JP2005191402A - Chip resistor, chip component, and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chip resistor wherein the possibility of the generation of burrs in its bottom-surface electrodes and the possibility of the disconnection of its resistive substances can be reduced. <P>SOLUTION: The chip resistor A has an insulating substrate 10, resistive substances 12 formed into thick films of 3-12 μm in thickness, top-surface electrodes 14 formed into thick films similarly to the resistive substances 12, and bottom-surface electrodes 22 formed into thin films of 0.2-0.4 μm in thickness. The bottom-surface electrodes 22 are formed by using a metal organic-substance paste (e.g., Au resinate or Ag resinate). Still, the sum of the lengths of the bottom-surface electrodes 22 which are measured in the direction of the space between the electrodes is set preferably to 40-60 % of the length of the insulating substrate. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a chip component and a manufacturing method thereof, and more particularly to a chip resistor and a manufacturing method thereof.

  Conventionally, some chip parts have a bottom electrode, but the bottom electrode is formed of a thick film having a thickness of about 10 μm.

  An example of the chip resistor in this case is shown in FIG. 8. The chip resistor B includes the insulating substrate 110, the resistor 112, the upper surface electrode 114, the protective film 120, the lower surface electrode 122, and the side surface electrode 124. , And plating 126. The plating 126 has a nickel plating 128 and a tin plating 130.

  Here, the upper surface electrode 114 and the lower surface electrode 122 are formed of thick films. That is, the resistor 112 is formed of, for example, a ruthenium oxide-based metal glaze thick film, the upper surface electrode 114 is formed of a silver-based metal glaze thick film, and the lower surface electrode 122 is formed of a silver-based metal glaze thick film. Yes.

  An outline of the manufacturing process of the chip resistor B in this case is as follows. That is, the lower surface electrode is formed on the lower surface of the alumina substrate (in this case, the lower surface electrode is formed at the same time for the adjacent chip resistors. That is, one lower surface electrode is formed so as to straddle the boundary position between the two adjacent chip resistors. After forming the upper surface electrode on the upper surface of the alumina substrate (in this case, the upper surface electrode is formed at the same time for the adjacent chip resistors. That is, the two adjacent chip resistors are straddled across the boundary position). One top electrode is formed). Thereafter, a resistor is formed so as to connect the upper surface electrodes. Then, after trimming the resistor, a protective film is formed. When the protective film is formed, it is divided into strips along the primary dividing slit (this is referred to as primary division). After the division, side electrodes are formed. When forming the side electrode, the side electrode is formed simultaneously on one strip-shaped substrate. After this side electrode is formed, division is performed (this is referred to as secondary division), and plating is performed after the division.

On the other hand, there is a chip resistor in which both the upper surface electrode and the lower surface electrode are formed into a thin film with a metal organic electrode paste and the resistor is formed into a thin film (see Patent Document 1).
JP-A-6-45118 JP 2003-209006 A

  However, in the case where the upper electrode and the lower electrode are formed with a thick film, there is a problem that burrs are generated at the end of the lower electrode when dividing along the primary dividing slit in the manufacturing process. That is, when the alumina substrate is divided, the alumina substrate is divided so that the lower surface side of the alumina substrate is bent as a base point. Therefore, if the lower electrode is formed of a thick film, burrs are easily generated at the end of the lower electrode, and the chip There was a problem of affecting the external dimensions of the resistor. In particular, in recent years when chip resistors are being miniaturized, the generation of burrs has a great effect.

  On the other hand, as in Patent Document 1 and Patent Document 2, when the resistor is formed into a thin film, the resistor itself is formed into a thin film, and thus there is a problem that the resistor may be disconnected. .

  Accordingly, an object of the present invention is to provide a chip resistor that can reduce the risk of occurrence of burrs on the lower surface electrode and the risk of disconnection of the resistor.

  The present invention has been created to solve the above problems. First, a chip resistor is an insulating substrate and a resistor formed on the upper surface side of the insulating substrate. It has a resistor formed in a thick film of 3 to 12 μm, and a lower electrode formed on the lower surface side of the insulating substrate and formed thinner than the thickness of the thick film.

  In the chip resistor having the first configuration, the resistor is formed in a thick film having a thickness of 3 to 12 μm, so that the risk of disconnection of the resistor can be reduced. In addition, since the lower surface electrode is formed thinner than the thickness of the thick film, when manufacturing the chip resistor, if the lower surface electrode is divided after being formed on the substrate, burrs may occur at the end of the lower surface electrode. Can be reduced. In other words, in the case of forming simultaneously in one forming region together with the lower surface electrode of the adjacent chip resistor, the lower surface electrode is also divided when dividing the substrate, but the lower surface electrode is formed in a thin film, The risk of occurrence of burrs can be reduced.

  The first configuration may be as follows. That is, the chip resistor includes an insulating substrate, a resistor formed in a thick film having a thickness of 8 to 12 μm, and a bottom electrode formed thinner than the thickness of the thick film. It is good to do.

  Second, the chip resistor includes a resistor formed in a thick film having a thickness of 3 to 12 μm, and a bottom electrode formed in a thin film having a thickness of 0.2 to 0.4 μm. It is characterized by having.

