EP0726152B1 - Method of manufacturing an inkjet printhead - Google Patents

Description

The invention relates to a manufacturing method for an inkjet printhead according to the preamble of claim 1 specified Art.

Such an ink jet print head can be small fast printers. Such will be for example for franking machines for franking Postage used.

It is known that ink jet printheads after Edge shooter or built according to the face shooter principle are (First annual ink jet printing workshop, March 26-27, 1992, Royal Sonesta Hotel, Cambridge, Massachusetts). Efforts have been made so far to minimize the dimensions of the chambers to reduce the nozzle density to increase. The nozzle chambers were also already arranged concentrated to the front edge. However is this principle only applies to inkjet modules with few Nozzles in a row make sense and fail at a high Number of nozzles.

It is well known that a first generation of inkjet printheads based on the edge shooter principle were made up of individual pulse emitters that from an elongated ink chamber with rectangular Cross-section and a glued on top Piezo crystal exist (BIS CAP Ink Jet Printing Conference, Monterey, California, November 11-13, 1991).

A later generation then became a nozzle plate in front of a one-piece inkjet printhead, which has several chambers, arranged. The chambers are no longer with the smaller chamber area, but now with the larger chamber area parallel to each other. The piezo crystals form the chamber walls (shared wall concept, Ink Jet Printing Conference, 11-13 November 1991).

DE 34 45 761 A1 describes a process for the production a single plate converter assembly a transducer material known. After coating the lower plate surface with a membrane layer the material is removed from the upper surface, to create separate areas on the Membrane above each pressure chamber (area 25.4 mm * 2.54 mm) are arranged. This eliminates the Need an adhesive connection with adhesive between transducer material and membrane and the uniformity of all distances is improved. The resulting nozzle spacing is, however, relatively large.

Furthermore, from US 46 80 595 is a face shooter a nozzle line between two groups of ink chambers known, which has a doubled nozzle density having. Each rectangular pressure chamber is one Supply channel and a nozzle and a vibrating plate assigned with piezoceramic element. The disadvantage is here, however, that in the ink supply and in pressure waves occurring in each chamber a crosstalk can effect on other pressure chambers. Only by This crosstalk can be very costly be eliminated later. Another disadvantage is that these inkjet printheads in one complex and expensive manufacturing process Need to become.

The through openings are made by etching, but not in a parallel process, i.e. not in all parts (plates) manufactured at the same time.

EP 67 653 already discloses UV exposure and Etching of a photosensitive glass plate known. Indeed here, too, the production of individual ones takes place Serial plates head for head, not parallel. This way of working, in which first separated and then each separated plate part individually edited, gives problems with very small Structures. For high accuracy from very small Structures it is known that when annealing everyone Plate part is subject to an approximately 10% shrinkage. The very small structures result from the Requires a very high image resolution in inkjet printing.

From US 47 03 333 is also known from Edge shooter modules arranged diagonally one above the other built-in inkjet printheads for an inclined Arrangement to the surface of a record carrier to manufacture. Inkjet printheads with one inclined arrangement to the surface of a record carrier generate a more even record too if the thickness of the recording medium fluctuates. The However, manufacturing such printheads requires one Variety of manufacturing steps. It's tough, the required accuracy with such a complex To guarantee the overall structure of each printhead. Operation is also complex required electrical control of such Printheads with rows of staggered nozzles.

The one with the face-shooter-ink-jet module with two Groups of. arranged symmetrically to the nozzle line Ink chambers achieved double nozzle density in one So far, series has been used with edge shooter ink jet modules one row of nozzles is not reached. To double the image density to achieve, several rows of nozzles horizontally and vertically offset from each other.

Such an offset arrangement of two rows of nozzles is also in an edge shooter module - shown in Figure 2 known (First Annual Ink Jet Printing Workshop, March 26-27, 1992, Royal Sonesta Hotel, Cambridge, Massachusetts). Such a module exists from a total of only three parts (glass pieces), one Central part with openings and two side parts each with a row of ink chambers and a row of nozzles on the front of the respective side part. The two rows of ink chambers and the rows of nozzles are on the front of each side part offset from each other, which again the ones already mentioned Disadvantages when assembling the module and when controlling it brings with it.

