KR101200425B1 - Multilayer inductor and method for manufacturing the same - Google Patents

Abstract

According to an aspect of the present invention, there is provided a multilayer inductor including an inductor sheet having an inductor pattern that is intaglio formed downward from an upper surface thereof; A conductive material filled along the indented inductor pattern; And external terminals connected to both ends of the inductor pattern exposed to the outside of the inductor sheet.
Multilayer inductor according to the present invention is an inductor sheet; A pattern sheet stacked on the inductor sheet and having an inductor pattern formed through the upper and lower surfaces; A conductive material filled along the inductor pattern; And external terminals connected to both ends of the inductor pattern exposed to the outside of the pattern sheet.
According to embodiments of the present invention, the inductor pattern may be precisely controlled to improve DC superposition characteristics, and defects such as blisters and delays may be stably controlled. In addition, it is possible to increase productivity by preventing damage to cracks and defects in the inductor sheet, and to manufacture a thin and thin multilayer inductor by a simple process, thereby lowering the manufacturing cost. In addition, since the inductor pattern having a variety of complex shapes can be formed, it is possible to manufacture a multilayer inductor that variously adjusts the inductance value.

Description

Multilayer Inductor and Method for Manufacturing the Same {MULTILAYER INDUCTOR AND METHOD FOR MANUFACTURING THE SAME}

The present invention relates to a multilayer inductor and a method of manufacturing the same, and more particularly, to a multilayer inductor having high reliability and excellent performance by forming a precise inductor pattern and a method of manufacturing the same.

The high frequency of step-down DC-DC converter ICs, which supply power to the standby, is rapidly progressing. Increasing the switching frequency makes the peripheral components of the power supply much smaller and thinner, ultimately miniaturizing and thinning portable devices. That is, the higher the switching frequency, the smaller and thinner the capacitors and inductors of the peripheral components can be. The reason is that both the inductive impedance is a function of the frequency f. The capacitive impedance can be expressed as ZC = 1 / (jωωC) and the inductive impedance as ZL = jωωL, where ωω is ωω = 2ππf at angular velocity. Thus, in the case of obtaining some capacitive or inductive impedance, increasing the frequency f allows the use of small and thin components, both capacitors and inductors. As a result, the overall power circuit mounting area and thickness can be reduced, so that these circuits can be contained in a very small package. This, in turn, contributes greatly to the compactness and thickness of the device.

Currently, multilayer inductors are used to miniaturize DC-DC converters. Stacked inductors, unlike wired inductors, are a manufacturing method that can be miniaturized. In general, a multilayer inductor alternately prints a conductor pattern on a ceramic sheet, etc., and stacks the conductor patterns to connect via patterns to via conductors to form coils inside the laminate, and external terminals are provided at both ends of the laminate to form internal conductor patterns. It is structured to connect with the edge part of.

Sheets constituting the multilayer inductor are generally manufactured by screen printing a conductive paste on a ceramic substrate. Screen printing is a method in which a predetermined pattern is printed on a ceramic substrate while the paste passes over the screen mask on which the circuit pattern is formed and passes through the pattern portion. The multilayer inductor is made by drying sheets in which the inductor pattern is manufactured in this manner, combining them in a desired order, arranging them in a predetermined order, and compressing by applying heat and pressure.

Multilayer inductors require various inductances depending on the specifications of the electrical products using them. Therefore, inductors having various inductance values are required. In general, inductors change the inductance by changing the number of windings of the coil formed therein. In the multilayer inductor, the inductance value is changed by changing the shape and the stacking order of the conductor pattern.

In addition, the multilayer inductor requires a low series resistance value. For this purpose, the resistivity of the lead wire should be as low as possible, and the cross-sectional area of the lead wire should be made thick.

However, since the conventional multilayer inductor forms an inductor pattern by using screen printing on a flat sheet, the inductor is embossed to protrude upward from the sheet. Damage occurred and there was a problem in durability and reliability.

The present invention provides a multilayer inductor and its manufacturing method for improving the inductor DC overlapping characteristics.

The present invention provides a multilayer inductor and a method of manufacturing the same that can manufacture various and complex inductors.

In addition, the present invention provides a multilayer inductor having excellent reliability and a method of manufacturing the same.