  In the chip resistor having the second configuration, since the resistor is formed in a thick film having a thickness of 3 to 12 μm, the risk of disconnection of the resistor can be reduced. In addition, since the bottom electrode is formed as a thin film having a thickness of 0.2 to 0.4 μm, when the chip resistor is manufactured, when the bottom electrode is divided after being formed on the substrate, the end of the bottom electrode is variably formed. It is possible to reduce the possibility of the occurrence of In other words, in the case of forming simultaneously in one forming region together with the lower surface electrode of the adjacent chip resistor, the lower surface electrode is also divided when dividing the substrate, but the lower surface electrode is formed in a thin film, The risk of occurrence of burrs can be reduced.

  The second configuration may be as follows. That is, the chip resistor has a resistor formed in a thick film having a thickness of 8 to 12 μm and a bottom electrode formed in a thin film having a thickness of 0.2 to 0.4 μm. It is good also as what to do.

  Third, a chip resistor is an insulating substrate, a resistor formed on the upper surface side of the insulating substrate, a resistor formed in a thick film having a thickness of 3 to 12 μm, and an insulating substrate. The lower surface electrode is formed on the lower surface side, and is formed on a thin film having a thickness of 0.2 to 0.4 μm.

  In the chip resistor having the third configuration, since the resistor is formed in a thick film having a thickness of 3 to 12 μm, the risk of disconnection of the resistor can be reduced. In addition, since the bottom electrode is formed as a thin film having a thickness of 0.2 to 0.4 μm, when the chip resistor is manufactured, when the bottom electrode is divided after being formed on the substrate, the end of the bottom electrode is variably formed. It is possible to reduce the possibility of the occurrence of In other words, in the case of forming simultaneously in one forming region together with the lower surface electrode of the adjacent chip resistor, the lower surface electrode is also divided when dividing the substrate, but the lower surface electrode is formed in a thin film, The risk of occurrence of burrs can be reduced.

  The third configuration may be as follows. That is, it is a chip resistor, which is formed on the insulating substrate, the resistor formed on the upper surface side of the insulating substrate, the resistor formed on a thick film having a thickness of 8 to 12 μm, and the lower surface side of the insulating substrate. A lower electrode formed on a thin film having a thickness of 0.2 to 0.4 μm.

  Fourthly, in the first or third configuration, the insulating substrate has a substantially rectangular parallelepiped shape, and a lower surface electrode is provided along opposite sides of the lower surface of the insulating substrate. The total length in the inter-electrode direction that is the direction along the lower surface of the insulating substrate in the direction perpendicular to the side portion of the two lower surface electrodes is 40% or more and 60% or less of the length in the inter-electrode direction of the insulating substrate. It is characterized by being.

  Therefore, since the length of the lower surface electrode is formed longer, the lower electrode portion including the lower surface electrode, that is, the distance between the lower surface side electrode portions is shortened accordingly, and thus mounted on the wiring board. Even in this case, the bending strength can be increased. In addition, the area of the lower surface of the lower surface side electrode portion can be increased, and therefore, when mounted on the wiring board, the contact area with the solder fillet can be increased, thereby fixing the chip resistor to the wiring board. Can be increased. In addition, since the bottom electrode is formed to be long, it is possible to increase the moment for suppressing chip standing when the chip resistor is mounted on a wiring board and soldered by a reflow furnace. The chip standing phenomenon can be prevented.

  Further, fifthly, in any one of the first to fourth configurations, the chip resistor is a top electrode connected to end regions on both sides of the resistor, and has a thickness of 5 to 5. It has a top electrode formed in a 12 μm thick film. Therefore, since both the resistor and the upper surface electrode are formed of a thick film, the bonding strength between the resistor and the upper surface electrode can be kept strong.

  Sixth, a chip resistor is a resistor formed in a thick film having a thickness of 3 to 12 μm by an insulating substrate having a substantially rectangular parallelepiped shape and a resistor provided on the upper surface side of the insulating substrate. And the upper surface electrode provided on the upper surface side of the insulating substrate and connected to the end regions on both sides of the resistor, respectively, and formed into a thick film having a thickness of 5 to 12 μm. The upper surface electrode and the lower surface electrode provided on the lower surface side of the insulating substrate, the lower surface electrode provided on both sides in the inter-electrode direction which is the direction between the pair of upper surface electrodes, and has a thickness of 0.2 to 0.4 μm A bottom electrode formed on the thin film, and a side electrode formed on a side surface of the insulating substrate, and at least the side electrode connected to the top electrode and the bottom electrode.

  In the chip resistor having the sixth configuration, since the resistor is formed in a thick film having a thickness of 3 to 12 μm, the possibility of disconnection of the resistor can be reduced. In addition, since the bottom electrode is formed as a thin film having a thickness of 0.2 to 0.4 μm, when the chip resistor is manufactured, when the bottom electrode is divided after being formed on the substrate, the end of the bottom electrode is variably formed. It is possible to reduce the possibility of the occurrence of In other words, in the case of forming simultaneously in one forming region together with the lower surface electrode of the adjacent chip resistor, the lower surface electrode is also divided when dividing the substrate, but the lower surface electrode is formed in a thin film, The risk of occurrence of burrs can be reduced. Furthermore, since both the resistor and the upper electrode are formed of a thick film, the bonding strength between the resistor and the upper electrode can be kept strong.

