201037736 六、發明說明： 【發明所屬之技術領域】 本發明是關於一種即使有大電流流在特定配線部時’ 也高精度地可檢測出電流，可抑制對於電子機器的電路的 損傷的具有優異的散熱性的電流檢測用金屬板電阻器及其 製造方法。 0 【先前技術】 爲了附與對於電子機器的過電流的電路的保護功能， 作使用金屬板電阻體的電流檢測用電阻器之利用。該電流 檢測用電阻器是爲了檢測出特定配線部的電流所設置，利 用具有數ιηΩ〜數十ηιΩ的微少電阻値的電阻器必須高精 度地檢測出電流。又，該電阻器是爲了即使被通電於電子 機器的電流爲大電流也可檢測出，而作成額定電力高，更 降低電阻値的設計。 〇 但是，依此種設計的電阻器是具有藉由大電流會發生 熱，而在配線基板上給與熱性損傷的問題。 如此，爲了避免此種熱性損傷等，眾知利用傳送模技 術以形成厚保護層的電阻器。 例如，如第3圖所示地，作爲具備此種保護層的電阻 器，眾知具備：金屬板電阻體31，及設於該電阻體31的兩 端部的一對電極層32，及位於該電極層32間，設於電阻體 31的上面及下面的絕緣性的保護層33的電阻器30[參照日 本特開2007-220859號公報（第7圖），日本特開平6-20802 201037736 號公報）。 然而，在此種構造的電阻器中，也可說無法充分地避 免依大電流的熱性損傷，更期盼開發散熱作用更優異的電 流檢測用電阻器的開發。 【發明內容】 本發明的課題是提供一種可抑制電子機器的過電流對 於電路的損傷，具有優異的散熱性，以高精度可檢測出電 流的電流檢測用金屬板電阻器及其製造方法。 依照本發明，提供一種電流檢測用金屬板電阻器，其 特徵爲：具備：金屬板電阻體、及設於該金屬板電阻體的 至少一方的一面的中央部的耐熱性保護層，及以覆蓋設於 金屬板電阻體的一方的一面的中央部的耐熱性保護層的兩 端部的方式，設於金屬板電阻體的一方的一面的一對底子 電極層，及以覆蓋該底子電極層全面的方式，設於金屬板 電阻體的兩端部的一對端面電極層。 又，依照本發明，提供一種電流檢測用金屬板電阻器 的製造方法，其特徵爲，包括：在帶狀金屬板電阻體的至 少一方的一面的中央部施以網印耐熱性保護層，使之硬化 的工程（a) •，及以覆蓋設於該金屬板電阻體的一方的一 面的中央部的耐熱性保護層的兩端部的方式，在金屬板電 阻體的一方的一面施以網印一對底子電極層，使之硬化的 工程（b);及以覆蓋該底子電極層全面的方式，藉由鍍 法形成端面電極層的工程（c):及將帶狀金屬板電阻體 • 6 - 201037736 以所定間隔切斷的工程（d )。 上述耐熱性保護層是可設於金屬板電阻體的一方的一 面的中央部，及金屬板電阻體的另一方的一面的全面。又 ，也可設於金屬板電阻體的兩面的中央部。欲將耐熱性保 護層設於金屬板電阻體的兩面的中央部的情形，將端面電 極層延長至未設置底子電極層的金屬板電阻體的一面的未 具有耐熱性保護層的部分面上爲止，可擴大實效性電極面 0 積，而可更提高散熱效率。 作爲耐熱性保護層，可使用耐熱性樹脂，尤其是，在 薄膜也表示優異的耐熱性及絕緣性的聚醯胺醯亞胺樹脂較 佳。又，在該耐熱性樹脂層，利用含有二氧化矽粉，可提 昇製造時的印刷特性。尤其是作爲二氧化矽粉，調配具有 微米階及奈米階的不相同粒徑的粉末，可有效率地防止印 刷時塌口或滲出等，而可提昇耐熱性保護層的寬度尺寸的 精度等，而抑制出現電阻値的參差不齊。 〇 二氧化矽粉的調配比例，是與耐熱性樹脂的合計量， —般爲30〜55質量％，較佳爲40〜50質量％。又，在調配 具有微米階及奈米階的不相同粒徑的粉末時，則對於與耐 熱性樹脂的合計量，通常可將前者作爲1 8〜40質量％，而 可將後者作爲1 2〜1 5質量％。 又，除了二氧化矽粉以外，也可調配CuO、Fe203、 Μπ203等的黑色顏料。 底子電極層是可網印，且藉由可熱硬化的金屬含有導 電性樹脂糊等的公知電極材料所形成。 201037736 在本發明中，底子電極層爲覆蓋耐熱性保護層的兩端 部的方式，或是藉由端面電極層覆蓋整體的方式所形成之 故，因而底子電極層爲藉由包括銀粉與苯酚環氧樹脂的糊 所形成較佳。藉由使用銀粉，可改善熱傳導性，也有助於 電阻器本體的散熱作用。 端面電極層是可藉鍍法可形成，一般藉由鍍銅層、鍍 鎳層或鍍錫層的公知電極材料所形成。 金屬板電阻體是具有所期望的電阻値的金屬板就未特 別地加以限定。例如可使用Cu-Mn系金屬板、Ni-Cr系金屬 板、Fr-Cr系金屬板。 本發明的電流檢測用金屬板電阻器是特別具有耐熱性 保護層，覆蓋該耐熱性保護層的兩端部的方式具備底子電 極層，而覆蓋該底子電極層全面的方式具備端面電極層之 故，因而實效性地可擴大電極面積，即使將額定電力設定 成高時，也可確保優異的散熱性。因此，本發明的金屬板 電阻器是可抑制電子機器對於依過電流的電路的損傷，以 高精度可檢測出電流，還有對於電子機器的小型化、薄型 化也有貢獻。 【實施方式】 以下，針對於本發明的實施形態，參照圖式加以說明 〇 第1圖是表示本發明的一實施形態的電流檢測用金屬 板電阻器10的斷面圖。在第1圖中，11是具有電阻功能的 201037736 金屬板電阻體，在該金屬板電阻體π的上下的面上的大約 中央部分，有第1耐熱性保護層I2及第2耐熱性保護層13設 於金屬板電阻體11的所有寬度方向全面。 在第1耐熱性保護層12的兩端側，覆蓋著該兩端部分 ，爲了確保導電性，一部分接觸於金屬板電阻體11的上面 ，而留下該金屬板電阻體11的兩端側上面的一部分的方式 ，設有一對導電性的底子電極層14。 該一對底子電極層14是藉由被覆一對端面電極層15成 爲全面被覆蓋，如圖示地，該一對端面電極層15是被覆於 金屬板電阻體11的端面，而分別延長到設於該金屬板電阻 體11下面的中央部的第2耐熱性保護層13的兩端所形成。 如圖示地，在一對端面電極層1 5的上方間隙部分，形 成有第3耐熱性保護層16。該耐熱性保護層16是可藉由與 第1及第2耐熱性保護層（1 2，1 3 )同樣的材料所形成，惟 在本發明中並不是必需的構成。 ❹ 表示於第1圖的電流檢測用金屬板電阻器10是下面的 端面電極層I5的部分，爲藉由焊料等被安裝於基板的型式 第2圖是表示本發明的其他實施形態的電流檢測用金 屬板電阻器20的斷面圖。在第2圖中，21是具有電阻功能 的金屬板電阻體，在該金屬板電阻體21的下面上的大約中 央部分，有第1耐熱性保護層22設於金屬板電阻體21的所 有寬度方向全面，又，在金屬板電阻體21的上全面設有第 2耐熱性保護層2 3。 201037736 在第2耐熱性保護層23的兩端側，覆蓋著該兩端部分 ，爲了確保導電性，一部分接觸於金屬板電阻體21的下面 ，而覆蓋該金屬板電阻體21的兩端側下面全面的方式’設 有一對導電性的底子電極層24。 該一對底子電極層24是藉由被覆一對端面電極層25成 爲全面被覆蓋，如圖示地，該一對端面電極層25是被覆於 金屬板電阻體21的端面所形成。 表示於第2圖的電流檢測用金屬板電阻器10是下面的 端面電極層25的部分，爲藉由焊料等被安裝於基板的型式 者。 本發明的製造方法，是包括在帶狀的金屬板電阻體的 至少一方的一面的中央部施以網印耐熱性保護層，使之硬 化的工程（a )。如第1圖及第2圖所示地，在本發明的製 造方法中，在帶狀的金屬板電阻體的另一方的一面也施以 網印耐熱性保護層，而可使之硬化。 帶狀的金屬板電阻體是最後以所定間隔進行切斷，藉 此，可作成所期望的金屬板電阻器，在該切斷前，綜合形 成所必需的耐熱性保護層、底子電極層及端面電極層所形 成者，例如可使用Cu-Mn系帶狀金屬、Ni-Cr系帶狀金屬、 Fe-Cr系帶狀金屬。 在此，作爲帶狀的金屬板電阻體，使用在最後輥軋以 後未經退火處理者，在不會降低金屬板電阻體的彈性上較 佳。帶狀的金屬板電阻體的彈性降低’則在電阻器的製程 中’帶狀的金屬板電阻體彎曲時，無法復原’而有成爲不 -10 - 201037736 良品之虞。 耐熱性保護層是例如將含有二氧化矽粉的聚醯 胺樹脂分散於溶劑的耐熱性樹脂糊，施以網印， 3 00 °C左右施以加熱硬化就可形成。 本發明的製造方法是包括覆蓋設於金屬板電阻 方的一面的中央部的耐熱性保護層的兩端部的方式 屬板電阻體的一方的一面施以網印一對底子電極層 0 硬化的工程（b )。 