Network Chip Resistors

Abstract

This invention provides a network chip resistor that can form a voltage divider circuit on a single chip and does not suffer from the Manhattan phenomenon during soldering. A pair of thick film terminal electrodes 2,2 is provided on the front surface 1A of an insulating substrate 1, and a thick film intermediate electrode 3 is provided between the pair of thick film terminal electrodes 2,2. One or more plating layers 8 are formed on the pair of thick film terminal electrodes 2,2 and two pairs of thin film side electrodes 4,4 and 5,5, and on the thick film intermediate electrode 3 and pair of thin film intermediate side electrodes 6,6, respectively. The resistor further includes a thin film intermediate extension electrode 9 extending from the pair of thin film intermediate side electrodes 6,6 onto the back surface 1B of the insulating substrate 1.

Description

[Technical field]

[0001] The present invention relates to a network chip resistor capable of forming a voltage divider circuit on a single chip. [Background technology]

[0002] Japanese Patent Laid-Open No. 10-208901 (Patent Document 1), Japanese Patent Laid-Open No. 2018-6726 (Patent Document 2), Japanese Utility Model Laid-Open No. 64-37002 (Patent Document 3), etc. disclose a network chip resistor that forms a voltage divider circuit by forming a pair of terminal electrodes at both opposing ends of the front and back surfaces of an insulating substrate, separately forming electrodes for a voltage divider circuit between the pair of terminal electrodes, and then forming a film resistor to bridge the pair of opposing terminal electrodes on the front surface of the insulating substrate and cross the electrodes for the voltage divider circuit on the front surface of the insulating substrate. In all of these chip resistors, end surface electrodes covering both longitudinal end surfaces of the substrate are connected to the pair of terminal electrodes. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 10-208901 [Patent Document 2] JP 2018-6726 A [Patent Document 3] Japanese Utility Model Application Publication No. 64-37002 Summary of the Invention [Problem to be solved by the invention]

[0004] The longer the insulating substrate, the higher the possibility of the so-called Manhattan phenomenon occurring, in which the chip resistor stands up when the solder hardens, if end electrodes are provided on both longitudinal ends of the insulating substrate.

[0005] An object of the present invention is to provide a network chip resistor that does not cause the Manhattan phenomenon during soldering and that can form a voltage dividing circuit on a single chip. [Means for solving the problem]

[0006] The network chip resistor of the present invention comprises an elongated insulating substrate having a front surface and a back surface, a pair of terminal electrodes provided at both ends of the front surface of the insulating substrate in the longitudinal direction, two pairs of side electrodes provided at least on a pair of side surfaces located in the width direction perpendicular to the longitudinal direction of the insulating substrate and electrically connected to the pair of terminal electrodes, an intermediate electrode provided between the pair of terminal electrodes on the front surface of the insulating substrate, a pair of intermediate side electrodes provided at least on the pair of side surfaces and electrically connected to the intermediate electrodes, a pair of resistors provided between the pair of terminal electrodes and the intermediate electrode, and a pair of protective layers formed of a material resistant to plating solution and provided on the pair of resistors.The network chip resistor of the present invention particularly comprises one or more plating layers formed on the pair of terminal electrodes and the two pairs of side electrodes, and on the intermediate electrode and the pair of intermediate side electrodes.

[0007] By providing two pairs of side electrodes and a pair of intermediate side electrodes as in the present invention, the sides of the long insulating substrate are fixed with solder at three points on each side, making it difficult for the Manhattan phenomenon to occur. Also, if there are no side electrodes on both ends in the longitudinal direction of the insulating substrate, the spacing between adjacent chip resistors can be shortened even if the chip resistors are arranged in a straight line in the longitudinal direction, and the mounting density can be increased.

