JP5829658B2 - Ink jet head and manufacturing method thereof - Google Patents

Description

  Embodiments described herein relate generally to an inkjet head and a method for manufacturing the same.

  A conventional piezoelectric drive type ink jet head is a PZT (lead zirconate titanate) substrate having an electrode formed on the inner surface of a groove forming an ink flow path and a head drive unit driven by applying a voltage to the electrode. And a nozzle plate provided with nozzles at positions corresponding to the grooves. After forming an epoxy adhesive on the nozzle plate, the nozzle plate is pressed against the PZT substrate and the front surface of the plate covering the ink flow path with the nozzle of the nozzle plate aligned with the ink flow path. Have been attached.

  However, the adhesive poured into the upper portion of the piezoelectric element protrudes due to the pressure applied to the nozzle plate at the time of bonding, and reaches the nozzle along the back surface of the nozzle plate, thereby affecting printing.

JP 2004-122684 A

  The problem to be solved by the present invention is to provide an ink jet head capable of reliably attaching a nozzle plate and a method for manufacturing the same.

The inkjet head according to the embodiment includes a long laminated piezoelectric member disposed on the substrate in a state where the polarization directions are opposite to each other, and an ink flow path orthogonal to the longitudinal direction of the laminated piezoelectric member. A plurality of pressure chambers formed by grooves; an electrode formed in the pressure chamber; an electrodeposition film formed on the electrode; and a nozzle that discharges the ink. The nozzle is disposed on the laminated piezoelectric member. A nozzle plate attached with an adhesive corresponding to the pressure chamber; and a protective film covering the pressure chamber and the surface of the laminated piezoelectric member to which the nozzle plate is attached, and ejecting ink from the laminated piezoelectric member the edges of the electrodes located on the surface, the upstream portion Sheng by formed electrodeposition film on the edges are formed.

It is a perspective view which shows the inkjet head concerning 1st Embodiment. It is a perspective view which decomposes | disassembles and shows the principal part of an inkjet head. It is a front view of the principal part of FIG. 3 is a partially cutaway perspective view showing an enlarged main part. It is the Ia-Ib sectional view taken on the line of FIG. 5 is an enlarged cross-sectional view showing the main part. It is the IIa-IIb sectional view taken on the line of FIG. It is sectional drawing which expands and shows the inside of the broken-line circle | round | yen in FIG. It is explanatory drawing for demonstrating the inkjet head manufacturing method concerning 1st Embodiment. It is explanatory drawing for demonstrating the inkjet head manufacturing method concerning 1st Embodiment. It is explanatory drawing for demonstrating the inkjet head manufacturing method of the next process shown in FIG. It is a perspective view which shows the inkjet head concerning 2nd Embodiment. It is sectional drawing of FIG. 12 is a partially cutaway enlarged perspective view of the main part of FIG.

  Hereinafter, embodiments will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a perspective view showing an ink jet head according to the first embodiment. FIG. 2 is an exploded perspective view showing a main part of the inkjet head 100, and FIG. 3 is a front view of the main part of FIG.

  1 is a so-called side shooter type ink circulation type inkjet head. The ink jet head 100 includes an ink discharge unit 11, a pair of circuit modules 13, and a cover 12. The pair of circuit modules 13 are respectively attached to the ink ejection unit 11.

  The ink ejection unit 11 includes a manifold 21, a substrate 22, a frame member 23, and a nozzle plate 24. Further, the ink ejection unit 11 has an ink chamber 25 inside. The frame member 23 and the nozzle plate 24 are stacked on the substrate 22. The ink chamber 25 is surrounded by the substrate 22, the frame member 23, and the nozzle plate 24, and is supplied with printing ink.

As shown in FIG. 2, the manifold 21 has a pair of first surfaces 211, a pair of second surfaces 212, and a fitting portion 213. The pair of first surface 211 and second surface 212 are each formed flat. The second surface 212 is provided on the opposite side of the corresponding first surface 211. The flat fitting portion 213 is provided between the pair of first surfaces 211 and is recessed from the first surface 211 by the thickness of the substrate 22. The fitting portion 213, the substrate 22 is fitted, they are bonded in a state of closely wear.

