Chip resistance

Abstract

Chip resistor (1) comprising: a ceramic substrate (2) shaped like a cuboid; a pair of front electrodes (3) provided at longitudinally opposite end sections of a front face of the ceramic substrate (2); a resistive body (4) provided between and connected to the pair of front electrodes (3); a protective layer (5) covering the resistive body (4); a pair of back electrodes (6) provided at longitudinally opposite end sections of a rear face of the ceramic substrate (2); end-surface electrodes (7) by which the front electrodes (3) and the back electrodes (6) are each electrically connected to each other; and outer electrodes (8) covering the end-surface electrodes (7), wherein a pair of insulating resin layers (9) is formed on the rear face of the ceramic substrate (2) with a predetermined interval between them to cover edge sections of the back electrodes (6);and at least end sections of the insulating resin layers (9) on opposite sides from the outer electrodes (8) are exposed, wherein the end surface electrodes (7) are formed on areas of the back electrodes (6), except at the edge sections thereof, in order to be connected with the insulating resin layers (9), wherein the outer electrodes (8) cover areas of the end surface electrodes (7) that overlap with the back electrodes (6) so that they are connected with the insulating resin layers.

Description

Technical field

[0001] The present invention relates to a chip resistor that is surface-mounted on a printed circuit board by soldering. Current state of the art

[0002] This type of chip resistor comprises a ceramic substrate, a pair of front electrodes, a resistor body, a protective layer, a pair of back electrodes, a pair of end-face electrodes, and a pair of outer electrodes. The ceramic substrate is cuboid-shaped. The pair of front electrodes is located at longitudinally opposite end sections of a front face of the ceramic substrate. The resistor body is located at the front of the ceramic substrate so that it is connected to the pair of front electrodes. The protective layer is located to cover the resistor body. The pair of back electrodes is located at longitudinally opposite end sections of a rear face of the ceramic substrate. The pair of end-face electrodes is located at opposite end faces of the ceramic substrate so that they cover the front and back electrodes.The pair of outer electrodes is formed by a plating treatment applied to the outer surfaces of the end-surface electrodes.

[0003] The chip resistor configured in this way is surface-mounted on a printed circuit board (PCB) as follows. After solder paste is printed onto pads provided in the PCB, the back electrodes are oriented downwards and the outer electrodes are attached to the pads. In this state, the solder paste melts and solidifies, thereby surface-mounting the chip resistor to the PCB. However, material fatigue, cracks, fractures, etc., can occur at the solder joints due to thermal stress.

[0004] To solve this problem according to the prior art, a chip resistor was proposed, as disclosed in patent literature 1. The chip resistor has a configuration in which each of the back electrodes is formed into a two-layer structure consisting of an inner layer made of sintered silver and an outer layer made of an electrically conductive resin (resin silver), and in which a solder joint is applied to outer electrodes covering the back electrodes, each of which has such a two-layer structure. In the chip resistor configured thus according to the prior art, the outer layers of the back electrodes, which contact solder joint sections on webs of a printed circuit board, are made of electrically conductive resin.Therefore, thermal stress acting on the soldered joint sections can be reduced compared to a case where each of the back electrodes is made exclusively of sintered silver.

[0005] In addition, another chip resistor was proposed, as disclosed in patent literature 2. This chip resistor has a configuration in which each of the back electrodes consists of a first electrode layer made of sintered silver and a second electrode layer, also made of sintered silver, laminated to the first electrode layer at a position separated by an edge section of the first electrode layer. A solder joint is applied to outer electrodes covering such back electrodes. In the chip resistor configured thus according to the prior art, a step is formed on a section extending from a side face of the second electrode layer to a front face of the first electrode layer, and a step section corresponding to the step is also formed in each of the outer electrodes.Therefore, the strength of solder joint sections can be increased by the step sections, thus relieving thermal stress. List of citations from patent literature

[0006] Patent Literature 1: JP-A-2008-84905 Patent Literature 2: JP-A-2013-74044 Summary of the invention: Technical problem

[0007] However, in the chip resistor described in patent literature 1, the solder joint is applied to the outer electrodes, which cover the outer layers of the back electrodes made of electrically conductive resin. For this reason, a gas is released from the resin components of the back electrodes due to heating during the soldering process, raising concerns that the solder might crack or that the bond might weaken due to the escaping gas.