These disadvantages are exacerbated when an ink print head composed of several such modules is. So the offset of the individual rows of nozzles be exactly the same. In addition, every module would be individually via an ink supply line and connect a filter to an ink reservoir.

With an offset arrangement of two Rows with a low nozzle density in each Row are due to a minimum size requirement the minimum distance between the ink chamber Nozzles cannot be further reduced.

Due to manufacturing reasons it is impossible for all nozzles to achieve a constant nozzle size because it channels must be etched into separate pieces of glass. Already small size or material differences between the glass pieces lead to deviations in the nozzle shape and position.

It is the problem of the disadvantages of the prior art eliminate and a manufacturing process with low Manufacturing cost of an inkjet printhead with a high nozzle density per row.

The object is achieved with the features of claim 1 solved.

Starting from the goal, inkjet printheads for an inclined arrangement to the surface of a recording medium to produce a more even Recording even if the thickness of the recording medium fluctuates an inkjet printhead, which has an in-line module with an edge ejection, suggested.

The process of making the inkjet printhead, starts from the CAD development of a printhead design and a mask production for a photosensitive Glass plate.

To generate the sensitive to etchants from the Glass plate to be removed parts are the masked Glass plates at least once irradiated with UV light corresponding wavelength with subsequent Exposed to heat treatment.

In a parallel processing process, the Removed areas from the plate (etched out) and then the individual parts for the middle part and the parts supporting the chambers are separated.

This is followed by separate manufacturing process steps for the parts bearing the chambers, to the To manufacture ink chambers and the nozzles. The duration of the Etching bath determines the layer thickness of the removed Materials.

Three individual parts, each consisting of two Chamber-bearing parts and a central part aligned and tacked together and then annealed.

Finally, the nozzle channels are specially treated and the cavities (chambers) and the outer edge the module before the printhead contacts and is assembled.

The invention assumes that the edge ejection the row of nozzles with a high number of nozzles in one side part of a module can be accommodated. For the first time is a higher nozzle density in the manner according to the invention, completely independent of the dimensions of the ink chambers, reachable.

The dimensions of the ink chambers can now even be enlarged without reducing the nozzle density.

• Durch die in demselben Glasstück angeordneten Düsen, ist es möglich, für alle Düsen eine gleichbleibende Düsengröße und einen gleichen Abstand zu erreichen. Das ist dann der Fall, wenn vor dem Diffusions-Bond-Prozeß entsprechende Kanäle in das das Seitenteil des Moduls bildende Glasstück geätzt werden. Das reduziert auch die Herstellungskosten.
• Gegenüber der üblichen Konstruktion mit einer horizontalen Ausrichtung von zwei Reihen von Düsen ist ein Überlappen des jeweils zweiten Kammern tragenden Teils mit einer versetzten Kammergruppe mit größerer Toleranz möglich.
• Die erfindungsgemäße vertikale Ausrichtung des Teils mit den Düsen und eines Kammern tragenden Teils mit einer seitlich versetzten Kammergruppe ist unkritisch, da alle Düsen nur auf einer Seite des Druckkopfes sind. Dies reduziert auch die Kosten.
• Die Düsenreihe macht es in unaufwendiger Weise möglich, den Druckkopf in einer geneigten Anordnung zum Aufzeichnungsträger anzuordnen.
• Die elektrische Ansteuerung des Tintenstrahldruckkopfes kann einfacher ausgeführt werden, weil keine Kompensation des Düsenreihenabstandes durch zeitliche Staffelung der Drucksteuersignale erforderlich ist.

In addition to the increased nozzle density of the edge shooter ink jet in-line print head (ESIJIL print head), the other advantages are:

• Due to the nozzles arranged in the same piece of glass, it is possible to achieve a constant nozzle size and an equal distance for all nozzles. This is the case if appropriate channels are etched into the glass piece forming the side part of the module before the diffusion bonding process. This also reduces manufacturing costs.
• Compared to the usual construction with a horizontal alignment of two rows of nozzles, an overlap of the part carrying the second chamber with an offset chamber group with greater tolerance is possible.
• The vertical alignment of the part with the nozzles and a chamber-bearing part with a laterally offset chamber group according to the invention is not critical, since all nozzles are only on one side of the print head. This also reduces costs.
• The row of nozzles makes it possible in a straightforward manner to arrange the print head in an inclined arrangement relative to the recording medium.
• The electrical control of the inkjet printhead can be carried out more simply because no compensation of the nozzle row spacing is required by staggering the pressure control signals over time.

