Static electricity countermeasure component and method for manufacturing static electricity countermeasure component
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
- Filing Date
- 2026-01-23
- Publication Date
- 2026-08-06
Smart Images
Figure JP2026002182_06082026_PF_FP_ABST
Abstract
Description
Electrostatic protection component and method for manufacturing the same
[0001] The present disclosure relates to an electrostatic protection component for absorbing static electricity and a method for manufacturing the same.
[0002] In recent years, in order to meet the demands for miniaturization and high performance of electronic devices such as mobile phones, further miniaturization and high integration of ICs (Integrated Circuits) have been progressing. On the other hand, the breakdown voltage has been decreasing. Therefore, even a small-energy surge such as an electrostatic discharge surge generated when a human body contacts a terminal of an electronic device may cause damage or malfunction of the IC.
[0003] As a countermeasure, a method is adopted in which an electrostatic protection component is provided between a wiring through which static electricity enters and a ground to bypass the static electricity and suppress the high voltage applied to the IC. The electrostatic protection component has a high resistance value and does not conduct electricity in a normal state, but has a characteristic that when a high-voltage electricity such as static electricity is applied, the resistance value becomes low and electricity flows.
[0004] The electrostatic protection component described in Patent Document 1 has a ceramic body including a cavity, and two discharge electrodes exposed in the cavity and facing each other in the thickness direction of the cavity.
[0005] International Publication No. 2009 / 069270
[0006] In the electrostatic protection component described in Patent Document 1, due to manufacturing errors or the like, one of the two discharge electrodes may be deformed toward the other discharge electrode at the edge portion of the cavity. In this case, if the two discharge electrodes face each other at the edge portion of the cavity, the distance between the opposing portions of the two discharge electrodes becomes narrow, so that the insulation resistance value between the discharge electrodes decreases.
[0007] An electrostatic discharge (ESD) countermeasure component according to one aspect of the present disclosure comprises a base body, a first discharge electrode, and a second discharge electrode. The base body has a discharge cavity located inside, and a first opposing surface and a second opposing surface facing the discharge cavity and facing each other in a first direction. The first discharge electrode has a first exposed portion extending along the first opposing surface on the first opposing surface and to one side in a second direction perpendicular to the first direction, and exposed to the discharge cavity, and a first embedded portion continuous with the other side of the first exposed portion in the second direction and embedded in the base body. The second discharge electrode has a second exposed portion extending along the second opposing surface on the second opposing surface and to the other side in the second direction, and exposed to the discharge cavity, and a second embedded portion continuous with the one side of the second exposed portion in the second direction and embedded in the base body. The first exposed portion and the second exposed portion are positioned offset from each other in the third direction such that, when viewed in the first direction, a portion of the third direction perpendicular to the second direction overlaps with each other.
[0008] A method for manufacturing an electrostatic discharge (ESD) component according to one aspect of the present disclosure comprises a first step, a second step, a third step, a fourth step, a fifth step, and a sixth step. In the first step, a first discharge electrode substrate extending to one side in one direction is printed on the upper surface of a first substrate. In the second step, a paste-like substrate is printed on the first substrate on which the first discharge electrode substrate is printed, such that an opening is formed that exposes the one end of the first discharge electrode substrate in the one direction. In the third step, a cavity-forming material with a lower thermal decomposition temperature than the first substrate and the paste-like substrate is placed in the opening. In the fourth step, a second discharge electrode substrate extending to the other side in the one direction is printed on the cavity-forming material and the paste-like substrate. In the fifth step, a second substrate is placed on the cavity-forming material on which the second discharge electrode substrate is printed and on the paste-like substrate. In the sixth step, the unfired laminate, which is a stack of the first base material, the first discharge electrode base material, the paste-like base material, the cavity-forming material, the second discharge electrode base material, and the second base material, is heated while being pressed vertically to volatilize the cavity-forming material and fire the unfired laminate. In the fourth step, the second discharge electrode base material is printed such that, when viewed from above, a portion of one side of the first discharge electrode base material in one direction and a portion of the second discharge electrode base material in the other direction overlap each other in a part of the orthogonal direction perpendicular to the one direction.
[0009] According to one embodiment of the electrostatic discharge (ESD) countermeasure component and the method for manufacturing the ESD countermeasure component, the distance between the opposing portions of the two discharge electrodes is less likely to become narrow.
[0010] Figure 1 is a front cross-sectional view showing an electrostatic discharge (ESD) protection component according to one embodiment of the present disclosure. Figure 2 is a cross-sectional view of the ESD protection component of Figure 1 along line A-A. Figure 3 is a cross-sectional view of the ESD protection component of Figure 1 along line B-B. Figure 4 is a schematic diagram showing the layer formation for each step of the manufacturing method of the ESD protection component. Figure 5 is an exploded perspective view showing the unfired laminate forming the ESD protection component. Figure 6 is a cross-sectional view showing a modified example of the ESD protection component. Figure 7 is a cross-sectional view showing yet another modified example of the ESD protection component. Figure 8 is a cross-sectional view showing yet another modified example of the ESD protection component.
[0011] The electrostatic discharge (ESD) countermeasures components according to the embodiments will be described below with reference to the drawings. The figures described in the embodiments below are schematic diagrams, and the ratios of the size and thickness of each component do not necessarily reflect the actual dimensional ratios. Furthermore, the configurations described in the embodiments below are merely examples of the present disclosure. The present disclosure is not limited to the embodiments below, and various modifications are possible depending on the design, etc., as long as the effects of the present disclosure can be achieved.
