JPH05282988A - Fuse resistor - Google Patents
Fuse resistorInfo
- Publication number
- JPH05282988A JPH05282988A JP10920592A JP10920592A JPH05282988A JP H05282988 A JPH05282988 A JP H05282988A JP 10920592 A JP10920592 A JP 10920592A JP 10920592 A JP10920592 A JP 10920592A JP H05282988 A JPH05282988 A JP H05282988A
- Authority
- JP
- Japan
- Prior art keywords
- resistance
- resistance film
- film
- temperature coefficient
- insulating substrate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000000758 substrate Substances 0.000 claims description 28
- 238000010438 heat treatment Methods 0.000 claims description 5
- 230000020169 heat generation Effects 0.000 claims description 3
- 230000001960 triggered effect Effects 0.000 claims 1
- KJTLSVCANCCWHF-UHFFFAOYSA-N Ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 description 5
- 229910052707 ruthenium Inorganic materials 0.000 description 5
- 230000007423 decrease Effects 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 239000010953 base metal Substances 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 229910052839 forsterite Inorganic materials 0.000 description 2
- HCWCAKKEBCNQJP-UHFFFAOYSA-N magnesium orthosilicate Chemical compound [Mg+2].[Mg+2].[O-][Si]([O-])([O-])[O-] HCWCAKKEBCNQJP-UHFFFAOYSA-N 0.000 description 2
- 239000007769 metal material Substances 0.000 description 2
- 229910000510 noble metal Inorganic materials 0.000 description 2
- 238000013459 approach Methods 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 238000005476 soldering Methods 0.000 description 1
- 230000002195 synergetic effect Effects 0.000 description 1
Landscapes
- Fuses (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】この発明は、絶縁基板上に被着形
成した抵抗膜の発熱作用によって上記絶縁基板を砕裂
し、もって過電流の通電を遮断するよう構成したヒュー
ズ抵抗器に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuse resistor which is constructed so as to crush the insulating substrate by the heat generating action of a resistance film formed on the insulating substrate, thereby cutting off the overcurrent.
【０００２】[0002]
【従来の技術】従来、電話回線等の通信回線を構成する
線路間にガスアレスタ等のサージ吸収素子を接続し、誘
導雷等のサージから電話器等の電子回路を保護すること
が行われている。すなわち、上記線路にサージ等の過電
圧が瞬間的に印加されると、上記サージ吸収素子が動作
してサージを即座に吸収するため、電子回路側にサージ
が印加されることを防止できる。2. Description of the Related Art Conventionally, a surge absorbing element such as a gas arrester is connected between lines constituting a communication line such as a telephone line to protect an electronic circuit such as a telephone from a surge such as an induced lightning. There is. That is, when an overvoltage such as a surge is instantaneously applied to the line, the surge absorbing element operates and immediately absorbs the surge, so that the surge can be prevented from being applied to the electronic circuit side.
【０００３】ここで、電源ラインへの誤接続や接触事
故、或いはこれらの事態を想定した過電圧試験の実施等
により、上記線路に上記サージ吸収素子の定格電圧以上
の過電圧が連続して印加された場合には、該過電圧によ
る過電流によってサージ吸収素子が破壊されるおそれが
あるため、上記線路を遮断して上記電子回路を連続過電
圧から保護する必要がある。この遮断手段として、一般
的なヒューズを用いるのが最も簡単であるが、ヒューズ
はその溶断特性が不安定であるため、最近では、図４に
示すヒューズ抵抗器50が用いられている。このヒューズ
抵抗器50は、アルミナやフォルステライト等の絶縁基板
52上に、ルテニウム系ペースト等の抵抗膜54を被着形成
し、該抵抗膜54の両側辺に電極パターン56，56を形成
し、該電極パターン56，56から外部端子58，58を導出し
てなる。Here, due to an erroneous connection to the power supply line, a contact accident, or an overvoltage test assuming these situations, an overvoltage continuously exceeding the rated voltage of the surge absorbing element is continuously applied to the line. In this case, the surge absorbing element may be destroyed by the overcurrent caused by the overvoltage. Therefore, it is necessary to shut off the line to protect the electronic circuit from the continuous overvoltage. Although it is easiest to use a general fuse as the breaking means, the fuse resistor 50 shown in FIG. 4 has recently been used because the fuse has an unstable fusing characteristic. This fuse resistor 50 is an insulating substrate such as alumina or forsterite.