Such an inkjet print head can advantageously be made up of several modules, whereby only one of the modules carries the nozzle row or off consists of a multi-part module. It is still provided that the front edge of the chambers bearing Part that carries the row of nozzles, on the edge or in the Middle of a module is arranged.

Figur 1a,

Prinzip eines Edge-Shooter-Ink-Jet-Druckkopfes nach dem Stand der Technik

Figur 1b,

Prinzip eines Face-Shooter-Ink-Jet-Druckkopfes nach dem Stand der Technik

Figur 1c,

Prinzip des erfindungsgemäßen Aufbaues eines Edge-Shooter-Ink-Jet-In-Line-Druckkopfes

Figur 2,

Aufbau eines Edge-Shooter-Ink-Jet-Druckkopfes nach dem Stand der Technik

Figur 3,

Aufbau des ESIJIL-Druckkopfes in einer ersten Variante

Figur 4,

Röntgenbild des ESIJIL-Druckkopfes in Draufsicht,

Figur 5a,

Detail des Röntgenbildes

Figur 5b,

Schnitt durch die Linie A-A

Figur 5c,

Schnitt durch die Linie B-B

Figur 6a,

Detail des Röntgenbildes einer zweiten Variante des ESIJIL-Druckkopfes in Draufsicht,

Figur 6b,

Schnitt durch die Linie A-A

Figur 6c,

Schnitt durch die Linie B-B

Figur 6d,

Röntgenbild der Frontansicht

Figur 7a,

Frontansicht einer dritten Variante des ESIJIL-Druckkopfes,

Figur 7b,

Röntgenbild der Frontansicht nach Figur 7a

Figur 8,

Herstellungsverfahren für den ESIJIL-Druckkopfes,

Advantageous developments of the invention are characterized in the subclaims or are shown in more detail below together with the description of the preferred embodiment of the invention with reference to the figures. Show it:

Figure 1a,

Principle of an edge shooter ink jet print head according to the state of the art

Figure 1b,

Principle of a face shooter ink jet print head according to the state of the art

Figure 1c,

Principle of the construction according to the invention of an edge shooter ink jet in-line print head

Figure 2,

Construction of an edge shooter ink jet print head according to the state of the art

Figure 3,

Construction of the ESIJIL print head in a first variant

Figure 4,

X-ray image of the ESIJIL printhead in top view,

Figure 5a,

Detail of the x-ray image

Figure 5b,

Section through the line AA

Figure 5c,

Section through the line BB

Figure 6a,

Detail of the X-ray image of a second variant of the ESIJIL printhead in a top view,

Figure 6b,

Section through the line AA

Figure 6c,

Section through the line BB

Figure 6d,

X-ray image of the front view

Figure 7a,

Front view of a third variant of the ESIJIL printhead,

Figure 7b,

X-ray image of the front view according to FIG. 7a

Figure 8,

Manufacturing process for the ESIJIL printhead,

FIG. 1a shows the known principle of an edge shooter inkjet print head in perspective view shown. It consists of a module on the Front two offset to each other in the y direction There are rows of nozzles. Thereby belongs to the nozzle group 1.1 the first row a first group 101 of ink chambers and a group to the nozzle group 1.2 of the second row 102 on ink chambers.

FIG. 1b shows the known principle of a face shooter ink jet ink jet print head in perspective Shown view. It consists of a module in its base two to each other in the z direction offset nozzle groups 1.1 and 1.2 in a row lie. An intake chamber 151 or 152 becomes in each case a group of ink chambers 101 and 102 for the nozzle group 1.1 or for the offset nozzle group 1.2 inked.