  The sixth configuration may be as follows. That is, a chip resistor, which is an insulating substrate having a substantially rectangular parallelepiped shape, a resistor provided on the upper surface side of the insulating substrate, formed in a thick film having a thickness of 8 to 12 μm, and the insulating film An upper surface electrode provided on the upper surface side of the substrate, connected to the end regions on both sides of the resistor, and an upper surface electrode formed in a thick film having a thickness of 5 to 12 μm; A lower electrode provided on the lower surface side of the insulating substrate, and formed on a thin film having a thickness of 0.2 to 0.4 μm with lower electrode provided on both sides in the inter-electrode direction which is the direction between the pair of upper electrode. The lower surface electrode and the side surface electrode formed on the side surface of the insulating substrate may include at least the upper surface electrode and the side surface electrode connected to the lower surface electrode.

  Seventhly, in the sixth configuration, the total length in the inter-electrode direction, which is the direction along the lower surface of the insulating substrate in the direction perpendicular to the side portion of the two lower surface electrodes, It is characterized by being 40% or more and 60% or less of the length of the substrate in the direction between the electrodes.

  Therefore, since the length of the lower surface electrode is formed longer, the lower electrode portion including the lower surface electrode, that is, the distance between the lower surface side electrode portions is shortened accordingly, and thus mounted on the wiring board. Even in this case, the bending strength can be increased. In addition, the area of the lower surface of the lower surface side electrode portion can be increased, and therefore, when mounted on the wiring board, the contact area with the solder fillet can be increased, thereby fixing the chip resistor to the wiring board. Can be increased. In addition, since the bottom electrode is formed to be long, it is possible to increase the moment for suppressing chip standing when the chip resistor is mounted on a wiring board and soldered by a reflow furnace. The chip standing phenomenon can be prevented.

  Eighth, in any one of the first to seventh configurations, the lower surface electrode is formed using a metal organic paste.

  Ninth, the chip component has a top electrode formed in a thick film having a thickness of 5 to 12 μm and a bottom electrode formed in a thin film having a thickness of 0.2 to 0.4 μm. It is characterized by that.

  In the chip component having the ninth configuration, the upper surface electrode is formed in a thick film having a thickness of 5 to 12 μm. Therefore, even when the resistor is connected to the upper surface electrode, the resistor is made thick. It is easy to form on the film, and therefore the risk of breakage of the resistor can be reduced. Further, since the lower surface electrode is formed as a thin film having a thickness of 0.2 to 0.4 μm, when the chip resistor is manufactured, when the lower surface electrode is divided after being formed on the substrate, the end surface of the lower surface electrode is variably formed. It is possible to reduce the possibility of the occurrence of That is, in the case of forming simultaneously in one forming region together with the lower surface electrode of the adjacent chip resistor, the lower surface electrode is also divided when dividing the substrate, but the lower surface electrode is formed in a thin film, The risk of occurrence of burrs can be reduced.

  The tenth is a method for manufacturing a chip resistor, in which a metal organic paste is applied in a lower electrode forming step of forming a lower electrode on a lower surface side of an insulating substrate into a thin film having a thickness of 0.2 to 0.4 μm. Bottom electrode formation formed in one forming area together with the bottom electrode of the adjacent chip resistor in the bottom electrode forming step of printing and drying the printed metal organic paste after drying the printed metal organic paste A step of forming a resistor in a thickness of 3 to 12 μm on the upper surface side of the insulating substrate, and a step of forming the resistor after the lower surface electrode forming step; And a dividing step of dividing together with the lower surface electrode formed in one forming region.

  In the method of manufacturing the chip resistor having the tenth configuration, since the lower surface electrode is formed into a thin film having a thickness of 0.2 to 0.4 μm, when the division is performed in the dividing step, the end portion of the lower surface electrode is formed. It is possible to reduce the risk of occurrence of burrs. Further, since the resistor is formed in a thick film having a thickness of 3 to 12 μm, the risk of disconnection of the resistor can be reduced.

  In the lower surface electrode forming step in the tenth configuration, not only the lower surface electrodes adjacent in the direction between the pair of lower surface electrodes when finally becoming a chip resistor are formed in one forming region, but also the lower surface electrode The lower surface electrodes adjacent to each other in the direction perpendicular to the inter-electrode direction may also be formed in one formation region, and the lower surface electrodes may be formed together by a band-shaped formation region in the direction perpendicular to the inter-lower electrode direction. .