A resistance film 54 of ruthenium-based paste or the like is deposited on 52, electrode patterns 56, 56 are formed on both sides of the resistance film 54, and external terminals 58, 58 are derived from the electrode patterns 56, 56. It becomes.
【０００４】このヒューズ抵抗器50を上記線路に直列接
続することにより、過電圧が連続して印加された場合に
は、過電圧による過電流が上記抵抗膜54に流れ、抵抗膜
54が急激に発熱する。そして、急激な温度上昇に伴う熱
歪みによって、上記絶縁基板52が砕裂し、該絶縁基板52
上に被着形成された抵抗膜54自身も切断される。その結
果、上記線路が遮断されるため、上記サージ吸収素子及
び電子回路側に連続過電圧が印加されることを防止でき
る。なお、絶縁基板52の砕裂を容易にするため、絶縁基
板52の下辺には切欠部60が形成されており、絶縁基板52
は、切欠部先端62の延長線（ロ）に沿って左右に砕裂す
る。By connecting the fuse resistor 50 in series to the line, when an overvoltage is continuously applied, an overcurrent due to the overvoltage flows through the resistance film 54, and
54 heats up rapidly. Then, the insulating substrate 52 is ruptured by thermal strain due to the rapid temperature rise, and the insulating substrate 52 is
The resistance film 54 deposited on the upper surface is also cut. As a result, since the line is cut off, continuous surge voltage can be prevented from being applied to the surge absorbing element and the electronic circuit side. In order to facilitate the crushing of the insulating substrate 52, a cutout portion 60 is formed on the lower side of the insulating substrate 52.
Breaks left and right along the extension line (b) of the tip 62 of the notch.
【０００５】ところで、上記サージ吸収素子及び電子回
路を連続過電圧から有効に保護するには、上記絶縁基板
が短時間のうちに確実に砕裂する必要がある。そのため
には、上記抵抗膜の抵抗値を高く設定すればよいのであ
るが、当初から高い抵抗値に設定しておくと、上記線路
における電送損失が大きくなる。そこで、上記抵抗膜を
抵抗温度係数の高い材料で構成すると共に、その初期抵
抗値を低く抑えることがなされている。By the way, in order to effectively protect the surge absorbing element and the electronic circuit from a continuous overvoltage, it is necessary to surely crush the insulating substrate within a short time. For that purpose, the resistance value of the resistance film may be set high. However, if the resistance value is set to a high value from the beginning, the transmission loss in the line becomes large. Therefore, the resistance film is made of a material having a high resistance temperature coefficient, and its initial resistance value is kept low.
【０００６】このようにすれば、過電圧の印加されない
平常時や、サージ吸収素子で対処可能な瞬間的なサージ
印加時においては、抵抗膜の抵抗値が低く維持され、電
送損失を最小限に抑えることができる。一方、過電圧が
連続して印加された場合には、過電圧の印加による過電
流の通電によって上記抵抗膜が発熱し、その自己発熱を
契機としてその抵抗値が急激に上昇し、上記絶縁基板を
確実に砕裂し得る。By doing so, the resistance value of the resistance film is kept low during normal times when an overvoltage is not applied or when an instantaneous surge is applied which can be dealt with by the surge absorbing element, and transmission loss is minimized. be able to. On the other hand, when an overvoltage is continuously applied, the resistance film generates heat due to the application of an overcurrent due to the application of the overvoltage, and the self-heating causes the resistance value to rise sharply to ensure the insulation substrate. Can be shredded into
【０００７】[0007]
【発明が解決しようとする課題】しかしながら、上記の
ように、ヒューズ抵抗器の抵抗膜の抵抗温度係数を高く
設定すると、今度は周囲の温度変化によっても抵抗膜の
抵抗値が変化してしまい、その結果、上記電子回路の入
力インピーダンスが容易に変動してしまう点で問題であ
った。However, as described above, when the resistance temperature coefficient of the resistance film of the fuse resistor is set to be high, the resistance value of the resistance film also changes due to the ambient temperature change. As a result, there is a problem in that the input impedance of the electronic circuit easily fluctuates.