According to an aspect of the present invention, there is provided a multilayer inductor including an inductor sheet having an inductor pattern that is intaglio formed downward from an upper surface thereof; A conductive material filled along the indented inductor pattern; And external terminals connected to both ends of the inductor pattern exposed to the outside of the inductor sheet.

Multilayer inductor according to the present invention is an inductor sheet; A pattern sheet stacked on the inductor sheet and having an inductor pattern formed through the upper and lower surfaces; A conductive material filled along the inductor pattern; And external terminals connected to both ends of the inductor pattern exposed to the outside of the pattern sheet.

In the stacked inductor according to the present invention, a plurality of inductor sheets are stacked, and the inductor patterns are connected to each other through via holes formed in the inductor sheet.

In the stacked inductor according to the present invention, it is preferable that an insulator pattern or dummy sheet for protecting the inductor pattern is further stacked on the stacked inductor sheet or pattern sheet uppermost.

Laminated inductor manufacturing method according to the present invention comprises the steps of preparing a sheet for the inductor; Forming an inductor pattern which is intaglio formed downward on an upper surface of the inductor sheet; And filling the conductive material along the inductor pattern negatively formed in the inductor sheet.

Laminated inductor manufacturing method according to the present invention comprises the steps of preparing a sheet for the inductor; Providing a pattern sheet having an inductor pattern formed through the upper and lower surfaces on an inductor sheet; And filling a conductive material along the inductor pattern.

In the multilayer inductor manufacturing method according to the present invention, the inductor pattern is preferably formed by either screen printing or laser forming processing.

In the method of manufacturing a multilayer inductor according to the present invention, it is preferable to further include flattening the pattern sheet after filling the conductive material.

According to embodiments of the present invention, the inductor pattern may be precisely controlled to improve DC superposition characteristics, and defects such as blisters and delays may be stably controlled.

In addition, it is possible to increase productivity by preventing damage to cracks and defects in the inductor sheet, and to manufacture a thin and thin multilayer inductor by a simple process, thereby lowering the manufacturing cost.

In addition, since the inductor pattern having a variety of complex shapes can be formed, it is possible to manufacture a multilayer inductor that variously controls the inductance value.

1 is a conceptual diagram of an inductor sheet of a multilayer inductor according to an exemplary embodiment of the present invention.
2 is a schematic structural diagram of a multilayer inductor according to an embodiment of the present invention.
3 is a schematic structural diagram of a multilayer inductor according to a modified embodiment of the present invention.
4 is a schematic manufacturing process diagram of a method of manufacturing a multilayer inductor according to an exemplary embodiment of the present invention.
5 is a schematic manufacturing process diagram of a method of manufacturing a multilayer inductor according to a modified embodiment of the present invention.
6 is a graph showing a correlation between temperature and rated current of a multilayer inductor manufactured according to an exemplary embodiment of the present invention.

Hereinafter, a method of manufacturing a multilayer inductor according to the present invention will be described in detail with reference to the accompanying drawings. It will be apparent to those skilled in the art that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, It is provided to let you know. Wherein like reference numerals refer to like elements throughout.

1 is a conceptual diagram of an inductor sheet of a stacked inductor according to an embodiment of the present invention, Figure 2 is a schematic structural diagram of a stacked inductor according to an embodiment of the present invention.

1 and 2, the multilayer inductor includes an inductor sheet 100 having an inductor pattern 110 that is intaglio formed from an upper surface thereof downward; A conductive material 300 filled along the indented inductor pattern 110; And an external terminal 400 connected to the exposed end 111 of the inductor pattern exposed to the outside of the inductor sheet 100.

The inductor sheet 100 may be formed of, for example, a ferrite-based and low dielectric constant low-temperature calcined (LTCC) ceramic. Of course, the component of the inductor sheet 100 is not limited thereto, and an inductor sheet of various components having such a property may be used.

The inductor sheet 100 is provided with an inductor pattern 110 engraved with a predetermined depth (see FIG. 4). That is, the inductor pattern 110 is formed with a recess recessed in the depth direction with respect to the entire thickness of the inductor sheet 100. The depth and width of these grooves remain constant throughout the pattern and can be precisely controlled according to the desired inductance value. As shown in FIG. 2, the inductor sheet 100 may be formed by stacking a plurality of sheets. In this case, each inductor sheet 100 has a via hole 120 penetrating up and down the sheet surface. The inductor 110 patterns formed on the inductor sheet 100 stacked up and down through the via hole 120 may be connected to each other, which will be described later.