[0012] In the following, the configuration of each electrostatic discharge (ESD) countermeasure component will be described using the mutually orthogonal first direction (X direction), second direction (Y direction), and third direction (Z direction) shown in this drawing. Note that the X, Y, and Z directions are not intended to specify the direction in which the ESD countermeasure component is used. To further clarify the directions, directions X1, Y1, and Z1, which are the X, Y, and Z directions respectively, are defined, and directions X2, Y2, and Z2, which are opposite to directions X1, Y1, and Z1, respectively, are defined.
[0013] (One Embodiment) 1. As shown in the schematic diagrams 1 and 2, the electrostatic discharge countermeasure component 1 comprises a base body 2, a first discharge electrode 3, and a second discharge electrode 4. The base body 2 has a discharge cavity 20 located inside, and a first opposing surface 240 and a second opposing surface 250 facing the discharge cavity 20 and facing each other in the first direction (Z direction), which is direction Z1. The first discharge electrode 3 has a first exposed portion 30 that extends along the first opposing surface 240 and to one side in the second direction (Y direction) perpendicular to the first direction (Z direction), and is exposed to the discharge cavity 20. In this embodiment, the first exposed portion 30 is provided on the first opposing surface 240. The first discharge electrode 3 further has a first embedded portion 31 that is continuous with the other side of the first exposed portion 30 in the second direction (Y direction) and is embedded in the base body 2. The second discharge electrode 4 has a second exposed portion 40 that extends along the second opposing surface 250 to the other side in the second direction (Y direction) and is exposed to the discharge cavity 20, and a second embedded portion 41 that is continuous with one side of the second exposed portion 40 in the second direction (Y direction) and is embedded in the base body 2. In this embodiment, the second exposed portion 40 is provided on the second opposing surface 250. The first exposed portion 30 and the second exposed portion 40 are positioned offset from each other in the third direction (X direction) such that, when viewed in the first direction (Z direction), a part of the third direction (X direction) which is perpendicular to the second direction (Y direction) overlaps with each other. In this embodiment, the first exposed portion 30 of the first discharge electrode 3 extends in direction Y1. The first embedded portion 31 of the first discharge electrode 3 is continuous with the end 30p of the first exposed portion 30 in the direction Y2 opposite to direction Y1. The second exposed portion 40 of the second discharge electrode 4 extends in direction Y2. The second embedded portion 41 of the second discharge electrode 4 is continuous with the end 40p of the second exposed portion 40 in direction Y1. When viewed in the Z direction, the first exposed portion 30 and the second exposed portion 40 are positioned offset from each other in the X direction, such that the portion of the first exposed portion 30 in direction X2 and the portion of the second exposed portion 40 in direction X1 overlap each other. That is, when viewed in the Z direction, the portion of the first exposed portion 30 in direction X1 does not overlap with the second exposed portion 40, and the portion of the second exposed portion 40 in direction X2 does not overlap with the first exposed portion 30.
[0014] In the electrostatic discharge protection component 1 having the above configuration, the exposed portions 30 and 40 exposed in the discharge cavity 20 are positioned offset in the third direction such that a portion of them overlap when viewed in the first direction, so that the exposed portions 30 and 40 are less likely to face each other at the end of the discharge cavity 20 in the third direction. Therefore, in the electrostatic discharge protection component 1, even if the thickness of the end of the discharge cavity 20 in the third direction is small, the two discharge electrodes 3 and 4 are less likely to face each other at the end of the discharge cavity 20 in the third direction, and the distance between the opposing portions of the two discharge electrodes 3 and 4 is less likely to become narrow.
[0015] 2. Details Next, we will describe in more detail the electrostatic discharge countermeasure component 1 of one embodiment shown in Figures 1 to 5.
[0016] The electrostatic discharge (ESD) countermeasure component 1 comprises a base body 2, a first discharge electrode 3, and a second discharge electrode 4. The ESD countermeasure component 1 further comprises a first terminal electrode 5 electrically connected to the first discharge electrode 3, and a second terminal electrode 6 electrically connected to the second discharge electrode 4. The first terminal electrode 5 and the second terminal electrode 6 are formed on the outside of the base body 2.
[0017] 2-1. As shown in Figures 1 to 3, the base body 2 has a discharge cavity 20 inside. The base body 2 is made of an insulator and has a roughly rectangular parallelepiped shape. The base body 2 is made of ceramic, which has excellent heat resistance and thermal shock resistance, so that it is not damaged even if a discharge occurs in the discharge cavity 20 inside.
[0018] More specifically, the base body 2 is made of a ceramic insulator containing at least one ceramic composition selected from alumina, forsterite, steatite, mullite, and cordierite as its main component. These ceramic insulators have a low relative permittivity of 15 or less, which can reduce the parasitic capacitance between the first discharge electrode 3 and the second discharge electrode 4.
[0019] The base body 2 has a first opposing surface 240 and a second opposing surface 250 facing the discharge cavity 20 and in the first direction (specifically the Z direction). When an overvoltage is applied to the first discharge electrode 3 and the second discharge electrode 4, a discharge occurs within the discharge cavity 20.