【０００８】本発明は、上記した従来例の問題点に鑑み
てなされたものであり、抵抗膜の抵抗温度係数を高く設
定しても、周囲の温度変化によってその抵抗値が容易に
変動することがなく、したがって、電子回路の入力イン
ピーダンスを一定に保てるヒューズ抵抗器を実現するこ
とを目的とする。The present invention has been made in view of the problems of the above-described conventional example, and even if the resistance temperature coefficient of the resistance film is set high, the resistance value thereof easily fluctuates due to the ambient temperature change. Therefore, it is an object of the present invention to realize a fuse resistor which can keep the input impedance of an electronic circuit constant.
【０００９】[0009]
【課題を解決するための手段】上記目的を達成するため
に、本発明に係るヒューズ抵抗器は、絶縁基板と、該絶
縁基板の表面に被着形成される第１の抵抗膜と、上記絶
縁基板の表面に被着形成され、上記第１の抵抗膜と直列
接続される第２の抵抗膜とを有してなり、上記第１の抵
抗膜の抵抗値が、連続した過電流の通電による自己発熱
を契機として、上記絶縁基板を砕裂するに十分な発熱量
が得られる値まで上昇するように、上記第１の抵抗膜の
抵抗温度係数を設定すると共に、上記第２の抵抗膜の抵
抗温度係数を、上記第１の抵抗膜の抵抗温度係数に対応
する負の値に設定するよう構成した。In order to achieve the above object, a fuse resistor according to the present invention includes an insulating substrate, a first resistance film formed on the surface of the insulating substrate, and the insulating film. A second resistance film that is deposited on the surface of the substrate and is connected in series with the first resistance film, and the resistance value of the first resistance film depends on the continuous overcurrent. The temperature coefficient of resistance of the first resistance film is set so that the amount of heat generation sufficient for crushing the insulating substrate is increased by self-heating, and the temperature coefficient of resistance of the second resistance film is set. The temperature coefficient of resistance was set to a negative value corresponding to the temperature coefficient of resistance of the first resistance film.
【００１０】上記第１の抵抗膜の抵抗温度係数は、その
初期抵抗値（連続した過電流の通電によって第１の抵抗
膜が発熱する前の、平常時における抵抗値）、予想され
る過電流の電流値、或いは絶縁基板の割れ易さ等を基
に、実験を通じて具体的に決定される。この第１の抵抗
膜の抵抗温度係数は、例えば２８００ｐｐｍ／゜Ｃ乃至
４０００ｐｐｍ／゜Ｃの範囲に設定される。また、上記
第２の抵抗膜の抵抗温度係数は、例えば−２８００ｐｐ
ｍ／゜Ｃ乃至−４０００ｐｐｍ／゜Ｃの範囲に設定され
る。The temperature coefficient of resistance of the first resistance film is defined by its initial resistance value (resistance value in normal times before the first resistance film generates heat due to continuous overcurrent conduction) and expected overcurrent. It is specifically determined through experiments based on the current value of, the fragility of the insulating substrate, and the like. The temperature coefficient of resistance of the first resistance film is set, for example, in the range of 2800 ppm / ° C to 4000 ppm / ° C. The temperature coefficient of resistance of the second resistance film is, for example, -2800 pp.
It is set in the range of m / ° C to -4000 ppm / ° C.
【００１１】なお、上記「連続した過電流」における
「連続した」という表現は、「一定時間継続した」を意
味するものであり、「連続した過電流」には、直流電流
のみならず、時間の経過と共に電流値が変化する交流電
流も当然に含まれるものである。以下においても同様で
ある。The expression "continuous" in "continuous overcurrent" means "continuous for a certain period of time", and "continuous overcurrent" means not only direct current but also time. As a matter of course, an alternating current whose current value changes with the passage of is included. The same applies to the following.
