Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01C—RESISTORS
  • H01C7/00—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01C—RESISTORS
  • H01C17/00—Apparatus or processes specially adapted for manufacturing resistors
  • H01C17/02—Apparatus or processes specially adapted for manufacturing resistors adapted for manufacturing resistors with envelope or housing
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01C—RESISTORS
  • H01C1/00—Details
  • H01C1/02—Housing; Enclosing; Embedding; Filling the housing or enclosure
  • H01C1/034—Housing; Enclosing; Embedding; Filling the housing or enclosure the housing or enclosure being formed as coating or mould without outer sheath
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01C—RESISTORS
  • H01C17/00—Apparatus or processes specially adapted for manufacturing resistors
  • H01C17/006—Apparatus or processes specially adapted for manufacturing resistors adapted for manufacturing resistor chips

Definitions

• the present invention relates to a low-resistance chip resistor having a low resistance value.
• low resistance used as a current limit resistor that measures the charge / discharge current of a secondary battery such as a lithium-ion battery or limits the current when an IC terminal connection error occurs.
• resistors such as thin-film resistors in which a resistor is formed by a thin film, wound resistors in which a linear conductor is wound in a coil shape, and plate resistors are used. I have. These low-resistance resistors cost 20 to 40 yen each. A low-resistance paste is applied to the surface of a ceramic substrate to form a resistance paste layer, and the resistance paste layer is used to form a resistive resistor. If low-resistance resistors can be manufactured, the power of such low-resistance resistors can be reduced to 20 yen or less.
• TCR temperature coefficient
• T o resistance value Z target resistance value
• An object of the present invention is to provide a low-resistance chip resistor using a thick-film resistor having a small temperature coefficient and small resistance value deviation. Disclosure of the invention
• a resistor is formed on the surface of an insulating substrate, and the resistor is formed on both ends of the insulating substrate.
• a pair of electrically connected soldering electrodes ⁇ formed low-resistance chip resistors are targeted for improvement.
• a ceramic substrate is typically used as the insulating plate.
• a paste layer is formed by applying a low-resistance paste from one end or near one end of the surface of the insulating substrate to the other end or near the other end, and the paste layer is formed to form a low-resistance resistance antibody. (Low resistance).
• Such a low-resistance paste includes a metal glaze paste containing Ag and Pd and having a ratio of (weight of Pd) / (weight of Pd + weight of Ag) of 10 to 20%.
• g powder and Pd powder are preferably used.
• By changing the mixing ratio of Ag and Pd an arbitrarily low resistance value can be obtained.
• the ratio of (weight of Pd) / (weight of Pd + weight of Ag) is in the range of 10% to 20%, a resistance value of 100m ⁇ to 5 ⁇ ⁇ ⁇ can be obtained, and ⁇ 100ppm to soil 800 p pmZ.
• the temperature coefficient of C can be obtained, and the resistance deviation can be JIS J class (5% class).
• the addition amount of Ag and the resistance value are in an example relationship.
• the powder of Pd and Ag contained in the metal glaze paste is preferably a spherical powder having an average particle diameter of 5 m or less (preferably). Use of such a powder makes it possible to further reduce the temperature coefficient and the resistance value deviation.
• this kind of metal glaze paste may contain a temperature coefficient adjuster such as Mn, Bi, Ti, Nb, if necessary.
• An overcoat layer made of an insulating material is formed on the resistor so as to leave a pair of connection electrode portions having a small width required for connecting the soldering electrodes to both ends of the resistor.
• the insulating material glass or a synthetic resin such as an epoxy resin can be used.
• a pair of soldering electrodes are formed so as to be electrically connected to the corresponding connection electrode portions of the resistor, respectively.
• the length of the overcoat layer (the length extending in the longitudinal direction of the insulating substrate) is preferably as long as possible. This means that the soldering electrode force is formed on the end of the resistor that is not covered by the overcoat layer.
• the length that extends on the surface of the insulating substrate (the length that extends in the longitudinal direction of the substrate) The longer the force, the larger the resistance value of the electrode for soldering. The lower the resistance of the resistor, the greater the effect of the resistance of the soldering electrode on the resistance of the chip resistor. Although it depends on the structure of the soldering electrode, if the length of the soldering wire extending on the surface of the insulating substrate becomes longer, the resistance value of the soldering electrode becomes larger than the resistance value of the resistor. Events also occur. Therefore, as described above, the overcoat layer is formed so as to leave a pair of connection electrode portions having a small width dimension necessary for connecting the soldering electrode.
• the overcoat layer should leave a pair of connection m3 ⁇ 4 parts with a width of 0.3 mm or less at both ends of the resistance element.
• the resistance value of the antibody is 10 to 5 ⁇ ⁇
• the overcoat layer is formed as described above. With the connection electrode portion having the width dimension of ⁇ , the influence of the resistance value of the soldering electrode on the resistance value of the low-resistance chip resistor can be reduced.