[0020] As shown in Figure 5, the base body 2 is formed by firing a laminate composed of a first base body substrate 24 made up of multiple insulating sheets 21, a paste-like base body substrate 22, and a second base body substrate 25 made up of multiple insulating sheets 21.
[0021] Each of the multiple insulating sheets 21 is an unfired ceramic green sheet. The paste-like base material 22 is an unfired ceramic paste. Each of the multiple insulating sheets 21 and the paste-like base material 22 is formed from, for example, low-temperature co-fired ceramics (LTCC).
[0022] The multiple insulating sheets 21 include a first insulating sheet 21a, a second insulating sheet 21b, a third insulating sheet 21c, a fourth insulating sheet 21d, a fifth insulating sheet 21e, and a sixth insulating sheet 21f. The first insulating sheet 21a, the second insulating sheet 21b, the third insulating sheet 21c, the fourth insulating sheet 21d, the fifth insulating sheet 21e, and the sixth insulating sheet 21f are arranged in this order from bottom to top. The multiple insulating sheets 21 are all the same in shape.
[0023] The first base material 24 is composed of a first insulating sheet 21a, a second insulating sheet 21b, and a third insulating sheet 21c. The second base material 25 is composed of a fourth insulating sheet 21d, a fifth insulating sheet 21e, and a sixth insulating sheet 21f.
[0024] The paste-like substrate 22 is provided between the first substrate 24 and the second substrate 25 by printing. The paste-like substrate 22 is printed on the first substrate 24 such that it forms openings 220 in the center in the X and Y directions.
[0025] A cavity-forming material 23, which volatilizes during firing, is placed in the opening 220. The opening 220 is rectangular when viewed in the Z direction.
[0026] The cavity-forming material 23 is made of, for example, an acrylic resin with a low thermal decomposition temperature, and in this embodiment, it is formed of acrylic beads. The cavity-forming material 23 is in the shape of a rectangular plate. The cavity-forming material 23 is slightly longer than the opening 220 in the X, Y, and Z directions.
[0027] The cavity-forming material 23 placed in the opening 220 volatilizes during firing of the laminate, thereby forming a base body 2 having a discharge cavity 20 inside.
[0028] As shown in Figures 1 to 3, the discharge cavity 20 is formed in the shape of an inverted pyramidal The pair of wall surfaces 260a and 260b facing the discharge cavity 20 in the X direction are inclined surfaces that are positioned outward in the X direction as you move towards the upper part, i.e., towards the Z1 direction. The pair of wall surfaces 260c and 260d facing the discharge cavity 20 in the Y direction are inclined surfaces that are positioned outward in the Y direction as you move towards the upper part. That is, wall surface 260a is inclined with respect to the first opposing surface 240 so that it extends in the X1 direction as you move towards the Z1 direction from the first opposing surface 240. Wall surface 260b is inclined with respect to the first opposing surface 240 so that it extends in the X2 direction as you move towards the Z1 direction from the first opposing surface 240. Wall surface 260c is inclined with respect to the first opposing surface 240 so that it extends in the Y1 direction as you move towards the first opposing surface 240. Wall surface 260d is inclined with respect to the first opposing surface 240 so that it extends in the Y2 direction as you move towards the Z1 direction from the first opposing surface 240. In this embodiment, each inclined surface is flat, but it may also be a curved surface.
[0029] The portion of the upper surface of the first substrate 24 (i.e., the upper surface of the third insulating sheet 21c) that faces the discharge cavity 20 is the first opposing surface 240. The portion of the lower surface of the second substrate 25 (i.e., the lower surface of the fourth insulating sheet 21d) that faces the discharge cavity 20 is the second opposing surface 250. The second opposing surface 250 is slightly longer than the first opposing surface 240 in both the X and Y directions.
[0030] 2-2. Discharge Electrode As shown in Figure 1, the first discharge electrode 3 is embedded in the base body 2. The first discharge electrode 3 is formed by firing the first discharge electrode base material 3a (see Figure 5). The first discharge electrode 3 contains, for example, Au (gold).
[0031] As shown in Figure 2, the first discharge electrode 3 is rectangular in shape when viewed in the Z direction. The first discharge electrode 3 extends in the Y direction. As shown in Figures 1 and 2, the first discharge electrode 3 has a first exposed portion 30 that extends along the first opposing surface 240 and to one side in the Y direction (right side in the figure) and is exposed to the discharge cavity 20. In this embodiment, the first exposed portion 30 is provided on the first opposing surface 240. The first discharge electrode 3 further has a first embedded portion 31 that is continuous with the other side in the Y direction (left side in the figure) of the first exposed portion 30 and is embedded in the base body 2.
[0032] The second discharge electrode 4 is embedded in the base body 2. The second discharge electrode 4 is formed by firing the second discharge electrode base material 4a (see Figure 5). The second discharge electrode 4 contains, for example, Au (gold).
[0033] As shown in Figure 2, the second discharge electrode 4 is rectangular in shape when viewed in the Z direction. The second discharge electrode 4 extends in the Y direction. As shown in Figures 1 and 2, the second discharge electrode 4 has a second exposed portion 40 that extends along the second opposing surface 250 and to the other side in the Y direction (left side in the figure) and is exposed to the discharge cavity 20. In this embodiment, the second exposed portion 40 is provided on the second opposing surface 250. The second discharge electrode 4 further has a second embedded portion 41 that is continuous with one side in the Y direction (right side in the figure) of the second exposed portion 40 and is embedded in the base body 2.