底子電極層是例如將含有銀粉與苯酚環氧樹脂 硬化的金屬含有導電性樹脂糊，施以網印，在80 -左右施以加熱硬化就可形成。 本發明的製造方法是包括覆蓋底子電極層全面 ，藉由鍍法形成端面電極層的工程（c )。 端面電極層是藉由例如將銅（Cu )、鎳（Ni ) Sn)，其他金屬或此些的合金單獨或複合地施以鑛 〇 可形成。 本發明的製造方法是包括將帶狀金屬板電阻體 所定間隔的工程（d )。 藉由工程（d )，可得到所盼望的電流檢測用 電阻器，並不是將耐熱性保護層、底子電極層及端 層形成在各個金屬板電阻體’而是綜合進行在帶狀 板電阻體之故，因而在製造效率上優異。 實施例 胺醯亞 在80〜 體的一 ，在金 ，使之 的可熱 ^ 3 00°C 的方式 、錫（ 處理就 切斷成 金屬板 面電極 的金屬 -11 - 201037736 以下’參照圖式來說明本發明的實施例，惟本發明是 並不被限定於此些。 實施例1 表示於第1圖的金屬板電阻器10的製造 在最終輥軋以後未經退火處理的Cu-Μη系的帶狀金屬 板電阻體的上下面的中央部，藉由網印法塗佈含有二氧化 矽粉的聚醯胺醯亞胺樹脂糊，以100 °c加熱10分鐘，以200 °C加熱10分鐘及以250 °C加熱30分鐘之後使之硬化，以形 成第1耐熱性保護層12及第2耐熱性保護層13。 在此，所使用的樹脂糊是使用將平均粒徑4//m的3.5 〜4.5 // m粒徑的結晶二氧化矽粉對於聚醯胺醯亞胺樹脂與 二氧化矽粉的合計量含有3 6質量％，以及將平均粒徑20 nm 的合成二氧化矽粉對於聚醯胺醯亞胺樹脂與二氧化矽粉的 合計量含有1〇質量％的聚醯胺醯亞胺樹脂糊。該樹脂糊是 利用硬化，所含有的平均粒徑20 nm的合成二氧化矽粉的 約4質量％左右藉由溶膠凝膠反應等，成爲2〜5 nm粒徑的 二氧化矽粉，而可將粒徑不相同的二氧化矽粉均勻地分散 於所得到的耐熱性樹脂層。 之後，重疊於帶狀的金屬板電阻體的上面的第1耐熱 性保護層12的左右兩端部上的方式’或是一部分接觸於帶 狀的金屬板電阻體的上面的方式，藉由網印法進行塗佈混 練銀粉與苯酚環氧樹脂及溶劑所成的含有銀粉導電性樹脂 糊，以200 °C加熱30分鐘使之硬化’形成一對底子電極層 -12- 201037736 14 ° 然後，如第1圖所示地，覆蓋一對底子電極層14的方 式，藉由電鍍法，以鍍銅、鍍鎳、鍍錫的順序施以電鏟’ 形成一對端面電極層15。 之後，在一對端面電極層1 5之間隙’與形成第1耐熱 性保護層12及第2耐熱性保護層13同樣地形成第3耐熱性保 護層1 6。 0 最後，以所定間隔切斷帶狀的金屬板電阻體’以製造 電流檢測用金屬板電阻器1 〇。 實施例2 表示於第2圖的金屬板電阻器20的製造 在最終輥軋以後未經退火處理的Cu-Mn系的帶狀金屬 板電阻體的上下面的中央部及上全面與實施例1同樣地， 藉由網印法塗佈含有二氧化矽粉的聚醯胺醯亞胺樹脂糊， 加熱使之硬化，以形成第1耐熱性保護層22及第2耐熱性保 護層23。 之後，重疊於帶狀的金屬板電阻體的下面的第2耐熱 性保護層23的左右兩端部上的方式，或是一部分接觸於帶 狀的金屬板電阻體的下面的方式，與實施例1同樣地，藉 由網印法進行塗佈混練銀粉與苯酚環氧樹脂及溶劑所成的 含有銀粉導電性樹脂糊，使之硬化，形成一對底子電極層 24 ° 然後，如第2圖所示地，覆蓋—對底子電極層24的方 -13- 201037736 式，藉由電鍍法，以鍍銅、鍍鎳、鍍錫的順序施以電鍍’ 形成一對端面電極層25。 最後，以所定間隔切斷帶狀的金屬板電阻體，以製造 電流檢測用金屬板電阻器20。 在實施例1及2所得到的金屬板電阻器的耐熱性保護層 ，是都沒有寬尺寸的參差不齊，也沒有邊緣的塌邊。 又，在耐熱性保護層，含有粒徑不相同的二氧化矽粉 ，而在底子電極層含有銀粉之故，因而耐熱性保護層、底 子電極層及端面電極層的各接觸面，是牢固地密接著。 試驗例 使用與實施例1同樣地製造的電阻値不相同的兩種類 金屬板電阻器，及表示於第3圖的習知型的電阻値不相同 的兩種類金屬板電阻器來進行以下的性能試驗。又，作爲 構成習知型的金屬板電阻器的各構件的材料，除了未包括 底子電極層以外，藉由與實施例1同樣的材料所製造。 將各金屬電阻器，設於Cu箔貼70 a m銅的玻璃環氧基 板，包圍周圍使該基板成爲無風狀態，在電阻値5.1 πιΩ 的各金屬板電阻器以19.8Α及在電阻値4.84 πιΩ的各金屬 電阻器以20.3Α的電流分別通電15分鐘。在金屬電阻器的 中央部及端面電極層的上方1 cm的位置設置溫度計進行測 定通電前後的金屬板電阻器的上面中央部及端面電極層的 表面溫度。將使用電阻値5 _1 m Ω的各金屬板電阻器的結 果表示於表1’又’將使用電阻値4.84 ηιΩ的各金屬板電 -14- 201037736 阻器的結果表示於表2。 表1 測定部位 通電前溫度 rc) 通電後溫度 CC) 通電前後的溫度 上昇分ΓΟ 實施例1型 中央部 27.3 102.3 75.0 端面電極層部 27.3 95.7 68.4 習知型 中央部 29.1 117.2 88.1 端面電極層部 29.1 101.5 72.4 表2 測定部位 通電前溫度 fc) 通電後溫度 fc) 通電前後的溫度 上昇分fc) 實施例1型 中央部 26.9 103.7 76.8 端面電極層部 26.9 98.2 71.3 習知型 中央部 28.0 116.5 88.5 端面電極層部 28.0 97.4 69.4 ❹ 由表1及表2的結果，任何情形也比習知型的金屬電阻 器，設置本發明的底子電極層，加大端面電極層的面積作 成大者，則中央部及端面電極層表面的溫度上昇分量較少 ，而散熱作用優異。 【圖式簡單說明】 第1圖是表示本發明的一實施形態的電流檢測用金屬 板電阻器的斷面圖。 第2圖是表示本發明的其他實施形態的電流檢測用金 屬板電阻器的斷面圖。 -15- 201037736 第3圖是具有習知的耐熱性保護層的電流檢測用金屬 板電阻器的斷面圖。 【主要元件符號說明】 10 、 20 ： 電流檢測用金屬板電阻器 11、 21: 金屬板電阻體 12 、 22 ： 第1耐熱性保護層 13、 23 ： 第2耐熱性保護層 14 、 24 ： 底子電極層 15、 25 ： 端面電極層 1 6 :第3耐熱性保護層[Technical Field] The present invention relates to an excellent method for detecting a current with high precision even when a large current flows in a specific wiring portion, and is excellent in suppressing damage to a circuit of an electronic device. A metal plate resistor for current detection of heat dissipation and a method of manufacturing the same. [Prior Art] For the protection function of a circuit that overcurrents an electronic device, the use of a current detecting resistor using a metal plate resistor is used. This current detecting resistor is provided for detecting the current of a specific wiring portion, and a resistor having a small resistance 数 having a number of ιη Ω to several tens of η Ω must be detected with high precision. Further, the resistor is designed to detect a high current even when the current is supplied to the electronic device, and the design is high in rated power and lower in resistance. 