill the ink storage modules 45, if necessary. To further extend the life of the printhead, the cartridge unit carries an integral printhead maintenance assembly 23 that covers and wipes the printhead to moisten it.

Printhead assembly

The printhead assembly 22 is shown in more detail in FIGS. 7-10 and is adapted to be attached to the bottom of the body 20 to receive ink from outlet molding 27.

The printhead assembly 22 generally includes an elongate upper member 62 formed to extend below the body 20 between posts 26. A plurality of U-shaped clips 63 protrude from the upper member 62. These members are lugs (not shown) formed in the main body 20 through the recesses 37 formed in the rigid plate 34 to secure the printhead assembly 22. Are held by

The upper element 62 includes a plurality of feed tubes 64 that are received into outlets in the outlet molding 27 when the printhead assembly 22 is secured to the body 20. ) The feed tubes 64 are coated externally to protect against ink leakage.

The upper member 62 is made of liquid crystal polymer (LCP) which has many advantages. Since the coefficient of thermal expansion (CTE) of the liquid crystal polymer is similar to that of silicon, it may be molded. It will be appreciated that any significant difference between the printhead integrated circuit 74 (described below) and the basic molding can result in curvature of the overall structure. However, since the CTE of the LCP in the molding direction is much smaller than the CTE in the non-molding direction (˜5 ppm / ° C. or less than ˜20 ppm / ° C. or less), the molding direction of the LCP molding is greater than that of the printhead integrated circuit (IC) 74. Care should be taken that the same orientation as the longitudinal extension of is secured. LCPs also typically have relatively high stiffness, with elastic modulus five times the modulus of ordinary plastics such as polycarbonates, styrene, nylon, PET and polypropylene. Have

As shown in FIG. 8, the upper member 62 has an open channel array for receiving the lower member 65 coupled to the adhesive film 66. The lower member 65 also has a plurality of ink channels 67 made of LCP and formed along its length. Each of the ink channels 67 receives ink from one of the supply tubes 64 and also distributes ink along the length of the printhead assembly 22. The channels are 1 mm wide and are separated by 0.75 mm thick walls.

In the illustrated embodiment, the lower member 65 has five channels 67 extending along its length. Each channel 67 receives ink from only one of the five supply tubes 64 and one of the ink storage modules 45 (FIG. Alternately to receive the ink. In this regard, the adhesive film 66 also serves to seal the individual ink channels 67 to prevent ink mixing of the cross channels when the lower member 65 is coupled to the upper member 62.

At the bottom of each channel 67, there are a series of holes 69 of equal intervals so that five rows of holes 69 are imparted to the bottom surface of the lower member 65. The intermediate rows of holes 69 extend along the centerline of the lower member 65, just above the printhead IC 74. As shown in FIG. 15, the holes 69 in any other row of the central row require conduits 70 from each hole 69 to the center whereby ink is supplied to the printhead IC 74. Can be.

Referring to FIG. 10, the printhead IC 74 is installed on the lower surface of the lower member 65 as a polymer sealing film 71. Such films are in the form of thermoplastic films such as PET or polysulphone films, or thermoset films made by AL technologies and Rogers Corporation. The polymer sealing film 71 is a laminate having an adhesive layer on both sides of the central film, and is laminated on the lower surface of the lower member 65. As shown in Figs. 9, 14 and 15, a plurality of holes 72 are arranged at a center of ink distribution point (holes) for fluid communication between the printhead IC 74 and the channels 67. Perforations through the adhesive film 71 with a laser to coincide with the middle row of 69 and the ends of the conduits 70.

The thickness of the polymer sealing film 71 is important for the sealing effect of the ink. As best shown in FIGS. 13 and 15, the polymer sealing film seals the etch channel 77 on the opposite side of the printhead IC 74 and the conduits 70 on the other side of the film. .

However, as the film 71 is sealed across the open ends of the conduits 70, the film can also swell or sag toward the conduit. The film portion that sags toward the conduit 70 extends across some etched channels 77 in the printhead IC 74. This deflection causes a gap between the walls separating the respective etched channels 77. This obviously breaks the seal and also causes the ink to leak from the printhead IC 74 and / or between the etched channels 77.

To exclude this, the polymer sealing film 71 should be thick enough to eliminate all sagging into the conduit 70 while sealing is maintained over the etch channels 77. The minimum thickness of the polymer sealing film (71) is:

1. the width of the pipeline where deflection occurs;

2. thickness of the adhesive layers in the thin film structure of the film;

3. the rigidity of the adhesive layer when the printhead IC 74 is pushed in; And,

4. Modulus of central film thin film material

The thickness of the polymer sealing film 71 for the printhead assembly 22 appears to be sufficient to be 25 microns. However, increasing the thickness to 50, 100 or 200 microns will increase the reliability of correspondingly mounted seals.