[0034] As shown in Figures 2 and 3, the first exposed portion 30 and the second exposed portion 40 are positioned offset in the X direction such that, when viewed in the Z direction, a portion of them overlaps in the X direction. In this embodiment, the first exposed portion 30 is positioned towards one side of the discharge cavity 20 in the X direction, and the second exposed portion 40 is positioned towards the other side of the discharge cavity 20 in the X direction. The first discharge electrode 3 and the second discharge electrode 4 have the same length in the X direction.
[0035] As shown in Figure 2, the first exposed portion 30 and the second exposed portion 40 each include opposing portions 30a and 40a that face each other in the Z direction, and non-opposing portions 30b and 40b that do not face each other in the Z direction. The non-opposing portions 30b and 40b are the entire remaining parts of the exposed portions 30 and 40, excluding the opposing portions 30a and 40a.
[0036] The opposing portions 30a and 40a face each other at the center of the discharge cavity 20 in the X and Y directions. The opposing portions 30a and 40a are rectangular in shape when viewed in the Z direction. The length L2 of the opposing portions 30a and 40a in the X direction is shorter than the length L1 of the opposing portions 30a and 40a in the Y direction.
[0037] The non-opposing portion 30b of the first exposed portion 30 includes a first portion 300 located outside the opposing portion 30a in the X direction, and a second portion 301 located outside the opposing portion 30a in the Y direction (to the left in the figure). The non-opposing portion 30b further includes a third portion 302 located outside the opposing portion 30a in both the X and Y directions. The first portion 300, the third portion 302, and the second portion 301 are continuous in an L-shape when viewed in the Z direction.
[0038] The non-opposing portion 40b of the second exposed portion 40 includes a first portion 400 located outside the opposing portion 40a in the X direction, and a second portion 401 located outside the opposing portion 40a in the Y direction (to the right in the figure). The non-opposing portion 40b further includes a third portion 402 located outside the opposing portion 40a in both the X and Y directions. The first portion 400, the third portion 402, and the second portion 401 are continuous in an L-shape when viewed in the Z direction.
[0039] The non-opposing portion 30b of the first exposed portion 30 is located at one end in the X direction and one end in the Y direction (left side in Figure 2) of the discharge cavity 20. The non-opposing portion 40b of the second exposed portion 40 is located at the other end in the X direction and the other end in the Y direction (right side in Figure 2) of the discharge cavity 20.
[0040] 2-3. Terminal Electrodes As shown in FIGS. 1 to 3, the first terminal electrode 5 is provided at one end of the element body 2 in the Y direction, and the second terminal electrode 6 is provided at the other end of the element body 2 in the Y direction. The first terminal electrode 5 is connected to the first discharge electrode 3, and the second terminal electrode 6 is connected to the second discharge electrode 4.
[0041] Each of the first terminal electrode 5 and the second terminal electrode 6 is made of a mixture of Ag (silver) and resin that has been fired. On the surface of each of the first terminal electrode 5 and the second terminal electrode 6, a nickel plating layer and a tin plating layer are provided so as to be laminated in this order.
[0042] Each of the first terminal electrode 5 and the second terminal electrode 6 is in the shape of a rectangular box that opens inward in the Y direction. The first terminal electrode 5 covers both end faces in the X direction, both end faces in the Z direction, and one end face in the Y direction (the left end face in the figure) of one end of the element body 2 in the Y direction (the left end in the figure). The second terminal electrode 6 covers both end faces in the X direction, both end faces in the Z direction, and the other end face in the Y direction (the right end face in the figure) of the other end of the element body 2 in the Y direction (the right end in the figure).
[0043] The first terminal electrode 5 is connected to an electronic component to be protected from overvoltage, and the second terminal electrode 6 is connected to the ground side. Note that the connection destinations of the terminal electrodes 5 and 6 may be reversed.
[0044] When a normal voltage is applied, no discharge occurs between the first discharge electrode 3 and the second discharge electrode 4 separated by the discharge cavity 20, and electricity flows to the electronic component. When an overvoltage is applied, a discharge occurs between the first discharge electrode 3 and the second discharge electrode 4, and electricity due to the overvoltage flows to the electrostatic countermeasure component 1, and no overvoltage is applied to the electronic component.
[0045] 3. Manufacturing Method of Electrostatic Countermeasure Component Subsequently, the manufacturing method of the above-described electrostatic countermeasure component 1 will be described.
[0046] The manufacturing method of the electrostatic countermeasure component 1 includes a first step S1, a second step S2, a third step S3, a fourth step S4, a fifth step S5, and a sixth step S6. Here, the Z direction (direction Z1) is the upward direction, and the direction Z2 is the downward direction.
[0047] As shown in Figure 4, in the first step S1, the first discharge electrode substrate 3a is printed on the upper surface of the first base material 24 so as to extend in one direction to one side (in this embodiment, the right side, which is one side in the Y direction, i.e., direction Y1). The first discharge electrode substrate 3a is printed so as to extend from the left end (end in direction Y2) to the right end (end in direction Y1) of the upper surface of the first base material 24.
