JP6556452B2 - Magnetic sheet - Google Patents

Description

The present invention relates to a magnetic sheet, relates in particular to low-frequency noise in the magnetic sheet which can be efficiently suppressed.

  In recent years, various tablet terminals such as notebook computers, mobile phones, and portable game machines have become widespread. Various tablet-type terminals are equipped with a display such as a liquid crystal panel, and recent displays have a selling point that high-definition images can be obtained.

  One of the selling points is that tablet-type terminals are thinner and lighter. With the reduction in thickness and weight, tablet terminals are becoming more airtight and technical improvements are being continued in the direction of eliminating extra parts.

  As the display becomes finer, thinner and lighter in this way, there has been a problem that electromagnetic noise in the vicinity of several hundred kHz degrades the performance of the display. Specifically, when electromagnetic noise near several hundred kHz is generated, the noise enters the display, causing problems such as screen flickering. This problem occurs not only in tablet terminals but also in thin liquid crystal displays.

  Until now, with regard to electromagnetic noise, high frequency noise of several tens of MHz or more has become an international standard by the International Radio Interference Special Committee (CISPR) as a target for EMC (Electromagnetic Compatibility) countermeasure parts. Conventionally, as a high-frequency noise countermeasure component of several tens of MHz or more, a magnetic sheet (electromagnetic interference) obtained by mixing Fe—Si—Al alloy powder and resin as disclosed in JP 2011-49406 A (Patent Document 1). Suppressor) has been proposed.

  The magnetic sheet obtained by mixing the Fe-Si-Al alloy powder and the resin can achieve a certain degree of suppression effect on high-frequency noise, but does not necessarily have a satisfactory suppression effect on low-frequency noise near several hundred kHz. It was not done.

  On the other hand, as a low-frequency noise suppression component, for example, JP 2006-196520 A (Patent Document 2) proposes a magnetic shield component using a Co-based amorphous alloy ribbon.

JP 2011-49406 A JP 2006-196520 A

  By using a Co-based amorphous alloy ribbon as described in Patent Document 2, a noise reduction effect in a low frequency region can be obtained. However, as described in paragraph [0030] of Patent Document 2, this alloy ribbon has a structure in which about 30 to 300 Co-based amorphous alloy ribbons are laminated. It was not intended to reduce the thickness.

  Moreover, even if the display in recent years is a tablet-type terminal, the size is increasing so that the short side becomes 100 mm or more. In order to reduce low frequency noise in the vicinity of several hundred kHz in the display, a large magnetic sheet corresponding to the display size is required.

  On the other hand, the amorphous alloy ribbon is manufactured by applying a roll quenching method as represented by a single roll method. The roll quenching method is a method of manufacturing an amorphous gold ribbon by putting a molten metal on a cooling roll that rotates at high speed, and rapidly solidifying the molten metal.

  However, since the roll quenching method is a method of producing a long thin strip by continuously supplying a certain amount of molten metal onto the cooling roll, it has been difficult to widen the strip. At present, in consideration of mass productivity, the Co-based amorphous alloy ribbon is manufactured with a width of 50 mm or less, and the Fe-based amorphous alloy ribbon is manufactured with a width of 100 mm or less. For this reason, there has been a technical demand for realizing a magnetic sheet that is wider than the alloy ribbon according to the display size.

  The present invention is intended to address such problems and demands, and it is possible to efficiently suppress low-frequency noise and to provide a magnetic sheet that is wider than the width of an alloy ribbon. It is what.

The magnetic sheet of the present invention is a magnetic sheet having a structure in which both sides of a magnetic foil body are laminated with a resin film via an adhesive layer, the magnetic sheet has a short side of 100 mm or more and a short side width of 3 It has a structure in which a plurality of magnetic foil bodies having a thickness of ˜90 mm are arranged in a plane direction, the longest distance between the adjacent magnetic foil bodies is 0.06 mm or more and 1.00 mm or less, and the shortest distance is 0 mm or more and 0 .93mm Ri der below, the gap between the magnetic foil adjacent the is characterized in that there is an air layer.

  Moreover, in the said magnetic sheet, it is preferable that the short side of a magnetic sheet is 100 mm or more. Moreover, it is preferable that an air layer exists in the clearance gap between adjacent magnetic foil bodies. Moreover, it is preferable that the thermal expansion coefficient of a magnetic foil body is 5-40 ppm / degrees C. The magnetic foil body is preferably a Co-based amorphous alloy. Moreover, it is preferable that an air layer does not exist between the surface of the magnetic foil body and the adhesive layer. The flatness of the magnetic sheet surface is preferably 0.02 mm or less. Moreover, it is preferable that the said magnetic sheet is for noise reduction of 500-800 kHz. Moreover, it is preferable that the said magnetic sheet is for displays.

  The display according to the present invention is characterized by comprising the magnetic sheet of the present invention.

  The magnetic sheet according to the present invention has a structure in which two or more magnetic foil bodies are arranged, and the gap between adjacent magnetic foil bodies is controlled on the magnetic sheet body, so that a wide magnetic sheet can be provided. . In addition, the flexibility and flatness of the magnetic sheet can be imparted. Further, it can be attached to the rear surface of the display, and low frequency noise in the vicinity of several hundred kHz can be effectively reduced. Therefore, the display including the magnetic sheet of the present invention can provide a high-definition image with reduced screen flicker.