Ink delivery inlets 73 are formed on the front side of the printhead IC 74. The inlets 73 supply ink to respective nozzles 801 (described below with reference to FIGS. 16-31) located above the inlets. Ink must be sent to the inlet of the IC to supply ink to all respective individual inlets 73. Thus, the inlets 73 in the individual printhead ICs 74 are practically grouped to reduce the complexity of the ink supply and the wiring. Inlets are also grouped logically to minimize power consumption and to enable various printing speeds.

Each printhead IC 74 is configured to receive and print five different color inks (C, M, Y, K and IR) and also includes 1280 ink inlets per color, these nozzles being even and odd nozzles. It is divided into two (640 each). The even and odd nozzles for each color are installed in different rows on the printhead IC 74 and vertically arranged to carry out an accurate 1600 dpi print, as shown in FIG. Means arranged in columns. While the vertical distance between nozzle rows is determined based on the spraying order of the nozzles, the horizontal distance between two adjacent nozzles 801 in a single row is 31.75 microns, but the rows are typically the correct number of dot lines. By a small amount of dot line corresponding to the distance the paper is transported during the thermal spraying time. In addition, as will be described later, it should be possible to distribute the ink channel at intervals between even and odd rows of nozzles for a given color.

The printhead ICs 74 are arranged to extend horizontally across the width of the printhead assembly 22. To accomplish this, the individual printhead ICs 74 are connected together in adjacent arrangements across the surface of the adhesive layer 71, as shown in FIGS. 8 and 9. The printhead IC 74 is polymer sealed by heating the IC's beyond the melting point of the adhesive layer and then pressing it with a sealing film 71 or melting the adhesive layer under the IC with a laser before pressing it with a film. It is attached to the film 71. Another option is to heat both the IC (not exceeding the melting point of the adhesive) and the adhesive layer before pressing the IC's into the film 71.

13 and 14, a plurality of trenches 85 are etched into the backside of each printhead IC 74. These trenches provide additional surface area for bonding of the adhesive to the printhead IC 74. Once the film 71 is heated beyond the adhesive melting point, the adhesive flows into the trenches 85 when the printhead IC 74 is pressed into the film. The adhesive is drawn into the trenches by capillary action or simply pressed into the trench during bonding, depending on the surface tension of the adhesive and the dimensions of the trenches. The trenches 85 are etched from the wafer stage to the backside of the printhead IC 74 at the same time as the channels 77 are etched.

If the printhead IC 74 is heated prior to bonding, when the printhead IC is cooled, a partial vacuum is formed in the trenches 85 over the adhesive contained in the trenches. This partial vacuum assists in holding the printhead IC 74 at a position opposite the film 71 and keeps this state properly aligned during mating.

The individual printhead ICs 74 are approximately 20-22 mm long. 11 to 12 individual printhead ICs 74 are connected together in succession to print A4 / US character sized paper. The number of individual ICs 74 is varied to accommodate different widths of paper.

The printhead ICs 74 are connected together in various ways. The connection method of one particular IC 74 is shown in FIG. In this arrangement, the ICs 74 are formed connected together to form a horizontal line of ICs at their ends without a vertical offset between neighboring ICs. A slotping join with an angle of substantially 45 ° is made between the ICs. The coupling end is not straight and has a toothed side to assist in positioning, and the ICs 74 are spaced approximately 11 microns apart and are exactly perpendicular to the coupling end. In this arrangement, most of the remaining ink dispensing nozzles 73 are arranged in a triangular arrangement with 10 drops of ink per pitch in each row. This arrangement defines the overlap between the nozzles to some extent at the point of engagement to maintain the pitch between the nozzles to ensure that the droplets are sent consistently along the print area. This arrangement also ensures that more silicon is added to the ends of the IC 74 to secure sufficient connections. While the operation control of the nozzles is performed by the SoPEC mechanism (described later), depending on the required storage amount, a correction for the nozzles in the printhead is performed or also by the SoPEC mechanism. In this regard, the spaced triangular arrangement of nozzles disposed at one end of the IC 74 provides the minimum required storage amount on the printhead. However, the required storage amount is not so important and a shape other than triangular may be used, for example, the dropped heat may have a trapezoidal shape.

The upper surface of the printhead ICs has a plurality of coupling pads 75 installed along the end of the upper surface to provide a means for receiving data and / or a power source to control the operation of the nozzles 73 from the SoPEC mechanism. In order to help the alignment of the IC 74 to the surface of the adhesive layer 71 and the alignment of the holes 74 formed in the adhesive layer 71 by aligning the IC 74 in a straight line, the reference point ( 76 are also installed on the surface of the ICs 74. The reference points 76 are in the form of markers so that they are easily identified by appropriate positioning mechanisms to point to the correct position of the ICs 74 with respect to the surface of the neighboring IC and adhesive layer 71. It is also possible, and at the end of the IC (74), is intentionally located along the length of the adhesive layer (71).