〇 However, a resistor designed in this way has a problem that heat is generated by a large current to cause thermal damage on the wiring substrate. Thus, in order to avoid such thermal damage and the like, a resistor using transfer die technology to form a thick protective layer is known. For example, as shown in FIG. 3, a resistor having such a protective layer is known to include a metal plate resistor 31, a pair of electrode layers 32 provided at both end portions of the resistor 31, and The resistor 30 of the insulating protective layer 33 provided on the upper surface and the lower surface of the resistor 31 between the electrode layers 32 [refer to Japanese Laid-Open Patent Publication No. 2007-220859 (Fig. 7), Japanese Patent Laid-Open No. Hei 6-20802 201037736 Bulletin). However, in the resistor of such a structure, it can be said that thermal damage due to a large current cannot be sufficiently avoided, and development of a resistor for current detection which is more excellent in heat dissipation is desired. SUMMARY OF THE INVENTION An object of the present invention is to provide a metal plate resistor for current detection which can suppress damage of an overcurrent of an electronic device and which has excellent heat dissipation and can detect current with high precision, and a method of manufacturing the same. According to the invention, there is provided a metal plate resistor for current detection, comprising: a metal plate resistor; and a heat-resistant protective layer provided at a central portion of at least one surface of the metal plate resistor; a pair of bottom electrode layers provided on one surface of the metal plate resistor, and a plurality of base electrode layers covering the bottom electrode layer, provided at both ends of the heat-resistant protective layer at the center of one of the one side of the metal plate resistor A pair of end surface electrode layers provided at both ends of the metal plate resistor. Moreover, according to the present invention, there is provided a method of manufacturing a metal plate resistor for current detection, comprising: applying a screen printing heat-resistant protective layer to a central portion of at least one surface of a strip-shaped metal plate resistor; In the hardening process (a), a mesh is applied to one side of the metal plate resistor body so as to cover both end portions of the heat-resistant protective layer provided at one central portion of one of the metal plate resistor bodies. Engineering (b) for printing a pair of bottom electrode layers to harden them; and engineering (c) for forming an end electrode layer by plating in a manner covering the entire surface of the base electrode layer: and a strip-shaped metal plate resistor 6 - 201037736 Engineering (d) cut at regular intervals. The heat-resistant protective layer is provided at the central portion of one surface of the metal plate resistor and the other surface of the metal plate resistor. Further, it may be provided at the central portion of both surfaces of the metal plate resistor. When the heat-resistant protective layer is to be provided in the central portion of both surfaces of the metal plate resistor, the end surface electrode layer is extended to a portion of the surface