Figure 1c shows a perspective view of the invention Principle of an edge shooter ink jet in-line print head (ESIJIL). It consists of a module on the end face k≥2 horizontally to each other offset nozzle groups 1.1, 1.2 etc. in a row lie. Ink flow from chamber groups 101-104 in the volume of the module is on the front edge of the first Chamber-bearing part, which is quasi a side part of the module forms. The chambers of a group 101-104 are staggered in the y direction and theirs associated outgoing ink channels are thus sent to the Print edge led that they form nozzles 1.1 - 1.4, the however, there are very few in a row Distance. This is achieved in FIG. 1c, in which the outgoing ink channels a certain have a lateral offset in the z direction. As well can the chambers in another embodiment 101 - 104 even this lateral offset in the z direction exhibit. The sequence of such Orders finally give the desired number Nozzles in a row. In Fig. 1c are the overview for the sake of only two such arrangements. The There is a lateral distance between the nozzles in the z direction much smaller than the lateral distance between two in the z direction adjacent chambers 101 and 101 or 102 and 102 etc. The ink drops are made from the Nozzles ejected in the x direction. The axes x, y, z are orthogonal to each other. The addition further chambers 105, 106 etc. in the y direction in principle possible, and only from the effort limited. Its positive effect, namely education only a row of nozzles with minimal nozzle spacing the inventive principle already with 2 chamber groups 101 and 102.

The structure of a known - shown in Figure 2 - double row edge shooter ink jet module consists of 3 Ceramic or glass parts. A first part, which on carries a first chamber group on its left side over a middle part with a second part, which on on its right side carries a second chamber group, see above connected in the y direction that the chambers on the inside of the middle part fit and side to side (horizontal) are offset. Each chamber is through a first channel with a suction space and with a second channel connected to the front edge of the module. Every second Channels form a nozzle. It is relatively difficult Keep the distance between the two rows of nozzles exactly. Deviations lead but with constant timing of the two rows of nozzles to deviations in Print image, which reduces the print quality. The middle part has a first opening that the Intake spaces of both outer parts with each other and with one Ink supply port connects. There are also openings available for the fasteners.

The module of a first variant shown in FIG. 3 an ESIJIL printhead (k = 2) also consists of 3 Divide, however, the part containing the first chambers 2 carries all the nozzles 1, the middle part 3 one Number of second and third openings 14 and 9 in addition to the first opening 18 which the Ink supply opening 16 with one in FIG. 3 Connects suction chamber 15, not shown, has. An ink chamber group 101 and the suction space 15 are not on the in Figure 3 visible left side of the first part 2. The second Part 4 contained chambers carries no nozzles but only still the second ink chamber group 102, which over the second openings 14 of the middle part 3 supplied with ink becomes. The associated other nozzles are over the third openings of the middle part 3 with the ink chambers of the second part 4 connected. Parts 2 - 4 are mounted in the direction of the y-axis.

The X-ray image of the Top view of ESIJIL printhead modules illustrates the in-line arrangement of the nozzles and the lateral offset of the ink chamber groups 101 des first chamber-bearing part 2 and the group 102 of the second chamber-bearing part 4, shows the location the first opening 18 in the middle part 3 to the Ink supply opening 16 and the suction space 15, the second openings 14, which with the suction chamber 15 in Connect and the third openings 9 that the Feed ink to the nozzles of the second nozzle group 1.2. It is envisaged that the nozzles of the nozzle group 101 with the nozzles of the nozzle group 102 within the Alternate row of nozzles.

A detail of the X-ray image is shown in FIG. 5a the figure 4 shown enlarged. The one in the first part 2 located chambers 11 of the first chamber group 101 Nozzles of the first nozzle group 1.1 in the same part 2 assigned. Chamber 11 becomes suction chamber 15 supplied with ink via one of the channels 13. On corresponding section on line A-A through the Drawing in Figure 5a is shown in Figure 5b. The chambers 12 of the second located in the second part 4 Chamber group 102 are nozzles of the second nozzle group 1.2 assigned in the other chambers bearing part 2, as from the section B-B shown in Figure 5c is. From part 2 bearing in the first chambers located suction chamber 15 passes ink through a other of the channels 13 and via one of the middle part 3 located second openings 14 in the chamber 12 of the second chamber supporting part 4. From the chamber 12 to the corresponding part in the first chamber 2 located nozzle of the nozzle group 12 is one Connection via a third opening 9 in each Middle part 3.