【００１２】[0012]
【作用】上記第１の抵抗膜の初期抵抗値を比較的低く設
定しても、過電流が連続して流れた場合には、該過電流
の通電によって第１の抵抗膜が発熱し、この自己発熱に
よってその抵抗値が急激に上昇する。その結果、第１の
抵抗膜における発熱量も相乗的に増加し、絶縁基板が確
実に砕裂される。Even if the initial resistance value of the first resistance film is set to be relatively low, when the overcurrent continuously flows, the first resistance film generates heat due to energization of the overcurrent. Due to self-heating, the resistance value rises sharply. As a result, the amount of heat generated in the first resistance film also increases synergistically, and the insulating substrate is reliably shredded.
【００１３】一方、周囲の温度変化によっても、第１の
抵抗膜の抵抗値が上昇するが、これに呼応して第２の抵
抗膜の抵抗値が低下するため、ヒューズ抵抗器全体とし
ての抵抗値は一定に保たれる。On the other hand, the resistance value of the first resistance film also rises due to the ambient temperature change, but in response to this, the resistance value of the second resistance film decreases, so that the resistance of the fuse resistor as a whole is reduced. The value is kept constant.
【００１４】[0014]
【実施例】以下に本発明を、図示の実施例に基づいて説
明する。図１に示すように、本発明に係るヒューズ抵抗
器２は、絶縁基板４と、該絶縁基板４の表面６に被着形
成された第１の抵抗膜８と、第２の抵抗膜10とを有して
いる。上記絶縁基板４は、アルミナ、フォルステライ
ト、ステアタイト等のセラミックによって形成され、そ
の板厚は０．５ｍｍ〜１．５ｍｍ程度に設定される。上
記絶縁基板４の下辺12における、上記第１の抵抗膜８側
には、絶縁基板４の砕裂を容易にするため、切欠部14が
形成される。DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the illustrated embodiments. As shown in FIG. 1, a fuse resistor 2 according to the present invention includes an insulating substrate 4, a first resistance film 8 deposited on a surface 6 of the insulating substrate 4, and a second resistance film 10. have. The insulating substrate 4 is made of ceramics such as alumina, forsterite, and steatite, and its plate thickness is set to about 0.5 mm to 1.5 mm. A notch 14 is formed on the lower side 12 of the insulating substrate 4 on the side of the first resistance film 8 in order to facilitate the crushing of the insulating substrate 4.
【００１５】上記第１の抵抗膜８と第２の抵抗膜10は、
共にルテニウム系ペースト等によって形成され、その膜
厚は１０μｍ〜２５μｍ程度に設定されている。上記第
１の抵抗膜８の抵抗温度係数は、２８００ｐｐｍ／゜Ｃ
〜４０００ｐｐｍ／゜Ｃの範囲に設定されている。ま
た、上記第２の抵抗膜10の抵抗温度係数は、−２８００
ｐｐｍ／゜Ｃ〜−４０００ｐｐｍ／゜Ｃの範囲で、上記
第１の抵抗膜８の抵抗温度係数に略対応する負の値に設
定される。例えば、第１の抵抗膜８の抵抗温度係数が２
８００ｐｐｍ／゜Ｃの場合には、第２の抵抗膜10の抵抗
温度係数は、−２８００ｐｐｍ／゜Ｃ付近となる。上記
第１の抵抗膜８の抵抗温度係数は、上記ルテニウム系ペ
ーストに所定の貴金属材料を所定量混入することによっ
て、任意の値に設定することが可能である。また、上記
第２の抵抗膜10の抵抗温度係数は、上記ルテニウム系ペ
ーストに所定の卑金属材料を所定量混入することによっ
て、任意の値に設定することが可能である。The first resistance film 8 and the second resistance film 10 are
Both are formed of ruthenium-based paste or the like, and the film thickness thereof is set to about 10 μm to 25 μm. The temperature coefficient of resistance of the first resistance film 8 is 2800 ppm / ° C.