of the metal plate resistor body on which the base electrode layer is not provided, and the heat-resistant protective layer is not provided. , can expand the effective electrode surface 0 product, and can improve the heat dissipation efficiency. As the heat-resistant protective layer, a heat-resistant resin can be used, and in particular, a polyimide-based imide resin which exhibits excellent heat resistance and insulating properties in a film is preferable. Further, in the heat-resistant resin layer, by using cerium oxide powder, printing characteristics at the time of production can be improved. In particular, as the cerium oxide powder, a powder having a micron-order or a nano-order having a different particle diameter can be efficiently prevented from collapsing or oozing during printing, and the accuracy of the width dimension of the heat-resistant protective layer can be improved. While suppressing the occurrence of unevenness in the resistance 値. The blending ratio of the cerium oxide powder is a total amount of the heat-resistant resin, and is usually 30 to 55 mass%, preferably 40 to 50 mass%. Further, when a powder having a micron-order or a nano-order having a different particle diameter is blended, the total amount of the heat-resistant resin may be 18 to 40% by mass, and the latter may be 1 2 to 2 15 mass%. Further, in addition to the cerium oxide powder, black pigments such as CuO, Fe203, and Μπ203 may be blended. The base electrode layer is screen printable, and is formed of a known electrode material containing a conductive resin paste or the like by a heat-curable metal. 201037736 In the present invention, the bottom electrode layer is formed to cover both ends of the heat-resistant protective layer, or is formed by covering the entire end electrode layer, so that the bottom electrode layer is composed of a silver powder and a phenol ring. The paste of the oxyresin is preferably formed. By using silver powder, thermal conductivity can be improved, and heat dissipation of the resistor body can also be facilitated. The end face electrode layer can be formed by a plating method, and is generally formed by a known electrode material of a copper plating layer, a nickel plating layer or a tin plating layer. The metal plate resistor is a metal plate having a desired resistance 就 and is not particularly limited. For example, a Cu-Mn based metal plate, a Ni-Cr based metal plate, or a Fr-Cr based metal plate can be used. The metal plate resistor for current detection according to the present invention particularly has a heat-resistant protective layer, and includes a base electrode layer so as to cover both end portions of the heat-resistant protective layer, and an end electrode layer is provided so as to cover the entire surface of the base electrode layer. Therefore, the electrode area can be expanded in an effective manner, and excellent heat dissipation can be ensured even when the rated power is set to be high. Therefore, the metal plate resistor of the present invention can suppress the damage of the electronic device to the current-dependent circuit, can detect the current with high precision, and contribute to downsizing and thinning of the electronic device. [Embodiment] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a cross-sectional view showing a current detecting metal plate resistor 10 according to an embodiment of the present invention. In the first