  The substrate 22 has a plurality of ink supply ports 221 for supplying ink to the center in the longitudinal direction, and ink discharge ports 222 and 223 at left and right positions of the ink supply port 221 (see FIG. 3).

The nozzle plate 24 is formed of a rectangular film made of polyimide, for example. The nozzle plate 24 has a plurality of nozzles 241 arranged so as to be substantially parallel to the longitudinal direction. The nozzle plate 24, by an adhesive 71 to be described later (see FIG. 7), it is attached without a gap on the frame member 23 and the lamination pressure conductive members 32,. The nozzle plate 24 is disposed to face the substrate 22.

  As shown in FIG. 2, a pair of ink supply holes 26, a pair of ink discharge holes 27, and a pair of ink discharge holes 28 are formed in the fitting portion 213 of the manifold 21 in the longitudinal direction. An ink supply groove 29 is formed between the pair of ink supply holes 26. An ink discharge groove 30 is formed between the pair of ink discharge holes 27, and an ink discharge groove 31 is formed between the pair of ink discharge holes 28. The ink supply hole 26 is coupled to an ink supply path (not shown). The ink discharge grooves 30 and 31 are coupled to an ink discharge path (not shown).

  The ink supply port 221 and the ink supply groove 29 are formed at positions facing each other. Further, the ink discharge port 222 and the ink discharge groove 30 are formed at positions facing each other, and the ink discharge port 223 and the ink discharge groove 31 are formed at positions facing each other. That is, when the substrate 22 is joined to the fitting portion 213, the ink supply port 221 and the ink supply groove 29 are in communication with each other. The ink discharge port 222 and the discharge groove 30 are in communication, and the ink discharge port 223 and the ink discharge groove 31 are in communication.

  The ink supply path and the ink discharge path are combined with an ink tank to constitute a circulation type ink jet head.

  The board | substrate 22 is formed in the rectangle with plate-shaped ceramics, such as an alumina, for example. The substrate 22 has a flat surface 224. When the substrate 22 is fitted into the fitting portion 213 of the manifold 21, the surface 224 is formed in the same plane as the pair of first surfaces 211 of the manifold 21.

  FIG. 4 is a partially cutaway perspective view showing the main part of FIG. 3 in an enlarged manner. 5 is a cross-sectional view taken along line Ia-Ib in FIG.

  As shown in FIG. 4, a long pair of laminated piezoelectric members 32 and a plurality of wiring patterns 33 serving as a driving unit are attached to the surface 224 of the substrate 22. Each laminated piezoelectric member 32 is formed by bonding two piezoelectric plates 321, 322 made of, for example, PZT so that their polarization directions are opposite to each other (see FIG. 7).

  The laminated piezoelectric member 32 has a trapezoidal cross section and is attached to the surface 224 of the substrate 22, and extends parallel to each other in the longitudinal direction of the substrate 22. As shown in FIG. 5, one laminated piezoelectric member 32 is disposed between the ink supply port 221 and the ink discharge port 222. The other laminated piezoelectric member 32 is disposed between the ink supply port 221 and the ink discharge port 223.

  As shown in FIG. 6 in which the main part of FIG. 5 is enlarged, the laminated piezoelectric member 32 has a trapezoidal cross section to form a piezoelectric element oblique side 61. At this time, the surface of the lower substrate 22 of the piezoelectric element oblique side portion 61 is polished to form a concave smooth substrate polishing surface 62.

  A plurality of fine grooves extending in the direction (sub-scanning direction) intersecting the longitudinal direction (main scanning direction) are cut and formed on the laminated piezoelectric member 32 from the opposite surface side attached to the substrate 22. A plurality of elongated pressure chambers 34 arranged at equal intervals in the scanning direction are formed. For example, the width of the pressure chamber 34 is about 80 μm and the depth is about 300 μm.

  As shown in FIG. 7 showing a cross section taken along line IIa-IIb in FIG. 6, a plurality of pressure chambers 34 are formed in the laminated piezoelectric member 32, thereby dividing the pressure chambers 34 adjacent in the main scanning direction and driving. A side wall 35 to be an element is formed. The pressure chamber 34 and the side wall 35 are formed corresponding to the nozzle 241. That is, the pressure chambers 34 and the side walls 35 are formed at the same pitch as the nozzles 241.