It is set in the range of up to 4000 ppm / ° C. The temperature coefficient of resistance of the second resistance film 10 is −2800.
In the range of ppm / ° C to −4000 ppm / ° C, the negative value is set to substantially correspond to the temperature coefficient of resistance of the first resistance film 8. For example, the temperature coefficient of resistance of the first resistance film 8 is 2
In the case of 800 ppm / ° C, the temperature coefficient of resistance of the second resistance film 10 is around -2800 ppm / ° C. The resistance temperature coefficient of the first resistance film 8 can be set to an arbitrary value by mixing a predetermined amount of a predetermined noble metal material in the ruthenium-based paste. The temperature coefficient of resistance of the second resistance film 10 can be set to an arbitrary value by mixing a predetermined amount of a predetermined base metal material with the ruthenium-based paste.
【００１６】なお、第１の抵抗膜８の初期抵抗値ｒ
1と、第２の抵抗膜10の初期抵抗値ｒ2は、「ｒ1＝ｒ2」
及び「１Ω≦ｒ1＋ｒ2≦５０Ω」となるように設定され
る。ここにいう初期抵抗値とは、温度の上昇によって、
第１の抵抗膜８及び第２の抵抗膜10の抵抗値が変化する
前の、常温時における抵抗値をいう。この初期抵抗値ｒ
1及びｒ2は、上記ルテニウム系ペーストに混入させる上
記貴金属材料或いは卑金属材料の種類や量を調節するこ
とによって、任意の値に設定することが可能である。ま
た、第１の抵抗膜８の面積Ｓ1と、第２の抵抗膜10の面
積Ｓ2は、「Ｓ1≦Ｓ2」となるように設定される。The initial resistance value r of the first resistance film 8
1 and the initial resistance value r 2 of the second resistance film 10 are “r 1 = r 2 ”.
And “1Ω ≦ r 1 + r 2 ≦ 50Ω”. The initial resistance value here means that
The resistance value at room temperature before the resistance values of the first resistance film 8 and the second resistance film 10 change. This initial resistance value r
1 and r 2 can be set to arbitrary values by adjusting the type and amount of the noble metal material or base metal material mixed in the ruthenium-based paste. Further, the area S 1 of the first resistive film 8, the area S 2 of the second resistance film 10 is set to be "S 1 ≦ S 2".
【００１７】上記第１の抵抗膜８の左端辺には、第１の
電極パターン16が被着形成されると共に、上記第２の抵
抗膜10の右端辺には、第２の電極パターン18が被着形成
される。さらに、第１の抵抗膜８及び第２の抵抗膜10の
間には、接続パターン20が被着形成される。この結果、
第１の抵抗膜８と第２の抵抗膜10とは、この接続パター
ン20を介して、直列接続される。A first electrode pattern 16 is formed on the left end side of the first resistance film 8 and a second electrode pattern 18 is formed on the right end side of the second resistance film 10. Deposition is formed. Further, a connection pattern 20 is deposited between the first resistance film 8 and the second resistance film 10. As a result,
The first resistance film 8 and the second resistance film 10 are connected in series via the connection pattern 20.
【００１８】上記第１の電極パターン16と第２の電極パ
ターン18の下方には、それぞれ第１の外部端子接続部22
及び第２の外部端子接続部24が形成され、該第１の外部
端子接続部22には第１の外部端子26が、また第２の外部
端子接続部24には第２の外部端子28が、それぞれハンダ
付け等によって固着される。Below the first electrode pattern 16 and the second electrode pattern 18, a first external terminal connecting portion 22 is provided.
And a second external terminal connecting portion 24 is formed, the first external terminal connecting portion 22 has a first external terminal 26, and the second external terminal connecting portion 24 has a second external terminal 28. , Are fixed by soldering or the like.
