A kind of ink spray and manufacture method thereof
Technical field
The present invention relates to a kind of ink spray and manufacture method thereof.
Background technology
Existing shower nozzle is mainly divided into two kinds, one be by heating resistor as driving source make a return journey make shower nozzle spray ink droplet, another kind be utilize piezoelectric element as driving source to make shower nozzle spray ink droplet.
The shower nozzle utilizing piezoelectric element as actuator, ink to be sprayed, mainly contains following two types.Be that piezoelectric element is placed in and an outside of discharging the pressure generation chamber room that ink droplet respective nozzle is communicated with oscillating plate, by the distortion of piezoelectric element and oscillating plate, pressure generation chamber room volume changed, thus drops out from nozzles is sprayed.
Another kind of ink spray is by oscillating plate is arranged on pressure chamber inside, form cantilever beam or bridge type beam structure, by applying voltage to the piezoelectric element on cantilever beam or bridge type beam, cantilever or bridge type beam oscillating plate are vibrated, ink sprays from inkjet mouth because of the vibration of oscillating plate.This utilization in the patent of the shower nozzle of beam type oscillating plate such as Epson open application is in early days mentioned.But the manufacture method mentioned in these early stage patents utilizes adhesive technology that the various piece of shower nozzle is synthesized together, be difficult to the high-density arrangement realizing nozzle, as 600dpi, and manufacturing cost is higher.So MEMS (abbreviation of Micro-Electro-MechanicalSystems, is also microelectromechanical systems) one-body molded process technology can be passed through to improve the resolution ratio of shower nozzle and to reduce the cost.
In order to utilize MEMS integral molding techniques manufacture shower nozzle as shown in Figure 1, need to form a groove on a silicon substrate 1 to form ink feed chambers 21, so need in the fabrication process to fill groove, then form oscillating plate and piezoelectric element etc. filling on smooth surface.Owing to needing the high-temperature calcination technique of piezoelectric ceramics being carried out to 600 ° of C when forming piezoelectric element, so to have the capability of doing sth high temperature, requirement that thermal expansion factor is little to the filler being filled in groove.These fillers generally need to adopt the fillers such as the silica (BPSG) of porous silicon, amorphous silicon, polysilicon, silica, the silica (PSG) of Doping Phosphorus, Doping Phosphorus and boron, and dissolved organic matter that fusing point is not high can not be adopted as the filler of groove.
When adopting the filler such as silica (BPSG) of silica, the silica (PSG) of Doping Phosphorus, Doping Phosphorus and boron, vibration flaggy 42 can not adopt silica, because the silica of oscillating plate can be caused also to wash a part off when cleaning filler.At this moment need to adopt the material such as silicon nitride as oscillating plate, but little compared with silica of the elasticity of silicon nitride, cause the Oscillation Amplitude of oscillating plate to decline to a great extent, affect the ink-jet effect of shower nozzle, even can not spray ink droplet.
When the filler adopting porous silicon, amorphous silicon, polysilicon as groove; because silicon base and filler are all silicon materials; so need to protect silicon base when washing the filler of groove off at the inwall coating layer protecting film of groove, silicon base is not damaged.
When adopting the nozzle structure shown in Fig. 1 to carry out ink-jet, in order to improve print speed and print quality, can by improving the inking frequency of shower nozzle, this just needs the injection completing an ink droplet within the shorter time.So hydrophobic treatment can be carried out to the ink feed chambers 21 in Fig. 1, the ink in ink feed chambers 21 is made to flow in ink chamber 22 sooner, when again supplying ink to pressure chamber 2, ink is more easily gathered in ink chamber 22, thus the injecting time of contracting single ink droplet.
So the technical program proposes a kind of structure of piezoelectric type shower nozzle that MEMS integral molding techniques can be utilized to manufacture and the manufacture method of this structure, thus realize the high-resolution of shower nozzle and low manufacturing cost, high injection frequency.
Summary of the invention
The invention provides a kind of ink spray and manufacture method thereof, to solve the low technical problem of the low resolution of existing ink spray, high manufacturing cost and injection frequency.
In order to solve above technical problem, the technical scheme that the present invention takes is:
Concrete scheme is:
A kind of ink spray, comprising: silicon substrate, the oscillating plate being arranged on described silicon substrate top, the ink feed chambers formed with silicon substrate by described oscillating plate lower surface, the piezoelectric element being arranged on described oscillating plate surface, the nozzle that is arranged on described oscillating plate and the ink chamber on piezoelectric element, the through hole that described ink feed chambers is communicated with ink chamber and is communicated with described ink chamber; It is characterized in that: the inner wall surface of described ink feed chambers is also provided with protective layer, described protective layer is also provided with hydrophobic layer outward.
