JP2011187439A - Esd protection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ESD protection device capable of improving reliability of an ESD protection function. <P>SOLUTION: The ESD protection device 10x includes a ceramic multilayer substrate 12 wherein a plurality of insulating layers 31-34 composed of a ceramic material are laminated; a first connection conductor 17a formed so as to penetrate a principal plane of the insulating layer 32; a mixed section 20x formed so as to connect with the first connection conductor 17a along the principal plane of the insulating layer 32 where the first connection conductor 17a is formed and dispersed with a material containing at least one out of metal and a semiconductor, metal and ceramic, a semiconductor and ceramic, a semiconductor, and metal coated with an inorganic material; and a second connection conductor 14x, having conductivity, connected with the mixed section 20x and formed along the principal plane of the insulating layer 32 where the mixed section 20x is formed or formed so as to penetrate a principal plane of the insulating layer 32 where the mixed section 20x is formed or the neighboring insulating layer 31. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an ESD protection device, and more particularly, to an ESD protection device such as a single component (ESD protection device) having only an ESD protection function or a composite component (module) having an ESD protection function and other functions. .

  ESD (Electro-Static Discharge) means that when a charged conductive object (human body, etc.) is in contact with or sufficiently close to another conductive object (electronic device, etc.) It is a phenomenon. ESD causes problems such as damage and malfunction of electronic devices. In order to prevent this, it is necessary to prevent an excessive voltage generated during discharge from being applied to the circuit of the electronic device. An ESD protection device is used for such an application, and is also called a surge absorbing element or a surge absorber.

  The ESD protection device is disposed, for example, between a signal line of a circuit and a ground (ground). Since the ESD protection device has a structure in which a pair of discharge electrodes are spaced apart from each other, the ESD protection device has a high resistance in a normal use state, and a signal does not flow to the ground side. On the other hand, when an excessive voltage is applied, for example, when static electricity is applied from an antenna of a mobile phone or the like, a discharge is generated between the discharge electrodes of the ESD protection device, and the static electricity can be guided to the ground side. Thereby, a voltage due to static electricity is not applied to a circuit subsequent to the ESD device, and the circuit can be protected.

  For example, in the ESD protection device shown in the exploded perspective view of FIG. 10 and the cross-sectional view of FIG. 11, the cavity 5 is formed in the ceramic multilayer substrate 7 on which the insulating ceramic sheet 2 is laminated, and is electrically connected to the external electrode 1. A discharge electrode 6 is disposed oppositely in the cavity 5, and a discharge gas is confined in the cavity 5. When a voltage causing dielectric breakdown is applied between the discharge electrodes 6, a discharge is generated between the discharge electrodes 6 in the cavity 5, and an excessive voltage is guided to the ground by the discharge, thereby protecting the subsequent circuit. (For example, refer to Patent Document 1).

JP 2001-43954 A

  In this ESD protection device, when high voltage static electricity is continuously applied repeatedly, the discharge electrodes are melted and short-circuited between the discharge electrodes, or the interval between the discharge electrodes is increased, and the discharge start voltage is increased. Have the problem of becoming.

  In view of such circumstances, the present invention intends to provide an ESD protection device capable of improving the reliability of the ESD protection function.

  In order to solve the above problems, the present invention provides an ESD protection device configured as follows.

  The ESD protection device includes: (a) a ceramic multilayer substrate in which a plurality of insulating layers made of a ceramic material are stacked; and (b) a first connection formed so as to penetrate between main surfaces of at least one of the insulating layers. A conductor, and (c) formed so as to be connected to the first connection conductor along the main surface of the insulating layer on which the first connection conductor is formed, (i) a metal and a semiconductor, (ii) Metal and ceramic, (iii) metal and semiconductor and ceramic, (iv) semiconductor and ceramic, (v) semiconductor, (vi) metal coated with inorganic material, (vii) metal and semiconductor coated with inorganic material, ( viii) a mixed portion in which a material containing at least one of a metal and a ceramic coated with an inorganic material, (ix) a metal, a semiconductor and a ceramic coated with an inorganic material are dispersed; and (d) the mixed portion. Connected to The insulating layer formed along the main surface of the insulating layer in which the mixed portion is formed, or the insulating layer in which the mixed portion is formed or the insulating layer adjacent to the insulating layer in which the mixed portion is formed And a conductive second connection conductor formed so as to penetrate between the main surfaces.

  In the above configuration, the mixing portion is formed between the first connection conductor and the second connection conductor. When a voltage of a predetermined level or higher is applied between the first connection conductor and the second connection conductor, a discharge can be generated in the mixing portion.

  According to the above configuration, at least one of the discharge electrodes disposed via the mixing unit is an interlayer connection conductor, so that the heat generated when applying static electricity is higher than that of the in-plane connection conductor. It is possible to dissipate heat through the metal, suppress a temperature rise due to repeated discharge, and prevent the discharge electrode from melting. Furthermore, since the mixing portion can be provided at an arbitrary position in the stacking direction with respect to the interlayer connection conductor, the degree of design freedom can be increased.

  Preferably, a cavity is formed so as to be in contact with the first connection conductor, the mixing portion, and the second connection conductor.

  In this case, air discharge can be generated by forming the cavity, and the ESD characteristics can be further improved.

  Preferably, the mixing unit includes a dispersed metal material and a semiconductor material.

  In this case, since the metal material and the semiconductor material are dispersed in the mixing portion where the discharge occurs, electrons easily move, and a discharge phenomenon can be generated more efficiently and the ESD response can be improved.