drawing, reference numeral 11 denotes a 201037736 metal plate resistor having a resistance function, and a first heat-resistant protective layer I2 and a second heat-resistant protective layer are provided in a central portion of the upper and lower surfaces of the metal plate resistor π. 13 is provided in all width directions of the metal plate resistor body 11. On both end sides of the first heat-resistant protective layer 12, the both end portions are covered, and in order to ensure conductivity, a part of the first heat-resistant protective layer 12 is in contact with the upper surface of the metal plate resistor 11, and the both end sides of the metal plate resistor 11 are left. In a part of the manner, a pair of conductive bottom electrode layers 14 are provided. The pair of bottom electrode layer 14 is entirely covered by covering the pair of end surface electrode layers 15, and as shown in the figure, the pair of end surface electrode layers 15 are covered on the end faces of the metal plate resistors 11, and are respectively extended to Both ends of the second heat-resistant protective layer 13 at the central portion of the lower surface of the metal plate resistor 11 are formed. As shown in the figure, a third heat-resistant protective layer 16 is formed on the upper gap portion of the pair of end surface electrode layers 15. The heat-resistant protective layer 16 can be formed of the same material as the first and second heat-resistant protective layers (1, 2, 3), but is not essential in the present invention. ❹ The current detecting metal plate resistor 10 shown in Fig. 1 is a portion of the lower end surface electrode layer I5, and is attached to the substrate by solder or the like. Fig. 2 is a view showing current detection according to another embodiment of the present invention. A cross-sectional view of the metal plate resistor 20 is used. In Fig. 2, reference numeral 21 denotes a metal plate resistor having a resistance function, and at a central portion of the lower surface of the metal plate resistor 21, the first heat-resistant protective layer 22 is provided on all widths of the metal plate resistor 21. The second heat-resistant protective layer 23 is provided on the entire surface of the metal plate resistor 21 in a comprehensive direction. 201037736 The both end portions of the second heat-resistant protective layer 23 are covered with the both end portions, and in order to ensure conductivity, a part of the second heat-resistant protective layer 23 is in contact with the lower surface of the metal plate resistor 21, and covers the lower end sides of the metal plate resistor 21 The overall approach 'provides a pair of electrically conductive base electrode layers 24. The pair of base electrode layers 24 are entirely covered by the pair of end surface electrode layers 25, and as shown, the pair of end surface electrode layers 25 are formed to cover the end faces of the metal plate resistors 21. The current detecting metal plate resistor 10 shown in Fig. 2 is a portion of the lower end surface electrode layer 25, and is a type in which it is mounted on a substrate by solder or the like. The manufacturing method of the present invention is a process (a) in which a screen printing heat-resistant protective layer is applied to a central portion of at least one of the strip-shaped metal plate resistors to be hardened. As shown in Fig. 1 and Fig. 2, in the