Patent Publication Number: US-2023134880-A1

Title: Laminated varistor

Description:
TECHNICAL FIELD 
     The present disclosure relates to a laminated varistor to be used for various electronic devices. 
     BACKGROUND ART 
     In recent years, home electric appliances and in-vehicle electronic devices have been becoming smaller and smaller. Varistors that are components of these home electric appliances and in-vehicle electronic devices are also required to be small in size. In addition, as the frequency increases, the capacitance of the varistor affects the performance of a circuit that drives a home electric appliance or an in-vehicle electronic device. Therefore, there is a demand for a varistor having a small capacitance and a small variation in capacitance while securing a predetermined varistor voltage. In addition, when two varistors are used as a pair, it is proposed that the two varistors are combined and formed as one element in order to reduce a difference between the capacitances of the two varistors. As prior art literature information related to the invention of this application, PTL 1 is known as an example. 
     CITATION LIST 
     Patent Literature 
     PTL 1: Unexamined Japanese Patent Publication No. H04-277601 
     SUMMARY OF THE INVENTION 
     In the conventional laminated varistors, however, capacitance occurs between two internal electrodes facing each other exhibiting varistor performance, and also stray capacitance occurs between the internal electrode and another external electrode. In particular, the stray capacitance varies due to a variation in the thickness or shape of the external electrode. As a result, a variation in the capacitance of the varistor is likely to occur. Note that the stray capacitance refers, other than capacitance between internal electrodes included in a varistor, to capacitance occurring between the internal electrode and an external electrode and that occurring between the external electrodes or the like. 
     In response to this problem, the present disclosure discloses a laminated varistor described below. 
     That is, the laminated varistor according to the present disclosure includes a sintered body, a first external electrode, a second external electrode, a third external electrode, a first internal electrode, a second internal electrode, and a third internal electrode. The sintered body has a rectangular parallelepiped shape having an upper surface and a lower surface, and a first end surface, a first side surface, a second end surface, and a second side surface that are sequentially arranged in a counterclockwise direction as viewed from the upper surface. The sintered body is formed by laminating a plurality of varistor layers. Each of the plurality of varistor layers has a main surface, a back surface, and four end surfaces. Of two adjacent varistor layers, a main surface on one side and a back surface on the other side are joined. The four side surfaces of each of the plurality of varistor layers become the first end surface, the first side surface, the second end surface, and the second side surface of the sintered body. In addition, one of the plurality of varistor layers has a third internal electrode. At least one of the others of the plurality of varistor layers has at least one of a first internal electrode and a second internal electrode. The first external electrode is provided on the first end surface of the sintered body. The second external electrode is provided on the second end surface of the sintered body. The third external electrode is provided on the first side surface of the sintered body. The first internal electrode is electrically connected to the first external electrode. The second internal electrode is electrically connected to the second external electrode. The third internal electrode is electrically connected to the third external electrode. The first internal electrode and the third internal electrode have a first overlap when viewed from the upper surface of the sintered body. A first varistor region is formed by the first overlap. The second internal electrode and the third internal electrode have a second overlap when viewed from the upper surface of the sintered body. A second varistor region is formed by the second overlap. The first varistor region and the second varistor region are arranged at positions closer to the second side surface than to the first side surface. 
     With the configuration as described above, the stray capacitance to occur between the internal electrode and the external electrode can be reduced. Along with that, a variation in the stray capacitance due to a variation in the width or shape of a surface of the external electrode can also be reduced. As a result, when the two laminated varistors are used as a pair, a variation in the capacitance between the two laminated varistors can be reduced. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view of a laminated varistor according to a first exemplary embodiment of the present disclosure. 
         FIG.  2    is a transparent view of the laminated varistor according to the first exemplary embodiment. 
         FIG.  3    is a cross-sectional view of the laminated varistor. 
         FIG.  4    is an exploded perspective view of each layer of a sintered body constituting the laminated varistor. 
         FIG.  5    is a cross-sectional view of a laminated varistor according to a second exemplary embodiment of the present disclosure. 
         FIG.  6    is a cross-sectional view of a laminated varistor according to a third exemplary embodiment of the present disclosure. 
         FIG.  7    is a perspective view of a laminated varistor according to a fourth exemplary embodiment of the present disclosure. 
         FIG.  8    is a transparent view of the laminated varistor according to the fourth exemplary embodiment. 
         FIG.  9    is a perspective view of a laminated varistor according to a fifth exemplary embodiment of the present disclosure. 