  Further, the tenth configuration may be as follows. That is, in the chip resistor manufacturing method, a metal organic paste is printed and printed in a lower surface electrode forming step in which a lower surface electrode is formed on a lower surface side of an insulating substrate into a thin film having a thickness of 0.2 to 0.4 μm. A bottom electrode forming step of forming the metal organic paste in a single formation region together with a bottom electrode of an adjacent chip resistor when finally forming a chip resistor in the bottom electrode forming step of firing after drying the metal organic paste; In the resistor forming step performed after the electrode forming step, a resistor forming step of forming a resistor in a thickness of 8 to 12 μm on the upper surface side of the insulating substrate, and forming the insulating substrate in the one formation region And a dividing step of dividing together with the bottom electrode made.

  Eleventhly, in the tenth configuration, in the upper surface electrode forming step performed after the resistor forming step and before the dividing step, it is connected to the end regions on both sides of the resistor. And a top surface electrode forming step of forming the top surface electrode in a thick film having a thickness of 5 to 12 μm. Therefore, since both the resistor and the upper surface electrode are formed of a thick film, the bonding strength between the resistor and the upper surface electrode can be kept strong.

  Twelfth, in the tenth or eleventh configuration, the insulating substrate has a substantially rectangular parallelepiped shape, and a direction along the lower surface of the insulating substrate in a direction perpendicular to the side portion in the two lower surface electrodes. In the lower electrode forming step, the lower electrode is opposed to the opposite side of the lower surface of the insulating substrate so that the total length in the inter-electrode direction is 40% or more and 60% or less of the length in the inter-electrode direction of the insulating substrate. It is characterized by providing along each part.

  Therefore, since the length of the lower surface electrode is formed longer, the lower electrode portion including the lower surface electrode, that is, the distance between the lower surface side electrode portions is shortened accordingly, and thus when mounted on the wiring board However, the bending strength can be increased. In addition, the area of the lower surface of the lower surface side electrode portion can be increased, and therefore, when mounted on the wiring board, the contact area with the solder fillet can be increased, thereby fixing the chip resistor to the wiring board. Can be increased. In addition, since the bottom electrode is formed to be long, it is possible to increase the moment for suppressing chip standing when the chip resistor is mounted on a wiring board and soldered by a reflow furnace. The chip standing phenomenon can be prevented.

  According to the chip resistor, the chip component, and the chip resistor manufacturing method according to the present invention, it is possible to reduce the risk of burrs occurring on the lower surface electrode and to reduce the risk of breakage of the resistor. In particular, the bending resistance of the chip resistor is increased by setting the total length in the inter-electrode direction of the lower surface electrode to 40% to 60% of the length in the inter-electrode direction of the insulating substrate. In addition, when mounted on a wiring board, it is possible to increase the contact area with the solder fillet, thereby improving the adhesion of the chip resistor to the wiring board, and further, the chip resistance. It is possible to prevent the chip standing phenomenon of the vessel.

  In the present invention, the object of reducing the risk of occurrence of burrs on the lower surface electrode and reducing the risk of disconnection of the resistor is realized as follows.

  That is, as shown in FIG. 1, the chip resistor A in the embodiment according to the present invention includes an insulating substrate 10, a resistor (which may be a “resistor layer”) (functional element) 12, and an upper electrode ( It includes a “upper surface electrode layer” 14, a protective film (also referred to as a “protective layer”) 20, a lower surface electrode 22, a side electrode 24, and a plating 26.

  Here, the chip resistor A will be described in more detail. The insulating substrate 10 is an insulator formed of alumina having a content rate of about 96%. The insulating substrate 10 has a rectangular parallelepiped shape, and has a substantially rectangular shape in plan view. The insulating substrate 10 is used as a base member of the chip resistor A, that is, a base.

  The resistor 12 is provided on the upper surface of the insulating substrate 10 as shown in FIG. That is, the resistor 12 is formed in a strip shape in the longitudinal direction (inter-electrode direction or energization direction) (X1-X2 direction (see FIG. 1)), specifically, on the X1 side of the insulating substrate 10. It is formed in a strip shape from the end to the end on the X2 side. The resistor 12 is formed in a thick film having a thickness of 3 to 12 μm, and is specifically a ruthenium oxide thick film (for example, a ruthenium oxide metal glaze thick film). That is, the thickness of the resistor 12 is in the range of 3 to 12 μm. The resistor 12 is a functional element that bears electrical characteristics as the chip resistor A.

  Further, as shown in FIG. 1, a pair of upper surface electrodes 14 are formed at both end regions in the longitudinal direction (X1-X2 direction (see FIG. 1)) of the upper surface of the resistor 12. That is, the upper surface electrode 14 is formed with a predetermined length from the end portion on the X1 side of the upper surface of the insulating substrate 10, and the upper surface electrode 14 is formed with a predetermined length from the end portion on the X2 side of the upper surface of the insulating substrate 10. Is formed. That is, the upper surface electrode 14 is formed by being laminated on the upper surface of the resistor 12. The upper surface electrode 14 is formed in a thick film having a thickness of 5 to 12 μm, and specifically, is formed of a silver-based thick film (silver-based metal glaze thick film). Further, the width of the upper electrode 14 in the Y1-Y2 direction (the Y1-Y2 direction is a direction perpendicular to the X1-X2 direction and the Z1-Z2 direction) is substantially equal to the width of the resistor 12 in the Y1-Y2 direction. The end portions in the Y1-Y2 direction of the upper surface electrode 14 coincide with the end portions in the Y1-Y2 direction of the resistor 12 in a top view.