Figures 6a, b, c and d show a second variant the solution according to the invention. In Figure 6a again a top view of a detail as an X-ray image and in Figure 6d is a front view of a Printhead shown as an X-ray image. The x-ray cuts C-C, D-D and E-E are shown in the view Figure 6d overlaid. This becomes in connection with the 6a shows the position of the ink chamber groups 101, 102, 103 and 104 can be seen. Figure 6b shows one Overlays of sections through lines A-A and A1-A1 of Figures 6a and 6d. Figure 6c shows one Overlays of sections through lines B-B and B1-B1 of Figures 6a and 6d.

The in-line nozzle groups 1.1 - 1.4 of k = 4 chamber groups 101,102,103, 104 are in a first one Part 2, which itself is only a first 101 of k = 4 Has chamber groups. A second group of nozzles each 1.2 in the first part is related to a chamber 12 of the second chamber group 102 in the second chamber Part facing a chamber 11 of the first Chamber group 101 of the first chamber-bearing part 2 is arranged offset, the second chamber group 102 supplied with ink through openings 14 in the center piece 3 becomes.

According to the invention, 3 second openings are in the center piece 14 for supplying the second nozzle group 1.2 with ink available. Opposite the openings 9 in each The centerpiece is openings 10 in each of the first chambers supporting part and a connection of the second chambers supporting part for connecting the chambers of each second chamber group 102 with the nozzle channels of the second Nozzle group 1.2 in the first chambers Item available.

From a common suction chamber 15 each The first chamber-bearing part is supplied of the ink chambers 11, 12 in the first and each second chamber-bearing part. The ink supply to the Intake space 15 takes place via an opening 16 in that Part 2, which is a side part of the printhead forms, and via corresponding openings 18, 22 in respective center piece and further openings 17, 19, 21 in the chambers bearing parts 2, 4, 6 and one Opening 20 in the spacer 5.

A - not shown in Figures 1 to 6a - piezoelectric Element 31 serves as a well known Means for expelling ink from a chamber and can be placed on the chamber surface or in the chamber to be a pressure over at his arousal the compliant chamber wall onto the ink liquid in the chamber to exercise, causing an ink jet to escape from the nozzle connected to the chamber leads. Such is shown in FIGS. 6b, 6c and 6d piezoelectric element 31 on the chamber surface arranged. For example, the chamber 12 of the element 31 through a thin from the material of the chambers load-bearing part 4 existing layer 30 separately, which is so elastic that the bending energy of the Elements 31 is only slightly damped. On Spacer 5 has a corresponding recess 32 for the piezoelectric element 31.

In a further advantageous embodiment of the inventive concept is an elongated opening in each case the chamber-bearing parts provided with a correspondingly rotated by 90 ° elongated opening in the Middle parts and spacers are connected. One made up of such individual modules Inkjet printhead has no tolerance problems with Put together.

Through the - visible in Figures 6a, b, c - and indicated rectangular openings is not a complex Alignment with a very high accuracy when Assembling the parts more necessary, as was previously the case with Assembly of parts with staggered rows of nozzles required was. The shape of the openings can be in one another variant oval or designed as an elongated hole be, the small diameter of the openings den Passage cross section determined for the ink flow. At a larger deviation from the round or rectangular Cross-section, the openings 9 and 10 are also two rows Can be arranged on lines C-C and D-D.

It is envisaged that in the case of a construction of several modules, a first module supporting the row of nozzles consisting of two chambers 2 and 4, the chamber groups 101 and 102 of which face a central part 3, and at least a second module consisting of parts 6 and 8 supporting two chambers and a middle part 7, that each module has a suction space 15, 25, that there is a spacing part 5 at least between the modules, which has an ink supply opening 20 and ink through openings 23, 26, which are assigned to the chambers of the second module, and a recess 32 for the means for ejecting 31 ink from a chamber, the openings 23, 24 are connected to the third openings of the chamber-carrying parts and the central parts for supplying ink to the nozzles from the respective chambers, that the suction spaces 15, 25 each module via second openings 14, 24 with the chambers of the chamber groups 101, 102, 103, ..., 10k v are connected to supply ink and that in each module there are first openings 18, 22 to secure the supply of ink to the suction spaces.
The manufacturing process assumes that a module is composed of 3 parts each and is provided with piezoelectric elements and contacted. A second module is joined together with the first module via a spacer 5 to form an ESIJIL printhead, the second module with parts 6, 7, 8 not having any nozzles, but only corresponding openings which correspond to the openings provided in parts 2 , 3, 4 of the first module are connected.