[0008] On the other hand, in the chip resistor described in patent literature 2, both the first and second electrode layers, which form each of the back electrodes, are made of sintered silver without the use of any electrically conductive resin material. Accordingly, disadvantages such as solder cracking due to escaping gas originating from a resin component can be prevented. However, since both the first and second electrode layers are made of sintered silver, it is generally known that it is difficult to produce sintered silver with a film thickness comparable to that of an electrically conductive resin. For this reason, the step height in the single second electrode layer can only be specified at a very small value (no greater than 10 μm).To fully utilize the aforementioned effect of the step, it is therefore necessary to form a large number of secondary electrode layers on top of the first electrode layer. This leads to complications in the manufacturing process. Additionally, the first electrode layer, made of sintered silver, has an excellent bond to the ceramic substrate. However, if a stress caused by heating after the chip resistor has been mounted on the circuit board is repeated, a thermal stress caused by the difference in the coefficient of thermal expansion between the circuit board and the chip resistor acts in a direction that tends to detach the first electrode layer from the ceramic substrate.Therefore, there is also a problem that cracks can easily occur along a boundary between an edge section (front end-end section) of the first electrode layer and the ceramic substrate.

[0009] The invention was achieved taking into account such factual circumstances of the prior art. One objective of the invention is to provide a chip resistor that can reliably prevent cracks, fractures, etc., from occurring in solder joint sections due to thermal stress. Solution to the problem

[0010] To achieve the aforementioned objective, the invention provides a chip resistor comprising: a ceramic substrate shaped like a cuboid; a pair of front electrodes provided at longitudinally opposite end sections of a front face of the ceramic substrate; a resistor body provided between and connected to the pair of front electrodes; a protective layer covering the resistor body; a pair of back electrodes provided at longitudinally opposite end sections of a rear face of the ceramic substrate; end-surface electrodes by which the front electrodes and the back electrodes are each electrically connected to one another; and outer electrodes covering the end-surface electrodes.wherein: a pair of insulating resin layers is formed on the back of the ceramic substrate with a predetermined interval between them to cover edge sections of the back electrodes; and at least end sections of opposite sides of the insulating resin layers are exposed from the outer electrodes.

[0011] In the chip resistor configured in this way, the edge sections of the pair of back electrodes provided at the longitudinally opposite end sections of the back of the ceramic substrate are covered with the insulating resin layers, and at least the end sections from opposite sides of the insulating resin layers are exposed by the outer electrodes. Therefore, the insulating resin layers are not covered with solder when the chip resistor is assembled. Even if the back electrodes are formed from an electrically conductive resin, any escaping gas originating from the resin component (the insulating resin layers or the electrically conductive resin) cannot escape through the solder. Accordingly, it is possible to prevent solder from bursting due to escaping gas or to prevent a strong bond from weakening due to escaping gas.Additionally, even if a thermal stress generated after the chip resistor has been mounted acts in a direction that would detach the back electrodes from the ceramic substrate, the edge sections of the back electrodes are covered with insulating resin layers, thus preventing the formation of cracks along the interface between the back electrodes and the ceramic substrate. Furthermore, the insulating resin layers overlap the edge sections of the back electrodes, and steps in the sections extending from the side faces of the insulating resin layers to the front faces of the back electrodes can be used to increase the strength of the solder joint sections. Accordingly, it is possible to prevent the formation of cracks, fractures, etc., due to thermal stress.

[0012] In the configuration described above, this can work as long as the end-surface electrodes are connected to at least the end faces of the back electrodes that face their edge segments. However, if the end-surface electrodes are also formed on areas of the front of the back electrodes other than the edge segments intended to connect to the insulating resin layers, the interfaces between the back electrodes and the insulating resin layers are covered by the end-surface electrodes, and the end electrodes are covered by the outer electrodes. Consequently, the back electrodes lack interfaces between the outer electrodes and the insulating resin layers. Even if the chip resistor is used in a damaging environment with a large amount of sulfide gas, the silver contained in the back electrodes will therefore not react with the sulfide gas to form silver sulfide.Accordingly, it is possible to prevent the back electrode from becoming sulfurized and, consequently, to prevent the weakening of its bond. Therefore, it is possible to prevent the occurrence of cracks, fractures, etc., due to thermal stress in the back electrodes.