         FIG.  10    is a transparent view of the laminated varistor according to the fifth exemplary embodiment. 
         FIG.  11    is a transparent view of the laminated varistor before being cut. 
     
    
    
     DESCRIPTION OF EMBODIMENT 
     Hereinafter, laminated varistors according to exemplary embodiments of the present disclosure will be described with reference to the drawings. 
     First Exemplary Embodiment 
       FIG.  1    is a perspective view of a laminated varistor according to a first exemplary embodiment of the present disclosure.  FIG.  2    is a transparent view of the laminated varistor as viewed from above.  FIG.  3    is a cross-sectional view of the laminated varistor of  FIG.  2   , taken along line  FIG.  4    is an exploded perspective view of each layer of a sintered body constituting the laminated varistor according to the first exemplary embodiment of the present disclosure. The sintered body of the laminated varistor, excluding an external electrodes, has a rectangular parallelepiped shape with a length of 1.6 mm, a width of 0.8 mm, and a height of 0.6 mm. 
     Sintered body  11  contains ZnO as a main component, and contains, as accessory components, Bi 2 O 3 , Co 2 O 3 , MnO 2 , Sb 2 O 3 , and the like, or Pr 6 O 11 , Co 2 O 3 , CaCO 3 , Cr 2 O 3 , and the like. The sintered body has a form in which ZnO is sintered and at their grain boundaries, the other accessory components are precipitated. In addition, internal electrodes are formed in a plurality of varistor layers constituting sintered body  11 . 
     Sintered body  11  has upper surface  28  and lower surface  29 , and first end surface  13 , first side surface  19 , second end surface  16 , and second side surface  21  that are sequentially arranged in a counterclockwise direction as viewed from upper surface  28 . 
     Note that a direction perpendicular to first end face  13  is defined as an X axis. A direction moving from first end surface  13  toward second end surface  16  is defined as a positive direction of the X axis. A direction perpendicular to first side face  19  is defined as a Y axis. A direction moving from first side surface  19  toward second side surface  21  is defined as a positive direction of the Y axis. A direction perpendicular to lower surface  29  is defined as a Z axis. A direction moving from lower surface  29  toward upper surface  28  is defined as a positive direction of the Z axis. 
     First external electrode  12  is provided on first end surface  13  of sintered body  11 . Second external electrode  15  is provided on second end surface  16  of sintered body  11 . Third external electrode  18  is provided on first side surface  19  of sintered body  11 . An external electrode is not provided on second side surface  21  of sintered body  11 . 
     As illustrated in  FIGS.  3  and  4   , sintered body  11  includes first varistor layer  11   a , second varistor layer  11   b,  and third varistor layer  11   c.  Each of first varistor layer  11   a , second varistor layer  11   b,  and third varistor layer  11   c  includes a layer that contains ZnO as a main component, and contains, as accessory components, Bi 2 O 3 , Co 2 O 3 , MnO 2 , Sb 2 O 3 , and the like, or Pr 6 O 11 , Co 2 O 3 , CaCO 3 , Cr 2 O 3 , and the like. First varistor layer  11   a  has main surface  28   a  and back surface  29   a.  Third internal electrode  20  is formed in main surface  28   a.  Second varistor layer  11   b  has main surface  28   b  and back surface  29   b.  First internal electrode  14  and second internal electrode  17  are formed in main surface  28   b . Third varistor layer  11   c  has main surface  28   c  and back surface  29   c.  First varistor layer  11   a,  second varistor layer  11   b,  and third varistor layer  11   c  are overlapped such that: main surface  28   a  of first varistor layer  11   a  is in contact with back surface  29   b  of second varistor layer  11   b;  and main surface  28   b  of second varistor layer  11   b  is in contact with back surface  29   c  of third varistor layer  11   c.  First varistor layer  11   a,  second varistor layer, and third varistor layer  11   c  that are overlapped in this way are sintered to form sintered body  11 . Note that first back surface  29   a  matches lower surface  29  of sintered body  11 . Third main surface  28   c  matches upper surface  28  of sintered body  11 . Four side surfaces of each of first varistor layer  11   a,  second varistor layer, and third varistor layer  11   c  become first end surface  13 , first side surface  19 , second end surface  16 , and second side surface  21  of sintered body  11 , respectively. 
     First external electrode  12  is electrically connected to first internal electrode  14 . Second external electrode  15  is electrically connected to second internal electrode  17 . Third external electrode  18  is electrically connected to third internal electrode  20 . 