It is sectional drawing which shows one Example of the magnetic sheet of this invention. It is a figure which shows the other Example of the magnetic sheet of this invention, FIG. 2A is a top view, FIG. 2B is an enlarged view of the 2B part shown to FIG. 2A. It is sectional drawing which shows other Example of the magnetic sheet of this invention. It is sectional drawing which shows other Example of the magnetic sheet of this invention. It is a side view which shows one Example of the display which concerns on this invention.

The magnetic sheet according to the present invention is a magnetic sheet having a structure in which both sides of a magnetic foil body are laminated with a resin film through an adhesive layer. The short side of the magnetic sheet is 100 mm or more, and the short side has a width of 100 mm or more. It has a structure in which a plurality of magnetic foil bodies of 3 to 90 mm are arranged in a plane direction, the longest distance between adjacent magnetic foil bodies is 0.06 mm or more and 1.00 mm or less, and the shortest distance is 0 mm or more 0.93mm Ri der below, the gap between the magnetic foil adjacent the is characterized in that there is an air layer.

  1 and 2 show an embodiment of the magnetic sheet of the present invention. In FIG. 1, 1 is a magnetic sheet, 2 is a magnetic foil body, 3 is an adhesive layer, 4 is a resin film, L is the width of the magnetic foil body, and T is an adjacent magnetic foil body. It is the distance between them, and W is the width of the magnetic sheet. In FIG. 2, 2a is the first magnetic foil body, 2b is the second magnetic foil body, 2c is the third magnetic foil body, and W1 is the width in the lateral direction of the magnetic sheet. , W2 is the vertical width of the magnetic sheet, Tmax is the longest distance between adjacent magnetic foil bodies, and Tmin is the shortest distance between adjacent magnetic foil bodies.

  First, a magnetic sheet 1 according to the present invention has a structure in which both surfaces of a magnetic foil body 2 are laminated with a resin film 4 via an adhesive layer 3. Examples of the magnetic foil body 1 include soft magnetic alloy foil bodies such as amorphous alloys, Fe-based fine crystal alloys, and permalloy alloys. Examples of the amorphous alloy include a Co-based amorphous alloy (Co-based amorphous alloy) and an Fe-based amorphous alloy (Fe-based amorphous alloy). The Fe-based fine crystal alloy is an alloy having fine crystals of 100 nm or less in area ratio of 70% or more.

  As will be described later, in order to suppress low-frequency noise of several hundred kHz, particularly 500 to 800 kHz, it is preferable to use a Co-based amorphous alloy as the magnetic foil body. Co-based amorphous alloys are effective in reducing low-frequency noise because the permeability (100 kHz) can be easily controlled to about 2,000 to 50,000. Moreover, there is an advantage that the magnetic foil body need not be multi-layered more than necessary.

  Moreover, it is preferable that the magnetostriction of a magnetic foil body is substantially zero. When the magnetostriction is almost zero, vibration occurs when low frequency noise is received, and the “beat” in the audible frequency region becomes prominent, and there is no gap between the display and the magnetic sheet. It becomes easy to receive. In consideration of magnetostriction, the magnetic foil body is preferably a Co-based amorphous alloy.

  The magnetic foil body preferably has a thermal expansion coefficient of 40 ppm / ° C. or less, and more preferably 5 to 40 ppm / ° C. When the thermal expansion coefficient exceeds 40 ppm / ° C., the magnetic foil body expands due to the heat generated by the display when it is used by being attached to the back surface of the display, and the adhesion between the display and the magnetic sheet deteriorates.

  Further, when the thermal expansion coefficient is less than 5 ppm / ° C., it is difficult to stabilize the thermal expansion coefficient. Therefore, the thermal expansion coefficient of the magnetic foil is preferably 5 to 40 ppm / ° C, more preferably 6 to 20 ppm / ° C. In addition, the measuring method of a thermal expansion coefficient shall be the method performed with the push rod type dilatometer shown by JIS-Z-2285 (2003), for example.

  The width L of the magnetic foil is 3 to 90 mm. The width L of the magnetic foil body is the length of the short side of the magnetic foil body. There is no problem even if the long side of the magnetic foil exceeds 90 mm. The magnetic sheet of the present invention has a structure in which two or more magnetic foil bodies having a width L of 3 to 90 mm are arranged. The number to be arranged is not particularly limited as long as it is two or more, and it may be arranged according to the size of the display to be used.

  The magnetic sheet according to the present invention has a structure in which a magnetic foil body is laminated with a resin film via an adhesive layer. As shown in FIG. 1, since the resin film 4 is laminated | stacked on both surfaces of the magnetic foil body 2 via the contact bonding layer 3, deterioration, such as rust of a magnetic foil body, can be prevented. In addition, since the magnetic foil body is fixed by the adhesive layer, misalignment does not occur, so that the handleability of the magnetic sheet is improved.

