JP4511373B2 - Electronic component storage package and electronic device - Google Patents

Description

  The present invention relates to an electronic component storage package for storing an electronic component and an electronic apparatus.

  The conventional method of laminating ceramic green sheets (hereinafter also simply referred to as green sheets) is a basic method in which a metal paste is screen-printed on a green sheet, then the ceramic green sheets are laminated in a predetermined order, cut, and fired. FIGS. 4A and 4B show an electronic component storage package (hereinafter also simply referred to as a package) A manufactured through the steps. As shown in FIG. 2A, the package A has a mounting portion 1a on which an electronic component is mounted on the upper surface, and is provided on inner and outer surfaces of the side wall 12 attached so as to surround the mounting portion 1a. A ceramic base 11 in which an inner surface notch C-1 and an outer surface notch C-2 facing each other across the side wall 2 are formed, and an inner surface side notch C of the side wall 2 is formed on the surface of the base 11. -1 and the metallized layer 14 extending directly under the side wall 2 to the outer surface side cutout C-2, and brazed to the metallized layer 14 by the brazing material 15 outside the side wall 2. And a lead terminal 16 made of an iron (Fe) -nickel (Ni) -cobalt (Co) alloy or the like whose other end is joined to an external electric circuit.

  In general, the lead terminals 16 are brazed by placing the package A in a recess formed in a carbon jig, and, as shown in FIG. 5, a plurality of lead terminals 16 protruding from the inside of the lead frame. One end is placed on the outer metallization layer 14a via a preform F such as silver solder, and the preform F is applied to the outer metallization layer 14a from above the lead terminals 16 in a reducing atmosphere brazing furnace. It is performed by heating at ~ 900 ° C.

  Since the brazing material 15 has a low Young's modulus, the brazing material 15 also has a function of relieving thermal stress generated between the lead terminal 16 and the metallized layer 14 a outside the side wall 2. Cracks are prevented from starting from the portion of the substrate 1 that is in contact with the outer periphery of the outer metallized layer 14a.

  However, in the conventional brazing structure of the lead terminal 16 of the package A, as shown in FIG. 4B, the gap between the lead terminal 16 and the outer metallized layer 14a is originally greater than the thickness of the Ag braze preform. In other words, when the Ag brazing melts, the gap is further reduced, so that the thickness of the brazing material 15 existing in the gap is reduced. Therefore, the meniscus of the brazing material 15 contributing to the bonding strength of the lead terminal 16 is reduced. As a result, the brazing strength of the lead terminal 16 was reduced.

  In order to solve this problem, as shown in FIG. 6A, a metallization layer D having an outer shape slightly smaller than the outer metallization layer 14a is formed on the outer metallization layer 14a. Thus, a method has been proposed in which a large meniscus 15a is formed around the lead terminal 16 to be joined to the outer metallized layer 14a, whereby the joining strength of the lead terminal 16 can be increased (for example, Patent Document 1). reference).

  As another configuration, as shown in FIG. 6B, an extended portion E is formed by extending the outer metallized layer 14a from the shelf portion 13a to the side portion 13b, whereby the brazing material 15 extends. There has also been proposed a method in which a large meniscus 15a is formed so as to flow to the protruding portion E, and the stress concentration is dispersed by the meniscus 15a to increase the bonding strength of the lead terminals (for example, see Patent Document 2).

As another configuration, as shown in FIG. 7, a method is disclosed in which the protruding conductors 14c are arranged in a matrix on the outer metallized layer 14a and the lead terminals 16 are brazed. According to this method, the thickness of the brazing material 15 can be made constant and a large meniscus 15a can be formed, so that the bonding strength of the lead terminal 16 can be increased (see, for example, Patent Document 3).
JP-A-9-139439 (page 3-4, FIG. 1) JP-A-61-29547 (page 3-4, Fig. 1) JP 2004-235263 A (Page 5-8, FIG. 2)

  However, in the conventional method of Patent Document 1, even if the meniscus 15a around the lead terminal 16 can be increased by the thickness of the metallized layer D, the lower surface of the lead terminal 16 and the upper surface of the metallized layer D are The thickness of the brazing material 15 cannot be increased, and as a result, when a thermal stress is applied between the lead terminal 16 and the outer metallized layer 14a, the stress relaxation effect of the brazing material 15 works sufficiently. In other words, the lead terminal 16 may be easily peeled off.