[0008] When the pair of terminal electrodes and the pair of intermediate electrodes are formed by a pair of thick-film terminal electrodes and a pair of thick-film intermediate electrodes, the electrodes can be formed by printing. When the pair of side electrodes and the pair of intermediate side electrodes are formed by a pair of thin-film side electrodes and a pair of thin-film intermediate side electrodes, the side electrodes can be easily formed and the resistor can be easily miniaturized.

[0009] The insulating substrate may further include an intermediate extension electrode extending from the intermediate side electrode onto the rear surface of the insulating substrate, and the rear surface of the insulating substrate may be provided with a rear surface protective layer formed of a material resistant to plating solution and extending in the longitudinal direction of the insulating substrate so as to cover at least the center of the intermediate extension electrode. By adopting such a configuration, one or more plating layers are easily attached. Furthermore, since a continuous portion between the intermediate side electrode and the intermediate extension electrode exists at the corner of the insulating substrate corresponding to the intermediate electrode, the attached plating layer can be prevented from peeling off from the corresponding portion of the insulating substrate. If the intermediate extension electrode is formed of a thick-film intermediate extension electrode, the intermediate extension electrode can be easily formed. [Brief description of the drawings]

[0010] [Figure 1] 1A to 1C are a front view, a bottom view, and a plan view of the network chip resistor of the present embodiment. [Diagram 2] This is a cross section taken along line II-II in FIG. 1(B). [Diagram 3] 1(A) is a cross-sectional view taken along line IIIA-IIIA in FIG. 1(B), and FIG. 1(B) is a cross-sectional view taken along line IIIB-IIIB in FIG. 1(B). [Figure 4] 2 is an equivalent circuit of the network chip resistor of the present embodiment including resistors R1 and R2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an example of an embodiment of the network chip resistor of the present invention will be described in detail with reference to the drawings. Figures 1(A) to (C) are a front view, a bottom view, and a plan view of the network chip resistor of this embodiment, Figure 2 is a cross section taken along line II-II in Figure 1(B), Figure 3(A) is a cross section taken along line IIIA-IIIA in Figure 1(B), and Figure 3(B) is a cross section taken along line IIIB-IIIB in Figure 1(B). Note that hatching indicating a cross section is omitted in Figures 2, 3(A), and (B). In addition, the network chip resistor of this embodiment is mounted in an inverted manner so that the resistor faces the mounting circuit board, and therefore is shown in a position in which the surface of the insulating substrate faces downward in Figures 1(A), 2, and 3(A) and (B).

[0012] In these figures, reference numeral 1 denotes an insulating substrate having a front surface 1A and a back surface 1B formed in a long and narrow rectangular shape made of ceramic. A pair of thick-film terminal electrodes 2, 2 corresponding to a pair of terminal electrodes are provided on the front surface 1A of the insulating substrate 1, and a thick-film intermediate electrode 3 corresponding to an intermediate electrode is provided between the pair of thick-film terminal electrodes 2, 2. The thick-film terminal electrodes 2, 2 and the thick-film intermediate electrode 3 are each formed by firing an electrode pattern formed by screen printing using a conductive paste containing silver and palladium. A pair of resistors R1 and R2 are provided between the pair of thick-film terminal electrodes 2, 2 and the thick-film intermediate electrode 3. The resistors R1 and R2 are formed by firing a print pattern screen printed on the surface of the insulating substrate 1 using a resistive paste containing ruthenium oxide as a material. In this embodiment, the resistors R1 and R2 have the same resistance value.

[0013] FIG. 4 is an equivalent circuit of the network chip resistor of this embodiment including resistors R1 and R2.

[0014] The insulating substrate 1 also has a pair of thin-film side electrodes 4,4 and 5,5 provided on a pair of side surfaces 1C and 1D located in the width direction perpendicular to the longitudinal direction of the insulating substrate 1, and corresponding to two pairs of side electrodes electrically connected to a pair of thick-film terminal electrodes 2,2 [see FIG. 3(A)]. Also, a pair of thin-film intermediate side electrodes 6,6 corresponding to a pair of intermediate side electrodes electrically connected to the thick-film intermediate electrode 3 are formed on the pair of side surfaces 1C and 1D [see FIG. 3(B)]. The thin-film side electrodes 4,4 and 5,5 and the pair of thin-film intermediate side electrodes 6,6 are each formed by sputtering, and in this embodiment, are formed of a material such as titanium, nickel, aluminum, or copper.