  Further, the variation in the ESD response due to the variation in the interval between the discharge electrodes can be reduced, and the adjustment and stability of the ESD characteristics are facilitated.

  In a preferred embodiment, the semiconductor material dispersed in the mixing part is silicon carbide or zinc oxide.

  Preferably, in the mixing portion, a metal material coated with an insulating inorganic material is dispersed.

  In this case, since the metal materials in the mixing portion are not in direct contact with each other due to the coating of the inorganic material, the possibility that the metal materials are connected to each other to cause a short circuit is reduced.

  Preferably, a seal layer is further provided that extends between at least one of the insulating layer and the mixing portion and between the insulating layer and the cavity.

  In this case, the glass component in the ceramic multilayer substrate can be prevented from penetrating into the mixing portion.

  Preferably, the second connection conductor is formed so as to penetrate at least one insulating layer through which the first connection conductor penetrates. The cavity is formed so as to connect between the first and second connection conductors in the insulating layer through which the first and second connection conductors penetrate. The mixed portion is formed along a main surface on the insulating layer side of another insulating layer adjacent to both sides of the insulating layer through which the first and second connecting conductors penetrate, and is in contact with the cavity portion.

  In this case, the first and second connection conductors, which are interlayer connection conductors, are not only connected at the mixing portion, but also face each other through the cavity, so that discharge can be generated more reliably.

  Preferably, at least one of the first and second connection conductors is connected to an external terminal by a plurality of lead electrodes.

  In this case, the ESD protection apparatus can stably discharge using the other extraction electrodes even when some of the plurality of extraction electrodes are disconnected.

  According to the present invention, the reliability of the ESD protection function can be improved.

It is sectional drawing of an ESD protection apparatus. Example 1 It is sectional drawing of an ESD protection apparatus. (Example 2) It is sectional drawing of an ESD protection apparatus. (Modification of Example 2) It is the schematic which shows the structure | tissue of a mixing part typically. (Example 2) It is sectional drawing of an ESD protection apparatus. (Example 3) It is sectional drawing which shows the manufacturing process of an ESD protection apparatus. (Example 3) It is sectional drawing of an ESD protection apparatus. Example 4 It is sectional drawing of an ESD protection apparatus. (Example 5) It is sectional drawing of an ESD protection apparatus. (Example 6) It is a disassembled perspective view of an ESD protection apparatus. (Conventional example) It is sectional drawing of an ESD protection apparatus. (Conventional example)

  Embodiments of the present invention will be described below with reference to FIGS.

  <Example 1> An ESD protection apparatus 10x of Example 1 will be described with reference to FIG.

  FIG. 1 is a cross-sectional view of the ESD protection device 10x. As shown in FIG. 1, the ESD protection device 10 x includes a mixing unit 20 x, a first and a second in a ceramic multilayer substrate 12 in which first to fourth insulating layers 31 to 34 made of a ceramic material are stacked. In-plane connection conductors 14x and 16x, and first and second interlayer connection conductors 17a and 17b are formed.

  In the second and third insulating layers 32 and 33, via holes (through holes) 32p and 33p penetrating between the upper and lower main surfaces are formed. First and second interlayer connection conductors 17a and 17b are formed in the via holes 32p and 33p, respectively. The first and second interlayer connection conductors 17a and 17b are connected to each other at their opposite end faces.

  The mixing portion 20x is formed along the main surface on the second insulating layer 32 on which the first interlayer connection conductor 17a is formed, and is connected to the first interlayer connection conductor 17a. The first interlayer connection conductor 17a is a first connection conductor.

  The first in-plane connection conductor 14x is formed along the main surface on the second insulating layer 32 on which the first interlayer connection conductor 17a is formed. The first in-plane connection conductor 14x is connected to the mixing unit 20x. The first in-plane connection conductor 14x is a second connection conductor. The first in-plane connection conductor 14 x is formed up to one side surface 12 q of the ceramic multilayer substrate 12.

  Although not shown, the second connection conductor connected to the mixing unit 20x is not the first in-plane connection conductor 14x, but penetrates between the main surfaces of the first or second insulating layers 31 and 32. It may be connected to the interlayer connection conductor formed in the above. Further, similarly to FIG. 3 described later, the end portion of the mixing portion 20x may be connected so as to overlap the end surface of the first interlayer connection conductor 17a and the end portion of the first in-plane connection conductor 14x.

  The second in-plane connection conductor 16x is formed between the third and fourth insulating layers 33 and 34 along the main surfaces of the third and fourth insulating layers 33 and 34 facing each other. The second in-plane connection conductor 16x is connected to the second interlayer connection conductor 17b. The second in-plane connection conductor 16x is formed up to the other side surface 12p of the ceramic multilayer substrate 12.

  External terminals 16 s and 14 s are formed on the side surfaces 12 p and 12 q of the ceramic multilayer substrate 12, respectively. One external terminal 16s is connected to the second in-plane connection conductor 16x. The other external terminal 14s is connected to the first in-plane connection conductor 14x.

  The first and second in-plane connection conductors 14x and 16x, the first and second interlayer connection conductors 17a and 17b, and the first and second external terminals 14s and 16s have conductivity.

  The mixing unit 20x includes (i) metal and semiconductor, (ii) metal and ceramic, (iii) metal and semiconductor and ceramic, (iv) semiconductor and ceramic, (v) semiconductor, and (vi) metal coated with an inorganic material. (Vii) a metal and semiconductor coated with an inorganic material, (viii) a metal and ceramic coated with an inorganic material, and (ix) a material comprising at least one of a metal, semiconductor and ceramic coated with an inorganic material Are dispersed, and as a whole, have insulating properties.