In a third variant, an ESIJIL print head is made built into a single multi-part module. In the figure 7a is a front view with the in-line nozzle row and in FIG. 7b an X-ray image of the front view or an overlay of the cuts lines C-C and E-E are shown. On this line C-C are all third openings. More openings a line D-D are not provided. It is recognizable that only the nozzle dimensions the maximum Determine the number of nozzles in the row. Exists Need for increased chamber dimensions, should only the volume of the printhead can be increased. Of course, it is also possible if necessary, higher tolerance requirements due to such in the Figures 6 explained measures with third openings to solve on a line D-D.

In contrast to the spacer parts in FIGS. 6 here are the spacers in two parts and consist of the same material as the piezoelectric elements (marked in black). These elements are made from the worked out piezoelectric material, which is arranged on the chamber surface, however the edge is preserved and only in the immediate Surroundings of the elements 31 create cavities 32. in the Border are both ink supply openings as well second and third openings worked out. After this the piezoelectric elements are worked out, these are contacted, with conductor tracks also on the chamber floor and / or outside on the layer 30 can.

FIG. 8 shows the individual steps for a manufacturing process of the ESIJIL printhead shown.

The process of making the inkjet printhead, starts from the CAD development of a printhead design and a mask production for a photosensitive Glass plate.

Using masks that reflect the structure of the different parts to be produced, is a photosensitive Masked from amorphous glass and UV radiation exposed. The irradiated areas can later etched about 100 times faster than unirradiated ones Areas. After a heat treatment repeated UV radiation.

To generate the sensitive to etchants from the Glass plate to be removed parts are the masked Glass plates at least once irradiated with UV light corresponding wavelength with subsequent Exposed to heat treatment.

In a parallel processing process, the Removed areas from the plate (etched out) and then the individual parts for the middle part and the parts supporting the chambers are separated.

To the parallel processing steps for several Part of a module includes masking and subsequent Etching the through openings.

This is followed by separate manufacturing process steps for the parts bearing the chambers, to the To manufacture ink chambers and the nozzles. The duration of the Etching bath determines the layer thickness of the removed Materials.

Before making the ink chambers, the old one Mask layer by fine grinding the surface of the Chamber parts removed. Then the surface masked in areas that are not deeply etched should. After the ink chambers are etched a fine grinding of the individual parts to final dimensions and a subsequent masking to create the supply channels and the ink nozzle channels, which are less Depth than the chambers should have. The material removal done again by etching. In a special case only the etching sensitivity of the UV-irradiated areas exploited the material and a mask can omitted.

It is envisaged that for the three areas etchants are used with different concentrations, to the corresponding areas with different To be able to remove depth accuracy, the depth accuracy when etching the areas for continuous Holes is smaller than when etching very flat areas for the channels in the parts carrying the chambers and first the through holes, then the Chambers and then the nozzle channels are etched. It is further provided that the thickness of the bottom layer 30th is monitored during the etching of the chambers and that the for Completion of the manufacture of the chambers required Thickness of the bottom layer 30 of the chambers by fine grinding each of the parts carrying the chambers is reached.

When separating the individual parts, the finished ones are made Separated middle parts.

Three individual parts, each consisting of two Chamber-bearing parts and a central part aligned and tacked together and then annealed.

The individual parts are connected in a module, whereby the individual parts are aligned. After sticking together of the individual parts, a module was created, which is then annealed. When tempering finds a phase transition from amorphous to in the glass material crystalline instead.

When cutting off the nozzle tips with a rotating one Cutting disc creates a straight front edge. A flat surface is achieved by final grinding reached.

Finally, the nozzle channels are specially treated and the cavities (chambers) and the outer edge the module before the printhead contacts and is assembled.

By rinsing with a first suitable commercial one Liquid creates a hydrophilic inner coating. By treating the front edge with a The second suitable liquid becomes a hydrophobic External coating reached. After curing the The nozzles are finished.