     When viewed from upper surface  28  of sintered body  11 , a part of first internal electrode  14  and a part of third internal electrode  20  overlap. As a result, first varistor region  22  is formed. When viewed from upper surface  28  of sintered body  11 , a part of second internal electrode  17  and a part of third internal electrode  20  also overlap. As a result, second varistor region  23  is formed. With such a configuration, the laminated varistor can be efficiently produced. 
     First internal electrode  14  is connected to first external electrode  12  at a position closer to second side surface  21  than to first side surface  19 . First internal electrode  14  is extended from first end surface  13  toward second end surface  16 , and then is extended toward first side surface  19  by being bent at a substantially right angle. When viewed from upper surface  28  of sintered body  11 , first internal electrode  14  overlaps third internal electrode  20  at a portion where first internal electrode  14  is extended toward first side surface  19  by being bent. As a result, first varistor region  22  is formed. The position where first internal electrode  14  is bent is closer to second side surface  21  than third internal electrode  20  is. 
     Similarly, second internal electrode  17  is connected to second external electrode  15  at a position closer to second side surface  21  than to first side surface  19 . Second internal electrode  17  is extended from second end surface  16  toward first end surface  13 , and then is extended toward first side surface  19  by being bent at a substantially right angle. When viewed from upper surface  28  of sintered body  11 , second internal electrode  17  overlaps third internal electrode  20  at a portion where second internal electrode  17  is extended toward first side surface  19  by being bent. As a result, second varistor region  23  is formed. The position where second internal electrode  17  is bent is closer to second side surface  21  than third internal electrode  20  is. 
     Here, an interval (thickness of the varistor region) in a lamination direction (Z-axis direction) between first internal electrode  14  and third internal electrode  20  is set to about 35 μm. 
     First varistor region  22  and second varistor region  23  are formed at positions closer to second side surface  21  than to first side surface  19 . By doing in this way, it is possible to cause almost no stray capacitance between third external electrode  18  and first internal electrode  14  or second internal electrode  17 . As a result, stray capacitance to occur between the internal electrode and the external electrode of the laminated varistor can be reduced, and a variation in the stray capacitance due to a variation in the shape or dimension of the external electrode can also be reduced. Furthermore, it is more desirable to provide the whole of first varistor region  22  and second varistor region  23  at a position closer to second side surface  21  than an intermediate position between first side surface  19  and second side surface  21  is. 
     A tip portion of first internal electrode  14  protrudes from first varistor region  22  by about  50  Furthermore, a tip portion of second internal electrode  17  also protrudes from second varistor region  23  by about  50  Similarly, a tip portion of third internal electrode  20  also protrudes from first varistor region  22  and second varistor region  23  by about  50  By making the tip portions of the internal electrodes protrude in this way from the varistor regions where the internal electrodes overlap each other, a variation in capacitance can be suppressed with respect to a misalignment of the internal electrodes. The length of the protrusion is desirably more than or equal to the thickness of the varistor region and less than or equal to five times the thickness. This is because: if the length of the protrusion is less than the thickness of the varistor region, the variation in capacitance cannot be sufficiently suppressed with respect to the misalignment of the internal electrodes; and if the length is more than five times, the stray capacitance is likely to be large. 
     Second Exemplary Embodiment 
       FIG.  5    is a cross-sectional view of a laminated varistor according to a second exemplary embodiment of the present disclosure. The appearance of the laminated varistor is the same as in  FIG.  1   . In the laminated varistor illustrated in  FIG.  3   , first internal electrode  14  and second internal electrode  17  are provided in the same layer. On the other hand, in the laminated varistor illustrated in  FIG.  5   , fourth varistor layer  11   d  is provided between first varistor layer  11   a  and second varistor layer  11   b . First internal electrode  14  is formed in a main surface of second varistor layer  11   b.  Second internal electrode  17  is formed in a main surface of first varistor layer  11   a.  Third internal electrode  20  is formed in a main surface of fourth varistor layer  11   d.  First varistor region  22  and second varistor region  23  are provided not to overlap each other when viewed from the upper surface of sintered body  11 . With such a configuration, interaction between first internal electrode  14  and second internal electrode  17  can be reduced. 