【００１９】図２は、上記ヒューズ抵抗器２の使用例を
示す回路図である。すなわち、電話回線等を構成する線
路Ａ，Ａ’間に、ガスアレスタ等のサージ吸収素子30を
被保護回路32に対して並列に接続した保安回路におい
て、上記ヒューズ抵抗器２は線路Ａに直列接続される。FIG. 2 is a circuit diagram showing a usage example of the fuse resistor 2. That is, in a safety circuit in which a surge absorbing element 30 such as a gas arrester is connected in parallel to a protected circuit 32 between lines A and A'that constitute a telephone line or the like, the fuse resistor 2 is connected in series to the line A. Connected.
【００２０】しかして、上記線路Ａ，Ａ’に、上記サー
ジ吸収素子30の定格電圧以上のサージが瞬間的に印加さ
れた場合には、上記サージ吸収素子30が動作して、この
サージを吸収する。この場合、サージ電流の通電時間は
極めて短いため、上記第１の抵抗膜８はほとんど発熱せ
ず、したがってヒューズ抵抗器２全体の抵抗値が上昇す
ることはない。However, when a surge exceeding the rated voltage of the surge absorbing element 30 is instantaneously applied to the lines A and A ', the surge absorbing element 30 operates to absorb the surge. To do. In this case, since the surge current energization time is extremely short, the first resistance film 8 hardly generates heat, and therefore the resistance value of the entire fuse resistor 2 does not increase.
【００２１】また、電源ラインへの誤接続や過電圧試験
の実施等により、上記線路Ａ，Ａ’に、上記サージ吸収
素子30の定格電圧以上の過電圧が連続して印加された場
合には、該過電圧による過電流の通電によって上記第１
の抵抗膜８が発熱し、この自己発熱の持続によって、そ
の抵抗値が急激に上昇する。その結果、第１の抵抗膜８
による発熱量が相乗的に増加し、急激な温度上昇に伴う
熱歪みの発生によって、上記絶縁基板４がその切欠部14
の頂点34の延長線（イ）に沿って左右に砕裂する。この
ため、上記線路Ａは遮断され、サージ吸収素子30や被保
護回路32が、連続過電圧によって破壊されることを防止
できる。When an overvoltage higher than the rated voltage of the surge absorbing element 30 is continuously applied to the lines A and A'due to an erroneous connection to the power supply line, an overvoltage test, etc. The above-mentioned first
The resistance film 8 generates heat, and the resistance value rapidly increases due to the continuation of this self-heating. As a result, the first resistance film 8
Due to the synergistic increase in the amount of heat generated by the heat generation due to the thermal distortion caused by the sudden temperature rise,
Crush left and right along the extension line (a) of the apex 34 of. Therefore, the line A is cut off, and the surge absorbing element 30 and the protected circuit 32 can be prevented from being destroyed by the continuous overvoltage.
【００２２】そして、サージ等の印加されない平常時に
おいても、周囲温度の上昇によって、上記第１の抵抗膜
の抵抗値が上昇する可能性があるが、その場合には、第
２の抵抗膜10の抵抗値が低下するため、第１の抵抗膜８
と第２の抵抗膜10との合成抵抗はほとんど変化しない。
したがって、ヒューズ抵抗器２全体の抵抗値が上昇する
ことがなく、被保護回路32の入力インピーダンスは一定
に維持される。Even during normal times when no surge or the like is applied, the resistance value of the first resistance film may increase due to the increase in ambient temperature. In that case, the second resistance film 10 Since the resistance value of the first resistance film 8 decreases,
And the combined resistance of the second resistance film 10 hardly changes.
Therefore, the resistance value of the entire fuse resistor 2 does not rise, and the input impedance of the protected circuit 32 is maintained constant.