[0048] In the second step S2, a paste-like substrate 22 is printed on the first base material 24 on which the first discharge electrode substrate 3a is printed, such that an opening 220 is formed that exposes one side of the first discharge electrode substrate 3a in one direction (i.e., the right side, direction Y1). The opening 220 is formed to be rectangular (more specifically, square) when viewed in the Z direction. The opening 220 is formed so that one end of the first discharge electrode substrate 3a in one direction (i.e., the right side, direction Y1) is located in the center of the opening 220 in the Y direction, and the first discharge electrode substrate 3a is located away from the right edge of the opening 220 (the end in direction Y1). The opening 220 is also formed so that the first discharge electrode substrate 3a is located near the edge of one side of the opening 220 in the X direction (direction X1). The paste-like substrate 22 is printed on the entire upper surface of the first base material 24, excluding the central parts in the X and Y directions.
[0049] In the third step S3, a cavity-forming material 23, which has a lower thermal decomposition temperature than the first base material 24 and the paste-like base material 22, is placed in the opening 220. In the third step S3, the cavity-forming material 23 rests on the opening edge of the opening 220 of the paste-like base material 22 and is positioned in the opening 220 in such a way that it pushes the opening edge open. With the cavity-forming material 23 positioned in the opening 220, the upper surface of the cavity-forming material 23 is substantially flush with the upper surface of the paste-like base material 22 surrounding the opening 220. In this embodiment, the upper surface of the cavity-forming material 23 is located slightly above the upper surface of the paste-like base material 22.
[0050] In the fourth step S4, a second discharge electrode substrate 4a is printed on the cavity-forming material 23 and the paste-like substrate 22, extending in the other direction (i.e., the left side, which is the other side in the Y direction, direction Y2). The second discharge electrode substrate 4a is printed so as to extend from the right end (end in direction Y1) of the upper surface of the paste-like substrate 22 toward the left side (end in direction Y2). At this time, the second discharge electrode substrate 4a is printed so as to extend to the left side (direction 2) to the center of the cavity-forming material 23 in the Y direction, and away from the left end (end in direction Y2) of the cavity-forming material 23.
[0051] In the fourth step S4, the second discharge electrode substrate 4a is printed such that, when viewed from above (i.e., one side in the Z direction), i.e., in direction Z2, the portion of one side of the first discharge electrode substrate 3a in one direction (i.e., the right side, direction Y1) and the portion of the second discharge electrode substrate 4a in the other direction (i.e., the left side, direction Y2) overlap in a portion of the orthogonal direction (i.e., the X direction) perpendicular to one direction. In this embodiment, the second discharge electrode substrate 4a is printed so that it is located near the edge of the cavity forming material 23 on the other side in the X direction (direction X2) (i.e., the side opposite to the first discharge electrode substrate 3a). In this embodiment, the second discharge electrode substrate 4a is printed so that the edges of the cavity forming material 23 on the other side in the X direction (direction X2) overlap with each other. The second discharge electrode substrate 4a may be printed at a position slightly shifted in the X direction from the above position.
[0052] In the fifth step S5, the second base material 25 (specifically insulating sheets 21d, 21e, and 21f) is placed on top of the cavity forming material 23 and paste-like base material 22 on which the second discharge electrode base material 4a is printed. The second base material 25 is positioned to completely cover the second discharge electrode base material 4a, the cavity forming material 23, and the paste-like base material 22.
[0053] In the sixth step S6, the unfired laminate 26, which consists of the first base material 24, the first discharge electrode base material 3a, the paste-like base material 22, the cavity forming material 23, the second discharge electrode base material 4a, and the second base material 25, is heated while being pressed in the vertical direction (Z direction).
[0054] In this embodiment, the unfired laminate 26 is turned upside down so that directions Z1 and Z2 are downward and upward, respectively, that is, the first discharge electrode substrate 3a, the cavity forming material 23 and the paste-like substrate 22, and the second discharge electrode substrate 4a are arranged in this order from top to bottom, and the unfired laminate 26 is heated while being pressed. The pair of wall surfaces that sandwich the opening 220 of the cavity forming material 23 and the paste-like substrate 22 in the X direction, and the pair of wall surfaces that sandwich the opening 220 in the Y direction, are tilted by pressing. By firing the unfired laminate 26, the cavity forming material 23 volatilizes, and the first substrate 24, the first discharge electrode substrate 3a, the paste-like substrate 22, the second discharge electrode substrate 4a, and the second substrate 25 are fired and integrated. As a result, the first base material 24, the paste-like base material 22, and the second base material 25 are integrated to form a base body 2 having a frustoconical discharge cavity 20 inside. Then, the first discharge electrode 3 and the second discharge electrode 4a are fired to form the first discharge electrode 3 and the second discharge electrode 4, respectively. The multiple insulating sheets 21a, 21b, and 21c that make up the first base material 24 are bonded together by pressing. The multiple insulating sheets 21d, 21e, and 21f that make up the second base material 25 are bonded together by pressing. After firing, the base body 2 is positioned upside down.
[0055] Next, the first terminal electrode 5 and the second terminal electrode 6 are attached to both ends of the base body 2 in the Y direction to form the electrostatic discharge protection component 1 shown in Figures 1 and 2. The first terminal electrode 5 is in contact with and connected to the first discharge electrode 3, and the second terminal electrode 6 is in contact with and connected to the second discharge electrode 4.