[0013] In this case, the insulating resin layers are shaped like ribbons, extending from one end section of the width across the back of the ceramic substrate to the other end section across the back of the ceramic substrate. When the end-surface electrodes are formed by sputtering or coating, the insulating resin layers act as stops, allowing the end-surface electrodes to be formed with excellent linearity. Consequently, the linearity of the shape of each of the outer electrodes attached to the end-surface electrodes can be improved. Advantageous effects of the invention

[0014] According to the chip resistance in the invention, it is possible to prevent solder cracking or a decrease in bond strength due to escaping gas, and it is possible to prevent the formation of cracks along the boundaries between the back electrodes and the ceramic substrate. Furthermore, it is possible to reliably prevent the formation of cracks or fractures due to thermal stress in the soldered joint areas. Brief description of the drawings

[0015] [ Fig. 1] A cross-sectional view of a chip resistor according to a first embodiment of the invention.

[0016] [ Fig. 2] A sectional view showing a state in which the chip resistor is mounted.

[0017] [ Fig. 3] Explanatory view showing a manufacturing process of the chip resistor.

[0018] [ Fig. 4] Explanatory views showing the manufacturing process of the chip resistor.

[0019] [ Fig. 5] Cross-sectional view of a chip resistor according to a second embodiment of the invention.

[0020] [ Fig. 6] Rear view of the chip resistor. Description of the embodiments

[0021] Embodiments of the invention are described below with reference to the drawings. As in Fig. As shown in Figure 1, there is a chip resistance. 1 according to a first embodiment of the invention from a ceramic substrate 2 , a pair of front electrodes 3 , a resistance body 4 , a protective layer 5 , a pair of back electrodes 6 , a pair of end-surface electrodes 7 , a pair of external electrodes 8 and a pair of insulating resin layers 9 The ceramic substrate 2It is shaped like a cuboid. The pair of front electrodes 3 is located on longitudinally opposite end sections of a front face of the ceramic substrate 2 provided. The resistor body 4 is between the two front electrodes 3 provided and connected to them. The protective layer 5 covers the resistor body 4 The pair of back electrodes 6 is located on longitudinally opposite end sections of a back side of the ceramic substrate 2 provided. By the pair of end-surface electrodes 7 are the front electrodes 3 and the back electrodes 6 Each pair of outer electrodes is electrically connected to the other. 8 is at the front electrodes 3 , the end-surface electrodes 7 and the front sides of the back electrodes 6 arranged. The pair of insulating resin layers 9covers edge sections of the back electrodes 6 , which are from the external electrodes 8 are exposed.

[0022] The ceramic substrate 2 is an insulating substrate containing aluminum oxide as a major component. A large substrate, described later, is divided along primary and secondary dividing grooves extending longitudinally and laterally. Therefore, a large quantity of such ceramic substrates is used. 2 receive.

[0023] The pair of front electrodes 3 It is obtained by screen printing, drying, and sintering an Ag-based paste. The resistive body 4 It is obtained by screen printing, drying, and sintering a resistive paste made of ruthenium oxide, etc. Opposite end sections of the resistive body overlap longitudinally. 4 each with the front electrodes 3Although not shown, there is a trim groove in the resistor body. 4 formed to adjust a resistance value from it.

[0024] The protective layer 5 It is formed in a two-layer structure consisting of a base layer and a top layer. The base layer is obtained from the two-layer structure by screen printing, drying, and sintering a glass paste, while the top layer is obtained by screen printing and thermal curing of an epoxy resin-based paste.

[0025] The pair of back electrodes 6 is obtained by screen printing, drying, and sintering the Ag-based paste. The pair of end-surface electrodes 7 is formed from Ni-Cr etc., sputtered onto the end faces of the ceramic substrate 2 .

[0026] The pair of external electrodes 8 is formed from Ni, Sn or the like, with which the front faces of the end-surface electrodes 7They are electroplated. As will be described later, a soldered connection is made to the outer electrodes. 8 applied when the chip resistance 1 is mounted on a circuit board.

[0027] The pair of insulating resin layers 9 is obtained by screen printing and thermal curing of an epoxy resin-based paste. The one end faces of the insulating resin layers 9 They lie on the back of the ceramic substrate with a predetermined interval between them. 2 opposite. The other end faces of the insulating resin layers 9 overlap with the edge sections of the back electrodes 6 .