     Third Exemplary Embodiment 
       FIG.  6    is a cross-sectional view of a laminated varistor according to a third exemplary embodiment of the present disclosure. The appearance of the laminated varistor is the same as in  FIG.  1   . In the laminated varistor according to the third exemplary embodiment, fourth varistor layer  11   d  and fifth varistor layer  11   e  are sequentially provided between first varistor layer  11   a  and second varistor layer  11   b.  In addition, third internal electrodes  20   a,    20   b  are electrically connected to third external electrodes. First internal electrode  14  is formed in a main surface of second varistor layer  11   b.  Second internal electrode  17  is formed in a main surface of first varistor layer  11   a.  Third internal electrode  20   a  on one side is formed in a main surface of fifth varistor layer  11   e.  Third internal electrode  20   b  on the other side is formed in a main surface of fourth varistor layer  11   d.    
     With third internal electrode  20   a  overlapping first internal electrode  14  when viewed from upper surface  28  of first varistor layer  11   a,  first varistor region  22  is formed. With third internal electrode  20   b  overlapping second internal electrode  17  when viewed from upper surface  28  of first varistor layer  11   a,  second varistor region  23  is formed. First varistor region  22  and second varistor region  23  are provided not to overlap each other when viewed from upper surface  28  of first varistor layer  11   a.  With such a configuration, interaction between the first internal electrode and the second internal electrode can be further reduced. 
     Note that different materials may be used for the layers constituting first varistor region  22  and second varistor region  23  and for the other layers. In this case, a relative permittivity of the layer not constituting the varistor region is set to be smaller than a relative permittivity of the layer constituting the varistor region. By doing in this way, the stray capacitance can be further reduced, and the variation in capacitance of the laminated varistor can also be reduced. 
     Fourth Exemplary Embodiment 
       FIG.  7    is a perspective view of a further different laminated varistor according to a fourth exemplary embodiment of the present disclosure.  FIG.  8    is a transparent view of the laminated varistor as viewed from above. The laminated varistor of  FIG.  7    is different from the laminated varistor of  FIG.  1    in that convex part  24  is provided on first side surface  19  and third external electrode  18  is provided on convex part  24 . 
     Convex part  24  is provided in a central portion of first side surface  19  and from the bottom surface to the upper surface. Its height (a height protruding from the first side surface) is set to about 50 μm to 200 μm. 
     Usually, a laminated varistor is obtained by: laminating varistor green sheets on each of which an electrode pattern to become an internal electrode has been printed; then cutting into individual pieces; sintering the pieces; and forming external electrodes. When cutting into individual pieces, the cutting is performed with a blade having a shape in which a convex part is provided in a region to become a side surface. As a result, the convex part can be formed on the first side surface. By providing convex part  24  on first side surface  19  and providing third external electrode  18  on convex part  24  in this way, a distance between first internal electrode  14  and third external electrode  18  and a distance between second internal electrode  17  and third external electrode  18  can be increased. As a result, stray capacitance can be reduced. 
     In addition, by providing third external electrode  18  on convex part  24 , a shape of third external electrode  18  can be stabilized. As a result, a variation in capacitance can be reduced. 
     In addition, by providing convex part  24 , the surface on which third external electrode  18  is to be provided can be easily recognized. 
     Further, third external electrode  18  is formed by dipping only convex part  24  into electrode paste. As a result, the shape of third external electrode  18  can be stabilized. As a result, the variation in capacitance can be further reduced. In order to form third external electrode  18  by dipping only convex part  24  into electrode paste in this way, the height of convex part  24  is desirably set to be more than or equal to about 50 μm and less than or equal to 200 μm. If the height is small, an effect of suppressing the variation is decreased. On the other hand, if the height is large, connection of a terminal electrode becomes difficult when the height is more than or equal to a solder coating height. 
     Fifth Exemplary Embodiment 
       FIG.  9    is a perspective view of a laminated varistor according to a fifth exemplary embodiment of the present disclosure.  FIG.  10    is a transparent view of the laminated varistor as viewed from above. In this laminated varistor, concave part  25  is provided in first side surface  19 , and third external electrode  18  is provided on the inside of concave part  25 . Concave part  25  has an oval shape with a concave part length of about 300 μm and a radius dimension of about 50 μm when viewed from above. In this case, the length of concave part  25  is desirably about 10% to 30% of the entire length, and the radius dimension is desirably about 50 μm to 200 μm. By providing concave part  25  in first side surface  19  and providing third external electrode  18  on the inside of concave part  25 , the shape of third external electrode  18  can be stabilized. As a result, a laminated varistor with a small variation in stray capacitance or the like can be obtained. Note that the shape of the concave part may be an elliptical shape, a semicircular shape, or the like without being limited to an oval shape. 