In order to receive ink from the holes 72 formed in the polymer sealing film 71 and distribute the ink to the ink inlet 73, the bottom surface of each printhead IC 74 is configured as shown in FIG. A plurality of etch channels 77 is provided, each channel 77 in fluid communication with a pair of rows of inlets 73 to supply one specific color or type of ink. The width of the channels 77 is approximately 80 microns, which is the same as the width of the holes 72 in the polymer sealing film 71 and extends in the longitudinal direction of the IC 74. Channels 77 are divided into parts as silicon walls 78. The ink is directly supplied to the respective portions to shorten the flow path to the inlet 73, and to reduce the case of depletion of the ink at the individual nozzles 801. In this regard, each portion feeds approximately 128 nozzles 801 via its respective inlets 73.

15B more clearly shows how ink is supplied to the etching channels 77 formed on the bottom of the ICs 74 to supply ink to the nozzles 73. As shown, the holes 72 formed through the polymer sealing film 71 are aligned in line with one of the channels 77 at the point where the silicon wall 78 divides the channel 77 into parts. do. The holes 72 are approximately 80 microns wide and have substantially the same width as the channels 77 so that one hole 72 supplies ink to the two portions of the channel 77. It will be understood that the density of the holes 72 required for the polymer sealing film 71 is thereby reduced by half.

Following coupling and arrangement of the respective printhead ICs 74 to the polymer sealing film 71, a flex PCB 79 (shown in FIG. 18) is coupled along the ends of the ICs 74 to control signals. And power is delivered to the coupling pads 75 to control and operate the nozzles 801. As shown in more detail in FIG. 15, the flex PCB 79 extends from the printhead assembly 22 and wraps around the printhead assembly 22.

The flex PCB 79 also has a plurality of decoupling capacitors 81 arranged along its length to control the received power and data signals. As shown in FIG. 8, the flex PCB 79 includes a plurality of electrical contacts formed along the length thereof to receive power and / or data signals from the cradle unit 12 control circuit. 180). A plurality of holes 80 are also formed along the distal end of the flex PCB 79 to provide a means for attaching the flex PCB to the flange portion 40 of the rigid plate 34 of the body 20. The method in which the electrical contact portion of the flex PCB 79 contacts the power supply and data contact portion of the cradle unit 12 will be described later.

As shown in FIG. 10, a media shield 82 protects the printhead ICs 74 from damage caused by contact with the medium during passage. The media shield 82 is attached to the upper member 62 against the printhead ICs 74 via an appropriate clip locking mechanism or via adhesive. When attached to this method, the printhead ICs 74 are placed below the media shield 82 plane off the path of the media being passed.

Air compressed by an air compressor or the like may be accommodated in the space 83 formed between the medium shield 82, the upper member 62, and the lower member 65. This space 83 extends along the length of the printhead assembly 22 such that compressed air can be supplied to the space from either end of the printhead assembly 22 and distributed evenly along the assembly. Can be. Fins 84 are continuously installed on the inner surface of the media shield 82 to define a plurality of air outlets that are evenly distributed along the length of the media shield 82, through which the compressed air moves the printhead. It is directed in the medium conveyance direction across the ICs 74. This arrangement acts on the surface of the printhead ICs to prevent dust and other particulate matter from being transported together with the media to clog the nozzles and cause damage.

Inkjet nozzles

An example of the ink jetting nozzle mechanism of the type suitable for the printhead ICs 74 is described below with reference to Figs. 25 shows the arrangement of the ink jetting nozzle mechanism 801 formed on the silicon substrate 8015. Each nozzle mechanism 801 is the same, but groups of nozzle mechanisms 801 are arranged to be supplied with different colors of ink or fixing agent. In this regard, the nozzle mechanisms are arranged in rows and staggered to each other, so that the spacing between the ink dots is closer during printing than in the case of nozzles in a single row. Such a mechanism enables the provision of high density nozzles, for example, more than 5000 nozzles arranged in a plurality of staggered rows each having a space margin of about 32 microns between nozzles in each row and 80 microns between adjacent rows. do. By arranging in multiple rows, the redundancy is considered (if necessary), taking into account the failure rate per nozzle.

Each nozzle mechanism 801 is a product of integrated circuit manufacturing technology. In particular, the nozzle mechanism 801 defines a micro-electromechanical system (MEMS).

For clear and easy description, the structure and operation of the single nozzle mechanism 801 is described with reference to FIGS. 16 to 24.

The inkjet printhead integrated circuit 74 is located thereon including a silicon wafer substrate 8015 having CMOS microprocessing electronics of 0.35 microns and 1 P4M 12 volts.

A layer of silicon dioxide (or alternatively glass) 8017 is placed over the substrate 8015. The silicon dioxide layer 8017 defines CMOS dielectric layers. The CMOS upper metal defines a pair of linear aluminum electrode contact layers 8030 positioned in the silicon dioxide layer 8017. Both silicon wafer substrates 8015 and silicon dioxide layer 8017 are etched to define ink inlet channels 8014 that generally have circular cross sections (on a plane). An aluminum diffusion barrier 8028 of CMOS metal 1, CMOS metal 2/3 and the CMOS upper metal is located in the silicon dioxide layer 8017 around the ink inlet channel 8014. The diffusion barrier 8028 serves to suppress the diffusion of hydroxide ions through the CMOS oxide layers of the driving component layer 8017.