The application of the electrical conductor tracks to the Chamber surface, the application of the piezo crystals and the contact is made in a known manner Wise. The piezo crystals can be glued on individually are followed by curing. On the other hand, it can also a layer of piezoelectric material be applied to the surface of the chamber, which is then structured and contacted. The coating can be done by sputtering.

Finally, a nozzle cleaning is carried out using Compressed air.

The manufacture of chambers and through holes in the individual parts can be in a further variant of the manufacturing process in one step. To do this, it is necessary that the UV exposure is repeated through different masks before the Plate is etched. Another possibility is in UV exposure with different intensities. The plate then points in different areas a different sensitivity when etching. The dividing line between the individual parts is also etched with, which simplifies subsequent separation. The mask to be applied contains recessed areas for the chambers and the bores at the same time. After the etching, fine grinding is carried out to the final dimension, when the thickness of the layer 30 reaches the bottom of the chamber becomes. The manufacture of the ink nozzles and the piezoelectric Elements, as well as the edge production, takes place to the above known way. In this variant is used to contact the bottom of the chamber. Subsequently the plate is divided into individual parts that then be assembled into a module.

In a further variant also or only the back the chamber surface with piezoelectric elements assembled and contacted. When contacting before it is advantageous to separate the middle parts can be provided with conductor tracks. Thereby can lead from the other layers too the upper layers of the module are cross-free, even if there are a lot of elements to contact. The Module parts are aligned and stapled together and annealed, with a phase transition of amorphous too crystalline. It is contemplated that spacers lie between the modules or additionally arranged are and that the spacers from the plate material or from one to the surface of the plate applied layer of piezoelectric material can be produced, structuring by etching he follows. A printhead can be assembled from several modules be or consists of only one module that follows has externally guided conductor tracks, which makes external contact become. The print head is finally in one Housing housed and can function be tested to remove faulty copies. In a further embodiment, there is Sheet material or part of the individual parts from one photosensitive ceramics. Glass parts and / or ceramic parts can also be glued together get connected.

The invention is not based on the present embodiment limited. Rather is a number of Variants conceivable, which of the solution shown even with fundamentally different types Make use.

Claims (21)

1. A method for the production of ink-jet print heads comprising at least one module, the module being formed of at least one part carrying chambers (2) and one further part (3), involving the following steps:

   parallel plate treatment of photosensitive glass plates for making through bores in all parts; wherein masks are prepared for the pre-treatment process of plate material to make it possible to selectively remove from the plate material areas for at least the ink chambers, nozzle channels and feeding channels, for the suction space and for through openings; wherein, during the pre-treatment process, the plates at least once are exposed, through masks, to radiation with UV light of an appropriate wavelength followed by heat treatment; wherein the areas to be removed are etched out of the plate in a parallel process;

   separation of individual parts from the glass plates and production of ink chambers in the component parts carrying chambers (2, 4), which includes a deep etching of the non-masked areas;

   connection of the component parts (2, 3 and 4) into at least one module followed by a heating-up process;

   application and contacting of the piezoelectric elements with applied strip conductors; as well as