Described protective layer is metal oxide composition, and described hydrophobic layer is the monofilm be made up of phosphine base.
Described metal oxide is selected from TiO
2, Ta
2o
5, Nb
2o
5or ZrO
2.
Described oscillating plate and piezoelectric element one end are fixed.
Described oscillating plate and the another two ends of piezoelectric element are fixed.
A manufacture method for ink spray, comprises the following steps:
One, the recess of ink feed chambers is formed at silicon substrate;
Two, protective layer is formed at the recess of described ink feed chambers;
Three, fill at recess the filler that energy is high temperature resistant, thermal coefficient of expansion is little, recess is filled and led up.
Four, in the described recess surface filled and led up, oscillating plate and piezoelectric element is formed;
Five, ink chamber and nozzle is formed;
Six, remove filler and form hydrophobic layer on described protective layer.
Described protective layer is metal oxide composition, and described hydrophobic layer is the monofilm be made up of phosphine base.
Described metal oxide is selected from TiO
2, Ta
2o
5, Nb
2o
5or ZrO
2.
Described filler is selected from polysilicon, porous silicon or unformed silicon.
Ink spray provided by the invention is owing to being provided with protective layer and hydrophobic layer; and protective layer material is not while protection silicon base is destroyed; MEMS integral molding techniques can be utilized manufacture the resolution ratio, the reduction manufacturing cost that improve shower nozzle; the injection frequency of shower nozzle can be made to accelerate, improve print speed and print quality.Solve the technical problem that the low resolution of existing ink spray, high manufacturing cost and injection frequency are low.
Accompanying drawing explanation
The sectional view of the ink jet head that Fig. 1 does not improve.
Fig. 2 is the plan view of ink spray nozzle surface of the present invention.
Fig. 3 is the sectional view of ink jet head of the present invention along AC in Fig. 2.
Fig. 4 a be ink spray of the present invention under " drawing-push away-La " pattern during first time " drawing " bridge type beam away from the schematic diagram of nozzle variant.
Fig. 4 b be ink spray of the present invention under " drawing-push away-La " pattern time " pushing away " bridge type beam near the schematic diagram of nozzle variant.
Fig. 4 c is the ink spray of the present invention schematic diagram that during second time " drawing ", bridge type beam resiles under " drawing-push away-La " pattern.
It is the sectional view along DE direction in Fig. 2 in the step of the recess of the ink feed chambers forming shower nozzle of the present invention shown in Fig. 5 a.
It is the sectional view along AB direction in Fig. 2 in the step of the recess of the ink feed chambers forming shower nozzle of the present invention shown in Fig. 5 b.
It is the sectional view along DE direction in Fig. 2 in the step of the silicon dioxide layer of protection forming shower nozzle of the present invention shown in Fig. 6 a.
It is the sectional view along AB direction in Fig. 2 in the step of the silicon dioxide layer of protection forming shower nozzle of the present invention shown in Fig. 6 b.
It is the sectional view along DE direction in Fig. 2 in the step of the metal oxide protective layer forming shower nozzle of the present invention shown in Fig. 7 a.
It is the sectional view along AB direction in Fig. 2 in the step of the metal oxide protective layer forming shower nozzle of the present invention shown in Fig. 7 b.
It is the sectional view along DE direction in Fig. 2 when filling the recess of the ink feed chambers of shower nozzle of the present invention shown in Fig. 8 a.
It is the sectional view along AB direction in Fig. 2 when filling the recess of the ink feed chambers of shower nozzle of the present invention shown in Fig. 8 b.
Form the sectional view along DE direction in Fig. 2 in the vibration flaggy of shower nozzle of the present invention and the step of piezoelectric element shown in Fig. 9 a.
Form the sectional view along AB direction in Fig. 2 in the vibration flaggy of shower nozzle of the present invention and the step of piezoelectric element shown in Fig. 9 b.
It is the sectional view along DE direction in Fig. 2 in the step of the ink chamber's shape forming shower nozzle of the present invention shown in Figure 10 a.
It is the sectional view along AB direction in Fig. 2 in the step of the ink chamber's shape forming shower nozzle of the present invention shown in Figure 10 b.
It is the sectional view along DE direction in Fig. 2 in the step of the nozzle plate forming shower nozzle of the present invention shown in Figure 11 a.
It is the sectional view along AB direction in Fig. 2 in the step of the nozzle plate forming shower nozzle of the present invention shown in Figure 11 b.
It is the sectional view along DE direction in Fig. 2 in the step of the nozzle of the shower nozzle of the present invention of formation shown in Figure 12 a.