A passivation layer in the form of a layer of silicon nitride 8031 is positioned over the aluminum contact layers 8030 and the silicon dioxide layer 8017. Each portion of the passivation layer 8031 located above the contact layers 8030 has an opening 8302 defined in each portion of the passivation layer to allow access to the contact portion 8030.

The nozzle mechanism 801 includes a nozzle chamber 8029 defined by an annular nozzle wall 8033, which is circular in planar shape at the upper end of the nozzle roof 8034 and in planar shape. nozzle rim) 804 is radially defined. The ink inlet channel 8014 is in fluid communication with the nozzle chamber 8029. A movable seal lip 8040 is included at the lower end of the nozzle wall where the movable rim 8010 is disposed. An encircling wall 8038 surrounds the movable nozzle and includes a stationary seal lip 8039 that comes close to the movable rim 8010 when the nozzle is stationary as shown in FIG. 19. A fluidic seal 8011 is formed due to the surface mounting of the ink in which the fluidic seal 8011 is trapped between the stationary seal lip 8039 and the movable seal lip 8040. This fluidic seal allows the coupling of low resistance between the enclosed wall 8038 and the nozzle wall 8033 and thus prevents leakage of ink from the chamber.

As best seen in FIG. 23, a number of radially extending recesses 8035 are defined in the loop 8034 around the nozzle rim 804. These recesses 8035 serve to contain radial ink flow as a result of the ink exiting through the nozzle rim 804.

The nozzle wall 8033 forms part of a lever mechanism that is installed in a carrier 8036 having a U-shaped profile with a base 8037 that is typically attached to a layer 8031 of silicon nitride. .

The lever mechanism also includes a lever arm 8018 that extends from the nozzle walls and integrates with the horizontal rigid beam 8802. Lever arm 8018 is formed of titanium nitride (TIN) and attached to a pair of passive beams 806 located on both sides of the nozzle mechanism, as shown in FIGS. 19 and 24. . The other ends of the passive beams 806 are attached to the carrier 8036.

In addition, the lever arm 8018 is attached to the actuator beam 807 formed of TIN. Attachment to the actuator beam is higher than when attaching to the passive beam 806, but at a small but significant distance point.

16 and 22, the actuator beam 807 is substantially U-shaped in plane and defines a current path between the electrode 809 and the upper electrode 8301. As shown in FIG. Each electrode 809, 8081 is electrically connected to a respective point in the contact layer 8030. The actuator beam is not only electrically connected through the contacts 809, but also mechanically fixed by the anchor 808. The anchor 808 is configured to inhibit the operation of the actuator beam 807 to the left on FIGS. 19-21 when the nozzle mechanism is in operation.

The TiN of the actuator beam 807 is conductive, but has a sufficiently high electrical resistance to withstand self-heating when a current passes between the electrodes 809, 8021. The passive beams 806 do not expand without current flow.

In use, the instrument at rest is filled with ink 8013 defining a meniscus 803 under the influence of surface tension. Ink is retained by the meniscus in the chamber 8029 and usually does not leak due to lack of any other material action.

As shown in Fig. 17, in order to eject ink from the nozzle, a current is passed between the contact portions 809 and 8041 while passing through the actuator beam 807. Self-heating of the beam 807 due to its resistance results in expansion of the beam. The dimensions and design of the actuator beam 807 means that most of the flat window is in the horizontal direction with respect to FIGS. 16-18. This expansion is suppressed to the left by the anchor 808 so that the end of the actuator beam 807 adjacent to the lever arm 8018 is pushed to the right.

Performing a relatively horizontal fixation of the passive beams 806 prevents the allowance of more horizontal movement of the lever arm 8018. However, making relative replacement of the connecting points of the passive beams and the actuator beams with the lever arms respectively results in a twisting movement which moves the lever arm 8018 generally downward. This movement is effective for pivoting or hinged motion. However, the lack of an accurate pivot point means that it pivots around the pivot area defined by the bending of the passive beams 806.

The downward actuation (and slight rotation) of the lever arm 8018 is made large by the distance of the nozzle wall from the passive beams 806. Downward movement of the nozzle walls and loops causes an increase in pressure in the chamber 8029, causing the meniscus to protrude, as shown in FIG. 17. It will be understood that the surface tension of the ink means fluid seal 8011 that is stretched by this operation without leaking the ink.

As shown in Fig. 18, at an appropriate time, the drive current is cut off, and the actuator beam 807 is rapidly cooled and contracted. This contraction causes the lever arm to start returning to the rest position, which in turn causes a decrease in pressure in the chamber 8029. The interaction between the momentum of the ink protrusion and the surface tension originally possessed, and the negative pressure caused by the upward movement of the nozzle chamber 8029, continued upwards until the ink droplets 802 contacted adjacent to the print media. It causes thinning of the protruding meniscus and, ultimately, snapping.

Immediately after the droplet 802 is separated, the meniscus 803 forms the concave shape shown in FIG. 18. Surface tension causes pressure in the chamber 8029 to remain relatively low until the ink is absorbed upwards through the inlet 8014, thereby bringing the nozzle mechanism and the ink into the stationary situation shown in FIG. To return.