  Moreover, in the method of Patent Document 2, it is necessary to print and form the metal paste to be the extended portion E also on the side portion 13b. As a method therefor, there is a method of forming the metal paste so as to sag from the shelf portion 13a to the side portion 13b when the metal paste to be the outer metallized layer 14a is screen-printed. However, if the amount of sagging of the metal paste increases and the metal paste reaches the lower surface of the green sheet, it may be electrically connected to a ground conductor (not shown) formed on the lower surface of the package A. Therefore, it is necessary to control the amount of sagging. However, this control is extremely difficult, and as a result, there is a problem that the manufacturing yield is remarkably lowered and the productivity is lowered.

  Further, as a method of forming the extending portion E with a predetermined vertical length on the side portion 13b, another appropriate thickness green sheet is provided below the appropriate thickness green sheet provided with the outer metallized layer 14a. There is a method in which one layer is added and the side portion 13b is formed of an insulating layer composed of two layers, and the extending portion E is formed by dropping the metal paste only on the upper layer as described above. However, this method increases the number of processes, and when the metal paste wraps around the lower surface of the green sheet, delamination (delamination between the green sheets) is likely to occur between the two insulating layers. As a result, there is a problem that the lead terminal 16 is peeled off together with the upper insulating layer constituting the shelf portion 13a.

  Further, the method disclosed in Patent Document 3 is provided with a plurality of protruding conductors 14c on the outer metallized layer 14a as shown in FIG. 7, thereby making the thickness of the brazing material 15 a predetermined size, and By increasing the surface area of the projecting conductor 14c by increasing the surface area of the outer metallized layer 14a, it is possible to prevent peeling between the brazing material 15 and the metallized layer 14a.

  However, in the method disclosed in Patent Document 3, the bonding strength of the lead terminals 16 is higher than when the protruding conductors 14c are not formed. However, since the protruding conductors 14c are aligned in the vertical and horizontal directions. It has been found that when one end of the lead terminal 16 begins to peel off, it is difficult to stop it.

  Accordingly, the present invention has been completed in view of the above problems, and its purpose is to provide an electronic device that can operate normally and stably over a long period of time by connecting the lead terminal to the outer metallization layer firmly and reliably. A component storage package and an electronic device are provided.

The electronic component storage package of the present invention has a mounting portion on which the electronic component is mounted on the bottom surface of the recess formed on the upper surface, and faces each other with the side wall sandwiched between the inner and outer surfaces of the side wall surrounding the recess. A ceramic base having two cutouts formed thereon, and the formation of the outer cutout formed on the surface and inside of the base and passing from the inner cutout formation region of the side wall directly below the side wall In an electronic component storage package comprising a metallized layer led out to a region and a metal lead terminal brazed to the metallized layer outside the side wall, a matrix is formed on the surface of the metallized layer outside the side wall. A plurality of projecting conductors arranged in a shape are formed, and the projecting conductors of the other row are located between the projecting conductors of one row of the two adjacent projecting conductors. Together are arranged in sea urchin staggered, the protrusion conductor is an electronic component storing the row of outer end of the side wall of the metallized layer, characterized in that it is formed in contact with the edge of the metallized layer For package.

  Further, an electronic device of the present invention includes the electronic component storage package of the present invention, an electronic component that is placed and fixed on the mounting portion and electrically connected to the metallized layer inside the side wall, And a lid joined to cover the mounting portion on the upper surface of the side wall of the base.

  The electronic component storage case of the present invention has a mounting portion on which the electronic component is mounted on the bottom surface of the recess formed on the upper surface, and faces each other with the side wall sandwiched between the inner and outer surfaces of the side wall surrounding the recess. A ceramic base with two cutouts, and formed on the surface and inside of the base, and is led out from the inner surface side notch formation region to the outer surface side notch formation region directly under the side wall. The metallized layer and metal lead terminals brazed to the metallized layer outside the side wall are formed, and a plurality of protruding conductors arranged in a matrix form on the surface of the metallized layer outside the side wall. The plurality of protruding conductors are arranged in a staggered manner so that the protruding conductors in the other row are positioned between the protruding conductors in one row of the adjacent two rows of protruding conductors. Force in the direction of peeling the terminal Also use, force is dispersed in an oblique direction, brazing the lead terminal becomes difficult peeled from one after the other substrate. Therefore, the bonding strength of the lead terminals is increased, and an input / output unit with high bonding reliability can be provided.