  The ESD protection device 10x uses at least one of the discharge electrodes 14x and 17a arranged via the mixing unit 20x as an interlayer connection conductor, so that heat generated when static electricity is applied is more efficient than the in-plane connection conductor. It is possible to dissipate heat through the good interlayer connection conductor, suppress the temperature rise due to repeated discharge, and prevent the discharge electrode from melting. In this case, heat dissipation can be improved by connecting the external terminal 16s on the side of the interlayer connection conductor 17a to the ground. Furthermore, since the mixing portion can be provided at an arbitrary position in the stacking direction with respect to the interlayer connection conductor, the degree of design freedom can be increased.

  <Example 2> An ESD protection apparatus 10 of Example 2 will be described with reference to FIGS.

  FIG. 2 is a cross-sectional view of the ESD protection device 10. As shown in FIG. 2, the ESD protection apparatus 10 includes a mixing unit 20a, 20b, a first unit to a second unit in a ceramic multilayer substrate 12 in which first to fourth insulating layers 31 to 34 made of a ceramic material are stacked. Third in-plane connection conductors 14a, 14b, 16 and first and second interlayer connection conductors 17a, 17b are formed.

  In the second and third insulating layers 32 and 33, via holes (through holes) 32p and 33p penetrating between the upper and lower main surfaces are formed. First and second interlayer connection conductors 17a and 17b are formed in the via holes 32p and 33p, respectively. The first and second interlayer connection conductors 17a and 17b are connected to each other at their opposite end faces.

  The first and second mixing portions 20a and 20b are respectively formed along the upper and lower main surfaces of the second insulating layer 32 on which the first interlayer connection conductor 17a is formed, and the first interlayer connection conductor 17a. It is connected to the. The first interlayer connection conductor 17a is a first connection conductor.

  The first and second in-plane connection conductors 14a and 14b are respectively formed along the upper and lower main surfaces of the second insulating layer 32 on which the first interlayer connection conductor 17a is formed. The first and second in-plane connection conductors 14a and 14b are connected to the first and second mixing portions 20a and 20b, respectively. The first and second in-plane connection conductors 14a and 14b are second connection conductors. The first and second in-plane connection conductors 14a and 4b are formed up to one side surface 12q of the ceramic multilayer substrate 12, respectively.

  Although not shown, the second connection conductor connected to the first mixing portion 20a is not the first in-plane connection conductor 14a but between the main surfaces of the first or second insulating layers 31 and 32. You may connect to the interlayer connection conductor formed so that it might penetrate. The second connection conductor connected to the second mixing unit 20b is formed not to penetrate the second in-plane connection conductor 14b but between the main surfaces of the second or third insulating layers 32 and 33. It may be connected to the interlayer connection conductor.

  The third in-plane connection conductor 16 is formed between the third and fourth insulating layers 33 and 34 along the main surfaces of the third and fourth insulating layers 33 and 34 facing each other. The third in-plane connection conductor 16 is connected to the second interlayer connection conductor 17b. The third in-plane connection conductor 16 is formed up to the other side surface 12 p of the ceramic multilayer substrate 12.

  External terminals 14 s and 16 s are formed on the side surfaces 12 p and 12 q of the ceramic multilayer substrate 12, respectively. One external terminal 16 s is connected to the third in-plane connection conductor 16. The other external terminal 14s is connected to the first and second in-plane connection conductors 14a and 14b.

  In FIG. 2, both ends of the first and second mixing portions 20a and 20b are in contact with the outer periphery of the first interlayer connection conductor 17a and the edges of the first and second in-plane connection conductors 14a and 14b. Although the case where it is connected is illustrated, as shown in the perspective view of FIG. 3, the end portions of the first and second mixing portions 20a and 20b are connected to the end surface of the first interlayer connection conductor 17a and the first end portion. The second in-plane connection conductors 14a and 14b may be connected so as to overlap the end portions.

  The first to third in-plane connection conductors 14a, 14b, and 16, the first and second interlayer connection conductors 17a and 17b, and the first and second external terminals 14s and 16s have conductivity.

  The mixing portions 20a and 20b are coated with (i) metal and semiconductor, (ii) metal and ceramic, (iii) metal and semiconductor and ceramic, (iv) semiconductor and ceramic, (v) semiconductor, and (vi) inorganic material. (Vii) a metal and semiconductor coated with an inorganic material, (viii) a metal and ceramic coated with an inorganic material, and (ix) a metal, semiconductor and ceramic coated with an inorganic material. The contained material is dispersed, and as a whole, it has insulating properties.

For example, as schematically shown in the schematic diagram of FIG. 4, the mixing portions 20 a and 20 b include a metal material 80 coated (coated) with an insulating inorganic material 82, a semiconductor material 84, and a void 88. Are dispersed. For example, the metal material 80 is Cu particles having a diameter of 2 to 3 μm, the inorganic material 82 is Al ₂ O ₃ particles having a diameter of 1 μm or less, and the semiconductor material 84 is any one of silicon carbide, zinc oxide, and the like.

  An inorganic material and a semiconductor material react at the time of baking, and may change in quality after baking. In addition, the ceramic powder constituting the semiconductor material and the ceramic multilayer substrate also reacts during firing and may be altered after firing.