  In addition, the longest distance between adjacent magnetic foil bodies exceeds 0 mm and is 1 mm or less, and the shortest distance is 0 mm or more and 1 mm or less. In the distance T between adjacent magnetic foil bodies, the maximum distance Tmax of the distance between adjacent magnetic foil bodies is more than 0 mm and 1 mm or less, as shown in FIG. It indicates that there is always a portion that is not in contact with the gap with the magnetic foil body 2b (a portion where the longest distance Tmax exceeds 0 mm), and even the farthest portion is 1 mm or less.

  Further, the shortest distance Tmin between adjacent magnetic foil bodies being 0 mm or more and 1 mm or less means that the magnetic foil body 2a and the magnetic foil body 2b are in contact with each other (the place where the shortest distance Tmin is 0 mm). ) Or the closest location is 1 mm or less. Further, when the shortest distance Tmin is 1 mm, the longest distance Tmax is also 1 mm.

  On the other hand, if the longest distance Tmax is greater than 1 mm, low frequency noise leaks from the gap, and partial flickering of the display screen cannot be prevented. On the other hand, if the shortest distance Tmin is smaller than 0 mm, a portion where adjacent magnetic foil bodies overlap is formed. If the overlapping portions of the magnetic foil bodies are formed, the flatness of the magnetic sheet itself is lowered. When the flatness of the magnetic sheet is lowered, the adhesiveness between the magnetic sheet and the display is lowered because the overlapping portion of the adjacent magnetic foil bodies becomes a convex portion when being attached to the display.

  And in order to make noise suppression and flatness compatible, the longest distance Tmax which is the distance between adjacent magnetic foil bodies exceeds 0 mm and is 0.5 mm or less, and the minimum distance Tmin is 0 mm or more and 0.1 mm or less. It is preferable that In the description of the distance between the adjacent magnetic foil bodies, the gap between the magnetic foil body 2a and the magnetic foil body 2b has been described. However, the gap between the magnetic foil body 2b and the magnetic foil body 2c is also the longest distance Tmax and the shortest. The distance Tmin satisfies the above relationship.

  Moreover, as a method of adjusting the width L of the magnetic foil body to 3 to 90 mm, there is a method of preparing a magnetic ribbon having the desired width L by adjusting the conditions of the roll quenching method. Moreover, the method of cut | disconnecting a magnetic thin strip (long) and making it the target width L is mentioned. If the width L of the magnetic foil is thin and less than 3 mm, the labor for adjusting the distance T between adjacent magnetic foils increases and the mass productivity decreases. On the other hand, when the width L of the magnetic foil body exceeds 90 mm, it becomes difficult to manufacture by the roll quenching method, and the variation in the plate thickness becomes large, or a slender hole is formed in the ribbon. Considering the mass productivity of the magnetic sheet and the mass productivity of the magnetic ribbon, the width L of the magnetic foil is preferably 10 to 45 mm.

  Moreover, the plate | board thickness of a magnetic foil body can be 15-30 micrometers by using the said roll rapid cooling method. By using such a thin magnetic foil, the thickness of the magnetic sheet itself can be reduced. For example, when the thickness of the adhesive layer is 5 to 15 μm and the thickness of the resin film is 20 to 50 μm, the thickness of the magnetic sheet can be reduced to 65 to 160 μm. In addition, when multilayering a magnetic foil body, the thickness of a magnetic foil body and the thickness of an adhesive layer will increase.

  In either case of the method of adjusting the width L of the magnetic foil body by the roll quenching method or the method of adjusting the width L of the magnetic foil body by cutting a magnetic ribbon (long), the magnetic foil As shown in the circle of FIG. 2B, minute irregularities are easily formed on the end surface of the body. Although there is a method of cutting by laser processing so that minute irregularities are not formed, there is a possibility that a magnetic foil body such as an amorphous alloy may be altered by the heat of the laser. Further, if cutting or press punching is performed with a very strong stress, the magnetic ribbon (long) may be destroyed. In addition, the etching process is not suitable for increasing the size, which causes an increase in cost.

  As described above, when the width L of the magnetic foil body, the longest distance Tmax and the shortest distance Tmin which are distances between adjacent magnetic foil bodies are controlled, the short side of the magnetic sheet is increased to 100 mm or more. In addition, low frequency noise can be efficiently suppressed. In particular, even if minute irregularities exist on the end face of the magnetic foil body, it is possible to cope with an increase in size. In FIG. 2, the lateral width of the magnetic sheet 1 is shown as W1 and the longitudinal width of the magnetic sheet 1 is shown as W2. However, the shorter one of W1 and W2 is the shorter side of the magnetic sheet. Further, the length of the long side of the magnetic sheet 1 is not particularly limited. In the case of permalloy, it is preferable to adjust the width and thickness by a rolling method.

  Moreover, it is preferable that there is no air layer between the surface of a magnetic foil body and an adhesive layer. Further, it is preferable that there is no air layer between the adhesive layer and the resin film. Since there is no air layer between the surface of the magnetic foil body and the adhesive layer, the flatness of the magnetic sheet can be improved. In addition, since there is no air layer, it is possible to eliminate the problem that the resin film ruptures and breaks when the magnetic sheet is pressed against the display and the magnetic foil body is displaced.