  In addition, the bonding strength of the lead terminal can be increased because the bonding area is increased by the protruding conductor.

  Further, in the electronic component storage package of the present invention, preferably, the protruding conductor row is formed so that the outer end row of the side wall of the metallized layer is in contact with the edge of the metallized layer. It is possible to increase the bonding area at the edge of the metallized layer, thereby increasing the bonding strength of the edge of the metallized layer against peeling and making it difficult for the lead terminal to peel off.

  The electronic device of the present invention includes an electronic component storage package of the present invention, an electronic component that is mounted and fixed on the mounting portion and is electrically connected to the metallization layer on the inner side of the side wall, and the upper surface of the side wall of the substrate. Since the electronic component storage package of the present invention is used, the lead terminal has a high bonding strength and has an external device over a long period of time. It is highly reliable and can be connected stably and firmly.

  The electronic component storage package and electronic device of the present invention will be described in detail below. 1A is a plan view showing an example of an embodiment of a package of the present invention, FIG. 1B is a sectional view thereof, FIG. 2 is a sectional view of an electronic device of the present invention, and FIG. , (B) are a partially enlarged plan view and a partially enlarged sectional view of the package of FIG.

  In these drawings, reference numeral 1 denotes a base body having a mounting portion 1a on which an electronic component 7 is placed on the bottom surface of a recess formed on the upper surface, 2 a side wall surrounding the recess of the base body 3, and 3 an inner and outer surface of the side wall 2 The input / output unit 4 is provided at the lower part of the side wall 2 where the side wall 2 is partially thinned by two notches C-1 and C-2 whose bottom surfaces are opposed to each other with the side wall 2 interposed therebetween. The metallization derived from the formation region of the inner surface side notch C-1 of the side wall 2 of the input / output unit 3 to the formation region of the outer surface side notch C-2 directly under the side wall 2 or through the inside of the side wall 2. 4a is a metallized layer outside the side wall 2 of the metallized layer 4, 4b is a metallized layer inside the side wall 2 of the metallized layer 4, 4c is a plurality of protrusions arranged in a matrix on the surface of the outer metallized layer 4a Conductor, 5 is brazing material, 5a is meniscus of brazing material 5 Scan, 6 is the metal lead terminal that is brazed to the outer metallized layer 4a. 7 is an electronic component, 8 is a lid, and B is a package of the present invention.

  The base body 1 including the side wall 2 and the mounting portion 1a, the metallized layer 4 in which the protruding conductor 4c is formed on the outer metallized layer 4a, and the outer metallized layer 4a are brazed via the brazing material 5 The package B for accommodating the electronic component 7 with the lead terminals 6 is basically constituted, and the electronic component 7 placed and fixed on the placement portion 1a and electrically connected to the inner metallized layer 4b, and the side wall 2 The electronic device C is basically composed of the lid body 8 joined so as to cover the placement portion 1a on the upper surface of the electronic device C.

  The substrate 1 of the package B of the present invention is made of a ceramic such as an alumina sintered body (alumina ceramic). Since the substrate 1 is made of ceramics, the substrate 1 is much lighter than metal. When the electronic component 7 is accommodated in the package B to form the electronic device C, the weight of the electronic device C is extremely light. It can be.

The substrate 1 is manufactured as follows. When the substrate 1 is made of, for example, alumina ceramics, a suitable organic binder, organic solvent, or raw material powder such as aluminum oxide (Al ₂ O ₃ ), silicon oxide (SiO ₂ ), magnesium oxide (MgO), calcium oxide (CaO), A plasticizer is added and mixed to form a slurry. This slurry is formed into a green sheet by a doctor blade method, a calendar roll method, or the like, and then cut into a desired size.

  Next, through holes and notches that form the side walls 2 and the input / output portions 3 are formed in appropriate portions of a plurality of green sheets selected from them by an appropriate punching process, and the metallized layer 4 and the lid 8 are joined. In order to form a metal layer (not shown), a metal paste mainly composed of a metal powder such as tungsten (W) is printed on a predetermined position by screen printing, and then a plurality of green sheets are formed. It is produced by sequentially laminating and firing at a temperature of about 1600 ° C.