  When the metal material is not coated with an inorganic material, the metal materials may already be in contact with each other before firing, and the metal materials may be connected to each other to cause a short circuit. On the other hand, when the metal material is coated with an inorganic material, there is no possibility that the metal materials contact each other before firing. Further, even if the inorganic material is altered after firing, the state in which the metal materials are separated from each other is maintained. Therefore, when the metal material is coated on the inorganic material, the possibility that the metal materials are connected to each other to cause a short circuit is reduced.

  Note that, instead of a metal material coated with an inorganic material, a material that becomes a mixed portion may be formed of a metal material, a semiconductor, ceramic, or a combination thereof. Moreover, the material which becomes a mixing part may be comprised only with a semiconductor without using a metal material, only with a semiconductor, or only with a semiconductor and a ceramic, and also with a metal material coated with an inorganic material.

  2 is applied between the interlayer connection conductor 17a and the first and second in-plane connection conductors 14a and 14b when a voltage of a predetermined value or more is applied from the external terminals 14s and 16s. , Discharge occurs through the mixing portions 20a and 20b.

  The discharge start voltage is the length of the portion where the first interlayer connection conductor 17a and the first and second in-plane connection conductors 14a and 14b face each other via the first and second mixing portions 20a and 20b ( That is, the discharge width), the interval between the interlayer connection conductor 17a opposed via the mixing portions 20a and 20b, and the first and second in-plane connection conductors 14a and 14b (that is, the discharge gap), and the mixing portion 20a. , 20b, and the amount and type of material contained in the mixing sections 20a, 20b can be set to desired values.

  Since the first and second mixing portions 20a and 20b are connected in parallel between the first and second in-plane connection conductors 14a and 14b and the first interlayer connection conductor 17a, one of them fails. But the other works. Therefore, the reliability of the ESD protection function can be improved.

  In addition, a cavity may be provided so as to be in contact with one main surface of the mixing portions 20a, 20b, the first and second in-plane connection conductors 14a, 14b, and the outer periphery or end surface of the first interlayer connection conductor 17a. By forming the cavity, air discharge can be generated, and ESD characteristics can be further improved.

  Since the first and second mixing portions 20a and 20b can be formed by a thick film printing method in the same manner as the in-plane connection conductors 14a, 14a and 16, they can be easily formed and the thickness can be easily adjusted. It is. Since the 1st and 2nd mixing parts 20a and 20b can be formed along the main surface of the arbitrary insulating layers of a ceramic multilayer substrate, the freedom degree of arrangement design of mixing parts 20a and 20b goes up.

  Since the first and second mixing portions 20a and 20b contain not only a metal material but also a semiconductor material, the desired ESD response can be obtained even if the content of the metal material is small. And generation | occurrence | production of the short circuit by metal materials contacting can be suppressed.

  In the components of the material included in the first and second mixing portions 20a and 20b, the same or a part of the material constituting the ceramic multilayer substrate 12 may be included. If the same material is included, it becomes easy to match the shrinkage behavior of the first and second mixing portions 20a and 20b to the ceramic multilayer substrate 12 during firing, and the first and second mixing portions 20a and 20b Adhesion to the ceramic multilayer substrate 12 is improved, and peeling of the first and second mixing portions 20a and 20b during firing is less likely to occur. In addition, ESD repeatability is improved. In addition, the types of materials used can be reduced.

  The metal material contained in the first and second mixing portions 20a, 20b may be the same as or different from the first to third in-plane connection conductors 14a, 14b, 16. If they are the same, it becomes easy to match the shrinkage behavior of the first and second mixing portions 20a, 20b with the first to third in-plane connection conductors 14a, 14b, 16, and the type of material used. Can be reduced.

  Next, a method for manufacturing the ESD protection apparatus 10 will be described.

(1) Preparation of material A ceramic green sheet to be the first to fourth insulating layers 31 to 34 of the ceramic multilayer substrate 12 is prepared. As the ceramic material used as the material of the ceramic multilayer substrate 12, a material having a composition centered on Ba, Al, and Si is used. Each raw material is prepared and mixed so as to have a predetermined composition, and calcined at 800-1000 ° C. The obtained calcined powder is pulverized with a zirconia ball mill for 12 hours to obtain a ceramic powder. To this ceramic powder, an organic solvent such as toluene and echinene is added and mixed. Further, a binder and a plasticizer are added and mixed to obtain a slurry. The slurry thus obtained is molded by the doctor blade method to obtain a ceramic green sheet having a thickness of 50 μm which becomes the first to fourth insulating layers 31 to 34.

  In addition, an electrode paste for forming the first to third in-plane connection conductors 14a, 14b, 16 and the first and second interlayer connection conductors 17a, 17b is prepared. An electrode paste is obtained by adding a solvent to a binder resin composed of 80 wt% Cu powder having an average particle size of about 1.5 μm and ethyl cellulose, and stirring and mixing with a roll.

Further, a mixed paste for forming the first and second mixing portions 20a and 20b is prepared. The mixed paste is prepared by mixing Al ₂ O ₃ coated Cu powder with an average particle size of about 2 μm and silicon carbide (SiC) with an average particle size of 1 μm as a semiconductor material at a predetermined ratio, adding a binder resin and a solvent, Obtained by stirring and mixing. In the mixed paste, the binder resin and the solvent are 20 wt%, and the remaining 80 wt% is Al ₂ O ₃ coated Cu powder and silicon carbide.