  Furthermore, the flatness of the magnetic sheet can be 0.02 mm or less. The flatness of the magnetic sheet is the difference between the convex part and the concave part on the surface of the magnetic sheet. In the measurement of flatness, a magnetic sheet is placed on a flat surface, the height of the magnetic foil body at the highest position and the height of the magnetic foil body at the lowest position are obtained, and the difference is obtained. The flatter the magnetic sheet, the closer the flatness is to zero.

  Since the shortest distance Tmin is controlled in the range of 0 to 1 mm in the magnetic sheet, the flatness can be reduced to 0.02 mm or less because there is no portion where adjacent magnetic foil bodies overlap. Further, the flatness can be reduced to 0.02 mm or less even when there is no air layer between the magnetic foil body and the adhesive layer and between the adhesive layer and the resin film. When the flatness of the magnetic sheet is high, it is easy to adhere to the back surface of the display without a gap. It is also suitable for applications that require thinning, such as tablet terminals.

  Moreover, it is preferable that an air layer exists in the clearance gap between adjacent magnetic foil bodies. FIG. 3 shows an example of the magnetic sheet 1 in which the air layer 5 exists in the gap between the adjacent magnetic foil bodies 2 and 2. In FIG. 3, 1 is a magnetic sheet, 2 is a magnetic foil, 3 is an adhesive layer, 4 is a resin film, and 5 is an air layer.

  As described above, in the magnetic sheet according to the present invention, the longest distance Tmax between the adjacent magnetic foil bodies exceeds 0 mm and is 1 mm or less. Therefore, there is a portion where a gap is formed between adjacent magnetic foil bodies. By providing the air layer 5 at the location where the gap is formed, the flexibility of the magnetic sheet can be improved. When a pressing force is applied when attaching the magnetic sheet to the display, the air layer 5 can absorb the deformation of the adhesive layer 3. Moreover, handling property improves by improving the softness | flexibility of a magnetic sheet. It also functions as a part that effectively absorbs the thermal expansion caused by the heat of the display.

  Moreover, the air layer 5 should just be formed in the location where the longest distance Tmax of the distance between adjacent magnetic foil bodies exceeds 0 mm and is 1 mm or less at least 1 place or more. Moreover, the air layer 5 does not need to be formed continuously, and a plurality of air layers may be formed. Preferably, when the total area (volume) of locations where the longest distance Tmax is greater than 0 mm and equal to or less than 1 mm is 100%, the ratio of the air layer is a total area ratio (volume ratio) of 20 to 70%. . If the area ratio is less than 20%, the effect of providing an air layer is insufficient. On the other hand, if it exceeds 70%, the air layer increases so that the strength of the gap between the adjacent magnetic foil bodies decreases.

  It is also possible to make the magnetic foil body multilayer. Noise absorption characteristics can be further improved by multilayering the magnetic foil body. FIG. 4 illustrates a magnetic sheet in which magnetic foils are multilayered. In FIG. 4, 1 is a magnetic sheet, 2 is a magnetic foil body, 3 is an adhesive layer, and 4 is a resin film. FIG. 4 shows an example in which the magnetic foil body is configured in two layers in the thickness direction. T1 is a gap between the lower magnetic foil bodies, and T2 is a gap between the upper magnetic foil bodies. In the case of multilayering the magnetic foil bodies, the longest distance Tmax of the distances between the adjacent magnetic foil bodies is preferably more than 0 mm and 1 mm or less, and the shortest distance Tmin is preferably 0 mm or more and 1 mm or less. That is, the longest distance Tmax of the gap T1 between the lower magnetic foil bodies is greater than 0 mm to 1 mm or less, the shortest distance Tmin is 0 mm to 1 mm, and the longest distance Tmax of the gap T2 between the upper magnetic foil bodies is greater than 0 mm. 1 mm or less and the shortest distance Tmin is 0 mm or more and 1 mm or less. Even in the case of multi-layering, by setting Tmax and Tmin, which are gaps between adjacent magnetic foil bodies, within a predetermined range, the same effect as when the magnetic foil body is a single layer can be obtained. Also, the air layer 5 is preferably set in the same range as that of the single layer described above.

  In addition, it is preferable that the magnetic foil body is multilayered in the thickness direction, and the position of the gap between adjacent magnetic foil bodies is changed in the thickness direction. That is, as shown in FIG. 4, it is preferable to change the position of the gap T1 between the lower magnetic foil bodies and the position of the gap T2 between the upper magnetic foil bodies in the thickness direction. That is, the gap T1 and the gap T2 are not overlapped when viewed in the thickness direction. By preventing the positions of all the gaps T1 and T2 from overlapping, the noise reduction effect can be enhanced.

  In consideration of the total thickness of the magnetic sheet, the number of laminated magnetic foil members in the thickness direction is preferably 2 to 3. When the magnetic foil body is multilayered, it is preferable to provide the adhesive layer 3 between the magnetic foil bodies 2 and 2 that move up and down. By providing the adhesive layer 3 between the magnetic foil bodies 2 that move up and down, displacement of the magnetic foil body 2 can be prevented. Moreover, it is preferable that the thickness of the contact bonding layer 3 provided between the magnetic foil bodies 2 to move up and down is 5-15 micrometers. Moreover, you may arrange | position the adhesive sheet which has arrange | positioned the adhesive layer on both surfaces of the resin film (thickness 10-50 micrometers). When this adhesive sheet is used, the adhesive layer provided on one side preferably has a thickness in the range of 5 to 15 μm. Using the adhesive sheet improves the strength of the magnetic sheet itself.