[0028] As in Fig. Figure 2 shows the chip resistor configured in this way. 1 on the circuit board 10 attached, with the back electrodes 6 are directed downwards. In this state, the bridges 11, which are in the circuit board 10 and the external electrodes 8 are provided, each connected by plumb lines 12 connected. Therefore, the chip resistance is 1 on the circuit board 10 Surface-mounted. In this case, the edge sections of the pair are back electrodes. 6 each with the insulating resin layers 9 covered. The insulating resin layers 9 are continuous with the external electrodes 8 at outer positions than the edge sections of the back electrodes 6 Therefore, at least the sides of the opposite ends of the pair of insulating resin layers must be coated. 9 not with the plumb lines 12 covered, but exposed, when the chip resistance 1 is installed. Even if a gas escapes from the insulating resin layers. 9The gas generated by heating during soldering escapes to the outside from the areas not connected to the solder. 12 are covered. Therefore, it is possible to prevent the solder from bursting or the bond from weakening due to escaping gas.

[0029] Additionally, even if the force acts in one direction to drive the back electrodes 6 from the back of the ceramic substrate 2 due to thermal stress during the assembly of the chip resistor 1 The edge sections of the back electrodes need to be solved. 6 with the insulating resin layers 9 They are covered to protect them from being easily separated. Therefore, no cracks occur along the boundaries between the back electrodes. 6 and the ceramic substrate 2 Furthermore, the insulating resin layers overlap. 9with the front sides of the edge sections of the back electrodes 6 . Steps on sections extending from side surfaces of the insulating resin layers 9 to the front sides of the back electrodes 6 extend, can be used to determine the strength of the plumb lines 12 to increase. Therefore, it is possible to prevent the occurrence of cracks, fractures, etc. due to thermal stress.

[0030] Subsequently, a manufacturing process for the chip resistor configured as described above is established. 1 with reference to Fig. 3 and Fig. 4 described.

[0031] As in Fig. 3(a) and Fig. As shown in 4(a), a large substrate is first 20A produced, of which a large quantity of ceramic substrates 2 can be obtained. Primary partition grooves 21 and secondary partition grooves 22are provided in advance in a grid pattern on two surfaces, i.e., on a front and a back of the large substrate. 20A Each of the cells that pass through the two division grooves 21 and 22 Being divided up acts as a chip design area in which a chip resistor can be formed. Moreover, a large number of such chip design areas are representative of… Fig. 3 shown, and cross-sectional views according to such a chip area are in Fig. 4 shown. In reality, however, each step described below is performed collectively on the large substrate. 20A corresponding to a large number of such chip design areas.

[0032] That is, an Ag paste that is applied to the back surface of the large substrate. 20A The screen-printed material is then dried. Thus, as in Fig. 3(b) and Fig. 4(b) shows a variety of unsintered back electrodes6 formed to each use the primary partition grooves 21 to be laid. Then the Ag paste, which is applied to the front of the large substrate, is applied. 20A screen-printed, dried. As in Fig. 3(c) and Fig. As shown in 4(c), a variety of unsintered front electrodes are therefore used. 3 formed to each use the primary partition grooves 21 to be laid. Then the unsintered front electrodes are... 3 and the unsintered back electrodes 6 They are sintered simultaneously. Therefore, the back electrodes are 6 , which are made from sintered silver, on the back of the large substrate 20A formed, and the front electrodes 3 , which are made from sintered silver, are attached to the front of the large substrate 20A formed. Furthermore, a sequence in which the front electrodes 3 and the back electrodes 6are formed, reversed to the previously mentioned sequence. The back electrodes 6 can therefore be formed after the front electrodes 3 are educated.

[0033] Subsequently, a resistive paste made of ruthenium oxide or the like is applied to the front of the large substrate. 20A It is screen-printed, dried, and sintered. As in Fig. 3(d) and Fig. As shown in 4(d), a resistive body is thus formed. 4 formed at a central section of each of the chip areas. In this case, longitudinally opposite end sections of the resistor body are formed. 4 at the front electrodes 3 , which are provided at longitudinally opposite end sections of the chip area, interposed.

[0034] Subsequently, a glass paste is used as a material to reduce damage to the resistive elements. 4During the formation of trim grooves, the material is screen-printed, dried, and sintered. Therefore, an underlayer is formed, which contains the resistive elements. 4 It covers, is formed. Then the trim grooves in the resistor bodies are created. 4 formed from above the sublayer in order to increase the resistance values ​​of the resistive elements 4 to adapt. Then, a resin paste, such as an epoxy resin-based paste, screen-printed onto the substrate, is thermally cured to form a top layer covering the substrate. Therefore, as in Fig. 3(e) and Fig. 4(e) shows protective layers 5 , each having a two-layer structure, formed to form the resistive bodies 4 to cover.