  Further, as shown in FIG. 1, the protective film 20 is disposed so as to cover the upper surface of the resistor 12. That is, the arrangement position of the protective film 20 will be described in more detail. As shown in FIG. 2, the protective film 20 is formed in the Y1-Y2 direction so as to be substantially the same as the width of the insulating substrate 10 (may be the same). In the X1-X2 direction, the exposed portion of the resistor 12 and a part of the pair of upper surface electrodes 14 formed at both ends are provided. That is, the protective film 20 is provided in a region shown by hatching in FIG. 2 (that is, hatching from the upper left to the lower right). The protective film 20 is formed of lead borosilicate glass or resin (epoxy, phenol, silicon, etc.).

  Further, as shown in FIG. 1, a pair of lower surface electrodes 22 are formed in both end regions in the longitudinal direction (X1-X2 direction (see FIG. 1)) of the lower surface of the insulating substrate 10. That is, the lower surface electrode 22 is formed to have a predetermined length from the end portion on the X1 side of the lower surface of the insulating substrate 10, and the lower surface electrode 22 is formed to have a predetermined length from the end portion on the X2 side of the lower surface of the insulating substrate 10. Is formed. Note that the width of the bottom electrode 22 in the Y1-Y2 direction is substantially the same (or may be the same) as the width of the insulating substrate 10 in the Y1-Y2 direction. That is, the lower surface electrode 22 is provided in a region shown by hatching in FIG. 3 (that is, hatching from the upper left to the lower right). Furthermore, the total length of the length α2 of one lower surface electrode 22 in the X1-X2 direction and the length α3 of the other lower surface electrode 22 in the X1-X2 direction, that is, α2 + α3 is X1-X2 of the insulating substrate 10. It is formed to be 40% or more and 60% or less of the direction length α1. Further, the lengths of the lower surface electrodes 22 in the X1-X2 direction are formed to be substantially the same (may be the same) (that is, α2 = α3 in FIG. 1). The lower surface electrode 22 is formed as a thin film having a thickness of 0.2 μm to 0.4 μm (preferably 0.3 μm). Specifically, the lower surface electrode 22 is formed of a metal thin film using a metal organic paste. Yes. That is, the lower surface electrode 22 is formed by printing, drying and firing a metal organic paste. Here, Au resinate or Ag resinate is mentioned as a metal organic substance.

  Further, the side electrode 24 is formed in a layer shape with a substantially U-shaped cross section so as to cover a part of the upper surface electrode 14, a part of the lower surface electrode 22, and a part of the side surface and the lower surface of the insulating substrate 10. . The side electrodes 24 are provided at the end on the X1 side and the end on the X2 side, respectively. The side electrode 24 is formed of a thin film. The upper surface portion of the side electrode 24 is provided in a region shown by hatching (that is, hatching from the upper right to the lower left direction) in FIG. 2, and the lower surface portion of the side electrode 24 is hatched (that is, in FIG. 3). (Hatching from upper right to lower left). The side electrode 24 is formed as a thin film having a thickness of 0.2 μm to 0.4 μm (preferably 0.3 μm), specifically, a metal thin film.

  The plating 26 includes a nickel plating 28 and a tin plating 30, and is provided at an end portion on the X1 side and an end portion on the X2 side, respectively. The nickel plating 28 is formed so as to cover part of the protective layer 20, part of the upper surface electrode 14, side electrode 24, and part of the lower surface electrode 22. That is, it is formed so as to cover the exposed portions of the upper surface electrode 14, the side surface electrode 24, and the lower surface electrode 22. The nickel plating 28 is disposed with a substantially uniform film thickness by electroplating. The nickel plating 28 is made of nickel and is formed to prevent solder erosion of internal electrodes such as the upper surface electrode 14. In addition to nickel, the nickel plating 28 may be copper plating.

  Further, the tin plating 30 is disposed with a substantially uniform film thickness so as to cover the upper surface of the nickel plating 28. The tin plating 30 is formed to satisfactorily solder the chip resistor A to the wiring board. In addition, this tin plating 30 may use solder other than tin plating.

  The upper surface electrode 14, the lower surface electrode 22, the side surface electrode 24, and the plating 26 form an electrode portion 40. A portion of the electrode portion 40 located on the lower surface side of the insulating substrate 10 is a lower surface side electrode. Part 42.

  2 is a diagram showing the arrangement of each part when the chip resistor A is viewed from the upper surface side. When the resistor 12, the upper electrode 14, the protective film 20, and the side electrode 24 are viewed in plan, The outline of the outer shell is illustrated. In addition, each part is expressed similarly including the part which is actually hidden and cannot be seen. Similarly, FIG. 3 is a diagram illustrating the arrangement of each part when the chip resistor A is viewed from the lower surface side, and illustrates the outermost contour when the lower surface electrode 22 and the side electrode 24 are viewed in plan. It is. In addition, each part is expressed similarly including the part which is actually hidden and cannot be seen.