Hereinafter, another type of printhead nozzle mechanism suitable for the printhead ICs 74 is described with reference to FIG. Once again, for the sake of clarity and convenience, the structure and operation of the single nozzle mechanism 1001 is described.

The nozzle mechanism 1001 comprises a nozzle plate having a nozzle therein, a nozzle having a nozzle rim 1004, and an aperture 1005 extending through the nozzle plate and forming a bubble. Type. The nozzle plate 1002 is a plasma etched from a silicon nitride structure deposited over a material to be etched away after chemical vapor deposition (CVD).

The nozzle mechanism includes, for each nozzle 1003, side walls 1006 on which the nozzle plate is supported, a chamber 1007 defined by the walls and the nozzle plate 1002, a multilayer board, and the multilayer board. And an inlet passage 1009 that extends through to the far side of the substrate. The looped extended heater element 1010 is suspended in the chamber 1007 so that the element takes the form of a suspended beam. The nozzle mechanism shown is a micro electro mechanical system (MEMS) structure formed by a lithographic process.

When the nozzle mechanism is in use, ink 1011 from a reservoir (not shown) enters the chamber 1007 via the inlet passage 1009 and thereby fills the chamber. The heater element 1010 is then heated for a time shorter than approximately 1 microsecond (milliseconds per minute) so that the heating is in the form of a thermal pulse. It will be appreciated that the heater element 1010 thermally contacts the ink 1011 in the chamber 1007 when it is heated which causes the generation of vapor bubbles in the ink. Thus, the ink 1011 is made of a liquid that forms bubbles.

Once generated, the bubble 1012 causes an increase in pressure in the chamber 1007 which in turn causes the ejection of the ink droplets 1016 through the nozzle 1003. The rim 1004 is for minimizing the ejection of a droplet assisting the directionality of the sprayed droplet 1016 in the wrong direction.

The reason that there is only one nozzle 1003 and chamber 1007 per inlet passage 1009 is that in the heating of the element 1010 and the formation of bubbles 1012, the pressure waves generated within the chamber are adjacent to the adjacent chambers. This is to avoid affecting the nozzles corresponding to the chambers.

The pressure rise in the chamber 1007 not only pushes the ink 1011 out through the nozzle 1003 but also pushes some ink backward through the inlet passage 1009. However, the inlet passage 1009 is only about 200 to 300 microns in length and only about 16 microns in diameter. Therefore there is a substantial viscous drag. As a result, the main effect of the pressure rise in the chamber is that the ink is discharged out as spray droplets 1016 through the nozzle 1003 rather than pushing back through the inlet passage 1003.

As shown in Fig. 26, the ink droplet 1016 being ejected exhibits a necking phase during ejection before the droplet is separated. The bubble 1012 has already reached its maximum size at this stage and then starts to collapse towards the point of collapse 1017.

The collapse of the bubble 1012 towards the collapse point 1017 causes some ink 1011 to be drawn out of the nozzle 1003 (from the side 1018 of the droplet) and a portion of the inlet passage 1009. To be pulled towards the collapse point. Most of the ink 1011 drawn in this manner forms an annular neck 1019 at the base of the droplet 1016 prior to being drawn off and separated from the nozzle 1003.

The droplet 1016 needs a certain amount of elasticity to overcome surface tension in order to be separated. By reducing the amount of total surface tension that holds the droplets as the ink 1011 is withdrawn from the nozzle 1003 by the collapse of the bubble 1012, the diameter of the necking 1019 is reduced so that the droplets are droplets Sprayed out, it is elastic enough to separate.

Bubble 1012 collapses to the point of collapse 1017 when droplet 1016 separates, echoing in the direction of arrows 1020 to cause cavitation forces. It is found that there is no solid face near the collapse point 1017 where cavitation is in effect.

Now, another type of printhead nozzle mechanism suitable for printhead ICs will be described with reference to FIGS. 27 to 29. This type typically provides an ink jet nozzle mechanism having a nozzle chamber containing ink and a thermal bend actuator connected to a paddle located within the chamber. The thermal actuator device is activated to eject ink from the nozzle chamber. This preferred embodiment includes a characteristic thermal bending actuator that includes a series of tapered portions to provide conductive heating to the conductive diagram. The actuator is connected to the paddle via an arm received through a slotted wall of the nozzle chamber. The actuator arm has a fitting to substantially fit the slot face of the nozzle chamber wall.

Returning to Figures 27 (a) to 27 (c) at the outset, a schematic description of the basic operation of the nozzle mechanism of this embodiment is provided. The nozzle chamber 501 is filled with ink through the ink inlet channel 503, which may be etched through the wafer substrate on which the nozzle chamber 501 is placed. Moreover, the nozzle chamber 501 includes an ink injection port in which an ink meniscus is formed around it.