[0056] 4. Effects and Effects In the electrostatic discharge (ESD) countermeasure component 1 of this embodiment described above, as shown in Figure 2, the first exposed portion 30 of the first discharge electrode 3 and the second exposed portion 40 of the second discharge electrode 4 are positioned offset in the X direction. Therefore, in the ESD countermeasure component 1 of this embodiment, even if the formation position of the discharge cavity 20 is slightly shifted in the X direction due to printing misalignment of the paste-like base material 22 (see Figures 6 and 7), the first exposed portion 30 and the second exposed portion 40 do not face each other at both ends of the discharge cavity 20 in the X direction. Consequently, in the ESD countermeasure component 1 of this embodiment, even if one of the first discharge electrode 3 and the second discharge electrode 4 is deformed in the Z direction at both edges of the discharge cavity 20 in the X direction due to manufacturing errors, the distance between the Z-direction facing portions of the two discharge electrodes 3 and 4 does not narrow. As a result, the insulation resistance value between the discharge electrodes 3 and 4 is less likely to decrease in the ESD countermeasure component 1 of this embodiment.
[0057] Furthermore, in the electrostatic discharge (ESD) countermeasure component 1 of this embodiment, the first exposed portion 30 of the first discharge electrode 3 and the second exposed portion 40 of the second discharge electrode 4 are positioned offset in the Y direction. Therefore, in the ESD countermeasure component 1 of this embodiment, even if the formation position of the discharge cavity 20 is slightly shifted in the Y direction due to printing misalignment of the paste-like base material 22, the first exposed portion 30 and the second exposed portion 40 do not face each other at both ends of the discharge cavity 20 in the Y direction. Consequently, in the ESD countermeasure component 1 of this embodiment, even if one of the first discharge electrode 3 and the second discharge electrode 4 is deformed in the Z direction at both edges of the discharge cavity 20 in the Y direction due to manufacturing errors, the distance between the portions of the two discharge electrodes 3 and 4 facing each other in the Z direction does not narrow. As a result, the insulation resistance value between the discharge electrodes 3 and 4 is less likely to decrease in the ESD countermeasure component 1 of this embodiment.
[0058] Furthermore, in the electrostatic discharge protection component 1 of this embodiment, the opposing portions 30a and 40a of the first exposed portion 30 of the first discharge electrode 3 and the second exposed portion 40 of the second discharge electrode 4 face each other at the center of the discharge cavity 20 in the X and Y directions. Therefore, in the electrostatic discharge protection component 1 of this embodiment, the distance between the opposing portions 30a and 40a is easily stabilized, making it easier to maintain a constant insulation resistance value between the discharge electrodes 3 and 4.
[0059] Furthermore, in the electrostatic discharge countermeasure component 1 of this embodiment, the length L2 in the X direction of the opposing portions 30a and 40a of the first discharge electrode 3 and the second discharge electrode 4 is shorter than the length L1 in the Y direction, which makes it easier to tolerate a misalignment in the formation position of the discharge cavity 20 in the X direction.
[0060] 5. Modified Examples Next, modified examples of the electrostatic discharge countermeasure component 1 and its manufacturing method according to the above-described embodiment will be explained. Note that the modified examples shown below can be combined as appropriate.
[0061] The opposing portions 30a and 40a of the first exposed portion 30 and the second exposed portion 40 do not necessarily have a length L2 in the X direction that is shorter than or equal to the length L1 in the Y direction, and the length L2 in the X direction may be longer than the length L1 in the Y direction.
[0062] The opposing portions 30a and 40a of the first exposed portion 30 and the second exposed portion 40 do not necessarily have to be located in the center of the discharge cavity 20 when viewed in the Z direction, and may be offset from the center of the discharge cavity 20 in the X direction, the Y direction, or both directions.
[0063] In the modified electrostatic discharge (ESD) component 1 shown in Figure 8, the embedded portions 31 and 41 of the discharge electrodes 3 and 4 may be composed of extraction electrodes 13 and 14, respectively, where the Y-direction, i.e., the end portions in directions Y1 and Y2 of the base body 2 are formed of an AgPd alloy or a mixture of Ag and an insulator. In other words, the ESD component 1 further comprises a first extraction electrode 13 connecting the first discharge electrode 3 and the first terminal electrode 5, and a second extraction electrode 14 connecting the second discharge electrode 4 and the second terminal electrode 6. The insulator is, for example, aluminum oxide (Al ２ O ３ ), silicon dioxide (SiO ２ ), titanium oxide (TiO ２In this case, the combined resistance of the discharge electrodes 3 and 4 and the extraction electrodes 13 and 14 increases, so that the voltage waveform overshoot and undershoot can be suppressed without increasing the number of components and without worsening the operating voltage of the electrostatic discharge (ESD) component 1. Generally, it is known that the change in current with respect to time in the ESD component 1 generates a first peak at a high frequency (e.g., 300 MHz) and a second peak at a low frequency (e.g., 10 MHz or less). In this modified example, the combined resistance of the discharge electrodes 3 and 4 and the extraction electrodes 13 and 14 increases, so that the current of the first peak can be suppressed.
[0064] (Summary) As described above in the embodiment and its modified form, the electrostatic discharge protection component (1) of the first embodiment has the following configuration.