[0035] Furthermore, the back electrodes 6They are formed from resin silver instead of sintered silver. In this case, the sintering temperature of the resistive paste is significantly higher than the melting temperature of the resin silver. Therefore, the back electrodes can 6 formed from the resin silver after the resistance bodies 4 and the protective layers 5 are formed. Additionally, if the chip resistance 1 , in which the back electrodes 6 Once assembled from the resin silver formed in this way, escaping gas is also protected by the resin in the back electrodes. 6 The gas is contained within the solder and is generated by heating during the soldering process. However, the escaping gas cannot escape through the solder, but rather through insulating resin layers. 9 , the edge sections of the back electrodes 6Cover. Accordingly, it is possible to prevent the solder from bursting or the bond from weakening due to escaping gas, even if the back electrodes are covered. 6 are formed from the silver in the resin.

[0036] Next, an epoxy resin-based paste is applied to the back of the large substrate. 20A screen-printed, thermally cured. Therefore, as in Fig. 3(f) and Fig. As shown in 4(f), the insulating resin layers are 9 , which are the edge sections of the back electrodes 6 covering areas that are opposite each other in each of the chip regions.

[0037] All previous steps are now performed at once on the large substrate 20A completed. After the large substrate 20A along the primary splitting grooves 21 in strip-shaped substrates 20BOnce broken (predominantly subdivided), Ni-Cr is subsequently deposited on separate surfaces of the strip-shaped substrates. 20B sputtered. Thus, as in Fig. 3(g) and Fig. 4(g) shown, end surface electrodes 7 , through which the front electrodes 3 and the back electrodes 6 each is electrically connected to the opposite end faces of the strip-shaped substrates 20B educated.

[0038] Then the strip-shaped substrates 20B along the secondary splitting grooves 22 broken down (subdivided into subordinate components). Therefore, individual chips (individual parts) are obtained that are the same size as the chip resistor. 1 Then the individual chips, which have been separated and individually subdivided, are electroplated with Ni, Sn, or similar materials. This creates outer electrodes. 8 formed to attach to the exposed front electrodes3 , the exposed end-surface electrodes 7 and the front surfaces of the exposed back electrodes 6 to be arranged. As a result, chip resistors are 1 , which in Fig. 1 will be shown, completed.

[0039] Fig. Figure 5 is a cross-sectional view of a chip resistor. 30 according to a second embodiment of the invention. Fig. Figure 6 is a rear view of the chip resistor. 30 In Fig. 5 and Fig. 6 will each refer to sections corresponding to those in Fig. 1 correspond, referred to by the same characters.

[0040] The chip resistance 30 According to the second embodiment, it differs from the chip resistor. 1 according to the first embodiment in that each of the insulating resin layers is formed like a band to extend from one end section of the width to the back side of a ceramic substrate. 2to the other end section of the width towards the back of the ceramic substrate 2 (from a top side to a bottom side in Fig. 6) to extend, and each of the end-surface electrodes 7 is shaped into a U-shape in cross-section to separate itself from a top surface of a corresponding front electrode 3 to a lower surface of a corresponding back electrode 6 to extend. Regarding the remaining configuration, the chip resistance 30 According to the second embodiment, it is basically the same as the chip resistor. 1 according to the first embodiment.

[0041] That is, as in Fig. 5 and Fig. 6 showed that the remaining areas of the back electrodes 6 except for edge sections thereof, which are covered by the insulating resin layers 9 are covered with the end-surface electrodes 7 are covered, and that external electrodes 8on the front sides of the end-surface electrodes 7 are arranged accordingly. Border sections (see sections P in Fig. 5 and Fig. 6) between the back electrodes 6 and the insulating resin layers 9 with the end-surface electrodes 7 covered, and the back electrodes 6 are separated at inner sections from boundary sections (sections Q in Fig. 5 and Fig. 6) between the outer electrodes 8 and the insulating resin layers 9 arranged. Additionally, the insulating resin layers 9 , which are the edge sections of the back electrodes 6 covering, formed to extend from end to end of the side surfaces of the ceramic substrate 2 to extend. If sputtering is performed from the end-face sides to the end-face electrodes 7from Ni-Cr containing 20% ​​or more Cr or the like, which can be easily stretched around, to form, or when an Ag paste or the like is covered by dipping to coat the end-surface electrodes 7 The insulating resin layers act to form 9 , which are shaped like bridges, as stops so that the end-surface electrodes 7 with excellent linearity on the back sides of the ceramic substrate 2 can be formed.