Inside the nozzle chamber 501 is a paddle type mechanism 507 which is connected to each other with an actuator via a slot on the wall of the nozzle chamber 501. The actuator 508 comprises heater means, for example, reference numeral 509, positioned adjacent the end of the post 510. The pillar 510 is fixed to the substrate.

When droplets are to be ejected from the nozzle chamber 501, as shown in Fig. 27B, the heater means 509 is heated to withstand thermal expansion. Preferably, the heater means 509 itself or another part of the actuator is made of a material having high bending efficiency defined by the following equation.

Bending efficiency = {Young's modulus X (Coefficient of thermal expansion)} / {density X specific heat capacity}

Suitable materials as heater elements are alloys of copper and nickel which are formed to bend the glass material.

The heater means 509 is perfectly located near the end of the column 510 to maximize the activation action at the paddle end 507 so that the paddle end moves a lot with less thermal expansion near the column 510. Be sure to

The paddle movement inevitably following the heater means 509 causes a general pressure increase around the rapidly expanding ink meniscus 505, as shown in FIG. 27 (b). The heater current is pulsed so that ink is injected out of the port 504 in addition to the flow from the ink channel 503.

The paddle 507 is then deactivated and returned to rest. This deactivation generally causes back flow of ink into the nozzle chamber. Forward momentum of the ink out of the nozzle rim, and corresponding countercurrent, generally causes necking and separation of the droplets 512 leading to the print media. The collapsed meniscus 505 causes the normal absorption of ink into the nozzle chamber 502 via the ink flow channel 503. In time, the nozzle chamber is refilled to reach the position in Fig. 27 (a), and the nozzle chamber is then prepared for the ejection of another ink droplet.

28 shows a side perspective view of the nozzle mechanism. FIG. 29 shows a partial perspective view of the arrangement of the nozzle mechanism of FIG. 28. In this form, the numbering of the elements introduced above is maintained.

First, the actuator 508 is formed of an upper glass portion (amorphous silicon dioxide) 516 formed on the titanium nitride layer 517, for example, as shown in 515 It includes a series of tapered actuator units. Alternatively, an alloy layer of copper and nickel (hereinafter referred to as white copper) with higher bending efficiency may be used.

 The titanium nitride layer 517 is tapered in shape, which causes resistive heating near the end of the pillar 510. Adjacent titanium nitride / glass portions 515 are connected to each other with a block portion 519, which also provides mechanical structural support for the actuator 508.

The heater means 509, in principle, comprises a plurality of tapered actuator units 515, the actuator units extending and spaced apart so that the bending force appearing along the axis of the actuator 508 upon heating is maximized. Slots are defined between adjacent tapered units 515 to allow some differential actuation of each actuator 508 to adjacent actuators 508.

The block portions 519 are connected to the arm 520 with each other. The arms 520 are alternately connected to the paddles 507 inside the nozzle chamber 501 by a slot formed at the side of the nozzle chamber 501, for example, reference numeral 522. The slot 522 is generally designed to coincide with the surface of the arm 520 to minimize the chance of ink spilling around the arm 520. Ink is generally received in the nozzle chamber 501 by the surface tension effect around the slot 522.

When the arm 520 is to be activated, a conductive current passes through the titanium nitride layer 517 into the block portion 519 which connects to the lower CMOS layer 506 which provides the power and control circuits required for the nozzle mechanism. Passed. The conductive current heats the nitride layer 517 adjacent to the pillar 510 to cause the arm 20 to bend normally upward and thus ink is ejected out of the nozzle. The ejected droplet is printed on the paper by the printing method of a conventional inkjet printer, as described above.

An array of nozzle mechanisms is formed to draw out a single printhead. For example, in FIG. 29, various arrangements of multiple ink jet nozzle mechanisms assigned to inserted lines to form an array of printheads are shown in a partial cross-sectional view. Of course, other types of arrays can be organized, including full natural arrays and the like.

The configuration of the above-described printhead system is achieved through appropriate modeling of the steps as set forth in US Pat. No. 6,243,113, the contents of which are incorporated by reference in their entirety and the applicant has named "Image Generation Method and Apparatus (IJ41)". Proceed to the implementation of standard MEMS technology.

The integrated circuits 74 are arranged with 5000 to 100,000 ink spray nozzles described above, which are arranged along the surface of the integrated circuit, based on the length of the integrated circuits and the printing properties required. For example, to achieve desired printability for narrower media, only 5000 nozzles may be arranged along the surface of the printhead assembly, while the desired printability for wider media is desired. To achieve this, at least 10,000, 20,000 or 50,000 nozzles need to be installed along the length of the printhead assembly. For full color photographic quality images close to 1600 dpi or 1600 dpi on A4 or US paper size media, the integrated circuits 74 have 13824 nozzles per color. Therefore, when the printhead assembly 22 is capable of printing in four colors C, M, Y, K, the integrated circuits 74 are arranged with approximately 53396 nozzles along their surface. Furthermore, when the printhead assembly 22 is capable of printing six print fluids (C, M, Y, K, IR and fixer), 82944 nozzles will be installed on the surfaces of the integrated circuits 74. . In all these mechanisms, the electrical devices supporting each nozzle are identical.