manufacturing method of the present invention, a screen printed heat-resistant protective layer is applied to the other side of the strip-shaped metal plate resistor to be cured. The strip-shaped metal plate resistor is finally cut at a predetermined interval, whereby a desired metal plate resistor can be formed, and the heat-resistant protective layer, the base electrode layer, and the end face necessary for the formation are integrally formed before the cutting. As the electrode layer formed, for example, a Cu-Mn-based ribbon metal, a Ni-Cr-based ribbon metal, or a Fe-Cr-based ribbon metal can be used. Here, as the strip-shaped metal plate resistor, if it is not annealed after the last rolling, it is preferable not to lower the elasticity of the metal plate resistor. When the strip-shaped metal plate resistor is bent in the process of the resistor, it cannot be restored, and it is not good. The heat-resistant protective layer is, for example, a heat-resistant resin paste in which a polyamide resin containing cerium oxide powder is dispersed in a solvent, and is applied by screen printing at a temperature of about 300 ° C. In the manufacturing method of the present invention, one end of the heat-resistant protective layer covering the central portion of the one side of the resistance of the metal plate is applied to one surface of the plate resistor, and the pair of base electrode layers 0 are hardened by screen printing. Engineering (b). The base electrode layer is formed, for example, by using a conductive resin paste containing a silver powder and a phenol epoxy resin to be cured, applying a screen printing, and applying heat curing at about 80 Å. The manufacturing method of the present invention comprises a process (c) of covering the entire surface of the base electrode layer and forming the end electrode layer by plating. The end face electrode layer can be formed by, for example, applying copper (Cu), nickel (Ni) Sn, other metals or alloys thereof to the ore alone or in combination. The manufacturing method of the present invention is an engineering (d) including spacing of the strip-shaped metal plate resistors. According to the process (d), the desired current detecting resistor can be obtained, and the heat-resistant protective layer, the bottom electrode layer and the end layer are not formed on the respective metal plate resistors, but are integrated in the strip-shaped plate resistor. Therefore, it is excellent in manufacturing efficiency. The example of the amine oxime in the 80~ body of one, in the gold, so that it can be heated ^ 3 00 ° C way, tin (treatment is cut into metal plate surface electrode of metal -11 - 201037736 following 'reference schema The embodiment of the present invention will be described, but the present invention is not limited thereto. Embodiment 1 shows a Cu-Μη system in which the metal plate resistor 10 of Fig. 1 is manufactured without annealing after final rolling. A central portion of the upper and lower sides of the strip-shaped metal plate resistor is coated with a polyimide film containing cerium oxide powder by screen printing, heated at 100 ° C for 10 minutes, and heated at 200 ° C. After heating at 250 ° C for 30 minutes, it is cured to form the first heat-resistant protective layer 12 and the second heat-resistant protective layer 13. Here, the resin paste used is an average particle diameter of 4 / / m The crystal cerium oxide powder