[0042] In the chip resistor configured in this way, the edge sections of a pair of back electrodes are also 6 each in the same way with the insulating resin layers 9 covered, like the chip resistor 1according to the first embodiment. Accordingly, it is possible to prevent the occurrence of solder cracking or a decrease in the strength of the bond due to escaping gas, and it is possible to prevent the formation of cracks along the boundaries between the back electrodes. 6 and the ceramic substrate 2 to prevent this. Additionally, steps can be created on sections that extend from the side surfaces of the insulating resin layers. 9 to the front sides of the back electrodes 6 They can be used to increase the strength of soldered joint sections. Accordingly, it is possible to prevent the occurrence of cracks, fractures, etc., due to thermal stress.

[0043] Furthermore, the end-surface electrodes 7 in the chip resistor 30 According to the second embodiment, also in the areas of the back electrodes. 6formed, except for the edge sections thereof, which are covered by the insulating resin layers 9 to be connected. The boundary sections P between the back electrodes 6 and the insulating resin layers 9 are complete with the end-surface electrodes 7 covered. If the chip resistance 30 When used in a damaging environment where a large amount of sulfide gas is present, silver (Ag) in the back electrodes reacts 6 It contains, therefore, no sulfide gas to produce silver sulfide. Therefore, it is possible to prevent the back electrode from 6 is sulfated. Additionally, each of the insulating resin layers is 9 shaped like a ribbon to form an end section of the back of the ceramic substrate 2 widthwise to the other end section of the back of the ceramic substrate 2 to extend horizontally. If the end-surface electrodes 7Formed by sputtering or coating, the insulating resin layers act 9 like stops, so that the end-surface electrodes 7 They can be formed with excellent linearity. Accordingly, the linearity of the shape of each of the outer electrodes can be verified. 8 , which are located at the end surface electrodes 7 are arranged, will be improved. As a result, as in Fig. As shown in section 6, the rectangular outer electrodes can be used. 8 at longitudinally opposite end sections of the back of the ceramic substrate 2 to be formed. Since a soldered connection is made to the outer electrodes 8 When applied, a self-adjusting property can be improved during soldering.

[0044] When a pair of insulating resin layers 9, which are separated from each other by an intermediate layer with a predetermined interval between them, formed by screen printing a resin paste in the case of a chip resistor with a small external size, the two insulating resin layers can 9 They are connected to each other due to sagging pressure. Even in such a case, the functions and effects of the invention can still be maintained. Reference symbol list 1.30 chip resistor 2 Ceramic substrate 3 Front electrode 4 resistor bodies 5 protective layer 6 Back electrode 7 End surface electrode 8 External electrode 9 Insulating resin layer 10 circuit boards 11 Bridge 12 Lot 20A Large substrate 20B Strip-shaped substrate 21 Primary division groove 22 Secondary division groove

Claims

[1] Chip resistor comprising: a ceramic substrate shaped like a cuboid; a pair of front electrodes provided at longitudinally opposite end sections of a front face of the ceramic substrate; a resistive body provided between and connected to the pair of front electrodes; a protective layer covering the resistive body; a pair of back electrodes provided at longitudinally opposite end sections of a rear face of the ceramic substrate; end-surface electrodes by which the front electrodes and the back electrodes are each electrically connected to each other; and outer electrodes covering the end-surface electrodes; wherein: a pair of insulating resin layers is formed on the back of the ceramic substrate with a predetermined interval between them to cover edge sections of the back electrodes; and at least end sections of the insulating resin layers are exposed on opposite sides from the outer electrodes. [2] Chip resistor according to claim 1, wherein: the end surface electrodes are formed on areas of the back electrodes, except on the edge sections thereof, in order to be connected to the insulating resin layers. [3] Chip resistor according to claim 2, wherein: the insulating resin layers are formed as ribbons to extend from one end section of the back of the ceramic substrate in width to the other end section of the back of the ceramic substrate.