   assembling into a print head.
2. A method according to claim 1, characterised in that, in the pre-treatment process of the plates, all areas to be removed are exposed to UV light having the same wavelengths and intensity; that, before etching out the photosensitised areas of the plate, a first mask is applied on the plate so that first areas are etched out of the plate; that, after etching out said first areas, the first mask is removed again and a second mask is applied on the plate in order to etch second areas out of the plate, that, after etching out said second areas, the second mask is removed again and that third areas are etched out of the plate.
3. A method according to claim 1, characterised in that, during the pre-treatment process, different masks are used for the plate material, certain areas of the plate being exposed more often or to a stronger radiation with UV light of appropriate wavelengths than other areas of the plate so that there are formed areas of the plate material that are differently sensitised to the etchant, that, in the process of parallel plate treatment, a mask for areas of different depths to be removed is applied on the plate and that there is used etchant having a certain concentration.
4. A method according to claim 1, characterised in that, etchants of different concentrations are used for the three areas to make it possible to remove the respective areas with different degrees of depths precision, wherein the depth precision for the etching of areas for through bores is lower than that for etching very flat areas for the channels in the parts carrying chambers; and that there are first etched the through bores, then the chambers and then the nozzle channels.
5. A method according to claims 1 to 4, characterised in that the thickness of the bottom layer (30) is being monitored during the etching of the chambers and that the thickness of the bottom layer (30) of the chambers that is required at the end of making the chambers is realised by means of fine-grinding each of the parts carrying chambers.
6. A method according to claim 5, characterised in that the parts carrying chambers are masked after the fine-grinding of the surface; that hollow spaces or/and ink chambers are created in the parts carrying chambers by means of deep etching of the non-masked areas; that, by fine-grinding to size of the one surface, the depth of the chambers, that by fine-grinding to size of the other surface, the exact thickness of the bottom layer (30) on the chamber base are exactly adjusted; that the mask for the deep etching is removed by the fine-grinding; and that the ink nozzles are etched subsequently.
7. A method according to claim 6, characterised in that, upon etching the ink nozzles, there is mainly removed photosensitised plate material or that a third mask is applied before the etching.
8. A method according to claims 1, 3, 5 and 7, characterised in that the hollow spaces, chambers and through bores are produced in parallel in one step after the areas to be removed have been differently photosensitised on the plate material, which results in different etching speeds; that the forming of the required depth of the hollow spaces and of the chambers and of the required thickness of the bottom layer (30) of the parts carrying chambers is followed by a separation into individual parts, that subsequently, the ink nozzles are etched into the parts carrying chambers.
9. A method according to claim 8, characterised in that during the parallel plate treatment process, there are also slightly etched the separating lines between the individual parts on the plate in order to facilitate a following separation.
10. A method according to one of the preceding claims, characterised in that, after the etching of the ink nozzles, at least separated plate parts, such as parts carrying chambers, intermediate parts, are assembled into one module, wherein the component parts, after being aligned, are stuck together; that the component parts stuck together are permanently connected to each other and finally a straight face edge is made by cutting off the nozzle points and a plane surface of the face edge is produced by means of fine-grinding; that there are applied a hydrophilic inside coating by rinsing the hollow spaces of the module with a first special liquid and a hydrophobic outside coating by treating the surface of the face edge with a second special liquid, said coatings being subsequently cured.
11. A method according to one of the preceding claims 1 to 10, characterised in that, after the production of nozzles and coating, the electric strip conductors and piezoelectric crystals are applied on the chamber bottom or/and on the outside surface of the bottom layer (30) and that a contacting is effected.
12. A method according to claim 11, characterised in that the piezoelectric crystals are glued on and the glued joint is cured.
13. A method according to claim 10, characterised in that the plate that the component parts are made of consists of amorphous photosensitive glass; that the permanent connection of the component parts to form a module is made by means of a heating-up process, the temperature being selected in such a manner to provide for a phase transition from amorphous to crystalline.
14. A method according to claim 11, characterised in that the strip conductors and/or a layer of piezoelectric material are applied by means of sputtering, that the piezoelectric layer is structured and contacted.
15. A method according to one of the preceding claims 1 to 14, characterised in that individual modules connected with each other with at least one distance piece are assembled into a ink-jet print head or a multi-piece module is used and that the ink-jet print head is fitted into a housing and electric connections are installed.
16. A method according to one of the preceding claims, characterised in that the distance pieces are made of plate material or of a layer of piezoelectric material applied on the surface of the plate, a structuring being made by means of etching.
17. A method according to one of the preceding claims, characterised in that the distance pieces are structured out of the plate material in the parallel plate treatment process prior to separation.
18. A method according to one of the preceding claims, characterised in that the nozzles are cleaned by means of compressed air after the completion of every module and/or after the completion of the print head.
19. A method according to one of the preceding claims, characterised in that, upon completion of the print head, its functioning is tested and that any defective items are separated.
20. A method according to claim 19, characterised in that, during or after the parallel plate treatment process, electric strip conductors are applied on the intermediate parts so as to achieve a crossing-free line arrangement.
21. A method according to one of the preceding claims 1 to 20, characterised in that the plate material consists of a photosensitive ceramic material and/or a second plate material consists of photosensitive amorphous glass, that at least one component part of a module is made of glass or ceramic material and that the component parts are connected by means of glued joint.

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