  A method of manufacturing the chip resistor A having the above configuration will be described with reference to FIGS. First, an alumina substrate in which primary slits J1 and secondary slits J2 are provided in advance on the upper surface (which may be the front surface) and the lower surface (which may be the rear surface) (this alumina substrate is the size of an insulating substrate of a plurality of chip resistors). The lower surface electrode G22 is formed on the lower surface of the substrate having at least a large size (see S11 in FIG. 4, W1 in FIG. 5, lower electrode formation step). That is, the lower electrode paste is printed, dried and fired. In this case, a metal organic paste is used as the paste for the bottom electrode. Here, Au resinate or Ag resinate is mentioned as a metal organic substance. The lower electrode is formed as a thin film having a thickness of 0.2 μm to 0.4 μm (preferably 0.3 μm). That is, since the lower electrode paste is a metal organic paste, it can be formed into a thin film. As shown in FIG. 5, in forming the lower surface electrode, the lower surface electrode G22 is formed simultaneously for the adjacent chip resistors. That is, the lower electrode is formed in one printing region so as to straddle the boundary position (that is, the primary slit) in the alumina substrate region corresponding to two chip resistors adjacent in the X direction. Further, in the Y direction, a bottom electrode is formed continuously in a strip shape. That is, a plurality of chip resistors are collectively formed in the Y direction to form a lower surface electrode in a series of strips, and two lower surface electrodes adjacent to each other in the X direction are formed together. In addition, W1 of FIG. 5 is a figure which shows the state which looked at the alumina substrate from the lower surface side.

  Next, a resistor is formed on the front surface of the alumina substrate (S12 in FIG. 4, W2 in FIG. 5, resistor forming step). That is, after the resistor paste is printed, the resistor G12 is formed by drying and baking. This resistor paste is a ruthenium oxide paste (for example, ruthenium oxide metal glaze), and thereby forms the resistor in a thick film. Specifically, it is formed in a thick film having a thickness of 3 to 12 μm. The resistor G12 is a resistor corresponding to a plurality of resistors 12 in the X direction. When the resistor paste is printed, the resistor paste is continuously formed in a strip shape in the X direction (direction between the top electrodes) on the alumina substrate. And print. That is, in the alumina substrate, a series of regions of the insulating substrate 10 that are continuous in the X direction when finally becoming individual chip resistors (this is referred to as an “aggregate region”. In this case, the resistor paste is printed in a single band from one end to the other end of the aggregate region. That is, the resistor paste is printed in a series of strips together in a plurality of chip resistors in the X direction. In the Y direction, the resistor paste is formed with a width smaller than the width of the insulating substrate 10 in the Y direction. In FIG. 5, the resistor G12 is hatched for easy viewing. Further, W2 and W3 in FIG. 5 are views showing a state in which the alumina substrate is viewed from the upper surface side.

  Next, the upper surface electrode G14 is formed on the resistor 12 (see S13 in FIG. 4, W3 in FIG. 5, upper surface electrode forming step). That is, the upper surface electrode is formed in the end region of the region that becomes the resistor 12 when individual chip resistors are formed. That is, the top electrode paste is printed, dried and fired. The upper surface electrode paste in this case is a silver-based paste (for example, silver-based metal glaze), thereby forming the upper surface electrode in a thick film. Specifically, it is formed in a thick film having a thickness of 5 to 12 μm. In FIG. 5, the upper surface electrode G <b> 14 is the upper surface electrode for two of the upper surface electrodes 14 in the chip resistor A. That is, when the chip resistor is formed, the upper surface electrodes of the adjacent chip resistors adjacent to each other are formed by one printing region.

  Thereafter, the resistor 12 is trimmed to adjust the resistance value (see S14 in FIG. 4), and a protective film is formed (that is, the protective film is printed, dried, and baked (may be cured instead of baked)). (See S15 in FIG. 4).

  Then, primary division is performed along the primary slit J1 (see S16 in FIG. 4, division step). In this division, the alumina substrate is bent with the lower surface side as a base point. That is, a strip-shaped substrate formed by linearly arranging the alumina substrate portions for one chip resistor is bent downward from the upper surface side so as to be bent with respect to the adjacent strip-shaped substrate. At this time, since the lower surface electrode is formed of a metal thin film, the risk of burrs occurring at the end of the lower surface electrode can be reduced.

  Then, a side electrode is formed with respect to this strip-shaped board | substrate (refer S17 of FIG. 4, side electrode formation process). That is, a metal thin film is formed by sputtering. The side electrode paste may be printed, dried and fired (or hardened instead of fired), and formed into a thick film.

  After that, secondary division is performed along the secondary slit J2 (see S18 in FIG. 4). Then, plating is formed into a chip resistor (see S19 in FIG. 4).

  The chip resistor A having the above configuration is mounted on the wiring board as shown in FIG. That is, the chip resistor A is mounted on the land 52 formed on the wiring board 54 via the solder fillet 50.

  As described above, in the chip resistor of the present embodiment, the lower surface electrode is formed using a metal organic material, so that the lower surface electrode can be formed into a thin film. Therefore, when the chip resistor A is manufactured, the end portion of the lower surface electrode is formed. It is possible to reduce the risk of occurrence of burrs. That is, it is possible to reduce the risk of burrs occurring at the end of the lower electrode during the primary division.