【００２３】つぎに、第１の抵抗膜８と第２の抵抗膜10
の抵抗値の変化を、図３のグラフに基づいて説明する。
このグラフは、縦軸に抵抗値Ｒ（Ω）を、横軸に温度Ｔ
（゜Ｃ）をそれぞれ表している。この場合には、第１の
抵抗膜８の初期抵抗値ｒ1及び第２の抵抗膜10の初期抵
抗値ｒ2は、共に１２Ωに設定されている。また、第１
の抵抗膜８の抵抗温度係数は３７００ｐｐｍ／゜Ｃに、
第２の抵抗膜10の抵抗温度係数は−３７００ｐｐｍ／゜
Ｃにそれぞれ設定されている。まず、温度が２０゜Ｃ〜
８０゜Ｃの範囲内においては、第１の抵抗膜８の抵抗値
Ｒ1が上昇するにしたがって、その分第２の抵抗膜10の
抵抗値Ｒ2が低下してゆくため、両者の合成抵抗値は、
「ｒ1＋ｒ2＝２４Ω」のまま変化しない。Next, the first resistance film 8 and the second resistance film 10
The change in the resistance value will be described based on the graph of FIG.
In this graph, the vertical axis represents the resistance value R (Ω) and the horizontal axis represents the temperature T.
(° C) is shown. In this case, the initial resistance value r 2 of the initial resistance value r 1 and the second resistive film 10 of the first resistive film 8, are both set to 12 ohms. Also, the first
The temperature coefficient of resistance of the resistance film 8 is 3700 ppm / ° C,
The temperature coefficient of resistance of the second resistance film 10 is set to -3700 ppm / ° C. First, the temperature is 20 ° C ~
Within the range of 80 ° C, according to the resistance value R 1 of the first resistive film 8 is increased, the resistance value R 2 of the correspondingly the second resistive film 10 is slide into decline, both combined resistance value is,
It does not change as "r 1 + r 2 = 24Ω".
【００２４】一方、上記第１の抵抗膜８及び第２の抵抗
膜10それぞれの温度が８０゜Ｃを越えると、上記第２の
抵抗膜10の抵抗値Ｒ2は限りなく０Ωに近づくのに対
し、第１の抵抗膜８の抵抗値Ｒ1は急激な上昇を続ける
ため、ヒューズ抵抗器２全体の抵抗値「Ｒ1＋Ｒ2」が初
期の合成抵抗値「ｒ1＋ｒ2＝２４Ω」以上となり、その
発熱量も相乗的に増加してゆく。その結果、最終的に上
記絶縁基板４は熱歪みにより砕裂する。On the other hand, when the temperature of each of the first resistance film 8 and the second resistance film 10 exceeds 80 ° C., the resistance value R 2 of the second resistance film 10 approaches 0Ω without limit. On the other hand, since the resistance value R 1 of the first resistance film 8 continues to rapidly increase, the resistance value “R 1 + R 2 ” of the entire fuse resistor 2 is equal to or more than the initial combined resistance value “r 1 + r 2 = 24Ω”. And the amount of heat generated increases synergistically. As a result, the insulating substrate 4 is finally crushed by thermal strain.
【００２５】[0025]
【発明の効果】上記第１の抵抗膜の抵抗温度係数を上記
のように設定したため、その初期抵抗値を高く設定しな
くても、過電流が連続して流れた場合には、確実に上記
絶縁基板を砕裂できる。また、上記第２の抵抗膜の抵抗
温度係数を、第１の抵抗膜の抵抗温度係数に対応する負
の値に設定したため、周囲の温度変化によって第１の抵
抗膜の抵抗値が上昇しても、その分第２の抵抗膜の抵抗
値が低下するため、ヒューズ抵抗器全体の抵抗値は一定
に維持される。Since the temperature coefficient of resistance of the first resistance film is set as described above, even if the initial resistance value is not set to a high value, it is possible to ensure that the above value is obtained when an overcurrent continuously flows. The insulating substrate can be crushed. Further, since the resistance temperature coefficient of the second resistance film is set to a negative value corresponding to the resistance temperature coefficient of the first resistance film, the resistance value of the first resistance film increases due to the ambient temperature change. However, since the resistance value of the second resistance film is reduced by that amount, the resistance value of the entire fuse resistor is maintained constant.
【図１】本発明に係るヒューズ抵抗器の一実施例を示す
概略斜視図である。FIG. 1 is a schematic perspective view showing an embodiment of a fuse resistor according to the present invention.