  Preferably, on the surface of the conductive portion formed of the outer metallized layer 4a, the inner metallized layer 4b, and the metal layer for joining the lid 8 formed on the manufactured base body 1, it is excellent in corrosion resistance and has a brazing material 5 and It is preferable to sequentially deposit a metal having excellent wettability, specifically, a Ni layer having a thickness of 0.5 to 9 μm and an Au layer having a thickness of 0.5 to 9 μm by a plating method. These plated layers prevent oxidative corrosion of the conductive portion and make the outer metallized layer 4 a and the lead terminal 6 more firmly joined by a brazing material 5 such as silver brazing.

  The side wall 2 is provided around the mounting portion 1 a so as to surround the concave portion of the base body 1, and a metallized layer 4 provided in the side wall 2 so as to penetrate the inside and outside of the package B is formed in the input / output unit 3. Yes. Further, the lead terminal 6 is joined to the outer metallized layer 4 a via the brazing material 5. A metal seal ring (not shown) for joining the lid body 8 may be attached to the upper surface of the side wall 2. In this case, a seal is applied to the metal layer for joining the lid body 8. The ring is joined with brazing material or the like.

  As shown in FIG. 1, the metallization layer 4 is provided in an input / output unit 3 for inputting / outputting an electric signal provided in the lower part of the side wall 2 into / out of the package B, and is a signal line for conducting the inside / outside of the side wall 2 It becomes. Further, the inner surface side notch C-1 and the outer surface side notch C-2 are formed in a vertical groove shape in order to make a part of the inner and outer surfaces of the side wall 2 thinner.

  The lead terminal 6 is made of a rod-shaped metal such as an Fe—Ni alloy, an Fe—Ni—Co alloy, or Cu, and is opposite to cutting a metal plate into a predetermined dimension or joining to the metallized layer 4 of the lead terminal 6. It is manufactured by punching into a lead frame shape in which the end on the side is connected to the frame. The individual lead terminals 6 cut from the lead frame are electrically connected to an external electric circuit device (not shown) at the end opposite to that joined to the metallized layer 4 to form a package. B has a function of supplying an electric signal to an electronic component 7 such as a semiconductor laser (LD), a photodiode (PD), a signal amplifying semiconductor element, a piezoelectric element, and the like, which are mounted and fixed on the mounting portion 1a inside B.

  In the package B of the present invention, as shown in FIG. 3, one of the two rows of protruding conductors 4c adjacent to the surface of the metallized layer 4a outside the lower end of the outer surface side notch C-2 of the side wall 2 is provided. A plurality of protruding conductors 4c, which are arranged in a staggered manner so that the protruding conductors 4c in the other row are positioned between the protruding conductors 4c and support the lead terminals 6 at the upper ends, are formed in a matrix. Yes. Thereby, the lead terminal 6 is horizontally supported and brazed by an external carbon jig (not shown) used in brazing and the plurality of protruding conductors 4c, and the lead terminal 6 and the metallized layer 4a are brazed. Since a certain distance can be provided between the surface and the surface, the meniscus 5a of the large brazing material 5 can be formed between the outer metallized layer 4a and the periphery of the lead terminal 6, and the lead terminal 6 and the surface of the outer metallized layer 4a, the thickness of the brazing material 5 can be made uniform throughout, and the surface area of the outer metallized layer 4a can be increased. As a result, the brazing material The stress buffering effect by 5 can be obtained, and a strong joint structure can be realized.

  Since the protruding conductors 4c are arranged in a staggered manner, a force is applied in such a direction as to lift the side where the lead terminals 6 are not joined, and a force that peels the lead terminals 6 from the metallized layer 4a acts. However, since the thick portion of the brazing material 5 is continuously arranged in the oblique direction with respect to the longitudinal direction of the lead terminal 6 by the staggered arrangement, the force is dispersed in the oblique direction, and the brazing of the lead terminal 6 is continuously performed. Therefore, it becomes difficult to peel off from the substrate 1 and the bonding strength is increased. The distance between the adjacent rows of the protruding conductors 4c may be changed without being constant, and this also changes the angle of dispersion of the force in an oblique direction, so that the staggered arrangement in which the lead terminals 6 are twisted is changed. Even if a force matching the direction is applied, the bonding strength can be maintained.