In this embodiment, the inductor pattern 110 is formed in a refracted shape as shown in FIG. 1, and the exposed end 111 is exposed to the outside of the inductor sheet 100 for connection with the external terminal 400. Is formed. The inductor pattern 110 formed on the plurality of inductor sheets 100 may be formed in various refractive forms, such as 'b', 'c', or 'ㅁ', but is not limited thereto. You can change it. The inductor pattern 110 formed in each inductor sheet 100 may be sequentially connected through the via holes 120 formed in each inductor sheet 100, and may be formed in a spiral shape as a whole while overlapping along the stacking direction. Can be.

For example, when the first inductor sheet 100a to the fifth inductor sheet 100e are sequentially stacked as shown in FIG. 1, one end is an exposed end 111 exposed to the outside of the sheet. At the other end, the first inductor sheet 100a having the first inductor pattern 110a having a predetermined shape in which the first via hole 120a is disposed, and one end thereof are disposed at a position corresponding to the first via hole 120a. And a second inductor sheet 100b having a second inductor pattern 110b having a predetermined shape having a second via hole 120b disposed at the other end thereof, and one end thereof at a position corresponding to the second via hole 120b. A third inductor sheet (100c) having a third inductor pattern (110c) having a predetermined shape having a third via hole (120c) disposed at the other end thereof, and one end thereof corresponding to the third via hole (120c). And a fourth inductor pattern 110d of a predetermined shape having a fourth via hole 120d disposed at the other end thereof. The fourth inductor pattern 110e having a predetermined shape is a fourth inductor sheet 100d and an exposed end portion 112 having one end disposed at a position corresponding to the fourth via hole 120d and the other end exposed to the outside of the sheet. It is configured to include a fifth inductor sheet (100e) provided, it may be formed in the form of a coil of a spiral structure as a whole. The predetermined shape may be formed to be refracted in a semi-circular shape as shown in FIG. 2, but is not limited thereto. The predetermined shape may be provided in various shapes such as a straight line, a c-shape, and a c-shape. Both exposed ends 111 and 112 are connected to the first and second external terminals 400a and 400b, but are preferably spaced apart in the opposite direction of the sheet.

The via hole 120 is filled with a conductor to connect the inductor patterns between adjacent stacked inductor sheets. That is, one end of the second inductor pattern 110b formed in the second inductor sheet 100b is disposed at a position corresponding to the position of the first via hole 120a, and thus, the first inductor pattern ( 110b). The second inductor pattern 110b is refracted to form a semi-circular shape, and the second via hole 120b is disposed at the other end thereof, and the third inductor pattern 110c has one end at a position corresponding to the position of the second via hole 120b. The second inductor pattern 110b is connected to the second inductor 120b through the second via hole 120b. In this manner, the third inductor pattern 110c to the fifth inductor pattern 110e may be connected through the via hole.

In this embodiment, inductor coil lines are formed by using five inductor sheets and inductor patterns on each inductor sheet. However, the number of stacked inductor sheets is not limited thereto, and the number of inductor sheets not connected to external terminals varies. To change. By changing the number of stacked inductor sheets, inductance values can be varied.

The indented inductor pattern 110 is filled with the conductive material 300 along the inductor pattern 110 (see FIG. 4). The conductive material 300 formed in the inductor pattern 110 may be formed of a metal such as Ag, Pt, or Pd, or may be formed of a resistor such as Ni—Cr or RuO ₂ . The height of the conductive material 300 to be filled in the inductor pattern 110 is slightly higher than the height of the inductor sheet 100 or the same by shrinkage after firing in order to stably stack the plurality of inductor sheets 100. It is preferable to form at the height to say. This is because when the height of the conductive material to be filled exceeds the height of the inductor sheet 100, it may be damaged when the plurality of inductor sheets 100 are compressed and laminated.

Since the conductive material 300 is formed in the inductor pattern in which the depth and width of the inductor pattern are uniformly controlled, the conductive material 300 may precisely control the thickness and width of the conductive pattern and maintain the uniformity. From this, the precision and resolution of the conductive pattern can be improved, and fine line width can be manufactured.