  Further, when the thickness of the adhesive layer is less than 5 μm, the adhesive force may be insufficient. On the other hand, if the thickness of the adhesive layer exceeds 15 μm, there is a possibility that no further effect can be obtained.

  If it is the above magnetic sheets, a wide magnetic sheet can be provided. In addition, the flexibility and flatness of the magnetic sheet can be imparted. Further, it can be attached to the rear surface of the display, and low frequency noise in the vicinity of several hundred kHz can be effectively reduced. Therefore, the display including the magnetic sheet of the present invention can suppress screen flicker.

  FIG. 5 shows an embodiment of a display according to the present invention. In FIG. 5, 1 is a magnetic sheet, and 6 is a display body. The display body and magnetic sheet can be attached by various methods such as using an adhesive, sandwiching between the display and the circuit board (including secondary battery), sandwiching between the display and the housing, etc. It is. Since the magnetic sheet of the present invention has a plurality of magnetic foils arranged, even if the short side of the display is enlarged to 100 mm or more, the flickering of the screen due to low frequency noise can be suppressed. Further, since the flatness is improved by adjusting Tmin or the like, it can be suitably mounted even in a device field where the space in the thickness direction is thin, such as a tablet terminal. Further, the display can correspond to various displays such as an LCD (liquid crystal display). As for the display, low frequency noise of several hundred kHz, particularly 500 to 800 kHz, generated from a control circuit or the like can be efficiently suppressed.

  Further, when the display is a touch panel type, malfunction of the touch panel can be prevented. There are three types of touch panels: pressure-sensitive, electrostatic, and digitizer types, and there are also methods that combine electrostatic and digitizer types. The pressure-sensitive type is a method of sensing the pressure with which the touch panel is pressed with a finger or a touch pen. In addition, the electrostatic method is a method of detecting a change in electric capacity on the panel surface, and a method of detecting a slight current possessed by the user is general. The digitizer method is a method using a dedicated touch pen called a digitizer pen. The digitizer method is an electromagnetic induction method in which the coordinates of the digitizer pen are detected by a plurality of antenna coils. The digitizer pen includes a transmission coil and an oscillation circuit and a control circuit for generating an alternating magnetic field from the coil. In the digitizer system, a signal having a frequency of 500 to 800 kHz is sensed.

  Since the pressure-sensitive type senses the pressing force, it can be sensed even with a gloved finger. On the other hand, since the pressing force is required, the panel (display) is easily damaged. The electrostatic type can detect an operation with a human finger, but cannot detect it with a glove. In addition, the digitizer type requires a dedicated touch pen, but does not operate even if a human hand touches it, so that it can be prevented from being operated by mistake.

  Since the operation of electronic devices in recent years has become complicated, it is important to prevent them from being operated by mistake, and the digitizer method has attracted attention. As described above, the digitizer system is an electromagnetic induction system and senses a signal having a frequency of 500 to 800 kHz. In the case of a display equipped with a digitizer type, if there is a metal member (for example, an iron desk or the like) around the display, it may adversely affect the signal perception and cause malfunction. However, by using the magnetic sheet of this embodiment, even if there is a metal member around the display, it is possible to prevent adverse effects on signal perception and prevent malfunction.

  Next, a manufacturing method will be described. With respect to the magnetic sheet according to the present invention, the production method is not particularly limited, but the following method may be mentioned as a method for producing efficiently.

  First, a magnetic foil is prepared. In preparing the magnetic foil body, a roll quenching method or a rolling method is used. When an amorphous alloy ribbon is used, such as a Co-based amorphous alloy, a Fe-based amorphous alloy, or a Fe-based alloy having a fine crystal structure, a roll quenching method is used. In the case of permalloy, the rolling method is used. The conditions of the roll quenching method and the rolling method are adjusted to control the plate thickness, the end face shape of the ribbon, and the surface unevenness. Further, the magnetic permeability and magnetostriction are controlled by controlling the composition.

  Next, a step of slitting the obtained magnetic ribbon is performed. By adjusting slit processing conditions such as slit tooth shape and slit processing speed, the width of the magnetic foil body is adjusted, and microscopic irregularities are given to the cut side surface. In order to increase mass productivity, it is effective to wind the magnetic foil body after cutting into a spool shape.

  Next, a heat treatment step such as strain relief heat treatment is performed. This heat treatment step also adjusts magnetic characteristics such as magnetic permeability and magnetostriction.

  Next, a laminating process is performed. First, it is preferable to prepare a resin film in which an adhesive layer is integrated in advance. The adhesive layer may be applied on the resin film by a hot melt method or the like. A step of arranging the magnetic foil on the adhesive layer is performed. The magnetic foil body is gradually placed on the adhesive layer from one end face, thereby preventing an air layer from being formed between the adhesive layer and the magnetic foil body. Further, when arranging a plurality of magnetic foil bodies, the magnetic foil bodies are arranged while adjusting the gap.