having a particle size of 3.5 to 4.5 // m contains 36% by mass for the total amount of the polyimide and the cerium oxide powder, and the synthetic cerium oxide powder having an average particle diameter of 20 nm. The total amount of the polyamidoximine resin and the cerium oxide powder is 1% by mass of polyfluorene The bismuth imide resin paste is obtained by hardening, and about 2% by mass of the synthetic cerium oxide powder having an average particle diameter of 20 nm is formed by a sol-gel reaction or the like to form a particle size of 2 to 5 nm. The cerium oxide powder is uniformly dispersed in the obtained heat-resistant resin layer, and the first heat-resistant protective layer 12 is superposed on the upper surface of the strip-shaped metal plate resistor. Silver powder conductive resin formed by coating and kneading silver powder, phenol epoxy resin and solvent by screen printing method in a manner of contacting the upper and lower end portions or a part of the strip-shaped metal plate resistor Paste, heat at 200 ° C for 30 minutes to harden 'form a pair of bottom electrode layer -12- 201037736 14 ° Then, as shown in Figure 1, covering a pair of bottom electrode layer 14 by means of electroplating, A pair of end face electrode layers 15 are formed by applying a shovel in the order of copper plating, nickel plating, and tin plating. Thereafter, a gap ′ between the pair of end surface electrode layers 15 and the formation of the first heat-resistant protective layer 12 and the second heat-resistant layer are formed. The protective layer 13 similarly forms the third heat resistance First, the strip-shaped metal plate resistor ′ is cut at a predetermined interval to manufacture a metal plate resistor 1 电流 for current detection. Embodiment 2 The metal plate resistor 20 shown in FIG. 2 is manufactured. The central portion and the upper portion of the upper and lower surfaces of the Cu-Mn-based strip-shaped metal plate resistor which has not been annealed after the final rolling are coated with the cerium oxide powder by the screen printing method in the same manner as in the first embodiment. The amidoxime resin paste is heated and hardened to form the first heat-resistant protective layer 22 and the second heat-resistant protective layer 23. Thereafter, the second heat-resistant protection is superimposed on the lower surface of the strip-shaped metal plate resistor. In the same manner as in the first embodiment, the method of coating the kneaded silver powder and the phenol epoxy resin by the screen printing method is carried out in such a manner as to contact the left and right end portions of the layer 23 or a portion of the strip-shaped metal plate resistor. And a silver powder conductive resin paste formed by a solvent and hardened to form a pair of bottom electrode layers 24°, and then, as shown in FIG. 2, covers the square-13-201037736 of the base electrode layer 24, By electroplating, copper plating, nickel plating, tin plating Sequence is plated 'form a pair of end surface electrode layer 25. Finally, the strip-shaped metal plate resistor is cut at a predetermined interval to manufacture a current detecting metal plate resistor 20. The heat-resistant protective layers of the metal plate resistors obtained in Examples 1 and 2 were not uneven in width and had no edge collapse. Further, since the heat-resistant protective layer contains cerium oxide powder having a