The height of the protruding conductor 4c is preferably 10 to 30 μm. When the thickness is less than 10 μm, the size of the meniscus 5a is reduced, the bonding strength of the lead terminal 6 is reduced, and the stress relaxation effect of the brazing material 5 is almost lost. When the thickness exceeds 30 μm, the relaxation effect of thermal stress can be increased. However, since the thermal expansion coefficient of the brazing material 5 is as large as about 20 × 10 ⁻⁶ / ° C. at room temperature, the brazing material is activated when the electronic component 7 is operated. 5 and a substrate 1 made of ceramics such as alumina ceramics (thermal expansion coefficient: 7 × 10 ^{−6 to} 9 × 10 ⁻⁶ / ° C.) are generated, and as a result, microcracks are formed in the substrate 1. It tends to occur.

  Moreover, the planar view shape of the protrusion conductor 4c should just be a rectangle whose one side is 75-300 micrometers, and the increase rate of a joining area can be enlarged at this time, and the joining strength of the brazing material 5 can be enlarged. On the other hand, when the circular shape has a diameter of 75 to 300 μm or the elliptical shape has a major axis of 75 to 300 μm, the metal paste is prevented from coming off from the stainless mesh, and the printability is good. That is, when the shape of the protruding conductor 4c is a circle, an ellipse, an oval combined with a rectangle, or an oval, the bonding strength is slightly deteriorated, but good printability is obtained, and thus the protruding conductor 4c is obtained. It is possible to align the heights. Accordingly, a shape in which the shape in plan view is rectangular and the four corners are curved is also preferable.

  For screen printing, for example, a photosensitive emulsion for sealing is applied to a stainless mesh plate opened in a mesh shape, masked into a required pattern and irradiated with ultraviolet rays, thereby curing the photosensitive emulsion, A portion in which an opening pattern is formed in a required portion of a stainless mesh plate is used by dissolving a portion that has not been irradiated with ultraviolet rays by masking. Then, by supplying a metal paste to the upper surface of the stainless mesh plate and moving the squeegee, the metal paste is pushed out from the opening pattern, and a predetermined pattern to be the protruding conductor 4c is printed.

  However, if one side of the protruding conductor 4c is a rectangle of less than 75 μm, a frictional force acts between the photosensitive emulsion for sealing when printing the metal paste that forms the protruding conductor 4c on the outer metallized layer 4a. In some cases, the paste is difficult to be removed from the screen, resulting in printing defects such as fading. On the other hand, if the thickness exceeds 300 μm, the area of the protruding conductor 4c becomes too large, the volume of the brazing material 5 is reduced and the stress relaxation effect is reduced, and when the environmental test such as the temperature cycle is performed, the brazing material 5 In some cases, the bonding strength of the alloy becomes small.

  The interval between the protruding conductors 4c is preferably 0.15 to 0.3 mm. If the thickness is less than 0.15 mm, the width of the photosensitive emulsion for sealing must be reduced with respect to the screen made of stainless steel mesh used for printing, and therefore the photosensitive emulsion for sealing is retained on the screen. In the case where the photosensitive emulsion for sealing is peeled off and adjacent protrusions are united with each other. When the thickness exceeds 0.3 mm, the number of protruding conductors 4c formed at the joint portion is reduced. In some cases, the bonding area between the brazing material 5 and the outer metallized layer 4a decreases, resulting in a decrease in bonding strength.

  Further, as shown in FIG. 3A, the protruding conductor 4c is arranged such that the outer end side of the side wall 2 of the outer metallized layer 4a, that is, the row on the base side of the lead terminal 6 is in contact with the boundary of the outer metallized layer 4a. Further, it is preferable that the metallized layer 4a is formed to the end. As a result, a good meniscus 5a of the brazing material 5 is formed in the vicinity of the base of the lead terminal 6 to which a force for peeling off the lead terminal 6 is first applied, and the bonding area of the brazing material 5 is increased. The lead terminal 6 can be made difficult to peel off. In this case, if the apex of the protruding conductor 4c is on the metallized layer 4a, the base of the protruding conductor 4c may be at a position protruding from the edge of the metalized layer 4a.

  The protruding conductor 4c is formed by applying a metal paste mainly composed of metal powder such as tungsten (W) for forming the metallized layer 4 on the metal paste layer to be the metallized layer 4 by screen printing or the like. It is formed.