  When adjusting the gap between adjacent magnetic foil bodies, it is preferable to use a spool in which a long magnetic foil body is wound in advance. By arranging a plurality of spools and supplying the magnetic foil body on the adhesive layer, it becomes easy to uniformly arrange the gaps between adjacent magnetic foil bodies. Moreover, when arranging a long magnetic foil body using a spool, it is preferable to arrange | position on an adhesive layer, cutting | disconnecting by appropriate length. An air layer can be eliminated between the magnetic foil body and the adhesive layer by controlling the speed and pressure when arranging the long magnetic foil body using the spool. In addition, when the magnetic foil body is multilayered, the processing is performed after forming a laminated structure. Moreover, when making multilayer, it is preferable to provide an adhesive layer between the magnetic foil bodies which move up and down. Further, after the first magnetic foil body is disposed, an adhesive layer is applied or a resin film provided with adhesive layers on both sides is provided.

  Next, a resin film in which the adhesive layer is integrated can be covered, and a structure in which the resin film is provided on both surfaces of the magnetic foil body via the adhesive layer can be obtained. Moreover, by winding up the resin film with an adhesive layer on a spool, the upper resin film with an adhesive layer, the magnetic foil body, and the lower resin film can be laminated simultaneously. At this time, if the circumferential diameter of the spool is increased, the magnetic foil body and the resin film are not bent and wrinkled. If it is not bent, it will be cheaper to attach to the display.

  Moreover, after laminating | stacking an upper and lower resin film, it heat-presses and seals a resin film and forms a magnetic sheet. Further, post-processing such as cutting and Thomson processing may be performed as necessary. Moreover, when cut to a required length, the magnetic foil body of the cut surface may be exposed, or a magnetic foil body cut in advance to a required length is arranged and the gap is cut to form a magnetic foil body. You may make it not to be exposed.

  Moreover, it is preferable that the pressing force at the time of pressing and laminating | stacking an upper and lower resin film is 1 Mpa or less. When a large pressure is applied exceeding 1 MPa, air in the gap between adjacent magnetic foil bodies escapes and enters between the magnetic foil body and the adhesive layer. Further, if a large pressing force is applied, the magnetic foil body may be destroyed. Therefore, the pressing force at the time of stacking is preferably as low as 1 MPa or less, and more preferably 0.5 MPa or less. Moreover, an air layer can remain in the clearance gap between adjacent magnetic foil bodies by laminating | stacking with a small pressing force of 1 MPa or less, further 0.5 MPa or less.

  For example, if it is a magnetic sheet in which a long magnetic foil body and a resin film are integrated, it can be cut at a target length each time. Moreover, if the magnetic foil bodies cut in advance by a predetermined length are arranged, the end face of the magnetic foil body is not exposed, so that deterioration such as rust can be prevented.

(Example)
Example 1
A Co-based amorphous alloy ribbon (composition formula: Co ₆₈ Fe _4.5 Cr _2.5 Si ₁₅ B ₁₀ ) having a width of 33 mm and an average plate thickness of 20 μm was produced by a single roll method. The obtained Co-based amorphous alloy ribbon had a thermal expansion coefficient of 12 ppm / ° C. and zero magnetostriction.

  Next, this Co-based amorphous alloy ribbon was cut to a length of 150 mm to prepare a magnetic foil body (width 33 mm × length 150 mm). Moreover, as a resin film with an adhesive layer, a PET film with an adhesive layer (PET thickness 35 μm, adhesive layer 10 μm) was prepared and prepared on both surfaces of the magnetic foil body.

  Three magnetic foil bodies were arranged on the PET film adhesive layer with the longest distance Tmax = 0.200 mm and the shortest distance Tmin = 0.150 mm. The adhesive layer surface of the PET film with an adhesive layer was laminated on the magnetic foil body from above. The magnetic sheet according to Example 1 (W1 = 102 mm, W2 = 150 mm) was prepared by sandwiching with pressing force (0.1 MPa) and integrating by thermocompression bonding.

(Examples 2-4 and Comparative Examples 1-2)
Magnetic sheets according to Examples 2 to 4 and Comparative Examples 1 to 2 were prepared under the conditions shown in Table 1 using the same magnetic foil body as in Example 1 and a PET film with an adhesive layer. In Comparative Example 2, the end portions of adjacent magnetic foil bodies are fixed in a state of being overlapped by 1.00 mm.

(Example 5)
An Fe-based amorphous alloy ribbon (composition formula: Fe ₉₀ Si ₇ B ₃ ) having a width of 50 mm and an average plate thickness of 25 μm was prepared by a single roll method. The obtained Fe-based amorphous ribbon had a thermal expansion coefficient of 7 ppm / ° C. and a magnetostriction of 29 ppm.

  Next, this Fe-based amorphous alloy ribbon was cut into a length of 150 mm to prepare a magnetic foil body (width 50 mm × length 150 mm). Moreover, as a resin film with an adhesive layer, a PET film with an adhesive layer (PET thickness 35 μm, adhesive layer 10 μm) was prepared and prepared on both surfaces of the magnetic foil body.

  Two magnetic foil bodies were arranged on the PET film adhesive layer with the longest distance Tmax = 0.20 mm and the shortest distance Tmin = 0.15 mm. The adhesive layer surface of the PET film with an adhesive layer was laminated on the magnetic foil body from above. The magnetic sheet according to Example 5 (W1 = 102 mm, W2 = 150 mm) was prepared by sandwiching with pressing force (0.1 MPa) and integrating by thermocompression bonding.