  Further, an electrode 36 is provided on the surface of each side wall 35 of the laminated piezoelectric member 32 and the bottom of the pressure chamber 34 as shown in FIG. The electrode 36 is closely attached to the laminated piezoelectric member 32 in the pressure chamber 34. The electrode 36 is provided in close contact with the laminated piezoelectric member 32 in the pressure chamber 34. The electrode 36 is formed of, for example, a nickel thin film, but is not limited thereto, and may be formed of, for example, gold or copper. The thickness of the electrode 36 is, for example, 0.5 to 5 μm.

  The electrode 36 is electrically connected to the circuit module 13 (see FIG. 1) on which the driving IC 40 is mounted via the wiring pattern 33 formed on the piezoelectric element oblique side portion 61, the substrate polishing surface 62, and the substrate 22. It is connected to the connection part 37 for making a simple connection. Further, an electrodeposition film 38 having a film thickness of, for example, about 10 μm is formed on the electrode 36 by an electrodeposition method and heated. The electrodeposition film 38 is excellent in adhesion to the electrode 36 and insulation characteristics.

  Here, the edge 361 of the electrode 36 is formed up to the same surface as the ink ejection surface 323 of the laminated piezoelectric member 32 as shown in FIG. For this reason, the electrodeposition film 38 is also formed on the edge 361 of the electrode 36, and a swelled portion 381 that rises from the ink discharge surface 323 is formed. The electrode 36 has the same thickness at any position. The height of the raised portion 381 formed by electrodeposition on the edge 361 is formed substantially the same.

  In the inner region of the frame member 23, an organic protective film 39 is formed on the pressure chamber 34, the laminated piezoelectric member 32, the frame member 23, the electrodeposition film 38, and the substrate 22. The organic protective film 39 is cut outside the frame member 23 (see FIG. 6).

  The organic protective film 39 is insulative and is formed by, for example, a CVD (Chemical Vapor Deposition) method, and the thickness thereof is, for example, 3 to 10 μm. The organic protective film 39 is also formed as a protruding portion 391 on the rising portion 381 of the electrodeposition film 38.

  The electrode 36 is protected from the ink supplied to the pressure chamber 34 by the organic protective film 39. The organic protective film 39 is formed of, for example, a paraxylene polymer. The para-xylene polymer is excellent in uniform coverage. The organic protective film 39 protects the electrode 36 from corrosive components in the aqueous ink.

  Specific examples of the paraxylene-based polymer include parylene C (polychloroparaxylylene), parylene N (polyparaxylylene), and parylene D (polydichloroparaxylylene). The organic protective film 39 is not limited to this, and may be formed of other insulating materials such as polyimide.

  As described above, the nozzle plate 24 is attached by the adhesive 71 on the ink discharge surface 323 of the adhesive laminated piezoelectric member 32 and the organic protective film 39 on the frame member 23. The adhesive 71 is poured inside the protruding portion 391 to attach the nozzle plate 24. The protruding portion 391 prevents the adhesive 71 from reaching the nozzle 241 along the back surface of the nozzle plate 24. For this reason, it is possible to prevent the nozzle 241 from being blocked by the adhesive 71.

  As shown in FIG. 6, the connection portion 37 and the flexible circuit board 41 are connected by thermocompression bonding with an ACF (anisotropic conductive film) 63. The connecting portion 37 and the flexible circuit board 41 are not limited to the ACF 63 but may be connected by other means such as ACP (anisotropic conductive paste), NCF (non-conductive film), and NCP (non-conductive paste). good.

  The driving IC 40 applies a voltage to the electrode 36 via the wiring pattern 33 based on a signal input from a control unit (not shown) of the inkjet printer 100. When a voltage is applied via the electrode 36, the laminated piezoelectric member 32 is deformed, and the volume of the pressure chamber 34 is expanded or reduced. The ink pressurized by the reduction is ejected from the nozzle 241 corresponding to the pressure chamber 34.

  As described above, the electrodeposition film 38 is formed on the electrode 36 after patterning the electrode 36 and polishing the upper surface of the laminated piezoelectric member 32 (piezoelectric plate 321). The electrode 36 formed up to the ink discharge surface 323 that is the upper end of the side wall 35 of the pressure chamber 34 is covered with an electrodeposition film 38. The electrodeposition film 38 has a swelled portion 381 that extends to the ink ejection surface 323. The protruding portion 391 formed by the organic protective film 39 formed on the rising portion 381 can contribute to preventing the adhesive 71 from flowing out.