(2) Application of mixed paste and electrode paste by screen printing After forming a via hole penetrating between main surfaces in a ceramic green sheet to be the second and third insulating layers 32 and 33 using a laser or a mold Then, the via paste is filled with the mixed paste by screen printing to form the first and second interlayer connection conductors 17a and 17b.

  Next, a mixed paste is applied by screen printing on the ceramic green sheets to be the second and third insulating layers 32 and 33, and the portions to be the first and second mixing portions 20a and 20b are respectively applied. Form. The portion that becomes the first mixing portion 20 a may be formed on the ceramic green sheet that becomes the first insulating layer 31. The portion that becomes the second mixing portion 20 b may be formed on the ceramic green sheet that becomes the second insulating layer 32.

  Next, an electrode paste is applied by screen printing on the ceramic green sheets to be the second to fourth insulating layers 32, 33, 34, and the first to third in-plane connection conductors 14a, 14b, 16 are applied. Form the part to be. The portion that becomes the first in-plane connection conductor 14 a may be formed on the ceramic green sheet that becomes the first insulating layer 31. The portion that becomes the second in-plane connection conductor 14 b may be formed on the ceramic green sheet that becomes the second insulating layer 32. A portion that becomes the third in-plane connection conductor 16 may be formed on a ceramic green sheet that becomes the third insulating layer 33.

  After forming the first to third in-plane connection conductors 14a, 14a, and 16 portions, the portions to be the first and second mixing portions 20a and 20b may be formed.

  In the case where a cavity is provided so as to be in contact with one main surface of the mixing portions 20a, 20b and the first and second in-plane connection conductors 14a, 14b and the outer periphery or end surface of the first interlayer connection conductor 17a, it is formed first. A vanishing resin paste (for example, an acrylic paste, a carbon paste, etc.) is formed by screen printing on the portions to be the mixing portions 20a and 20b and the portions to be the in-plane connection conductors 14a and 14b.

(3) Lamination and pressure bonding In the same manner as a normal ceramic multilayer substrate, ceramic green sheets are stacked and pressure bonded.

(4) Cut, end face electrode application Like a chip-type electronic component such as an LC filter, it is cut with a micro cutter and divided into chips. Thereafter, electrode paste is applied to the end face to form external terminals.

(5) Firing Next, firing is performed in an N ₂ atmosphere in the same manner as a normal ceramic multilayer substrate. In the case of an electrode material (such as Ag) that does not oxidize, an air atmosphere may be used. By firing, the organic solvent in the ceramic green sheet and the binder resin and solvent in the mixed paste disappear. Thereby, the 1st and 2nd mixing parts 20a and 20b in which Al ₂ O ₃ coated Cu, SiC, and voids are dispersed are formed.

(6) Plating As with a chip-type electronic component such as an LC filter, electrolytic Ni—Sn plating is performed on the external terminals.

  Thus, the ESD protection device 10 whose cross section is configured as shown in FIG. 2 is completed.

  Note that the semiconductor material is not particularly limited to the above materials. For example, metal semiconductors such as silicon and germanium, carbides such as silicon carbide, titanium carbide, zirconium carbide, molybdenum carbide and tungsten carbide, nitrides such as titanium nitride, zirconium nitride, chromium nitride, vanadium nitride and tantalum nitride, titanium silicide , Silicides such as zirconium silicide, tungsten silicide, molybdenum silicide, chromium silicide, chromium silicide, titanium boride, zirconium boride, chromium boride, lanthanum boride, molybdenum boride, tungsten boride, etc. Oxides such as borides, zinc oxide, and strontium titanate can be used. In particular, silicon carbide and zinc oxide are particularly preferable because they are relatively inexpensive and various particle size variations are commercially available. These semiconductor materials may be used alone or in admixture of two or more. Further, the semiconductor material may be used by appropriately mixing with a resistance material such as alumina or BAS material.

  The metal material is not particularly limited to the above materials. Cu, Ag, Pd, Pt, Al, Ni, W, Mo, alloys thereof, or combinations thereof may be used.

  <Example 3> An ESD protection apparatus 10a of Example 3 will be described with reference to FIGS.

  FIG. 5 is a cross-sectional view of the ESD protection apparatus 10a according to the third embodiment. As shown in FIG. 5, the ESD protection apparatus 10a according to the third embodiment is configured in substantially the same manner as the ESD protection apparatus 10 according to the second embodiment. In the following description, the same reference numerals are used for the same components as those in the second embodiment, and differences from the second embodiment will be mainly described.

  As shown in FIG. 5, in addition to the configuration of the second embodiment, the ESD protection apparatus 10a of the third embodiment includes a seal layer between the first mixing unit 20a and the first and second insulating layers 31 and 32. 22 and 24 are formed, and seal layers 26 and 28 are formed between the second mixing portion 20b and the second and third insulating layers 32 and 33, respectively. The sealing layers 22, 24, 26, and 28 prevent the glass component in the ceramic multilayer substrate 12 from penetrating into the first and second mixing portions 20a and 20b. The seal layers 22, 24, 26, and 28 have insulating properties.

  In such a configuration, as shown in the cross-sectional views of FIGS. 6A to 6D, ceramic green sheets to be the first to fourth insulating layers 31 to 34 are formed, laminated, pressed, and fired. Can be produced.

  That is, as shown in FIGS. 6B and 6C, via holes 32p and 33p are formed in the ceramic green sheets to be the second and third insulating layers 32 and 33, and electrode paste is filled in the via holes 32p and 33p. Thus, portions to be the first and second interlayer connection conductors 17a and 17b are formed.