[0065] In other words, the electrostatic discharge countermeasure component (1) of the first embodiment comprises a base body (2), a first discharge electrode (3), and a second discharge electrode (4). The base body (2) has a discharge cavity (20) located inside, and a first opposing surface (240) and a second opposing surface (250) facing the discharge cavity (20) and facing each other in a first direction (Z direction). The first discharge electrode (3) has a first exposed portion (30) that extends along the first opposing surface (240) on the first opposing surface (240) to one side in a second direction (Y direction) perpendicular to the first direction (Z direction) and is exposed to the discharge cavity (20). The first discharge electrode (3) further has a first embedded portion (31) that is continuous with the other side of the first exposed portion (30) in the second direction and is embedded in the base body (2). The second discharge electrode (4) has a second exposed portion (40) that extends along the second opposing surface (250) on the second opposing surface (250) and to the other side in the second direction (Y direction), exposing it to the discharge cavity (20). The second discharge electrode (4) further has a second embedded portion (41) that is continuous with one side of the second exposed portion (40) in the second direction (Y direction) and is embedded in the base body (2). The first exposed portion (30) and the second exposed portion (40) are positioned offset from each other in the third direction (X direction) such that, when viewed in the first direction (Z direction), a portion of the third direction (X direction) which is perpendicular to the second direction (Y direction) overlaps with each other.
[0066] In the electrostatic discharge protection component (1) of the first embodiment having the above configuration, the first exposed portion (30) and the second exposed portion (40) exposed in the discharge cavity (20) are offset in the third direction (X direction). Therefore, in the electrostatic discharge protection component (1) of the first embodiment, the first exposed portion (30) and the second exposed portion (40) are less likely to face each other at the end of the discharge cavity (20) in the third direction (X direction). As a result, in the electrostatic discharge protection component (1) of the first embodiment, even if one of the first discharge electrode (3) and the second discharge electrode (4) is deformed in the first direction (Z direction) at the edge of the discharge cavity (20) in the third direction (X direction) due to manufacturing errors, the distance between the portions of the two discharge electrodes (3, 4) facing each other in the third direction (Z direction) is less likely to narrow.
[0067] Furthermore, as described above in one embodiment and its modified form, the electrostatic discharge protection component (1) of the second embodiment additionally includes the following configuration in addition to the configuration of the first embodiment.
[0068] In other words, in the electrostatic discharge protection component (1) of the second embodiment, when viewed in the first direction (Z direction), the portion where the first exposed portion (30) and the second exposed portion (40) overlap (opposing portions 30a, 40a) has a length (L2) in the third direction (X direction) that is shorter than the length (L1) in the second direction (Y direction).
[0069] In the second embodiment of the electrostatic discharge countermeasure component (1) having the above configuration, misalignment of the discharge cavity (20) in the third direction (X direction) is more easily tolerated.
[0070] Furthermore, as described in the embodiment and its modified form above, the electrostatic discharge protection component (1) of the third embodiment additionally includes the following configuration in addition to the configuration of the first or second embodiment.
[0071] In other words, in the electrostatic discharge protection component (1) of the third embodiment, when viewed in the first direction (Z direction), the portion where the first exposed portion (30) and the second exposed portion (40) overlap (opposing portions 30a, 40a) is located in the central part of the discharge cavity (20) in the third direction (X direction).
[0072] In the electrostatic discharge protection component (1) of the third embodiment having the above configuration, the first exposed portion (30) and the second exposed portion (40) do not face each other at both ends of the discharge cavity (20) in the third direction (X direction), so the distance between the opposing portions of the two discharge electrodes (3, 4) does not tend to become narrow.
[0073] Furthermore, as described in the embodiment and its modified form above, the electrostatic discharge protection component (1) of the fourth embodiment additionally includes the following configuration in addition to the configuration of the third embodiment.
[0074] In other words, in the electrostatic discharge protection component (1) of the fourth embodiment, when viewed in the first direction (Z direction), the portion where the first exposed portion (30) and the second exposed portion (40) overlap (opposing portions 30a, 40a) is located in the central part of the discharge cavity (20) in the second direction (Y direction).
[0075] In the electrostatic discharge protection component (1) of the fourth embodiment having the above configuration, the first exposed portion (30) and the second exposed portion (40) do not face each other at both ends of the discharge cavity (20) in the third direction (X direction) and both ends in the second direction (Y direction). Therefore, in the electrostatic discharge protection component (1) of the fourth embodiment, the distance between the opposing portions of the two discharge electrodes (3, 4) does not tend to become narrow.
[0076] Furthermore, as described above in one embodiment and its modified form, the manufacturing method for the electrostatic discharge countermeasure component (1) of the fifth embodiment comprises the following configuration.