different particle diameter and contains silver powder in the bottom electrode layer, the contact faces of the heat-resistant protective layer, the base electrode layer and the end surface electrode layer are firmly Close. In the test examples, two kinds of metal-plate resistors which are different in the same resistance as that of the first embodiment and two kinds of metal-plate resistors which are different from the conventional resistors of the third embodiment are used to perform the following performances. test. Further, the material of each member constituting the conventional metal plate resistor was produced by the same material as that of Example 1 except that the base electrode layer was not included. Each metal resistor was placed on a glass epoxy substrate with a copper foil of 70 am copper, and the substrate was surrounded by a windless state. The metal plate resistors at a resistance of 5.1 πιΩ were 19.8 Α and the resistance was 4.84 πιΩ. Each metal resistor was energized for 15 minutes with a current of 20.3 Torr. A thermometer was placed at a position 1 cm above the center portion of the metal resistor and the end surface electrode layer to measure the surface temperature of the upper center portion and the end surface electrode layer of the metal plate resistor before and after energization. The results of the respective metal plate resistors using the resistor 値 5 _1 m Ω are shown in Table 1' and the results of the resistors using the respective metal plates of the resistor 値 4.84 ηιΩ are shown in Table 2. Table 1 Temperature at the measurement site before energization rc) Temperature after energization CC) Temperature rise before and after energization 中央 Example 1 type center portion 27.3 102.3 75.0 End electrode layer portion 27.3 95.7 68.4 Conventional center portion 29.1 117.2 88.1 End electrode layer portion 29.1 101.5 72.4 Table 2 Temperature at the measurement site before energization fc) Temperature after energization fc) Temperature rise before and after energization is fc) Center portion of the first embodiment 26.9 103.7 76.8 End electrode layer portion 26.9 98.2 71.3 Conventional center portion 28.0 116.5 88.5 End electrode Layer 28.0 97.4 69.4 ❹ From the results of Tables 1 and 2, in any case, the substrate electrode layer of the present invention is provided in a metal resistor of a conventional type, and the area of the end electrode layer is increased to make the center portion and The surface of the end electrode layer has a small temperature rise component and is excellent in heat dissipation. [Brief Description of the Drawings] Fig. 1 is a cross-sectional view showing a metal plate resistor for current detection according to an embodiment of the present invention. Fig. 2 is a cross-sectional view showing a metal plate resistor for current detection according to another embodiment of the present invention. -15- 201037736 Fig. 3 is a cross-sectional view of a metal plate resistor for current detection having a conventional heat-resistant protective layer. [Description of main component symbols] 10, 20 : Metal plate resistors 11 and 21 for current detection: Metal plate resistors 12 and 22 : First heat-resistant protective layers 13 and 23 : Second heat-resistant protective layers 14 and 24 : Base Electrode layer 15, 25 : End surface electrode layer 16 : Third heat-resistant protective layer
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