External terminals 400a and 400b are formed outside the plurality of stacked inductor sheets, as shown in FIG. 2. The external terminal includes a first external terminal 400a and a second external terminal 400b connected to both exposed ends 111 and 112 of the inductor pattern, respectively, and serves as input / output terminals.

An insulator pattern (not shown) or a dummy sheet 150 may be further stacked on the top or bottom of the stacked inductor sheet to protect the pattern. The dummy sheet 150 may be configured in the same manner as the inductor sheet 100 described above.

3 is a schematic structural diagram of a multilayer inductor according to a modified embodiment of the present invention.

The multilayer inductor according to the embodiment shown in FIG. 3 includes a sheet 100 for the inductor; A pattern sheet 200 stacked on the inductor sheet 100 and having an inductor pattern 110 formed through the upper and lower surfaces; A conductive material 300 filled along the inductor pattern 110; And an external terminal 400 connected to the exposed end 111 of the inductor pattern 110 exposed to the outside of the pattern sheet 200.

The inductor sheet 100 may be formed of, for example, a ferrite-based and low dielectric constant low-temperature calcined (LTCC) ceramic. Of course, the components of the inductor sheet is not limited thereto, and the inductor sheet of various components having such a property may be used.

The pattern sheet 200 is a sheet in which the inductor pattern 110 penetrates the sheet surface up and down, and is stacked on the inductor sheet 100. The pattern sheet 200 may be formed of the same component as the sheet 100 for the inductor described above. Since the inductor sheet 100 and the pattern sheet 200 on which the inductor pattern 110 is formed are manufactured separately, the thickness of the entire sheet can be reduced, and the thickness of the pattern sheet 200 is adjusted to adjust the thickness of the inductor pattern 110. Easy to adjust thickness This also makes the stacked inductor even smaller and thinner.

The inductor pattern 110 in the present embodiment is formed to penetrate the pattern sheet 200 up and down, and the shape formed on the surface of the pattern sheet 200 is the same as the inductor pattern 110 in the above-described embodiment. Description is omitted.

The pattern sheet 200 is pressed onto the inductor sheet 100 by applying appropriate heat and pressure, for example, and is provided on the inductor sheet 100. In this case, when a plurality of inductor sheets 100 and pattern sheets 200 are alternately stacked, via holes 120 penetrating up and down the sheet surface may be formed in each inductor sheet 100. Each inductor pattern 110 may be sequentially connected through a via hole 120 formed in each inductor sheet.

For example, as illustrated in FIG. 1, the first inductor sheet 100a to the fifth inductor sheet 100e and the first pattern sheet 200a to the fifth pattern sheet 200e are alternately stacked. Each conductive material 300a to 300e may be filled in each inductor pattern 110a to 110e. In this case, the technical features of the inductor patterns 110a to 110e and the via holes 120a to 120b are the same as those of the above-described embodiment, and thus detailed description thereof will be omitted.

Since the formed conductive material 300 filled in the inductor pattern 21 is the same as the embodiment shown in FIG. 1 described above, a detailed description thereof will be omitted.

Outside terminals 400a and 400b are formed outside the inductor sheet 100 as shown in FIG. 2. Since the external terminal is the same as described above, detailed description thereof will be omitted.

In this embodiment, an insulator pattern (not shown) may be stacked or the dummy sheet 150 may be further stacked on the top of the stacked inductor sheet to protect the pattern.

Hereinafter, a method of manufacturing a multilayer inductor according to the present invention will be described in detail with reference to the drawings.

4 is a schematic manufacturing process diagram of a method of manufacturing a multilayer inductor according to an exemplary embodiment of the present invention.

In another embodiment, a method of manufacturing a multilayer inductor may include: preparing an inductor sheet 100; Forming an inductor pattern 110 that is intaglio formed downward on an upper surface of the inductor sheet 100; And filling the conductive material 300 along the inductor pattern 110 engraved in the inductor sheet 100.

First, an inductor sheet is prepared (FIG. 4A). For example, ferrite-based and low dielectric constant low-temperature baking (LTCC) ceramic slurries are manufactured by using a raw material powder having a predetermined composition, and the slurries are prepared to a desired thickness by a method such as a doctor blade. It can manufacture.