     In addition, it is more desirable not to provide a concave part in second side surface  21 . By doing in this way, the areas of the internal electrodes can be effectively used, and directionality becomes easier to identify by appearance. As a result, manufacturing process can be simplified. 
     As a method of providing concave part  25  only in first side surface  19 , there is the following method. First, internal electrodes are configured such that surfaces to become the first side surfaces face each other, and a varistor layer is laminated, as illustrated in  FIG.  11   . Thereafter, through hole  26  is formed by punching or the like, electrode paste to become the third external electrode is coated on the inside of through hole  26 , and the varistor layer is divided into individual pieces by cutting along cutting line  27  passing through through hole  26 . As a result, the formation of concave part  25  can be achieved. 
     (Aspects) 
     As apparent from the above exemplary embodiments, the present disclosure includes the following aspects. In the following, reference numerals are given in parentheses in order to clearly indicate the correspondence with the exemplary embodiments. 
     A laminated varistor according to a first aspect of the present disclosure includes sintered body ( 11 ), first external electrode ( 12 ), second external electrode ( 15 ), third external electrode ( 18 ), first internal electrode ( 14 ), second internal electrode ( 17 ), and third internal electrode ( 20 ). Sintered body ( 11 ) has a rectangular parallelepiped shape having upper surface ( 28 ) and lower surface ( 29 ), and first end surface ( 13 ), first side surface ( 19 ), second end surface ( 16 ), and second side surface ( 21 ) that are sequentially arranged in a counterclockwise direction as viewed from upper surface ( 28 ). In addition, sintered body ( 11 ) is formed by laminating a plurality of varistor layers ( 11   a,    11   b,    11   c ). Each of the plurality of varistor layers ( 11   a,    11   b,    11   c ) has main surface ( 11   a ), back surface ( 11   b ), and four side surfaces. Of two adjacent varistor layers ( 11   a,    11   b ), main surface ( 28   a,    28   b ) on one side and back surface ( 29   a,    29   b ) on the other side are joined. The four side surfaces of each of the plurality of varistor layers ( 11   a,    11   b,    11   c ) become first end surface ( 13 ), first side surface ( 19 ), second end surface ( 16 ), and second side surface ( 21 ) of sintered body ( 11 ). In addition, one varistor layer ( 11   a ) of the plurality of varistor layers ( 11   a,    11   b,    11   c ) has third internal electrode ( 20 ). At least one layer ( 11   b ) of the others of the plurality of varistor layers ( 11   a,    11   b,    11   c ) has at least one of first internal electrode ( 14 ) and second internal electrode ( 17 ). First external electrode ( 12 ) is provided on first end surface ( 13 ) of sintered body ( 11 ). Second external electrode ( 15 ) is provided on second end surface ( 16 ) of sintered body ( 11 ). Third external electrode ( 19 ) is provided on first side surface ( 19 ) of sintered body ( 11 ). First internal electrode ( 14 ) is electrically connected to first external electrode ( 12 ). Second internal electrode ( 17 ) is electrically connected to second external electrode ( 15 ). Third internal electrode ( 20 ) is electrically connected to third external electrode ( 18 ). First internal electrode ( 14 ) and third internal electrode ( 18 ) have a first overlap when viewed from upper surface ( 28 ) of sintered body ( 11 ). First varistor region ( 22 ) is formed by the first overlap. Second internal electrode ( 17 ) and third internal electrode ( 18 ) have a second overlap when viewed from the upper surface of sintered body ( 11 ). Second varistor region ( 23 ) is formed by the second overlap. First varistor region ( 22 ) and second varistor region ( 23 ) are arranged at positions closer to second side surface ( 21 ) than to first side surface ( 19 ). 
     According to the laminated varistor of the first aspect, it is possible to cause almost no stray capacitance between third external electrode ( 18 ) and first internal electrode ( 14 ) or second internal electrode ( 17 ). As a result, the stray capacitance to occur between first internal electrode ( 14 ) or second internal electrode ( 17 ) and third external electrode ( 18 ) can be reduced. Along with that, a variation in the stray capacitance due to a variation in third external electrode ( 18 ) can also be reduced. 
     In the laminated varistor of the first aspect according to a second aspect of the present disclosure, first internal electrode ( 14 ) is connected to first external electrode ( 12 ) at a position closer to second side surface ( 21 ) of sintered body ( 11 ) than third internal electrode ( 20 ) is. In addition, first internal electrode ( 14 ) extends toward second end surface ( 16 ) of sintered body ( 11 ). First internal electrode ( 14 ) bends at another position closer to second side surface ( 21 ) of sintered body ( 11 ) than third internal electrode ( 20 ) is, extends toward first side surface ( 19 ), and has the first overlap. 