It is the sectional view along AB direction in Fig. 2 in the step of the nozzle forming shower nozzle of the present invention shown in Figure 12 b.
It is the sectional view along DE direction in Fig. 2 in the step of the public chamber of formation shower nozzle of the present invention, cleaning filler formation ink chamber, passage shown in Figure 13 a.
It is the sectional view along AB direction in Fig. 2 in the step of the public chamber of formation shower nozzle of the present invention, cleaning filler formation ink chamber, passage shown in Figure 13 b.
Form sectional view along DE direction in Fig. 2 in the step of the ink feed chambers of shower nozzle of the present invention by cleaning filler shown in Figure 14 a.
Form sectional view along AB direction in Fig. 2 in the step of the ink feed chambers of shower nozzle of the present invention by cleaning filler shown in Figure 14 b.
It is the sectional view along DE direction in Fig. 2 in the step of the hydrophobic layer forming shower nozzle of the present invention shown in Figure 15 a.
It is the sectional view along AB direction in Fig. 2 in the step of the hydrophobic layer forming shower nozzle of the present invention shown in Figure 15 b.
Label declaration: 1 silicon base; 2 pressure chamber, comprise ink feed chambers 21 and ink chamber 22; The SiO of 31 ink feed chambers
2layer; The metal oxide layer of 32 ink feed chambers; The hydrophobic layer of 33 ink feed chambers; 4 bridge type beams, comprise 42 oscillating plates and 41 piezoelectric elements; 5 nozzle plates, 51 nozzles; 6 public chambers; 7 passages; 23 silicon class fillers; 24 resinae fillers.
Detailed description of the invention
Patent content of the present invention will be described in detail below by embodiment:
Fig. 2 is the plan view of ink spray nozzle surface of the present invention, and nozzle is dislocation arrangement in the horizontal direction.Fig. 3 is the sectional view of ink jet head along AC in Fig. 2.As shown in Figure 3, ink spray comprises: silicon substrate 1, be arranged on silicon substrate 1 upper surface oscillating plate 42, be arranged on oscillating plate 42 surface piezoelectric element 41, be arranged on silicon substrate 1 surface for holding the pressure chamber 2 of ink fluid, through hole, public ink chamber 6, passage 7 and nozzle plate 5, it is nozzle 51 that nozzle plate 5 has some apertures; Pressure chamber 2 comprises the ink feed chambers 21 that formed by oscillating plate 42 lower surface and silicon substrate 1 and is arranged on oscillating plate 42 and with the ink chamber 22 on piezoelectric element 41, through hole, ink feed chambers 21 is communicated with ink chamber 22; nozzle 51 is communicated with ink chamber 22; the inner wall surface of ink feed chambers 21 is provided with protective layer 32, and protective layer 32 is outside equipped with hydrophobic layer 33.Piezoelectric element 41 connects voltage makes it be out of shape, and oscillating plate 42 produces vibration by the distortion of piezoelectric element and makes ink flow, public ink chamber 6, is responsible for each pressure chamber 2 ink delivery for storage ink by passage 7, ink droplet is sprayed by described nozzle, piezoelectric element 41 is by bottom electrode, piezoelectric ceramics, top electrode forms, oscillating plate 42 and piezoelectric element 41 are positioned at the inside of pressure chamber 2, and its two ends are fixed in silicon base 1, form two ends support beam and bridge type beam structure 4, can certainly be one end support beam and suspension beam structure, because ink feed chambers 21 is positioned at the below of bridge type beam, its inwall is by silicon dioxide layer 31, metal oxide protective layer 32 and hydrophobic layer 33 form, and the inwall of ink chamber 22 does not have hydrophobic treatment, so there is surface tension gradient in ink feed chambers 21 and ink chamber 22, in order to reduce surface energy as far as possible, ink droplet will spontaneously move from ink feed chambers 21 to ink chamber 22, namely when filling ink, ink preferential build is at place of ink chamber 22, thus shorten the filling time of ink, shorten the injection cycle of ink droplet, improve print frequency.And carried out hydrophobic treatment due to ink feed chambers 21, make the surface tension between ink and chamber wall compared with little when not carried out hydrophobic treatment to ink feed chambers 21, thus the damping of ink to bridge type beam in ink feed chambers 21 diminishes, the amplitude to ink feed chambers 21 inner movement of bridge type beam under equal voltage is comparatively large, can spray larger ink droplet.