[0015] A pair of protective layers 7 made of a material resistant to plating liquid for protecting the pair of resistors R1 and R2 are formed on the pair of resistors R1 and R2. The protective layer 7 is composed of a first protective layer 7A made of a glass material and a second protective layer 7B made of an epoxy material.

[0016] The network chip resistor of this embodiment particularly includes one or more plating layers 8 formed on the pair of thick film terminal electrodes 2, 2 and two pairs of thin film side electrodes 4, 4 and 5, 5, and on the thick film intermediate electrode 3 and the pair of thin film intermediate side electrodes 6, 6. In this embodiment, the plating layer 8 is composed of a first plating layer 8A made of nickel (Ni) and a second plating layer 8B made of tin (Sn). The plating layer 8 is formed by barrel plating.

[0017] The network chip resistor of this embodiment further includes a thick-film intermediate extension electrode 9 that corresponds to an intermediate extension electrode extending onto the rear surface 1B of the insulating substrate 1 so as to be continuous with the pair of thin-film intermediate side electrodes 6, 6. This thick-film intermediate extension electrode 9 is also formed by firing an electrode pattern formed by screen printing using a conductive paste containing silver and palladium.

[0018] Furthermore, on the back surface 1B of the insulating substrate 1, a back surface side protective layer 10 made of an epoxy resin or the like is provided, which is made of a material resistant to plating liquid and extends in the longitudinal direction of the insulating substrate 1 so as to cover at least the center of the thick-film intermediate extension electrode 9. By providing the thick-film intermediate extension electrode 9 in this manner, one or more plating layers 8 are easily attached. Moreover, since there is a continuous portion between the thin-film intermediate side electrodes 6, 6 and the thick-film intermediate extension electrode 9 at the corners of the insulating substrate 1, the attached plating layer 8 can be prevented from peeling off from the portion corresponding to the corresponding corner of the insulating substrate 1.

[0019] In addition, the pair of thin-film intermediate side electrodes 6, 6 can be prevented from peeling off during soldering. Furthermore, the rear surface protective layer 10 forms the suction surface of the suction nozzle when the network chip resistor is suctioned with the suction nozzle and mounted on the circuit board, thereby preventing wear on the tip surface of the suction nozzle.

[0020] In the network chip resistor of this embodiment, a pair of thick film terminal electrodes 2, 2, resistors R1 and R2 bridging between the thick film terminal electrodes 2, 2, a thick film intermediate electrode 3 connected to the resistors R1 and R2, and thin film intermediate side electrodes 6, 6 are provided on an insulating substrate 1 as electrodes for a voltage dividing circuit, thereby forming a voltage dividing circuit on a single chip. As a result, the mounting area is reduced, enabling further miniaturization of electronic components. In addition, soldering and the like can be reduced, improving the efficiency of mounting work.

[0021] In this embodiment, the thick film intermediate extension electrode 9 is provided, but it is of course possible to omit the thick film intermediate extension electrode 9 or to cut it off midway. It is also of course possible to cover the thick film intermediate extension electrode 9 with a thin film electrode.

[0022] When mounting the network chip resistor of this embodiment on a circuit board, as shown in Fig. 2, the surface 1A of the insulating substrate 1 is faced toward the circuit board, and solder is applied onto the thick film terminal electrodes 2, 2 and the thick film intermediate electrode 3 via the plating layer 8 so that solder fillets are formed partway up the two pairs of thin film side electrodes 4, 4 and 5, 5 and the pair of thin film intermediate side electrodes 6, 6. In this way, solder fillets are not formed on both longitudinal end faces of the insulating substrate 1, and it is possible to prevent the Manhattan phenomenon, in which the chip resistor stands up during soldering.

