1311770 九、發明說明： 【發明所屬之技術領域】 本發明係關於一種過電流保護元件及其製作方法，特別 是關於一種具有正溫度係數（Positive Tempem⑽1311770 IX. Description of the Invention: [Technical Field] The present invention relates to an overcurrent protection element and a method of fabricating the same, and more particularly to a method having a positive temperature coefficient (Positive Tempem(10)
Coefficient ; PTC)特性之過電流保護元件及其製作方法。 【先前技術】 習知之PTC元件之電阻值對溫度變化的反應相當敏 Φ ϋρτ<:元件於正常使用狀況時，其電阻可維持極低值 而使電路得以正常運作。但是當發生過電流或過高溫的現 象而使溫度上升至一臨界溫度時，其電阻值會瞬間彈跳至 一雨電阻狀態（例如1〇4ohm以上）而將過量之電流反向抵 銷，以達到保護電池或電路元件之目的。由於PTC元件可 有效地保護電子產品，因此該ptc元件已見整合於各式電 路元件中’以防止過電流的損害。 圖1(a)顯示一習知之過電流保護元件1〇之立體圖，其係 • 將兩外接電極片11分別焊接於一 PTC元件12之上、下表面 而組成。該外接電極片u係作為連接至欲保護之電氣裝置 之介面，例如可連接至一主機板或印刷電路板等。圖1(b) 係該過電流保護元件1〇之側視圖。該pTC元件12係由一 PTC材料層122疊設於兩電極層ι21間組成，而該兩外接電 極片11係分別連接該兩電極層121。Coefficient; PTC) characteristics of overcurrent protection components and methods of making same. [Prior Art] The resistance value of a conventional PTC element is relatively sensitive to temperature changes. Φ ϋρτ<: When the element is in normal use, its resistance can be maintained at a very low value to allow the circuit to operate normally. However, when an overcurrent or excessive temperature occurs and the temperature rises to a critical temperature, the resistance value will instantaneously bounce to a rain resistance state (for example, 1 〇 4 ohm or more) and the excess current is reversely offset to achieve The purpose of protecting batteries or circuit components. Since the PTC element can effectively protect the electronic product, the ptc element has been integrated into various circuit elements to prevent damage from overcurrent. Fig. 1(a) shows a perspective view of a conventional overcurrent protection element 1B which is formed by soldering two external electrode pads 11 to a top surface and a lower surface of a PTC element 12. The external electrode tab u is used as an interface to the electrical device to be protected, for example, to a motherboard or a printed circuit board. Fig. 1(b) is a side view of the overcurrent protection element 1A. The pTC component 12 is composed of a PTC material layer 122 stacked between the two electrode layers ι 21, and the two external electrode pads 11 are respectively connected to the two electrode layers 121.
一般而言’該外接電極片11與PTC元件12間係利用錫膏 迴焊的方式接合。因迴焊時的溫度相當高，而使該PTC元 件12已達觸發（trip)溫度而使其電阻上升。為了降低pTC P28532 98942 005159270 1311770 元件12之電阻，必須以熱衝擊⑽打福等後段製 程加以處ί里如此一來，若該過電流保護元件⑺已焊接於 電路板時，此時因其體積較大，熱衝擊之容室無法―次容 納較多之組件（例如設有過電流保護元件之電路板），而將 降低大幅產出效率。再者，在進行熱衝擊時，設於電路板 件亦可能因高溫而損壞’而造成諸多限制。 【發明内容】In general, the external electrode sheet 11 and the PTC element 12 are joined by solder paste reflow. Since the temperature at the time of reflow is relatively high, the PTC element 12 has reached the trip temperature to increase its resistance. In order to reduce the resistance of the pTC P28532 98942 005159270 1311770 component 12, it must be treated with thermal shock (10) and other downstream processes. If the overcurrent protection component (7) is soldered to the board, the volume is relatively high. Large, thermal shock chambers cannot accommodate more components (such as boards with overcurrent protection components), which will reduce large output efficiency. Furthermore, in the case of thermal shock, the circuit board may be damaged by high temperature, which causes many restrictions. [Summary of the Invention]