  Next, as shown in FIGS. 6A to 6C, after the seal layer forming paste is screen-printed and dried, the ceramic green sheets that become the first to third insulating layers 31 to 33 are mutually bonded. Seal layers 22, 24, 26, and 28 are formed on the opposing surfaces 31t, 32s, 32t, and 33s.

  Next, as shown in FIGS. 6B and 6C, screen printing is performed on the ceramic green sheet sealing layers 24 and 28 to be the second and third insulating layers 32 and 33 using a mixed paste. Thus, the first and second mixing portions 20a and 20b are formed.

  Next, as shown in FIGS. 6B to 6D, the first to third in-plane connection conductors 14a are applied to the ceramic green sheets to be the second to fourth insulating layers 32 to 34 using electrode paste. , 14b, 16 are formed.

  In addition, the part used as the 1st and 2nd mixing parts 20a and 20b and the part used as the 1st thru | or 3rd in-plane connection conductors 14a, 14b, and 16 are the 1st thru | or 3rd insulating layers 31 on the opposite side. You may form in the ceramic green sheet which becomes -33.

  After the first to third in-plane connection conductors 14a, 14b, and 16 are formed, the first and second mixing portions 20a and 20b may be formed.

The seal layer forming paste for forming the seal layers 22, 24, 26, and 28 is produced by the same method as the electrode paste. For example, a seal layer forming paste (alumina paste) is obtained by adding a solvent to a binder resin composed of 80 wt% Al ₂ O ₃ powder having an average particle size of about 1 μm and ethyl cellulose, and stirring and mixing with a roll. As the solid component of the seal layer forming paste, a material having a higher sintering temperature than the material of the ceramic multilayer substrate, for example, alumina, zirconia, magnesia, mullite, quartz, or the like is selected.

  <Example 4> An ESD protection apparatus 10p of Example 4 will be described with reference to FIG.

  FIG. 7 is a cross-sectional view of the ESD protection device 10p. As shown in FIG. 7, the ESD protection apparatus 10p includes a mixing unit 20p, 20q, a first and a second mixing unit 20p, 20q inside a ceramic multilayer substrate 12 in which first to fourth insulating layers 31 to 34 made of a ceramic material are stacked. Second in-plane connection conductors 14p and 16p, first and second interlayer connection conductors 15p and 17p, and a cavity 21p are formed.

  The first and second in-plane connection conductors 14p and 16p are formed between the second insulating layer 32 and the third insulating layer 33, and are connected to the external terminals 14s and 16s.

  The first and second interlayer connection conductors 15p and 17p are formed in the second insulating layer 32, and one end thereof is connected to the first and second in-plane connection conductors 14p and 16p. A cavity 21p is formed in the second insulating layer 32 so as to connect the first and second interlayer connection conductors 15p and 17p. The cavity 21p is connected to the first and second interlayer connection conductors 15p and 17p. It touches.

  The cavity 21p is formed using a disappearing material that disappears during firing. For example, a through hole is formed in a predetermined position of a ceramic green sheet to be the second insulating layer 32 using a mold or a laser, and carbon paste is filled in the through hole as a disappearing material by screen printing. Cavity 21p is formed by eliminating the carbon paste when firing the sheet.

  One ends of the first and second interlayer connection conductors 15p and 17p are connected to the first and second in-plane connection conductors 14p and 16p.

  The mixing portions 20p and 20q are formed along the main surface on the second insulating layer 32 side of the first and third insulating layers 31 and 33 adjacent to both sides of the second insulating layer 32 in which the cavity 21p is formed. Has been. The mixing portions 20p and 20q are formed so as to be in contact with the cavity 21p.

  The first and second in-plane connection conductors 14p and 16p, the first and second interlayer connection conductors 15p and 17p, and the first and second external terminals 14s and 16s have conductivity.

  The mixing parts 20p and 20q are coated with (i) metal and semiconductor, (ii) metal and ceramic, (iii) metal and semiconductor and ceramic, (iv) semiconductor and ceramic, (v) semiconductor, and (vi) inorganic material. (Vii) a metal and semiconductor coated with an inorganic material, (viii) a metal and ceramic coated with an inorganic material, and (ix) a metal, semiconductor and ceramic coated with an inorganic material. The contained material is dispersed, and as a whole, it has insulating properties.

  The first and second interlayer connection conductors 15p and 17p are not only connected via the mixing portions 20p and 20q, but are opposed to each other via the cavity 21p, so that a discharge is generated in the portion exposed to the cavity 21p. appear. Therefore, the ESD protection apparatus 10p can generate discharge more reliably.

  Further, the ESD protection apparatus 10p uses the in-plane connection conductor to generate heat generated during discharge by applying static electricity by using both of the discharge electrodes arranged via the mixing portions 20p and 20q as interlayer connection conductors 15p and 17p. In addition, heat can be radiated through the interlayer connection conductors 15p and 17p having good heat conduction efficiency, temperature rise due to repeated discharge can be suppressed, and melting of the discharge electrode can be prevented. Furthermore, since the mixing portion can be provided at an arbitrary position in the stacking direction with respect to the interlayer connection conductor, the degree of design freedom can be increased.

  <Example 5> An ESD protection apparatus 10q of Example 5 will be described with reference to FIG.

  FIG. 8 is a cross-sectional view of the ESD protection device 10q. As shown in FIG. 8, the ESD protection device 10 q includes the mixing units 20 s and 20 t, the first and fourth mixing layers 20 s and 20 t inside the ceramic multilayer substrate 12 in which the first to fourth insulating layers 31 to 34 made of a ceramic material are stacked. Second in-plane connection conductors 14q and 16q and first and second interlayer connection conductors 15s and 15t; 17s and 17t are formed.