• the configuration of the soldering electrode is arbitrary.
• An electrode for soldering widely used in typical chip resistors may be used.
• a back electrode portion formed by metal glaze paste on the end of the back surface of the insulating substrate, and a metal glaze paste or a conductive resin paste (a thermosetting resin) extending over the back electrode portion and the connection electrode portion.
• An end surface electrode portion formed of a synthetic resin binder to which conductive powder such as Ag powder is added), an end surface electrode portion, a back surface electrode portion not covered by the end surface electrode portion, and the connection electrode portion.
• An electrode for soldering comprising a Ni plating layer covering the Ni plating layer and a solder plating layer covering the Ni plating layer can be used.
• An electrode for soldering having this structure is suitable for a low-resistance chip resistor because it has excellent solderability and the resistance of the electrode for soldering does not increase so much.
• one back electrode portion may be constituted by two divided back electrode portions formed apart from each other.
• the two split back electrode portions can be used separately for the current measurement electrode and the 3 ⁇ 4ff measurement electrode.
• the end face electrode portions are also formed separately from each other and connected to the two split end face electrode portions connecting the two split back face electrode portions to the connection electrode portions. May be configured.
• FIG. 1 is a schematic perspective view showing an example of a low-resistance chip resistor according to the present invention, partially cut away.
• FIG. 2 is a sectional view showing a state where the low-resistance chip resistor of FIG. 1 is connected by soldering to a soldered electrode on a circuit board.
• FIG. 3 is an enlarged sectional view showing an example of the structure of a soldered electrode.
• FIG. 4 is a schematic perspective view showing a low-resistance chip resistor according to another embodiment of the present invention with the back surface of the substrate facing upward.
• FIG. 5 is a view showing a state where the low-resistance chip resistor of FIG. 4 is soldered on a circuit board.
• FIG. 6 is a diagram showing a circuit for measuring the current and voltage of the low-resistance chip resistor of FIG.
• FIG. 7 is a schematic perspective view showing a low-resistance chip resistor according to still another embodiment of the present invention with the back surface of the substrate facing upward.
• FIG. 1 is a schematic perspective view showing an embodiment of the low-resistance chip resistor 1 according to the present invention, partially cut away, and FIG. 2 is a circuit diagram showing the low-resistance chip resistor 1 of FIG.
• FIG. 9 is a cross-sectional view showing a state where the soldering electrode 7 is connected to the upper soldering electrode by soldering.
• reference numeral 2 denotes an insulating substrate made of a ceramic substrate. On the surface 2 a of the insulating substrate 2, a resistor 3 of 1 ⁇ or less, specifically, 10 ⁇ ⁇ is formed.
• the resistor 3 is composed mainly of Ag powder and Pd powder, which are spherical powders having an average particle diameter of 5 m or less, and particularly a metal glaze paste not containing a temperature coefficient regulator (Ag powder is added to a glass binder). And a low-resistance base to which Pd powder has been added) is applied to one end 2 b of the surface 2 a of the insulating substrate 2 or this one. It is formed by firing a paste layer formed by coating from the vicinity of the end 2b to the other end 2c or the vicinity of the other end 2c.
• This metal glaze paste has a ratio (weight ratio) of (weight of Pd) / (weight of Pd + weight of Ag) (weight ratio) which is in the range of 10 to 20%.
• a metal glaze paste falling within this range almost any resistance value of 10 ⁇ or less can be obtained, and the temperature coefficient of resistance value and the resistance value deviation can be reduced.
• a metal glaze paste having a weight ratio of 10% was used in order to obtain a resistance value of 10 ⁇ . If the manufacturing conditions such as firing and the film thickness of the resistor 3 are appropriately selected, this paste can be used to achieve a resistance deviation (To) of ⁇ 1% and an SJt coefficient (TCR) of ⁇ 100 ppm / ° C. A resistor can be obtained.
• connection electrode portions 3a, 3a having a small width required for connecting the pair of soldering electrodes 4, 4 to both ends of the resistor 3 are left.
• An overcoat layer 5 made of an insulating material is formed on the substrate.
• the overcoat layer 5 is formed using glass or a synthetic resin such as an epoxy resin. In this example, the overcoat layer 5 is formed of glass.
• the width dimension of the pair of connection electrode portions 3 a and 3 a to be left at both ends of the resistor should be 0.3 mm or less.
• the overcoat layer is formed such that the width dimension falls within the range of 0.1 mm to 0.2 mm. With the connection electrodes 3a and 3a having such a width, the resistance of the soldering electrodes 4 and 4 has a small effect on the resistance of the low-resistance chip resistor 1. it can.
• the soldering electrodes 4 and 4 are connected to the back electrode portions 4 a and 4 a formed by metal glaze paste on both ends of the back surface 2 d of the insulating substrate 2 and the back electrode portions 4 a and 4 a.
• the end face electrode portions 4b, 4b and the back face electrode portions 4a, 4b, 4c which are not covered by the end face electrode portions, are generally enlarged and shown in detail in FIG. It is preferable to cover the portion 4a and the connection electrode portions 3a and 3a with the Ni plating layer 4c and the solder plating layer 4d.