(Example 6)
An Fe-based microcrystalline alloy ribbon (composition formula: Fe ₇₄ Nb ₂ Cu ₂ Si ₈ B ₁₄ ) having a width of 50 mm and an average plate thickness of 20 μm was prepared by a single roll method. The obtained Fe-based fine crystal alloy ribbon had an area ratio of fine crystals with an average grain size of 30 nm of 95% or more, a thermal expansion coefficient of 7 ppm / ° C., and a magnetostriction of 2 ppm.

  Next, the Fe-based fine crystal alloy ribbon was cut into a length of 150 mm to prepare a magnetic foil body (width 50 mm × length 150 mm). Moreover, as a resin film with an adhesive layer, a PET film with an adhesive layer (PET thickness 35 μm, adhesive layer 10 μm) was prepared and prepared on both surfaces of the magnetic foil body.

  Two magnetic foil bodies were arranged on the PET film adhesive layer with the longest distance Tmax = 0.20 mm and the shortest distance Tmin = 0.15 mm. The adhesive layer surface of the PET film with an adhesive layer was laminated on the magnetic foil body from above. The magnetic sheet (W1 = 102 mm, W2 = 154 mm) according to Example 6 was prepared by sandwiching with pressing force (0.1 MPa) and integrating by thermocompression bonding.

  In the magnetic sheets of Examples 1 to 6 and Comparative Examples 1 and 2, the ratio of the air layer in the gap between the adjacent magnetic foil bodies, the flatness, the presence or absence of an air layer between the magnetic foil body and the adhesive layer investigated. The results are shown in Table 2 below.

For the ratio of the air layer, the gap between the adjacent magnetic foil bodies was taken with an enlarged photograph, and the ratio G of the air layer was determined by the area ratio (G / S) with the total sheet area S. The flatness was obtained as a difference between the magnetic sheet placed on a flat surface, the height of the magnetic foil body at the highest position and the height of the magnetic foil body at the lowest position. The presence or absence of an air layer between the magnetic foil and the adhesive layer was determined by appearance inspection.

Next, the magnetic permeability, noise absorbability, and high temperature resistance were investigated for each magnetic sheet. The magnetic permeability was determined by making each magnetic ribbon into a toroidal shape. In addition, noise absorption was measured by attaching a magnetic sheet to the back of an LCD (100 × 150) for a tablet terminal, operating the terminal, and measuring radiation noise at 700 kHz. In this case, the ratio (relative value) when the noise absorption of Example 1 is set to 1 is shown. In addition, for high temperature resistance, 100 magnetic sheets were prepared, and the presence or absence of appearance defects such as flatness and bubbles was examined after leaving for 96 hours in an atmosphere at 60 ° C. and a relative humidity of 95%. The results are shown in Table 3 below.

  As is apparent from the results shown in Tables 1 to 3, noise leakage occurred in Comparative Example 1 because the gap was large. On the other hand, the magnetic sheets according to Examples 1 to 6 were excellent in noise absorption. In addition, as in Comparative Example 1 and Comparative Example 2, in the case where the gap between the magnetic foil bodies is too large or the magnetic foil bodies are overlapped with each other, many air layers (bubbles) are formed and thus the high temperature resistance is lowered. did. When bubbles were generated, the adhesion between the display and the magnetic sheet decreased.

  Thus, what was comprised in the scope of the embodiment as clearly shown in Examples 1-4 and Comparative Examples 1-2 using the same Co-based amorphous alloy ribbon, noise absorption characteristics, flatness and high temperature resistance It was excellent in nature. In addition, Example 5 has a low noise absorption value because the Fe-based amorphous alloy ribbon having a lower magnetic permeability than the Co-based amorphous alloy ribbon is used. Therefore, when the same Fe-based amorphous alloy ribbon is used, the characteristics within the range of the embodiment are improved by comparing the range within the range of the embodiment with that outside the range.

(Examples 7 to 9)
Next, a magnetic sheet in which magnetic foils are multilayered in the thickness direction will be described with reference to the following examples.

A Co-based amorphous alloy ribbon (composition formula: Co ₆₈ Fe ₅ Cr ₂ Si ₁₄ B ₁₁ ) having a width of 33 mm and an average plate thickness of 18 μm was produced by a single roll method. The obtained Co-based amorphous alloy ribbon had a thermal expansion coefficient of 11 ppm / ° C. and a magnetostriction of zero.

  Next, this Co-based amorphous alloy ribbon was cut to a length of 150 mm to prepare a magnetic foil body (width 33 mm × length 150 mm). Moreover, as a resin film with an adhesive layer, a PET film with an adhesive layer (PET thickness 35 μm, adhesive layer 10 μm) was prepared and prepared for both surfaces of a magnetic foil body.