  The first and second interlayer connection conductors 15s, 15t; 17s, 17t are formed in the second insulating layer 32 and the third insulating layer 33, respectively.

  The first and second in-plane connection conductors 14q and 16q are formed between the second insulating layer 32 and the third insulating layer 33, and are connected to the external terminals 14s and 16s. The in-plane connection conductors 14q and 16q are connected between the first and second interlayer connection conductors 15s and 15t; 17s and 17t, that is, between the interlayer connection conductors 15s and 15t and 17s and 17t.

  A cavity 21q is formed in the second and third insulating layers 32 and 33 so as to connect the first and second interlayer connection conductors 15s and 15t; 17s and 17t. The two interlayer connection conductors 15s and 15t are in contact with 17s and 17t.

  The mixing portions 20s and 20t are the second and third insulating layers 32 of the first and fourth insulating layers 31 and 34 adjacent to both sides of the second and third insulating layers 32 and 33 in which the cavity 21q is formed. , 33 along the main surface. The mixing portions 20s and 20t are formed in contact with the cavity 21q.

  The first and second in-plane connection conductors 14q and 16q, the first and second interlayer connection conductors 15s and 15t; 17s and 17t, and the first and second external terminals 14s and 16s have conductivity. Have.

  The mixing portions 20s and 20t are coated with (i) metal and semiconductor, (ii) metal and ceramic, (iii) metal and semiconductor and ceramic, (iv) semiconductor and ceramic, (v) semiconductor, and (vi) inorganic material. (Vii) a metal and semiconductor coated with an inorganic material, (viii) a metal and ceramic coated with an inorganic material, and (ix) a metal, semiconductor and ceramic coated with an inorganic material. The contained material is dispersed, and as a whole, it has insulating properties.

  The first and second interlayer connection conductors 15s, 15t; 17s, 17t are not only connected via the mixing portions 20s, 20t, but are opposed to each other via the cavity 21q, so that they are exposed to the cavity 21q. Discharge occurs at the part. Therefore, the ESD protection apparatus 10q can generate discharge more reliably.

  The ESD protection apparatus 10q increases the discharge area by forming the first and second interlayer connection conductors 15s, 15t; 17s, 17t serving as the discharge electrodes on the plurality of insulating layers 32, 33, thereby increasing the discharge area. Can be further suppressed.

  Further, the ESD protection device 10q uses the interlayer connection conductors 15s, 15t; 17s, 17t for both of the discharge electrodes arranged via the mixing unit 21q, so that the heat generated during discharge due to static electricity application is connected in-plane. It is possible to dissipate heat through the interlayer connection conductors 15s, 15t and 17s, 17t having better heat conduction efficiency than the conductor, and it is possible to suppress a temperature rise due to repeated discharge and to prevent the discharge electrode from melting. Furthermore, since the mixing portion can be provided at an arbitrary position in the stacking direction with respect to the interlayer connection conductor, the degree of design freedom can be increased.

  <Embodiment 6> An ESD protection apparatus 10r of Embodiment 6 will be described with reference to FIG.

  FIG. 9 is a cross-sectional view of the ESD protection device 10r. As shown in FIG. 9, the ESD protection apparatus 10r includes a mixing unit 20u and 20v and an in-plane connection inside a ceramic multilayer substrate 12 in which first to fourth insulating layers 31 to 34 made of a ceramic material are laminated. Conductors 14m and 14n; 16m and 16n, first and second interlayer connection conductors 15r and 17r, and a cavity 21r are formed.

  The first and second interlayer connection conductors 15 r and 17 r are formed in the second insulating layer 32. A cavity 21r is formed in the second insulating layer 32 so as to connect between the first and second interlayer connection conductors 15r and 17r. The cavity 21r is connected to the first and second interlayer connection conductors 15r and 17r. It touches.

  Two in-plane connection conductors 14m and 14n; 16m and 16n are formed on both sides of the cavity 21r along both main surfaces of the second insulating layer 32, respectively. The in-plane connection conductors 14m and 14n on one side of the cavity 21r are connected to one external terminal 14s, and the in-plane connection conductors 16m and 16n on the other side of the cavity 21r are connected to the other external terminal 16t.

  The first and second interlayer connection conductors 15r and 17r are connected to the external terminals 14s and 16s by the in-plane connection conductors 14m and 14n; 16m and 16n, which are a plurality of extraction electrodes, respectively. Even when a part of the electrode is disconnected, it is possible to stably discharge using another extraction electrode.

  The mixing portions 20u and 20v are formed along the main surface of the first and third insulating layers 31 and 33 adjacent to both sides of the second insulating layer 32 where the cavity 21r is formed, on the second insulating layer 32 side. Has been. The mixing portions 20u and 20v are formed so as to contact the cavity 21r.

  The in-plane connection conductors 14m, 14n; 16m, 16n, the first and second interlayer connection conductors 15r, 17r, and the first and second external terminals 14s, 16s have conductivity.

  The mixing portions 20u and 20v are coated with (i) metal and semiconductor, (ii) metal and ceramic, (iii) metal and semiconductor and ceramic, (iv) semiconductor and ceramic, (v) semiconductor, and (vi) inorganic material. (Vii) a metal and semiconductor coated with an inorganic material, (viii) a metal and ceramic coated with an inorganic material, and (ix) a metal, semiconductor and ceramic coated with an inorganic material. The contained material is dispersed, and as a whole, it has insulating properties.