     In the laminated varistor of the first aspect according to a third aspect of the present disclosure, first internal electrode ( 14 ) and second internal electrode ( 17 ) are provided in different varistor layers ( 11   a,    11   b ). First varistor region ( 22 ) and second varistor region ( 23 ) are arranged at different positions when viewed from upper surface ( 28 ) of sintered body ( 11 ). 
     According to the laminated varistor of the third aspect, interaction between first internal electrode ( 14 ) and second internal electrode ( 17 ) can be reduced. 
     In the laminated varistor of the first aspect according to a fourth aspect of the present disclosure, third internal electrodes ( 20   a,    20   b ) are provided in two different varistor layers ( 11   d,    11   e ). Third internal electrode ( 20   a ) in varistor layer ( 11   e ) on one side overlaps first internal electrode ( 14 ) when viewed from upper surface ( 28 ) of sintered body ( 11 ). As a result, first varistor region ( 22 ) is formed. Third internal electrode ( 20   b ) in varistor layer ( 11   d ) on the other side overlaps second internal electrode ( 17 ) when viewed from upper surface ( 28 ) of sintered body ( 11 ). As a result, second varistor region ( 23 ) is formed. First varistor region ( 22 ) and second varistor region ( 23 ) are arranged at different positions when viewed from the upper surface of sintered body ( 11 ). 
     According to the laminated varistor of the fourth aspect, the interaction between first internal electrode ( 14 ) and second internal electrode ( 17 ) can be further reduced. 
     In the laminated varistor of the first aspect according to a fifth aspect of the present disclosure, convex part ( 24 ) is provided on first side surface ( 19 ). Third external electrode ( 18 ) is provided on convex part ( 24 ). 
     According to the laminated varistor of the fifth aspect, a distance between first internal electrode ( 14 ) and third internal electrode ( 18 ) and a distance between second internal electrode ( 17 ) and third internal electrode ( 18 ) can be increased. As a result, stray capacitance can be reduced. In addition, by providing third external electrode ( 18 ) on convex part ( 24 ), a shape of third external electrode ( 18 ) can be stabilized. As a result, a variation in capacitance of the laminated varistor can be reduced. In addition, by providing convex part ( 24 ), the surface on which third external electrode  18  is to be provided can be easily recognized. 
     In the laminated varistor of the first aspect according to a sixth aspect of the present disclosure, concave part ( 25 ) is provided in first side surface ( 19 ). Third external electrode ( 18 ) is provided on the inside of concave part ( 25 ). 
     According to the laminated varistor of the sixth aspect, concave part ( 25 ) is provided in first side surface ( 19 ), and third external electrode ( 18 ) is provided on the inside of concave part ( 25 ). As a result, the shape of third external electrode ( 18 ) can be stabilized. As a result, a laminated varistor with a small variation in stray capacitance or the like can be obtained. 
     In the laminated varistor of the sixth aspect according to a seventh aspect of the present disclosure, second side surface ( 21 ) is flat. 
     According to the laminated varistor of the seventh aspect, the areas of internal electrodes ( 14 ,  17 ,  18 ) can be effectively used, and directionality becomes easier to identify by appearance. As a result, manufacturing process can be simplified. 
     INDUSTRIAL APPLICABILITY 
     The laminated varistor according to the present disclosure can reduce stray capacitance to occur between an internal electrode and an external electrode, and can also reduce a variation in the stray capacitance due to a variation in the external electrode. As a result, the laminated varistor is industrially useful. 
     REFERENCE MARKS IN THE DRAWINGS 
     
         
           11 : sintered body 
           11   a : first varistor layer 
           11   b : second varistor layer 
           11   c : third varistor layer 
           11   d : fourth varistor layer 
           11   e : fifth varistor layer 
           12 : first external electrode 
           13 : first end surface 
           14 : first internal electrode 
           15 : second external electrode 
           16 : second end surface 
           17 : second internal electrode 
           18 : third external electrode 
           19 : first side surface 
           20 ,  20   a,    20   b : third internal electrode 
           21 : second side surface 
           22 : first varistor region 
           23 : second varistor region 
           24 : convex part 
           25 : concave part 
           26 : through hole 
           27 : cutting line 
           28 : upper surface 
           28   a,    28   b,    28   c : main surface 
           29 : lower surface 
           29   a,    29   b,    29   c : back surface