Composition graphs 4 illustrates the ink-jet operation principle of shower nozzle under " drawing-push away-La " pattern: after piezoelectric element 41 receives voltage signal, the distortion of its moment is understood to the larger stress of oscillating plate 42, now, oscillating plate 42 can vibrate together with piezoelectric element 41, namely two ends support beam and bridge type beam 4 produce to ink feed chambers 21 inside mobile, and form " drawing " this process, at this moment the liquid level shape of the nozzle interior at nozzle plate place is recessed to ink chamber 22, formed " meniscus ", as shown in fig. 4 a.This first time " drawing " process, make bridge type beam to distortion away from nozzle, its distortion size be proportional to ejection drop size.Then apply with the contrary voltage signal of " drawing " pattern to piezoelectric element 41, the bridge type beam 4 that oscillating plate 42 meeting and piezoelectric element 41 form moves to nozzle place, ink in pressure ink water chamber 22 is extruded to nozzle place, and ink is discharged to outside nozzle plate, form " pushing away " this process as shown in Figure 4 b.When and then applying with voltage signal identical during first time " drawing " piezoelectric element 41, bridge type beam resiles, and ink, to chamber indoor moving, is broken the ink be squeezed in outside nozzle plate in Fig. 4 b, forms ink droplet, as illustrated in fig. 4 c.Ink droplet is ejected on print media due to effect of inertia, at this moment completes the injection of single ink droplet.
Manufacture method is:
One, the recess of ink feed chambers is formed at silicon substrate;
Two, metal oxide protective layer is formed at the recess of described ink feed chambers;
Three, fill at recess the filler that energy is high temperature resistant, thermal coefficient of expansion is little, filled and led up by recess, filler is selected from polysilicon, porous silicon or unformed silicon.
Four, in the recess surface filled and led up, oscillating plate and piezoelectric element is formed;
Five, ink chamber and nozzle is formed;
Six, remove filler and form hydrophobic layer on metal oxide protective layer, hydrophobic layer is the monofilm be made up of phosphine base, and metal oxide is selected from TiO
2, Ta
2o
5, Nb
2o
5or ZrO
2.
Concrete grammar is as shown in Fig. 5 a-Figure 15 b:
The sectional view along DE direction in Fig. 2 that the shower nozzle that Fig. 5 a-Figure 15 a shows the embodiment of the present invention is formed in each main manufacturing steps.
The sectional view along AB direction in Fig. 2 that the shower nozzle that Fig. 5 b-Figure 15 b shows the embodiment of the present invention is formed in each main manufacturing steps.
One, the recess of ink feed chambers is formed at silicon substrate, as shown in Fig. 5 a, Fig. 5 b:
1. in base silicon 1, formed the recess of ink feed chambers 21 by ion milling method, the degree of depth of recess is between 5-10 micron, and base silicon is monocrystalline silicon;
Two, metal oxide protective layer is formed, as shown in Fig. 6 a, Fig. 6 b, Fig. 7 a, Fig. 7 b at the recess of described ink feed chambers:
1. form silicon dioxide layer 31 at silicon substrate surface.Direct oxidation on a silicon substrate can be adopted to be formed or formed by physical vaporous deposition (PVD).The thickness of silica is about 100nm.
2. on silicon dioxide layer, form metal oxide protective layer 32, metal oxide can be TiO
2, Ta
2o
5, Nb
2o
5, ZrO
2deng.The thickness of metal oxide is about 12nm.
Three, fill at recess the filler that energy is high temperature resistant, thermal coefficient of expansion is little, recess filled and led up, as shown in Fig. 8 a, Fig. 8 b:
1. apply the recess of ink feed chambers 21 with packing material 23, and carry out chemically mechanical polishing (CMP) and make packing material planarized.Owing to needing the high-temperature calcination technique of piezoelectric ceramics being carried out to 600 ° of C when forming piezoelectric element in subsequent step, so to have the capability of doing sth high temperature, requirement that thermal coefficient of expansion is little to the filler being filled in recess place, so packing material can be polysilicon, porous silicon, unformed silicon etc.
Four, in the recess surface filled and led up, oscillating plate and piezoelectric element is formed, as shown in Fig. 9 a, Fig. 9 b:
1., at planarized packing material surface vibration plate 42, its component can be silica (SiO
2), thickness is about 1 μm, the methods such as physical vaporous deposition (PVD) formation or plasma enhanced chemical vapor deposition method (PECVD) can be passed through formed, its Main Function vibrates together with piezoelectric element as oscillating plate, squeeze pressure chamber 2, make shower nozzle spray ink, can prevent piezoelectric element from being corroded by ink as insulating barrier again.