  The first and second interlayer connection conductors 15r and 17r are not only connected via the mixing portions 20u and 20v, but are opposed to each other via the cavity 21r, so that discharge occurs in the portion exposed to the cavity 21r. appear. Therefore, the ESD protection apparatus 10r can generate discharge more reliably.

  In addition, the ESD protection apparatus 10r uses both of the discharge electrodes arranged via the mixing unit 21r as the interlayer connection conductors 15r and 17r, so that the heat generated during discharge due to the application of static electricity is higher than the in-plane connection conductor. Heat can be dissipated through the interlayer connection conductors 15r and 17r with good conduction efficiency, temperature rise due to repeated discharge can be suppressed, and the discharge electrode can be prevented from melting. Furthermore, since the mixing portion can be provided at an arbitrary position in the stacking direction with respect to the interlayer connection conductor, the degree of design freedom can be increased.

  <Summary> As described above, the reliability of the ESD protection function can be improved by using at least one of the discharge electrodes as an interlayer connection conductor.

  The present invention is not limited to the above embodiment, and can be implemented with various modifications.

  For example, although the case where the ESD protection device is a single component (ESD protection device) having only an ESD protection function is exemplified, the ESD protection device is a composite component (module) having an ESD protection function and other functions. It may be. When the ESD protection device is a composite part (module) or the like, at least the interlayer connection conductor, the first and second mixing sections connected to the interlayer connection conductor, and the first and second mixing sections respectively. What is necessary is just to provide the other connection conductor (In-plane connection conductor or another interlayer connection conductor) connected.

  Moreover, a mixing part and a connection conductor may be formed on the surface of the ceramic multilayer substrate. In this case, it is preferable that the mixed portion and the connection conductor exposed on the surface of the ceramic multilayer substrate are covered with an insulating cover layer or covered with a lid-like member with a gap.

10, 10a, 10x ESD protection device 12 Ceramic multilayer substrate 14x First in-plane connection conductor (second connection conductor)
14a First in-plane connection conductor (second connection conductor)
14b Second in-plane connection conductor (second connection conductor)
14p, 14q First in-plane connection conductor 14m, 14n In-plane connection conductor (lead electrode)
15p, 15s, 15t, 15r First interlayer connection conductor (first connection conductor)
16 3rd in-plane connection conductor 16p, 16q 2nd in-plane connection conductor 16m, 16n In-plane connection conductor (leading electrode)
16x Second in-plane connection conductor 17a First interlayer connection conductor (first connection conductor)
17b Second interlayer connection conductor 17p, 17s, 17t, 17r Second interlayer connection conductor (seventh connection conductor)
20a First mixing portion 20b Second mixing portion 20p, 20q, 20s, 20t, 20u, 20v Mixing portion 20x Mixing portion 21p, 21q, 21r Cavity 22, 24, 26, 28 Seal layer 31-34 Insulating layer 80 Metal Material 82 Inorganic material 84 Semiconductor material 88 Void

Claims (8)

A ceramic multilayer substrate in which a plurality of insulating layers made of a ceramic material are laminated;
A first connection conductor formed so as to penetrate between main surfaces of at least one of the insulating layers;
(I) a metal and a semiconductor, (ii) a metal and a ceramic, and (iii) formed so as to be connected to the first connection conductor along the main surface of the insulating layer on which the first connection conductor is formed. ) Metals and semiconductors and ceramics, (iv) Semiconductors and ceramics, (v) Semiconductors, (vi) Metals coated with inorganic materials, (vii) Metals and semiconductors coated with inorganic materials, (viii) Coated with inorganic materials And (ix) a mixed portion in which a material containing at least one of a metal coated with an inorganic material, a semiconductor, and a ceramic is dispersed;
The insulating layer connected to the mixing portion and formed along the main surface of the insulating layer in which the mixing portion is formed, or the insulating layer in which the mixing portion is formed or the insulating layer in which the mixing portion is formed A conductive second connecting conductor formed so as to penetrate between the main surfaces of the insulating layer adjacent to the insulating layer;
An ESD protection device comprising:   The ESD protection device according to claim 1, wherein a cavity is formed so as to be in contact with the first connection conductor, the mixing portion, and the second connection conductor.   The ESD protection apparatus according to claim 1, wherein the mixing unit includes a dispersed metal material and a semiconductor material.   The ESD protection device according to claim 3, wherein the semiconductor material dispersed in the mixing part is silicon carbide or zinc oxide.   5. The ESD protection device according to claim 1, wherein metal particles coated with an insulating inorganic material are dispersed in the mixing unit.   The sealing layer according to any one of claims 1 to 5, further comprising a sealing layer extending between at least one of the insulating layer and the mixing portion and between the insulating layer and the cavity. The ESD protection device according to one. The second connection conductor is formed to penetrate at least one insulating layer through which the first connection conductor penetrates.
The cavity is formed to connect between the first and second connection conductors in the insulating layer through which the first and second connection conductors penetrate.
The mixed portion is formed along a main surface on the insulating layer side of another insulating layer adjacent to both sides of the insulating layer through which the first and second connection conductors penetrate, and is in contact with the cavity portion. The ESD protection device according to any one of claims 2 to 6, wherein   8. The ESD protection apparatus according to claim 1, wherein at least one of the first and second connection conductors is connected to an external terminal by a plurality of lead electrodes.

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