  In this embodiment, since the protruding portion 391 is formed, the adhesive 71 can be prevented from flowing into the nozzle 241 through the nozzle plate 24. Thereby, the ink discharged from the nozzle 241 can maintain a good printing state.

  (A)-(e) shown in FIG.10 and FIG.11 is explanatory drawing for demonstrating the manufacturing method along the procedure of FIG. The manufacturing method here will be described from the formation of the pressure chamber 34 and electrode patterning to the formation of the organic protective film 39 and the attachment of the nozzle plate 24.

  In FIG. 9, as shown in FIG. 10A, the electrode 36 is formed by plating or the like on the entire surface including the side wall 35 in the pressure chamber 34 formed on the laminated piezoelectric member 32 with, for example, a diamond wheel of a dicing saw for cutting an IC wafer. Form (step S1).

Next, the wiring pattern 33 is formed by a method such as a photolithography method or a laser patterning method. (Step S2)
Next, as shown in FIG. 10B, the electrode 36 formed on the ink ejection surface 323 of the laminated piezoelectric member 32 is polished, and the electrode 36 in this portion is removed (step S3).

  Next, as shown in FIG. 10C, an electrodeposition film 38 is formed on the electrode 36 by using an electrodeposition method (step S4). The electrodeposition film 38 is also formed as a raised portion 381 on the edge 361 of the electrode 36 that is on the same plane as the ink ejection surface 323. In the electrodeposition method, an electrodeposition film is formed by applying a voltage on the electrode 36 patterned in advance in an electrolytic solution.

  Next, after the electrodeposition film 38 is formed, heat treatment of the electrodeposition film 38 (not shown in FIG. 10) is performed (step S5).

  Next, as shown in FIG. 11 (d), the organic protective film covers the inside of the pressure chamber 34, the inner region of the frame member 23 including the ink discharge surface 323 of the laminated piezoelectric member 32, and a part of the connection portion 37. 39 is formed (step S6) (see FIG. 6). At this time, the organic protective film 39 on the rising portion 381 is formed as the protruding portion 391.

  Finally, the adhesive 71 is poured inside the protruding portion 391, and the nozzle plate 24 is attached with the adhesive 71 while maintaining the level with the substrate 22 (step S7).

  Through the above steps S1 to S7, the production from the formation of the pressure chamber 34 and the electrode patterning to the formation of the organic protective film 39 and the attachment of the nozzle plate 24 can be realized.

  The ink jet head manufactured by this method is in a state where the adhesive 71 is partitioned by the protruding portion 391. The adhesive 71 can prevent the nozzle plate 24 from sticking out to the nozzle 241 after the nozzle plate 24 is bonded, and the nozzle plate 24 can be satisfactorily attached.

(Second Embodiment)
FIG. 12 is a perspective view showing an ink jet head according to the second embodiment. 13 is a cross-sectional view of FIG. 14 is a partially enlarged perspective view of the main part of FIG.

  Reference numeral 200 shown in FIG. 12 denotes a so-called end shooter type non-circulating ink jet head. Parts having the same functions as those of the inkjet 100 according to the first embodiment will be described using the same reference numerals.

  The ink-jet head 200 includes a laminated piezoelectric member 32, a lid member 101, a top plate frame 102, and a nozzle plate 24, and has an approximately rectangular shape in appearance.

  The laminated piezoelectric member 32 is formed by, for example, bonding two rectangular piezoelectric plates 321 and 322 made of PZT up and down so that their polarization directions are opposite to each other. On the side surface of the laminated piezoelectric member 32, a nozzle plate 24 is attached at a position straddling the piezoelectric plate 321 and the piezoelectric plate 322 serving as an ink ejection surface 324 from which ink is ejected. A top plate frame 102 is attached to an ink supply surface 325 to which ink is supplied on the upper surface of the laminated piezoelectric member 32, and a lid member 101 is attached to the top plate frame 102. A plurality of pressure chambers 34 are formed in the laminated piezoelectric member 32.