As such, while the invention has been shown and described with respect to illustrative embodiments, it is evident that various and easy modifications are possible by those skilled in the art without departing from the scope and spirit of the invention. Accordingly, the technical scope of the claims appended hereto should not be understood as being limited to the description set forth herein, but rather should be construed broadly.

Claims (90)

(a) providing a first substrate having a plurality of etched trenches defined in a first bonding surface; (b) providing a second substrate having a second bonding surface; And (c) joining the first bonding surface and the second bonding surface together using an adhesive; Wherein said adhesive is at least partially received in said plurality of etched trenches during bonding. The method of claim 1, The first substrate has a thickness of less than 1000 microns (micron) bonding method of the first substrate and the second substrate. The method of claim 1, And wherein said first substrate has a thickness of approximately 250 microns or less. The method of claim 1, And the first substrate is an integrated circuit. The method of claim 1, And the first substrate is a printhead integrated circuit. The method of claim 5, And said second substrate is a molded ink manifold formed thereon for mounting a plurality of printhead integrated circuits thereon. The method of claim 1, And said etched trenches have a diameter or width sufficient to attract liquid adhesive by capillary action. The method of claim 1, And wherein said etched trenches have a diameter or width of less than about 10 microns. The method of claim 1, And the etched trenches have a depth of at least 20 microns. The method of claim 1, And the etched trenches have an aspect ratio of at least 3: 1. The method of claim 1, And the etched trenches increase the effective surface area of the first bonding surface by at least 20%. The method of claim 1, And the first bonding surface has a maximum surface roughness (R _max ) of approximately 20 nm or less. The method of claim 1, And the first bonding surface has a maximum surface roughness (R _max ) of approximately 5 nm or less. The method of claim 1, And said first bonding surface has an average surface roughness (R _a ) of about 20 nm or less. The method of claim 1, The first engagement surface is combined method of the first substrate and the second substrate, characterized in that having an average surface roughness (R _a) of about 5nm or less. The method of claim 1, And the first substrate has a total thickness variation (TTV) of about 5 microns or less. The method of claim 1, The adhesive is a bonding method of the first substrate and the second substrate, characterized in that the liquid-based adhesive. The method of claim 1, The adhesive is a bonding method of the first substrate and the second substrate, characterized in that the adhesive tape comprising a liquid-based adhesive. The method of claim 1, And the first substrate is cooled at least during bonding so that a partial vacuum is formed over the adhesive in the etched trenches. The method of claim 1, Wherein said first substrate is heated at least prior to bonding so as to cool during bonding. The method of claim 19, And wherein said partial vacuum holds said first substrate and said second substrate together, at least in part, during bonding. A first suitable for bonding to a second substrate using an adhesive, having a plurality of etched trenches defined on a first joining surface, the etched trenches being formed to receive the adhesive during bonding Board. The method of claim 22, A first substrate having a thickness of less than 1000 microns. The method of claim 22, A first substrate having a thickness of 250 microns or less. The method of claim 22, A first substrate, characterized in that the semiconductor integrated circuit. The method of claim 22, A first substrate, characterized in that the MEMS integrated circuit. The method of claim 22, A first substrate, characterized in that the printhead integrated circuit. The method of claim 22, And the etched trenches have a diameter or width sufficient to attract liquid adhesive by capillary action. The method of claim 22, And the etched trenches have a diameter or width of less than about 10 microns. The method of claim 22, And the etched trenches have a depth of at least 20 microns. The method of claim 22, And the etched trenches have an aspect ratio of at least 3: 1. The method of claim 22, And the etched trenches increase the effective surface area of the first bonding surface by at least 20%. The method of claim 22, Wherein the first bonding surface has a maximum surface roughness (R _max ) of approximately 20 nm or less. The method of claim 22, Wherein the first bonding surface has a maximum surface roughness (R _max ) of approximately 5 nm or less. The method of claim 22, The first mating surface includes a first substrate, characterized in that having an average surface roughness (R _a) of about 20nm or less. The method of claim 22, The first mating surface includes a first substrate, characterized in that having an average surface roughness (R _a) of about 5nm or less. The method of claim 22, And wherein said first substrate has a flatness (TTV) of approximately 5 microns or less. The method of claim 22, The adhesive is a first substrate, characterized in that the adhesive of the liquid base. The method of claim 22, The adhesive is a first substrate, characterized in that the adhesive tape comprising an adhesive of the liquid base. (a) a first substrate having a plurality of etched trenches defined in the first joining surface; And (b) having a second joining surface, the second joining surface having a second substrate coupled to the first joining surface with an adhesive, wherein the plurality of etched trenches, at least in part, receive an adhesive; Coupled assembly characterized in. The method of claim 40, And the first substrate has a thickness of less than 1000 microns. The method of claim 40, And the first substrate has a thickness of 250 microns or less. The method of claim 