  Preferably, the planar shape of the protruding conductor 4c is preferably a rectangular shape, and when a force is applied in the direction in which the lead terminal 6 is peeled off, the brazing material 5 is caught at the corners of the rectangle and is not easily peeled off. Since the bonding area between the brazing material 5 and the outer metallized layer 4a can be increased, the bonding strength can be improved. Further, a circular or elliptical shape is preferable in terms of improving the printability of the metal paste at the time of screen printing, but the effect of suppressing peeling is somewhat impaired, so depending on the area of the protruding conductor 4c. It is good to use properly.

  As shown in FIG. 2, the electronic component 7 is placed and fixed on the placement portion 1 a of the package B of the present invention thus manufactured with a low melting point brazing material such as (Sn) -lead (Pb) solder. The metallized layer 4b and the electrode of the electronic component 7 are electrically connected by a bonding wire or the like, and the lid 8 is joined to the upper surface of the side wall 2 or a seal ring (not shown) on the upper surface of the side wall 2 by a seam welding method or the like. By doing so, the electronic device C as a product is obtained. The electronic device B is used for an information processing device or the like in which the electronic component 7 is driven by an electric signal supplied from an external electric circuit, for example, and processes a large amount of information at high speed.

  It should be noted that the present invention is not limited to the above-described embodiments and examples, and various modifications may be made without departing from the scope of the present invention. For example, when the electronic component 7 is an optical semiconductor element such as a semiconductor laser (LD) or a photodiode (PD), the effect of the present invention is the same. In this case, a through hole for attaching an optical fiber is formed on the side wall 2. It becomes the provided structure. 1 to 2, the metallization layer 4 of the input / output unit 3 is shown as being formed one by one on the left and right, but it goes without saying that a plurality of metallization layers 4 may be formed. If the package B has a rectangular shape in plan view, the input / output unit 3 may be formed only on one side surface of the package B, or the input / output unit 3 may be formed on one side surface and a side surface adjacent thereto.

An example of embodiment of the electronic component storage package of this invention is shown, (a) is a top view of the electronic component storage package, (b) is sectional drawing of (a). It is sectional drawing of the electronic device of this invention. (A) is a principal part enlarged plan view of the electronic component storage package of this invention, (b) is sectional drawing of (a). (A) is sectional drawing which shows the example of the conventional package for electronic components accommodation, (b) is a principal part expanded sectional view of (a). It is sectional drawing explaining the brazing method of the lead terminal of an electronic component storage package. (A), (b) is a principal part expanded sectional view which shows the example of the input-output part in the conventional electronic component storage package, respectively. It is a principal part expanded sectional view which shows the other example of the input-output part in the conventional electronic component storage package.

Explanation of symbols

1: Base 1a: Placement part 2: Side wall 3: Input / output part 4: Metallization layer 4a: Outer metallization layer 4b: Inner metallization layer 4c Protruding conductor 5: Brazing material 5a: Meniscus 6: Lead terminal 7: Electronic component 8: Lid B: Electronic component storage package C: Electronic device C-1: Notch on the inner surface side C-2: Notch on the outer surface side

Claims (2)

There is a mounting portion on which the electronic component is mounted on the bottom surface of the recess formed on the upper surface, and two notches facing each other across the side wall are formed on the inner and outer surfaces of the side wall surrounding the recess. A ceramic base, and a metallized layer formed on the surface and inside of the base and led out from the inner surface side notch formation region of the side wall to the outer surface side notch formation region directly under the side wall; and An electronic component storage package comprising a metal lead terminal brazed to the metallization layer outside the side wall, and a plurality of protruding conductors arranged in a matrix on the surface of the metallization layer outside the side wall There are formed, several projections conductor plurality, together with projections conductor in the other row between the projections conductor of one row of projections conductors of two adjacent rows are staggered so as to be located The protrusion conductor is an electronic component storing package row of outer end of the side wall of the metallized layer, characterized in that it is formed in contact with the edge of the metallized layer. The electronic component storage package according to claim 1 , an electronic component that is placed and fixed on the mounting portion and is electrically connected to the metallized layer inside the side wall, and an upper surface of the side wall of the base body And a lid joined so as to cover the mounting portion.

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