  The pressure chamber 34 is formed by a groove that is opened on the lid member 101 side and the nozzle plate 24 side, and serves as an ink flow path. The pressure chamber 34 is closed by the lid member 101, the top plate frame 102, and the nozzle plate 24. The plurality of pressure chambers 34 correspond to the plurality of nozzles 241 of the nozzle plate 24 and are provided side by side in the longitudinal direction of the laminated piezoelectric member 32.

  Electrodes 36 are respectively formed throughout the plurality of pressure chambers 34. When a voltage is applied to the electrode 36, the laminated piezoelectric member 32 is deformed, and the volume of the pressure chamber 34 is expanded or reduced. A plurality of wiring patterns 33 are provided on the piezoelectric plate 321 of the laminated piezoelectric member 32. The electrode 36 is electrically connected to the connection portion 37 formed on the upper surface of the rear end portion 326 of the piezoelectric plate 321 through the wiring pattern 33. The connecting portion 37 is electrically connected to a circuit module (not shown) on which an IC or the like for driving the laminated piezoelectric member 32 is mounted.

  The lid member 101 has an ink supply hole 26 for supplying ink supplied from an ink supply path (not shown). The ink supply holes 26 open to the plurality of pressure chambers 34 and are connected to an ink tank (not shown). The ink in the ink tank is supplied to the pressure chamber 34 through the ink supply hole 26.

  The electrode 36 is formed to be in close contact with the entire pressure chamber 34 with a thickness of about 0.5 to 5 μm. As shown in FIG. 13, the edge 361 of the electrode 36 facing the nozzle plate 24 is formed up to the ink ejection surface 324. The edge 362 of the electrode 36 facing the top plate frame 102 is formed up to the ink supply surface 325.

  An electrodeposited film 38 is formed on the electrode 36 through an electrodeposition method and a heating process. At this time, the electrodeposition film 38 is formed on the edge 361 as a raised portion 381 protruding from the ink discharge surface 324, and on the edge 362 as a raised portion 382 protruding from the ink supply surface 325.

  An organic protective film 39 is formed on the electrodeposition film 38. As shown in FIGS. 13 and 14, the organic protective film 39 on the raised portions 381 and 382 is formed as protruding portions 391 and 392. A protrusion 391 is formed on the ink ejection surface 324 to which the nozzle plate 24 is attached, and a protrusion 392 is formed on the ink supply surface 325 to which the top plate frame 102 is attached. As shown in FIG. 14, the opening portion of each pressure chamber 34 is surrounded by the protruding portions 391 and 392.

  The organic protective film 39 is cut outside the top plate frame 102. The electrodeposition film 38 is excellent in adhesion and insulating properties. The organic protective film 39 protects the electrode 36 from corrosive components in the aqueous ink. The organic protective film 39 is insulative and has a thickness of 3 to 10 μm, for example. The organic protective film 39 is formed of, for example, a paraxylene polymer. The para-xylene polymer is excellent in uniform coverage.

  The nozzle plate 24 is attached by an adhesive 71 poured into the organic protective film 39 on the ink discharge surface 324. Further, it is attached by an adhesive 71 poured into the organic protective film 39 on the ink supply surface 325. At this time, the protrusions 391 and 192 can prevent the adhesive 71 from flowing into the pressure chamber 34, and can prevent the adhesive 71 from flowing into the nozzle 241 through the nozzle plate 24.

  In this embodiment, since the protrusion 391 is formed, the adhesive 71 can be prevented from flowing into the nozzle 241 through the nozzle plate 24. Thereby, the ink discharged from the nozzle 241 can obtain a good printing state.

  Below, with reference to FIGS. 12-14, the manufacturing method of the inkjet head 200 is demonstrated. In this manufacturing method, the steps from the formation of the pressure chamber 34 and the electrode patterning to the formation of the organic protective film 39 and the attachment of the nozzle plate 24 will be described.

  First, for example, the electrode 36 is formed by plating or the like on the entire surface including the side walls 35 in the plurality of pressure chambers 34 formed on the laminated piezoelectric member 32 by a diamond wheel of a dicing saw.

  Next, the electrode 36 formed on the ink discharge surface 324 of the multilayer piezoelectric member 32 is polished, and the electrode 36 in this portion is removed.