As shown in FIG. 4B, the inductor pattern 110 is intaglio formed at a predetermined depth on the upper surface of the inductor sheet 100. That is, the inductor pattern 110 is formed with a recess recessed in the depth direction with respect to the entire thickness of the inductor sheet 100. The depth and width of these grooves remain constant throughout the pattern and can be precisely controlled according to the desired inductance value. The inductor pattern 110 may be variously modified in various forms, such as a straight line or a curved straight line, and the detailed description thereof will be omitted.

At this time, the inductor pattern 110 may be precisely drilled the inductor sheet 100 by screen printing or laser molding processing. Laser molding is a method of processing an object using a laser with a high-density heat source. When the laser beam is irradiated onto the surface of the object, the temperature of the surface of the material rises rapidly and the surface near the surface melts and evaporates. As a result, the material is removed and processed. The laser is heated and processed at high speed, so the heat deformation layer is narrow and easy to process a very hard or brittle material. In addition, complex shaped parts can be machined finely. Of course, the method of forming the inductor pattern 110 is not limited thereto, and may be implemented by various methods capable of precisely engraving the inductor sheet 100.

After the inductor pattern 110 is negatively formed on the inductor sheet 100, the conductive material 300 is formed along the inductor pattern 110 formed on the inductor sheet 200 as shown in FIG. 4C. ) To make a coil wire. The conductive material to be filled in the inductor pattern 110 may be manufactured using, for example, a metal paste such as Ag, Pt, or Pd, or may be manufactured using a resistive paste such as Ni—Cr or RuO ₂ . The inductor pattern 110 may be filled and formed. At this time, the conductive material may be filled by a method such as screen printing. When the via hole 120 is formed through the inductor sheet 100, the via hole 120 may be filled with a conductive material in the same manner.

After the conductive material is filled in the inductor pattern 110 to form a coil line, the inductor sheet 100 may be flattened to prevent damage and to be in close contact when stacked in a multilayer. The height of the conductive material to be filled is preferably equal to or slightly above the sheet 100 for the inductor as described above. The inductor sheet 100 filled with the conductive material in the inductor pattern 110 may be heated at about 300 ° C. to bake out to remove all organic components, and then heated up to a suitable firing temperature ( For example, about 900 ° C.).

Thereafter, an external terminal 400 connected to the exposed end 111 of the inductor pattern 110 filled with the conductive material 300 is formed to complete the stacked chip. The external terminal 400 is coated with a silver paste (Ag-paste) on a rubber disk (disc) grooved in the circumferential surface according to the number and position of the electrode to be formed, and then rotate the disk close to the coil wire (dipping action) The electrode is printed and then fired at an appropriate temperature. In addition, an external terminal connected to the coil wire may be first formed on the outside of the sheet in which the coil wire is formed and laminated, and then an epoxy protective film or the like may be printed on the surface of the coil wire by screen printing and heat treated to form an insulating protective layer. .

By repeating the manufacturing process for the inductor sheet, the inductor pattern, and the conductive material, a multilayer inductor (see FIG. 2) having a multilayer may be manufactured. In this case, the via hole 120 is formed in the inductor sheet 100. The inductance value of the inductor can be adjusted by adjusting the number of stacks. In addition, in the manufacturing method, various inductors may be manufactured by changing the inductor pattern and the stacking order. The manufacturing method according to the present invention can form a fine inductor pattern (coil line), and can also variously adjust the line width and shape of the inductor coil line.

5 is a schematic manufacturing process diagram of a method of manufacturing a multilayer inductor according to a modified embodiment of the present invention.

According to an embodiment of the present invention, a method of manufacturing a stacked inductor may include: preparing an inductor sheet 100; Providing a pattern sheet (200) having an inductor pattern (110) formed through upper and lower surfaces on the inductor sheet (100); And filling the conductive material 300 along the inductor pattern 110.

First, the inductor sheet 100 is prepared in the same manner as described above.