[0023] The specific reference dimensions of the network chip resistor of this embodiment are L=0.6 mm, W=0.3 mm, T=0.22 mm, A=0.1 mm, B=0.95 mm, and C=0.16 mm. The resistance values ​​of the resistors R1 and R2 are 10 ohms to 1 megohm.

[0024] In the above embodiment, a ceramic substrate is used as the insulating substrate 1, but it is of course possible to use other insulating substrates. Also, in the above embodiment, the thin-film side electrodes 4, 4 and 5, 5 and the pair of thin-film intermediate side electrodes 6, 6 are formed by sputtering, but it is of course possible to form these by other thin-film formation techniques such as vapor deposition.

[0025] In the above embodiment, the pair of terminal electrodes and the intermediate electrode are composed of a pair of thick-film terminal electrodes and a pair of thick-film intermediate electrodes, but these electrodes may be formed of thin-film electrodes. In the present embodiment, the pair of side electrodes and the pair of intermediate side electrodes are composed of a pair of thin-film side electrodes and a pair of thin-film intermediate side electrodes, but it is of course possible to form these electrodes from thick films. Furthermore, in the present embodiment, the intermediate extension electrode is formed from a thick film, but it is of course possible to form this electrode from a thin film. [Industrial Applicability]

[0026] By providing two pairs of side electrodes and a pair of intermediate side electrodes as in the present invention, the sides of the long insulating substrate are fixed with solder at three points on each side, making it difficult for the Manhattan phenomenon to occur. Also, if there are no side electrodes on both ends in the longitudinal direction of the insulating substrate, the spacing between adjacent chip resistors can be shortened even if the chip resistors are arranged in a straight line in the longitudinal direction, and the mounting density can be increased. [Explanation of symbols]

[0027] 1. Insulating substrate 2 Thick film terminal electrode 3 Thick film intermediate electrode 4 Thin film side electrode 5 Thin film side electrode 6 Thin film intermediate side electrode 7 Protective layer 8 Plating layer 9 Thick film intermediate extension electrode 10 Back side protective layer

Claims

1. an elongated insulating substrate having a front surface and a back surface; a pair of terminal electrodes provided at both ends in a longitudinal direction of the surface of the insulating substrate; two pairs of side electrodes provided on at least a pair of side surfaces of the insulating substrate in a width direction perpendicular to the longitudinal direction, the pair of side electrodes being electrically connected to the pair of terminal electrodes; an intermediate electrode provided between the pair of terminal electrodes on the front surface of the insulating substrate; a pair of intermediate side electrodes provided at least on the pair of side surfaces and electrically connected to the intermediate electrode; a pair of resistors provided between the pair of terminal electrodes and the intermediate electrode; a pair of protective layers formed of a material resistant to a plating solution and provided on the pair of resistors; one or more plating layers formed on the pair of terminal electrodes and the two pairs of side electrodes, and on the intermediate electrode and the pair of intermediate side electrodes, There are no side electrodes on a pair of side surfaces of the insulating substrate located in the longitudinal direction, an intermediate extension electrode extending from the intermediate side electrode and extending onto the back surface of the insulating substrate; The intermediate extension electrode is composed of a thick film intermediate extension electrode, A network chip resistor characterized in that a back surface of the insulating substrate is provided with a back surface protective layer formed of a material resistant to plating liquid and extending in the longitudinal direction of the insulating substrate so as to cover the central portion of the intermediate extension electrode.

2. 2. The network chip resistor according to claim 1, wherein the pair of terminal electrodes and the intermediate electrode are constituted by a pair of thick film terminal electrodes and a thick film intermediate electrode.

3. 2. The network chip resistor according to claim 1, wherein the pair of side electrodes and the pair of intermediate side electrodes are constituted by a pair of thin-film side electrodes and a pair of thin-film intermediate side electrodes.

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