本發明之目的係提供一種過電流保護元件及其製作方 法’可有效解決目前焊接外接用電極片時所造成之元件電 阻值上升之情形’且適於大量生產。 為達到上述目#，本發明揭示一種過電流保護元件，其 包含兩第二電極層和一疊設於該兩第二電極層間之高分 子PTC元件。該尚分子PTC兀件包含兩第一電極層及—聶 設於該兩第一電極層間之一高分子PTC材料層。該兩第: 電極層係分別接觸該高分子吼元件之兩第一電極層之 表面而將該高分子PTC元件夾於其間，且該第二電^之 厚度大於該第一電極層之厚度。故整體而言，該高=子 PTC材料層、第—電極層和第二電極層係由内而外^層 疊結構。 該第二電極層與第一電極層間可利用錫膏迴焊的方式 進行結合，雖然此時該高分子PTC元件之電阻值將升高， 因尚未連接外接電極片（仍屬於元件階段， 二 小"王*取i。口階 奴）’使得整體體積不致於太大，而仍可大量置於容室内 進仃熱衝擊使其電阻值儘量回復其原始值，且不致影響其SUMMARY OF THE INVENTION An object of the present invention is to provide an overcurrent protection element and a method of fabricating the same that can effectively solve the problem of an increase in the component resistance caused by soldering an external electrode tab, and is suitable for mass production. In order to achieve the above object, the present invention discloses an overcurrent protection element comprising two second electrode layers and a high molecular PTC element stacked between the two second electrode layers. The PTC element further comprises two first electrode layers and a polymer PTC material layer disposed between the two first electrode layers. The two electrodes: the electrode layers are respectively in contact with the surfaces of the first electrode layers of the polymer germanium element, and the polymer PTC element is sandwiched therebetween, and the thickness of the second electrode is greater than the thickness of the first electrode layer. Therefore, as a whole, the high = sub-PTC material layer, the first electrode layer and the second electrode layer are laminated from the inside to the outside. The second electrode layer and the first electrode layer can be combined by solder paste reflow, although the resistance value of the polymer PTC component will increase, because the external electrode pad has not been connected (still belonging to the component stage, two small "王*取i. 口口奴)' makes the overall volume not too large, but can still be placed in a large amount of thermal shock in the chamber to make its resistance value return to its original value as much as possible without affecting its
Pa853a 98942 °〇515927〇 -6 - 1311770 產出效率。 不同於習知技藝，本發明之電流保護元件可以在高分子 PTC材料層之正上方進行點焊，而將第二電極層與外接之 電極片連接。然，若在習知之電流保護元件之ptc材料層 正上方進行點焊，將因局部高溫使PTC材料層裂解而產生 氣泡，導致整個電流保護元件被損毁。 該第二電極層之厚度大於該第一電極層之厚度，故外接 φ 電極片時可在高分子ptc元件之正上方利用熱產生較少 之點焊方式將其連接於該第二電極層，使其熱量亦不致迅 速傳導至該高分子PTC材料層，而仍得維持原始之低電阻 值。 該上、下兩片第二電極層可以是不同的厚度其中至少 一片是以點焊方式與外接之電極片連接。因連接點在高分 子PTC元件之正上方，所以用於點焊之第二電極層必須有 足夠厚度，通常厚度至少需0 2mm，才能保護正下方之高 鲁分子PTC材料層不致於被點焊時之局部高熱所破壞，該未 點焊之第一電極層可以使用較薄之金屬材料，其厚度通常 約 0.02至 0.1mm。 【實施方式】 以下將藉由圖式說明本發明之過電流保護元件及其製 作方法。 如圖2所示，一第一pTC元件22包含兩第一電極層221及 一疊設於該兩第一電極層221間之PTC材料層222，其中該 PTC材料層222係包含高分子PTC材料。該第一pTc元件22 P28532 98942 °°515927〇 1311770 係利用錫膏迴焊之方式於其上、下表面各自物理接觸連結 一第二電極層223，而形成一第二PTC元件23。換言之， 該第二PTC元件23係由該第一 PTC元件22外接兩第二電極 層223而成。該PTC材料層222於錫膏迴烊時或可能因溫度 過高而觸發升高其電阻值。 接著，針對該第二PTC元件23進行熱衝擊，使該PTC材 料層222之電阻值回復原始之電阻值，以消除錫膏迴焊對 ^ 該PTC材料層222之影響。 如圖3所示，利用點焊的方式將該第二PTC元件23之 上、下表面於焊接點25各自焊接一外接電極片24進行結 合，而形成本發明之過電流保護元件30。該焊接點25並不 限為一個，其視需要亦可利用多個焊接點進行接合。 該第一 PTC元件22係屬標準件，而得以大量生產。然其 第一電極層221 —般僅約0.02至0.1mm之間，故若以該第一 電極層221直接焊接外接電極片24，焊接期間所產生之高 • 熱將迅速傳導至該PTC材料層222而使其觸發，進而影響 PTC元件製成成品時之電阻值。 該第二電極層223之厚度將較該第一電極層221為厚，一 般約大於0.1 mm，且以0.2〜0.5mm為較佳。再者，本發明 利用點焊取代傳統之錫膏迴焊進行外接電極片24之結 合，可有效減低產生之熱及其傳導至該PTC材料層222之 速率，而可大幅減低觸發產生之機率。 再者，第二PTC元件23在未接合該外接電極片24之前， 因尚無該外接電極片24所造成突出之部分，而不致佔據太 P28532 98942 005159270Pa853a 98942 °〇515927〇 -6 - 1311770 Productivity. Unlike the conventional art, the current protection element of the present invention can be spot welded directly above the polymer PTC material layer, and the second electrode layer can be connected to the external electrode sheet. However, if the spot welding is performed directly above the ptc material layer of the conventional current protection element, the PTC material layer is cracked due to the local high temperature to generate bubbles, and the entire current protection element is destroyed. The thickness of the second electrode layer is greater