• Back electrode 4 a, 4a is eighty three? (Includes 1, and is formed using a metal glaze paste having a ratio of (weight of Pd) / (weight of Pd + weight of Ag) of about 5%. Also, end surface electrode portions 4b, 4b Is formed using a metal glaze paste containing Ag or an Ag-resin-based conductive paste obtained by adding Ag to xylene or epoxy phenol resin. First, a large-sized ceramic substrate with a grid-shaped dividing groove formed on one or one surface is prepared, and the portion surrounded by one square of this large-sized ceramic substrate is one chip resistor. Back electrodes 4a, 4a are formed on the large ceramic substrate corresponding to each cell (corresponding to the individual substrate 2 after division) on the large ceramic substrate.
• a g—P This metal layer is printed and formed using the metal glaze paste d, and the paste layer is fired at a temperature of 850 to 900 ° C. to form the back electrode portions 4a and 4a.
• a paste layer for forming the resistor 3 corresponding to each cell is formed by the above-described Ag-Pd metal.
• This paste layer is formed so as to be continuous from one end to the other end of the portion that becomes the individual substrate 2 after the division. The above paste is continuously applied to the individual substrates 2 arranged in a line. This paste layer can be applied on average 8
• the resistor 3 is formed by firing at a temperature of 50 ° C.
• a paste is applied to form a paste layer.
• the overcoat layer 5 is formed by glass coating, it is baked at an average temperature of 600 to 65 ° C.
• the overcoat layer 5 is formed by resin coating, baking is performed at 200 ° C. to 250 ° C.
• the large ceramic substrate is divided into a plurality of strip-shaped substrates such that the connection electrode portions 3a, 3a of the plurality of resistors are respectively positioned in the width direction.
• an end surface electrode portion 4b is formed at an end portion in the width direction of the plurality of strip-shaped substrates so as to straddle the connection electrode portions 3a, 3a and the back surface electrode portions 4a, 4a.
• a conductive paste is applied to form a paste layer.
• a metal glaze paste containing Ag is used as the conductive paste, baking is performed at an average temperature of 600 ° C.
• an Ag resin-based conductive paste is used as the conductive paste, the temperature is averaged at 200 ° C.
• the Ni plating layer 4c is formed so as to cover the end surface electrode portions 4b, 4b, the back surface electrode portions 4a, 4a not covered by the end surface electrode portions, and the connection electrode portions 3a, 3a.
• a solder plating 4d is formed on the Ni plating layer. Since the resistance value of the resistor 3 is low, the exposed connection electrode portions 3a, 3a are completely covered by the Ni plating layer 4c and the solder plating layer 4d.
• the strip-shaped substrate is divided into individual substrates 2.
• the electrode force having a large resistance value is not formed on the surface of the substrate as in the case of a chip resistor. 4b Direct connection, good 3 ⁇ 4Jg characteristics Overcoat layer 5 force ⁇ As it extends to near the end face of substrate 2, the amount of solder adhesion is reduced, and the variation in resistance value due to the amount of solder adhesion Less.
• the resistance value of the resistor 3 is 5 ⁇ or less (10 to 5 ⁇ when the resistor is formed by a metal glaze paste in which Ag and Pd are ⁇ minutes), the resistance value is Trimming the resistance value is too small.
• the variation in the resistance value is reduced, so that the yield force in the case of manufacturing such a low-resistance chip resistor having a low resistance value is greatly improved.
• FIG. 4 is a schematic perspective view showing a low-resistance chip resistor 11 according to another embodiment of the present invention with the back surface 12 d of the substrate 12 facing upward.
• the difference between the embodiment shown in FIG. 1 and FIG. 2 and the present embodiment is that two split back electrode portions 14 a, in which the back electrode portions 14 a, 14 a are respectively formed apart from each other, are formed. , 14 al. Since other points are the same as those of the embodiment of FIG. 1, the same parts are denoted by the reference numerals shown in FIG. 1 plus 10 and their description is omitted. It is preferable that the two divided back electrode portions 14 al, 14 al are also covered by the Ni plating layer and the solder plating layer.
• a low-resistance paste is applied from one end or near one end of the surface of the insulating substrate to the other end or near other end to form a paste layer, and the paste layer is fired to provide a low-resistance resistance.
• the body low-resistance body
• a low-resistance chip resistor having a small temperature-related and resistance value deviation can be obtained at low cost by using a thick-film resistor.

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• Engineering & Computer Science (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Manufacturing & Machinery (AREA)
• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Non-Adjustable Resistors (AREA)
• Details Of Resistors (AREA)

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Citations (1)

• 1997
  • 1997-06-25 KR KR1019980701388A patent/KR19990044154A/ko not_active Application Discontinuation
  • 1997-06-25 CN CN97190775A patent/CN1196820A/zh active Pending
  • 1997-06-25 WO PCT/JP1997/002201 patent/WO1997050094A1/ja not_active Application Discontinuation
  • 1997-06-25 TW TW086108899A patent/TW344827B/zh active

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