  Moreover, since the resistor 12 is formed of a thick film, it is possible to reduce the risk of disconnection of the resistor 12 itself. Here, since the upper surface electrode 14 is formed of a thick film, the resistor 12 is also easily formed in a thick film. That is, if the upper electrode 14 is a thin film and the resistor 12 is a thick film, there may be a problem in the bonding strength between the resistor 12 and the upper electrode 14, but in the case of the chip resistor of this embodiment, Such a problem does not occur.

  Further, the total length of the bottom electrode 22 in the inter-electrode direction (that is, α2 + α3) is formed to be 40% or more and 60% or less of the length α1 of the insulating substrate 10 in the inter-electrode direction. Can be high. That is, even when a force is applied from the upper surface side in a state where the chip resistor A is mounted on a wiring board or the like, the chip resistor A can be hardly broken. That is, the total length in the inter-electrode direction of the lower surface electrode 22 is set to 40% to 60% of the length in the inter-electrode direction of the insulating substrate 10, and the length of the lower surface electrode is made longer than usual. Since the length of the distance L (refer FIG. 1) between the lower surface side electrode parts 42 can be made small, the bending strength can be enlarged correspondingly. Specifically, the amount of deflection when an external force F is applied to the center portion of the chip resistor A increases in proportion to the cube of L, but since this L decreases, the amount of deflection can also be reduced. Thereby, the bending strength can be increased.

  In addition, since the length of the lower surface electrode 22 in the inter-electrode direction is made longer than usual, the area of the lower surface of the lower surface side electrode portion 42 can be increased, so that when the chip resistor A is mounted on the wiring substrate, the lower surface The contact area between the side electrode portion 42 and the solder fillet 50 can be increased, and thereby the adhesion of the chip resistor A to the wiring board can be enhanced. In addition, the chip standing phenomenon of the chip resistor A can be prevented. That is, when the length of the lower electrode 22 in the inter-electrode direction is short, the moment for suppressing the chip standing is low, and thereby one end of the chip resistor is lifted from the wiring board side, and the chip resistor Although there is a possibility that the chip resistor may stand up with the corner portion of the other end as a fulcrum, in the case of the chip resistor A of the present embodiment, the length of the lower surface electrode 22, and hence the length of the lower surface side electrode portion 42. When the chip resistor is mounted on the wiring board and soldered by the reflow furnace, the moment for suppressing the chip standing can be increased, so that such a chip standing phenomenon can be prevented.

  In the chip resistor A of the present embodiment, only the lower surface electrode 22 is formed using the metal organic material. Therefore, when the metal organic material is Au resinate, both the lower surface electrode 22 and the upper surface electrode 14 are formed. Compared to the case of using a metal organic material, it can be manufactured at a low cost. That is, since the Au resinate is relatively expensive, it is possible to reduce the manufacturing cost by forming only the lower electrode of the lower electrode and the upper electrode using the Au resinate.

  Although the total length of the lower surface electrode 22 is 40 to 60% of the length of the insulating substrate 10, the total length of the lower surface side electrode portion 42 in the inter-electrode direction (that is, β2 + β3 (see FIG. 1)). May be 40% or more and 60% or less of the length β1 of the chip resistor A in the inter-electrode direction.

  In the above description, the case where the primary slit and the secondary slit are provided in advance on both the upper surface and the lower surface of the alumina substrate has been described as an example. However, the present invention is not limited to this, and there are two primary slits on the upper surface and the lower surface. A solid alumina substrate not provided with a next slit may be used. In that case, after forming the lower surface electrode on the lower surface of the substrate, the primary slit and the secondary slit were formed on the lower surface of the alumina substrate, and then the primary slit and the secondary slit were formed on the upper surface of the alumina substrate. Later, the resistor formation step (S12) and subsequent steps are performed.

  Further, in the above description, the resistor 12 is formed on the upper surface of the insulating substrate 10 and the upper electrode 14 is formed on the upper surface of the resistor 12 as an example. A pair of upper surface electrodes may be formed, and the resistor may be formed so as to connect the upper surface electrodes. In that case, both ends of the resistor are configured to be stacked on the upper surface electrode.

  In the above description, the chip resistor has been described as an example, but the configuration other than the configuration of the resistor may be applied to a chip component other than the chip resistor. For example, the point that the bottom electrode and the side electrode are thin films and the top electrode 14 is a thick film may be applied to a chip component other than a chip resistor.

  In the above description, the resistor 12 has been described as having a thickness of 3 to 12 μm. However, the resistor 12 may have a thickness of 8 to 12 μm.

It is a longitudinal cross-sectional view which shows the structure of the chip resistor based on the Example of this invention. It is explanatory drawing which shows notionally arrangement | positioning of the principal part of the chip resistor based on the Example of this invention. It is explanatory drawing which shows notionally arrangement | positioning of the principal part of the chip resistor based on the Example of this invention. It is explanatory drawing which shows the manufacturing process of the chip resistor based on the Example of this invention. It is explanatory drawing which shows the manufacturing process of the chip resistor based on the Example of this invention. It is explanatory drawing which shows the state of the division | segmentation in the manufacturing process of the chip resistor based on the Example of this invention. It is a longitudinal cross-sectional view which shows the mounting state of the chip resistor based on the Example of this invention. It is a longitudinal cross-sectional view which shows the structure of the conventional chip resistor.