2. the operation forming piezoelectric element 41 on oscillating plate 42 is followed successively by: form bottom electrode, piezoelectric ceramics and top electrode.Bottom electrode is formed by electron beam evaporation plating or sputtering method, and its material is by titanium (Ti) layer, and platinum (Pt) layer, iridium (Ir) layer laminate is formed or platinum (Pt), and iridium (Ir) individual layer is formed, and its thickness is about 50-100nm.Piezoelectric ceramics can pass through sol-gel process, pulsed laser deposition physical film deposition method (PLD) and hydro-thermal method etc.As piezoelectric ceramic material, preferably by with lead zirconate titanate [Pb (ZrTi) 0
3: PZT] for the material of main component is formed, the solid solution [Pb (Mg of lead magnesio-niobate and lead titanates also can be used in addition
l/3nb
2/3) 0
3-PbTi0
3: PMN-PT], the solid solution [PbZn of the plumbous and lead titanates of zinc niobate
1/3nb
2/3) O
3-PbTi0
3: PZN-PT] etc., also can use bismuth ferrite (BiFeO
3) etc. leadless piezoelectric material material.The thickness of piezoelectric ceramics is suitable with the thickness of oscillating plate, is about 1 μm.Top electrode is formed by electron beam evaporation plating or sputtering method, and its material is made up of individual layers such as platinum (Pt), iridium (Ir), gold (Au), and its thickness is about 50-100nm.Predetermined shape is formed to vibration flaggy and piezoelectric element pattern layers.
Five, ink chamber and nozzle is formed, as shown in Figure 10 a, Figure 10 b, Figure 11 a, Figure 11 b, Figure 12 a, Figure 12 b, Figure 13 a, Figure 13 b:
1. form layer 24 with the crosslinkable polymeric material of conventional spin coating method coating around bridge type beam 4, and make layer 24 upper surface smooth by chemically mechanical polishing (CMP); The crosslinkable polymeric material that this process uses is known Photoimageable macromolecular material, the epoxy resin of such as Photoimageable (such as conventional photoresist SU8 etc.), light sensitivity silicones or photosensitive epoxy siloxanes etc.Its thickness is about 20--70 μm, adopt mask and with conventional electromagnetic wave as UV photo-crosslinking exposure filler 24, if filler 24 is positive photo glue, then become negative photoresist after exposure, if filler 24 is negative photoresist, then become positive photo glue after exposure.
2. apply crosslinkable polymeric material with conventional spin coating method in the both sides of filler 24 and upper surface and form nozzle plate layer 5, and make nozzle plate layer 5 upper surface smooth by chemically mechanical polishing (CMP); The material of layer 5 is identical with the material of filler 24.Its thickness is 20-50 μm.
3. adopt the mask that can form nozzle 51 shape and select the little as far as possible electromagnetic wave of wavelength as exposure source, nozzle plate layer 5 is exposed.Its objective is and process the less and nozzle of inner wall smooth of size, wavelength can be selected short and the gamma-rays that penetration power is stronger is exposed source as the crosslinked of nozzle plate layer 5.And wash with developer solution the region 51 be exposed and form nozzle.The diameter of nozzle is about 10-25 μm, is highly the thickness 20-50 μm of nozzle plate 5.
4. first form public chamber 6 by back side wet etching or dry etching silicon base 1 and silicon dioxide layer 31, then washed the filler 24 be exposed by developer solution, form ink chamber 22 and passage 7.
Six, remove filler and on metal oxide protective layer, form hydrophobic layer, as shown in Figure 14 a, Figure 14 b, Figure 15 a, Figure 15 b:
1. wash filler 23 by cleaning fluid and form ink feed chambers 21, define the through hole of ink feed chambers and UNICOM of ink chamber simultaneously, release bridge type beam.When filler 23 is polysilicon, amorphous silicon, cleaning fluid can be TMAH (TMAH).But when no matter adopting which kind of filler and cleaning fluid, cleaning fluid can not react with the material of oscillating plate, in order to avoid cause the damage to oscillating plate.
2. form the hydrophobic film of one deck on the surface of metal oxide.As employing TiO
2, Ta
2o
5, Nb
2o
5, ZrO
2as the dodecyl phosphorus ammonium (ammoniumdodecylphosphate (CH passing through immersion 0.5 person of outstanding talent mole (mmol) concentration during diaphragm in ink feed chambers 21
3(CH
2)
11pO
4(NH
4)
2)) soak after 48 hours in solution or 1-isobutyl-3,5-dimethylhexylphosphoric acid (DDPO4) and hydroxydodecyl phosphoric acid (OH-DDPO4) mixed liquor and rinse with clear water, the surface of metal oxide can be made to form the monofilm of phosphine base, thus there is hydrophobicity (water droplet and surface contact angle reach 110 °).