  Next, the wiring pattern 33 is formed by a method such as a photolithography method or a laser patterning method.

  Next, an electrodeposition film 38 is formed on the electrode 36 by using an electrodeposition method. The electrodeposition film 38 is also formed as a raised portion 381 on the edge 361 of the electrode 36 that is on the same plane as the ink ejection surface 323. After the electrodeposition film 38 is formed, heat treatment of the electrodeposition film 38 is performed.

  Next, an organic protective film 39 is formed so as to cover the pressure chamber 34, the ink discharge surface 323 of the laminated piezoelectric member 32, and a part of the connection portion 37. At this time, the organic protective film 39 on the rising portion 381 is formed as the protruding portion 391.

  Finally, the adhesive 71 is poured inside the protruding portion 391, and the nozzle plate 24 is attached with the adhesive 71 while maintaining the level with the substrate 22.

  Through the above steps, it is possible to realize the production from the formation of the pressure chamber 34 and the electrode patterning to the formation of the organic protective film 39 and the attachment of the nozzle plate 24.

  The ink jet head manufactured by this method is in a state where the adhesive 71 is partitioned by the protruding portion 391. The adhesive 71 can prevent the nozzle plate 24 from sticking out to the nozzle 241 after the nozzle plate 24 is bonded, and the nozzle plate 24 can be satisfactorily attached.

  It is not limited to the above-described embodiments. For example, the ink jet system may be an ink jet head of another system that ejects ink using bubbles.

  The ink jet head according to the first embodiment is a circulation side shooter type, but may be a non-circulation end shooter type. The inkjet head of the second embodiment is a non-circulating end shooter type, but may be a circulating side shooter type.

  Although several embodiments have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, combinations, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

100, 200 Inkjet head 23 Frame member 24 Nozzle plate 32 Multilayer piezoelectric member 34 Pressure chamber 36 Electrode 38 Electrodeposition film

Claims (5)

A long laminated piezoelectric member disposed on the substrate in a state where the polarization directions are opposite to each other;
A plurality of pressure chambers by grooves serving as ink flow paths orthogonal to the longitudinal direction of the laminated piezoelectric member;
An electrode formed in the pressure chamber;
An electrodeposition film formed on the electrode;
A nozzle plate that includes a nozzle that ejects the ink, and is attached to the laminated piezoelectric member with an adhesive so that the nozzle corresponds to the pressure chamber;
A protective film covering the pressure chamber, the laminated piezoelectric member surface to which the nozzle plate is attached,
The laminate to the edge of the electrode located on the ink ejection surface of the piezoelectric member, the upstream portion Sheng by formed electrodeposition film on the edges are formed, the ink jet head. The lower surface is attached to the substrate, and further includes a frame member that surrounds the laminated piezoelectric member and holds ink inside.
Said nozzle plate, said frame member, said that the nozzles are attached with adhesive so as to correspond to the pressure chamber, according to claim 1 ink jet head according. The inkjet head according to claim 1, wherein the protective film is also formed on a raised portion formed by the electrodeposition film. The pressure chamber is formed on the electrode so that pressure can be maintained by the nozzle plate attached to the laminated piezoelectric member on the ink discharge surface and the top plate frame attached to the laminated piezoelectric member on the ink supply surface. The inkjet head according to claim 2, wherein a swelled portion that rises from the ink ejection surface is formed on the electrodeposition film . A long laminated piezoelectric member bonded with the polarization directions opposite to each other, a pressure chamber formed by processing the laminated piezoelectric member to form an ink flow path, and a pressure chamber formed in the pressure chamber. A method of manufacturing an ink jet head comprising: an electrode; and a nozzle plate on which a nozzle is formed,
Polishing the electrode formed on the ink ejection surface of the laminated piezoelectric member and removing the electrode on the ink ejection surface;
Forming on the electrode using an electrodeposition method, a part of which forms an electrodeposition film having a raised portion from the ink discharge surface, and heating the electrodeposition film;
Forming a protective film so as to cover the pressure chamber and the ink discharge surface of the multilayer piezoelectric member;
A method of manufacturing an ink jet head, comprising: attaching the nozzle plate and the protective film on the ink discharge surface with an adhesive.

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