Explanation of symbols

A Chip resistor 10 Insulating substrate 12 Resistor 14 Upper surface electrode 20 Protective film 22 Lower surface electrode 24 Side electrode 26 Plating 28 Nickel plating 30 Tin plating 40 Electrode portion 42 Lower surface side electrode portion

Claims (12)

A chip resistor,
An insulating substrate;
A resistor formed on the upper surface side of the insulating substrate and formed in a thick film having a thickness of 3 to 12 μm;
A lower electrode formed on the lower surface side of the insulating substrate, the lower electrode formed thinner than the thickness of the thick film;
A chip resistor comprising: A chip resistor,
A resistor formed in a thick film having a thickness of 3 to 12 μm;
A bottom electrode formed in a thin film having a thickness of 0.2 to 0.4 μm;
A chip resistor comprising: A chip resistor,
An insulating substrate;
A resistor formed on the upper surface side of the insulating substrate and formed in a thick film having a thickness of 3 to 12 μm;
A bottom electrode formed on a thin film having a thickness of 0.2 to 0.4 μm with a bottom electrode formed on the bottom surface side of the insulating substrate;
A chip resistor comprising: The insulating substrate has a substantially rectangular parallelepiped shape, and a lower surface electrode is provided along opposite sides of the lower surface of the insulating substrate, and the lower surface of the insulating substrate in a direction perpendicular to the sides of the two lower surface electrodes. 4. The chip resistor according to claim 1, wherein the total length in the inter-electrode direction, which is a direction along the direction, is not less than 40% and not more than 60% of the length in the inter-electrode direction of the insulating substrate. vessel. The chip resistor further includes
5. The upper surface electrode connected to the end regions on both sides of the resistor, the upper surface electrode being formed in a thick film having a thickness of 5 to 12 [mu] m. Chip resistor. A chip resistor,
An insulating substrate having a substantially rectangular parallelepiped shape;
A resistor provided on the upper surface side of the insulating substrate and formed in a thick film having a thickness of 3 to 12 μm;
An upper surface electrode provided on the upper surface side of the insulating substrate, connected to the end regions on both sides of the resistor, and an upper surface electrode formed in a thick film having a thickness of 5 to 12 μm; ,
Formed as a thin film having a thickness of 0.2 to 0.4 μm with the lower surface electrode provided on the lower surface side of the insulating substrate and the lower surface electrode provided on both sides in the inter-electrode direction that is the direction between the pair of upper surface electrodes. A bottom electrode,
A side electrode formed on a side surface of the insulating substrate, at least a side electrode connected to the upper surface electrode and the lower surface electrode;
A chip resistor comprising: The total length in the inter-electrode direction, which is the direction along the lower surface of the insulating substrate in the direction perpendicular to the side portion of the two lower surface electrodes, is 40% or more of the length in the inter-electrode direction of the insulating substrate. The chip resistor according to claim 6, wherein the chip resistor is less than or equal to%. The chip resistor according to claim 1, 2, 3, 4, 5, 6, or 7, wherein the lower surface electrode is formed using a metal organic paste. Chip parts,
An upper surface electrode formed in a thick film having a thickness of 5 to 12 μm;
A bottom electrode formed in a thin film having a thickness of 0.2 to 0.4 μm;
A chip component comprising: A method of manufacturing a chip resistor,
In the lower surface electrode forming step of forming the lower surface electrode on the lower surface side of the insulating substrate into a thin film having a thickness of 0.2 to 0.4 μm, the metal organic paste is printed, and the printed metal organic paste is dried and then fired. A bottom electrode forming step of forming in one forming region together with a bottom electrode of an adjacent chip resistor when finally becoming a chip resistor in the process;
A resistor forming step performed after the lower surface electrode forming step, and forming a resistor in a thickness of 3 to 12 μm on the upper surface side of the insulating substrate;
A dividing step of dividing the insulating substrate together with the lower surface electrode formed in the one formation region;
A method of manufacturing a chip resistor, comprising: In the upper surface electrode forming step performed after the resistor forming step and before the dividing step, the upper surface electrode connected to the end regions on both sides of the resistor is formed into a thick film having a thickness of 5 to 12 μm. The method of manufacturing a chip resistor according to claim 10, further comprising an upper surface electrode forming step. The insulating substrate has a substantially rectangular parallelepiped shape, and the total length in the inter-electrode direction that is a direction perpendicular to the side portion and along the lower surface of the insulating substrate in the two lower surface electrodes is the electrode of the insulating substrate. The lower surface electrode is provided along the opposite side portions of the lower surface of the insulating substrate in the lower surface electrode forming step so as to be 40% or more and 60% or less of the length in the inter-direction, respectively. The manufacturing method of the chip resistor of description.

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