And a pattern sheet is provided on the inductor sheet (FIG. 5 (a)). The pattern sheet 200 is a sheet on which the inductor pattern 110 is formed. Since the pattern sheet 200 may be configured in the same manner as the inductor sheet 100 described above, the pattern sheet 200 may be manufactured by the same method. The pattern sheet 200 is pressed onto the inductor sheet 100 by applying appropriate heat and pressure, for example, and is provided on the inductor sheet 100 as shown in FIG. 5 (b). The inductor pattern 110 formed on the pattern sheet 200 may be formed by screen printing or laser molding as described above.

After the inductor pattern 21 is formed on the pattern sheet 200, the conductive material 300 is filled with the conductive material 300 along the inductor pattern 21 formed on the pattern sheet 200 as shown in FIG. 5C. Manufacture first line. Its manufacturing method is the same as in the above-described embodiment, detailed description thereof will be omitted.

After the conductive material is filled in the inductor pattern 110 to form a coil line, the inductor sheet 100 may be flattened to prevent damage and to be in close contact when stacked in a multilayer.

Thereafter, an external terminal 400 connected to the exposed end 111 of the inductor pattern 110 filled with the conductive material 300 is formed to complete the stacked chip. The method of forming the external terminal 400 is the same as in the above-described embodiment.

By repeating the manufacturing process for the inductor sheet, the pattern sheet, the inductor pattern, and the conductive material, a multilayer inductor (see FIG. 3) having a multilayer may be manufactured. In this case, the via hole 120 may be formed in the inductor sheet 100. The inductance value of the inductor can be adjusted by forming the film and controlling the number of stacked layers. In addition, in the manufacturing method, various inductors may be manufactured by changing the inductor pattern and the stacking order. The manufacturing method according to the present invention can form a fine inductor pattern (coil line), and can also variously adjust the line width and shape of the inductor coil line.

Hereinafter, the effect of the multilayer inductor manufactured according to an exemplary embodiment of the present invention will be described with reference to the accompanying drawings.

6 is a graph showing a correlation between temperature and rated current of a multilayer inductor manufactured according to an exemplary embodiment of the present invention.

Table 1 below is a table showing the temperature according to the rated current in the graph of FIG.

Rated Current (A) 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 Temperature when resistance is 280 mΩ 33.0 35.4 38.5 42.1 46.3 51.0 56.9 63.6 70.1 Temperature when resistance is 450 mΩ 36.7 40.9 46.2 52.3 61.4 71.4 84.9 101.7 120.2

In the case where the resistance values of the multilayer inductor are 280 mΩ and 450 mΩ, respectively, the static current values according to temperature are shown in the graph of FIG. 6 and Table 1.

Looking at the rated current value at about 60 ℃, the proper operating temperature of the inductor, the rated current value is 0.9 A when the DC resistance value of the multilayer inductor is 450 mΩ, and the rated current value is 280 mΩ when the DC resistance value is 280 mΩ. As 1.2 A, it can be seen that the multilayer inductor according to the present invention has a high rated current value.

The embodiments and drawings attached to this specification are merely to clearly show some of the technical ideas included in the present invention, and those skilled in the art can easily infer within the scope of the technical ideas included in the specification and drawings of the present invention. Modifications that can be made and specific embodiments will be apparent that both are included in the scope of the invention.

100: Inductor Sheet
110: inductor pattern
111: exposed end
120: via hole
200: pattern sheet
300: conductive material
400: external terminal

Claims (9)

delete An inductor sheet;
A pattern sheet stacked on the inductor sheet and having an inductor pattern formed through upper and lower surfaces;
A conductive material filled along the inductor pattern;
And an external terminal connected to an exposed end of the inductor pattern exposed to the outside of the pattern sheet. delete The method according to claim 2,
And a plurality of inductor sheets and a pattern sheet are alternately stacked, and each inductor pattern is sequentially connected through a through hole formed in each inductor sheet. The method according to claim 2,
The multilayer inductor of the stacked inductor sheet or pattern sheet is further laminated with an insulator pattern or dummy sheet to protect the inductor pattern. delete Providing a sheet for the inductor;
Pressing a pattern sheet having an inductor pattern formed through upper and lower surfaces on the inductor sheet; And
Filling a conductive material along the inductor pattern;
Laminated inductor manufacturing method comprising a. The method of claim 7,
The inductor pattern is a laminated inductor manufacturing method formed by screen printing or laser molding processing. The method of claim 7,
And filling the conductive material, and then planarizing the pattern sheet.

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