40, And said first substrate is a semiconductor integrated circuit. The method of claim 40, And said first substrate is a MEMS integrated circuit. The method of claim 40, And the first substrate is a printhead integrated circuit. The method of claim 40, And said second substrate is a polymer. The method of claim 45, And said second substrate is a molded ink manifold formed thereon for mounting a plurality of printhead integrated circuits. The method of claim 40, Wherein the etched trenches have a diameter or width sufficient to attract liquid adhesive by capillary action. The method of claim 40, And wherein said etched trenches have a diameter or width of less than approximately 10 microns. The method of claim 40, And wherein said etched trenches have a depth of at least 20 microns. The method of claim 40, And said etched trenches have an aspect ratio of at least 3: 1. The method of claim 40, And the etched trenches increase the effective surface area of the first engagement surface by at least 20%. The method of claim 40, And said first bonding surface has a maximum surface roughness (R _max ) of approximately 20 nm or less. The method of claim 40, And the first bonding surface has a maximum surface roughness (R _max ) of approximately 5 nm or less. The method of claim 40, And said first bonding surface has an average surface roughness (R _a ) of approximately 20 nm or less. The method of claim 40, And said first bonding surface has an average surface roughness (R _a ) of approximately 5 nm or less. The method of claim 40, And said first substrate has a flatness (TTV) of approximately 5 microns or less. The method of claim 40, And said adhesive is a liquid base adhesive. The method of claim 40, And said adhesive is an adhesive tape comprising an adhesive of a liquid base. (a) a plurality of nozzles formed on the front side of the printhead integrated circuit; A plurality of ink supply channels for supplying ink from the printhead integrated circuit to the nozzles; And A plurality of printhead integrated circuits each having a plurality of etched trenches defined on its backside; And (b) an ink manifold having a mounting surface, wherein the back surface of each printhead integrated circuit is adhesively bonded to the mounting surface And the adhesive is received, at least in part, in the plurality of etched trenches. The method of claim 60, Each printhead integrated circuit has a thickness of 250 microns or less. The method of claim 60, And the ink manifold is a molded ink manifold formed of a polymer. The method of claim 60, And wherein said etched trenches have a diameter or width sufficient to attract liquid adhesive by capillary action. The method of claim 60, And the etched trenches have a diameter or width of less than approximately 10 microns. The method of claim 60, And the etched trenches have a depth of at least 20 microns. The method of claim 60, And the etched trenches have an aspect ratio of at least 3: 1. The method of claim 60, And said etched trenches to increase the effective surface area of each back side by at least 20%. The method of claim 60, Each backside has a maximum surface roughness (R _max ) of approximately 20 nm or less. The method of claim 60, Each back side has a maximum surface roughness (R _max ) of approximately 5 nm or less. The method of claim 60, Each back side has an average surface roughness (R _a ) of 20 nm or less. The method of claim 60, Each back side has an average surface roughness (R _a ) of 5 nm or less. The method of claim 60, Each printhead integrated circuit has a flatness (TTV) of approximately 5 microns or less. The method of claim 60, And the adhesive is a liquid base adhesive. The method of claim 60, The adhesive is a printhead assembly, characterized in that the adhesive tape containing the adhesive of the liquid base. A printer comprising the printhead assembly of claim 60. 76. The method of claim 75, The printer is a page-width inkjet printer. A plurality of nozzles formed on the front side of the printhead integrated circuit; A plurality of ink supply channels for supplying ink to nozzles from the back side of the printhead integrated circuit; And A printhead integrated circuit having a plurality of etched trenches defined thereon and adapted to receive an adhesive during bonding and suitable for bonding to the mounting surface of the ink manifold using the adhesive. 78. The method of claim 77 wherein The printhead integrated circuit has a thickness of less than 250 microns. 78. The method of claim 77 wherein And the etched trenches have a diameter or width sufficient to attract liquid adhesive by capillary action. 78. The method of claim 77 wherein And the etched trenches have a diameter or width of less than approximately 10 microns. 78. The method of claim 77 wherein And the etched trenches have a depth of at least 20 microns. 78. The method of claim 77 wherein And the etched trenches have an aspect ratio of at least 3: 1. 78. The method of claim 77 wherein And the etched trenches increase the effective surface area of the first mating surface by at least 20%. 78. The method of claim 77 wherein And the first mating surface has a maximum surface roughness (R _max ) of approximately 20 nm or less. 78. The method of claim 77 wherein And the first mating surface has a maximum surface roughness (R _max ) of approximately 5 nm or less. 78. The method of claim 77 wherein The first mating surface printhead integrated circuits, characterized in that having an average surface roughness (R _a) of about 20nm or less. 78. The method of claim 77 wherein The first mating surface printhead integrated circuits, characterized in that having an average surface roughness (R _a) of about 5nm or less. 78. The method of claim 77 wherein And the printhead integrated circuit has a flatness (TTV) of approximately 5 microns or less. 78. The method of claim 77 wherein The adhesive is a first substrate, characterized in that the adhesive of the liquid base. 78. The method of claim 77 wherein The adhesive is a first substrate, characterized in that the adhesive tape comprising an adhesive of the liquid base.

Images