[0077] In other words, the manufacturing method of the electrostatic discharge countermeasure component (1) of the fifth embodiment comprises a first step (S1), a second step (S2), a third step (S3), a fourth step (S4), a fifth step (S5), and a sixth step (S6). In the first step (S1), a first discharge electrode substrate (3a) extending to one side in one direction (Y direction) is printed on the upper surface of a first base material (24). In the second step (S2), a paste-like base material (22) is printed on the first base material (24) on which the first discharge electrode substrate (3a) is printed, such that an opening (220) is formed that exposes one side of the first discharge electrode substrate (3a) in one direction (Y direction). In the third step (S3), a cavity-forming material (23) with a lower thermal decomposition temperature than the first base material (24) and the paste-like base material (22) is placed in the opening (220). In the fourth step (S4), a second discharge electrode substrate (4a) extending to the other side in one direction (Y direction) is printed on the cavity forming material (23) and the paste-like substrate (22). In the fifth step (S5), the second substrate (25) is placed on top of the cavity forming material (23) and the paste-like substrate (22) on which the second discharge electrode substrate (4a) is printed. In the sixth step (S6), the unfired laminate (26), which is a stack of the first substrate (24), the first discharge electrode substrate (3a), the paste-like substrate (22), the cavity forming material (23), the second discharge electrode substrate (4a), and the second substrate (25), is heated while being pressed in the vertical direction to volatilize the cavity forming material (23) and fire the unfired laminate (26). In the fourth step (S4), the second discharge electrode substrate (4a) is printed such that, when viewed from above, one side of the first discharge electrode substrate (3a) in one direction (Y direction) and the other side of the second discharge electrode substrate (4a) in one direction (Y direction) overlap with each other in a part of the orthogonal direction (X direction) perpendicular to the one direction (Y direction).
[0078] In the manufacturing method of the electrostatic discharge protection component (1) of the fifth embodiment having the above configuration, the portion of the first discharge electrode (3), which consists of a first discharge electrode substrate (3a) formed by firing an unfired laminate (26), and the portion of the second discharge electrode (4), which consists of a second discharge electrode substrate (4a), that are exposed to the opening (220) are offset in the orthogonal direction (X direction). Therefore, in the electrostatic discharge protection component (1) manufactured by the manufacturing method of the fifth embodiment, the first discharge electrode (3) and the second discharge electrode (4) are less likely to face each other at the orthogonal direction (X direction) edge of the opening (220). Therefore, in the manufacturing method of the fifth embodiment, even if one of the first discharge electrode (3) and the second discharge electrode (4) is deformed in one direction (Z direction) at the orthogonal direction (X direction) edge of the opening (220) due to manufacturing errors, the distance between the portions of the two discharge electrodes (3, 4) that face each other in one direction (Z direction) is less likely to narrow. Therefore, the manufacturing method of the fifth embodiment makes it possible to manufacture an electrostatic discharge (ESD) component (1) in which the distance between the opposing portions of the two discharge electrodes (3, 4) does not easily become narrow.
[0079] 1 Static electricity countermeasure component 2 Base body 20 Discharge cavity 22 Paste-like base material 220 Opening 23 Cavity forming material 24 First base material 25 Second base material 26 Unfired laminate 3 First discharge electrode 3a First discharge electrode base material 30 First exposed part 31 First embedded part 4 Second discharge electrode 4a Second discharge electrode base material 40 Second exposed part 41 Second embedded part L1 Length in the second direction (Y direction) L2 Length in the third direction (X direction) S1 First process S2 Second process S3 Third process S4 Fourth process S5 Fifth process S6 Sixth process
Claims
1. A static electricity countermeasure component comprising: a base body having an internal discharge cavity, a first opposing surface and a second opposing surface facing the discharge cavity and facing each other in a first direction; a first discharge electrode having a first exposed portion extending on the first opposing surface along the first opposing surface and to one side in a second direction perpendicular to the first direction, and exposed to the discharge cavity, and a first embedded portion continuous with the other side of the first exposed portion in the second direction and embedded in the base body; and a second exposed portion extending on the second opposing surface along the second opposing surface and to the other side in the second direction, and exposed to the discharge cavity, and a second embedded portion continuous with the one side of the second exposed portion in the second direction and embedded in the base body, wherein the first exposed portion and the second exposed portion are offset from each other in the third direction such that, when viewed in the first direction, a part of the third direction perpendicular to the second direction overlaps with each other.
2. When viewed in the first direction, the portion where the first exposed portion and the second exposed portion overlap has a length in the third direction that is shorter than the length in the second direction, as described in claim 1.
3. The electrostatic discharge countermeasure component according to claim 1 or 2, wherein, when viewed in the first direction, the portion where the first exposed portion and the second exposed portion overlap is located in the central portion of the discharge cavity in the third direction.
4. The electrostatic discharge countermeasure component according to claim 3, wherein, when viewed in the first direction, the portion where the first exposed portion and the second exposed portion overlap is located in the central part of the discharge cavity in the second direction.
5. The steps include: printing a first discharge electrode substrate extending to one side in one direction on the upper surface of a first substrate; printing a paste-like substrate on the first substrate on which the first discharge electrode substrate is printed, such that an opening is formed that exposes the one side portion of the first discharge electrode substrate in one direction; placing a cavity-forming material with a lower thermal decomposition temperature than the first substrate and the paste-like substrate in the opening; printing a second discharge electrode substrate extending to the other side in one direction on the cavity-forming material and the paste-like substrate; and placing a second substrate on the cavity-forming material and the paste-like substrate on which the second discharge electrode substrate is printed. A method for manufacturing an electrostatic discharge (ESD) component, comprising the steps of: heating an unfired laminate, in which the first base material, the first discharge electrode base material, the paste-like base material, the cavity-forming material, the second discharge electrode base material, and the second base material are laminated, while pressing the laminate in an up-and-down direction to volatilize the cavity-forming material and fire the unfired laminate, wherein the step of printing the second discharge electrode base material includes printing the second discharge electrode base material such that, when viewed from above, a portion of the first discharge electrode base material in one direction on one side and a portion of the second discharge electrode base material in one direction on the other side overlap each other in a portion of the orthogonal direction perpendicular to the one direction.