【図２】上記ヒューズ抵抗器の使用例を示す回路図であ
る。FIG. 2 is a circuit diagram showing a usage example of the fuse resistor.
【図３】第１の抵抗膜と第２の抵抗膜の抵抗値の変化を
示すグラフである。FIG. 3 is a graph showing changes in resistance values of a first resistance film and a second resistance film.
【図４】従来のヒューズ抵抗器を示す概略斜視図であ
る。FIG. 4 is a schematic perspective view showing a conventional fuse resistor.
２ ヒューズ抵抗器 ４ 絶縁基板 ６ 絶縁基板の表面 ８ 第１の抵抗膜 10 第２の抵抗膜 2 Fuse resistor 4 Insulating substrate 6 Surface of insulating substrate 8 First resistance film 10 Second resistance film
Claims (2)
成される第１の抵抗膜と、上記絶縁基板の表面に被着形
成され、上記第１の抵抗膜と直列接続される第２の抵抗
膜とを有してなり、上記第１の抵抗膜の抵抗値が、連続
した過電流の通電による自己発熱を契機として、上記絶
縁基板を砕裂するに十分な発熱量が得られる値まで上昇
するように、上記第１の抵抗膜の抵抗温度係数を設定す
ると共に、上記第２の抵抗膜の抵抗温度係数を、上記第
１の抵抗膜の抵抗温度係数に対応する負の値に設定する
よう構成したことを特徴とするヒューズ抵抗器。1. An insulating substrate, a first resistance film deposited on the surface of the insulating substrate, and a first resistance film deposited on the surface of the insulating substrate and connected in series with the first resistance film. 2 resistance film, and the resistance value of the first resistance film provides a sufficient amount of heat generation for crushing the insulating substrate when self-heating due to continuous application of overcurrent is triggered. The resistance temperature coefficient of the first resistance film is set so as to increase to a value, and the resistance temperature coefficient of the second resistance film is set to a negative value corresponding to the resistance temperature coefficient of the first resistance film. A fuse resistor configured to be set to.
００ｐｐｍ／゜Ｃ乃至４０００ｐｐｍ／゜Ｃの範囲に設
定すると共に、上記第２の抵抗膜の抵抗温度係数を−２
８００ｐｐｍ／゜Ｃ乃至−４０００ｐｐｍ／゜Ｃの範囲
に設定したことを特徴とする請求項１に記載のヒューズ
抵抗器。2. The resistance temperature coefficient of the first resistance film is set to 28.
The temperature coefficient of resistance of the second resistance film is set to -2 while setting the range of 00 ppm / ° C to 4000 ppm / ° C.
The fuse resistor according to claim 1, wherein the fuse resistor is set in the range of 800 ppm / ° C to -4000 ppm / ° C.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10920592A JPH05282988A (en) | 1992-04-02 | 1992-04-02 | Fuse resistor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10920592A JPH05282988A (en) | 1992-04-02 | 1992-04-02 | Fuse resistor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH05282988A true JPH05282988A (en) | 1993-10-29 |
Family
ID=14504270
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10920592A Pending JPH05282988A (en) | 1992-04-02 | 1992-04-02 | Fuse resistor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH05282988A (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5419079A (en) * | 1977-07-13 | 1979-02-13 | Hitachi Ltd | Reactor container |
| JPH0256821A (en) * | 1988-08-22 | 1990-02-26 | Tohoku Electric Power Co Inc | Current fuse device independent of ambient temperature |
| JPH03190758A (en) * | 1989-12-21 | 1991-08-20 | Seiko Epson Corp | Impact head drive device |
-
1992
- 1992-04-02 JP JP10920592A patent/JPH05282988A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5419079A (en) * | 1977-07-13 | 1979-02-13 | Hitachi Ltd | Reactor container |
| JPH0256821A (en) * | 1988-08-22 | 1990-02-26 | Tohoku Electric Power Co Inc | Current fuse device independent of ambient temperature |
| JPH03190758A (en) * | 1989-12-21 | 1991-08-20 | Seiko Epson Corp | Impact head drive device |
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