than the thickness of the first electrode layer, so that when the φ electrode sheet is externally connected, it can be connected to the second electrode layer by using a spot welding method with less heat directly under the polymer ptc element. The heat is not quickly transferred to the polymer PTC material layer, but the original low resistance value is still maintained. The upper and lower second electrode layers may be of different thicknesses, at least one of which is spot welded to the externally connected electrode sheets. Since the connection point is directly above the polymer PTC element, the second electrode layer for spot welding must have a sufficient thickness, usually at least 0 2 mm, in order to protect the high-ruth molecular PTC material layer directly underneath from being spot-welded. In the case of local high heat destruction, the unspotted first electrode layer may use a relatively thin metal material, and its thickness is usually about 0.02 to 0.1 mm. [Embodiment] Hereinafter, an overcurrent protection element of the present invention and a method of manufacturing the same will be described by way of drawings. As shown in FIG. 2, a first pTC component 22 includes two first electrode layers 221 and a PTC material layer 222 stacked between the two first electrode layers 221, wherein the PTC material layer 222 comprises a polymer PTC material. . The first pTc element 22 P28532 98942 °°515927〇 1311770 is formed by a solder paste reflow method in which a second electrode layer 223 is physically connected to the upper and lower surfaces thereof to form a second PTC element 23. In other words, the second PTC element 23 is formed by externally connecting the two second electrode layers 223 to the first PTC element 22. The PTC material layer 222 triggers an increase in its resistance value when the solder paste is turned back or may be too high. Then, the second PTC element 23 is thermally shocked, and the resistance value of the PTC material layer 222 is restored to the original resistance value to eliminate the influence of the solder paste reflow on the PTC material layer 222. As shown in Fig. 3, the upper and lower surfaces of the second PTC element 23 are soldered to the external electrode pads 24 at the solder joints 25 by spot welding to form the overcurrent protection element 30 of the present invention. The number of the solder joints 25 is not limited to one, and it may be joined by a plurality of solder joints as needed. The first PTC element 22 is a standard part and is mass-produced. However, the first electrode layer 221 is generally only between about 0.02 and 0.1 mm. Therefore, if the external electrode sheet 24 is directly soldered by the first electrode layer 221, the high heat generated during soldering will be quickly conducted to the PTC material layer. 222 causes it to trigger, thereby affecting the resistance value of the PTC component when it is finished. The thickness of the second electrode layer 223 will be thicker than the first electrode layer 221, and is generally greater than about 0.1 mm, and preferably 0.2 to 0.5 mm. Furthermore, the present invention utilizes spot welding instead of conventional solder paste reflow for bonding of the external electrode pads 24, which can effectively reduce the heat generated and the rate of conduction to the PTC material layer 222, and can greatly reduce the probability of trigger generation. Furthermore, before the external electrode tab 24 is joined, the second PTC component 23 does not occupy the protruding portion of the external electrode tab 24, and does not occupy too much P28532 98942 005159270