  On the adhesive layer of the PET film, three magnetic foil bodies were arranged as the lower magnetic foil body with the longest distance Tmax = 0.15 mm and the shortest distance Tmin = 0.10 mm. On top of that, three magnetic foil bodies as upper magnetic foil bodies were arranged with the longest distance Tmax = 0.15 mm and the shortest distance Tmin = 0.10 mm. Further, an adhesive sheet having a thickness of 10 μm was applied to both surfaces of the resin film (thickness 30 μm) so as to cover the first-layer magnetic foil body (lower magnetic foil body), and an adhesive sheet was disposed. Furthermore, the adhesive layer surface of the PET film with an adhesive layer was laminated on the magnetic foil body from above to obtain a laminate. The laminate was sandwiched by pressing force (0.3 MPa) and integrated by thermocompression bonding to prepare magnetic sheets (W1 = 102 mm, W2 = 150 mm) according to Examples 7-8.

  In Example 7, the gap between the lower magnetic foil bodies and the gap between the upper magnetic foil bodies were set at the same position. In Example 8, the position of the gap between the lower magnetic foil bodies and the gap between the upper magnetic foil bodies was displaced in the plane direction as shown in FIG.

  In Example 9, a magnetic sheet having a three-layer structure was used. The gap between the lower magnetic foil bodies, the gap between the middle magnetic foil bodies, and the gap between the upper magnetic foil bodies were arranged with the longest distance Tmax = 0.15 mm and the shortest distance Tmin = 0.10 mm, respectively. Further, the gaps were arranged so as not to overlap each other in the thickness direction. The other production conditions are the same as in Example 8.

For the magnetic sheets according to Examples 7 to 9, the ratio (area%) of the air layer in the gap between adjacent magnetic foil bodies, flatness (mm), the air layer between the magnetic foil body and the adhesive layer The presence or absence was investigated and the results shown in Table 4 below were obtained. In addition, the measuring method of each characteristic was made into the method similar to Example 1. FIG.

Next, the magnetic permeability, noise absorptivity, and high temperature resistance of the magnetic sheets according to the above examples were measured. The measurement conditions and method were the same as in Example 1. The measurement results are shown in Table 5 below.

  As is clear from the results shown in Table 5, the magnetic sheet according to each example exhibited excellent characteristics even when it was multilayered. Also, noise absorption characteristics have been improved by multilayering.

(Examples 1A-9A and Comparative Example 3)
The magnetic sheet which concerns on Examples 1-9 was arrange | positioned on the back surface of a digitizer-type touchscreen main body, and the touchscreen which concerns on Examples 1A-9A was manufactured. Each touch panel was placed on an iron desk and touched 1000 times using a digitizer pen (dedicated touch pen) to check for malfunctions. Moreover, the touch panel which does not provide a magnetic sheet as the comparative example 3 was also prepared. The results are shown in Table 6 below.

  As is clear from the results shown in Table 6 above, it was found that the magnetic sheet according to each example can prevent malfunction of the digitizer type touch panel. For this reason, it turned out that the magnetic sheet which concerns on an Example can be effectively used for both the noise reduction of a display, and prevention of the malfunctioning of a digitizer type touch panel.

  Although several embodiments of the present invention have been described as described above, these embodiments are presented as examples and are not intended to limit the technical scope of the present invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, 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.

DESCRIPTION OF SYMBOLS 1 ... Magnetic sheet 2 ... Magnetic foil body 3 ... Adhesion layer 4 ... Resin film 2a ... 1st magnetic foil body 2b ... 2nd magnetic foil body 2c ... 3rd magnetic foil body 5 ... Air layer 6 ... Display body

Claims (9)

In a magnetic sheet having a structure in which both surfaces of a magnetic foil body are laminated with a resin film through an adhesive layer, the magnetic sheet has a plurality of magnets having a short side of 100 mm or more and a short side width of 3 to 90 mm. has a side-by-side structure of foil in a planar direction, the longest distance of the gap between adjacent magnetic foil bodies is less 1.00mm or 0.06 mm, Ri der than 0.93mm or less the shortest distance 0 mm, A magnetic sheet, wherein an air layer is present in a gap between the adjacent magnetic foil bodies . The magnetic foil body is multilayered in the thickness direction, and the longest distance between gaps between adjacent magnetic foil bodies in the planar direction is 0.06 mm or more and 1.00 mm or less, and the shortest distance is 0 mm or more and 0.93 mm or less. The magnetic sheet according to claim 1, wherein there is a magnetic sheet. The magnetic foil multilayered in the thickness direction, to any one of claims 1 to 2, characterized in that for displacing at positions in the thickness direction of the gap between the magnetic foil adjacent to the planar direction The magnetic sheet as described. The magnetic sheet according to any one of claims 1 to 3 , wherein the magnetic foil body has a thermal expansion coefficient of 5 to 40 ppm / ° C. The magnetic sheet according to any one of claims 1 to 4 , wherein the magnetic foil body is a Co-based amorphous alloy. The magnetic sheet according to any one of claims 1 to 5, wherein an air layer is not present between the surface of the magnetic foil body and the adhesive layer. The magnetic sheet according to any one of claims 1 to 6 , wherein the magnetic sheet has a surface flatness of 0.02 mm or less. The magnetic sheet according to any one of claims 1 to 7 , wherein the magnetic sheet is for noise reduction or prevention of malfunction at 500 to 800 kHz. Magnetic sheet according to any one of claims 1 to 8, wherein the magnetic sheet is for display.

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