1270476 (1) 九、發明說明 - 【發明所屬之技術領域】 k 本發明疋關於熱印機所使用之熱印頭。再者，本發 是關於熱印頭之製造方法。 【先前技術】 以往，在感熱紙之記錄紙上執行印字之裝置，提案 g 各種熱印頭（例如，參照下述專利文獻1 )。本案之第 圖是表示本發明之關連技術之熱印頭之一例。具體而言 圖示之熱印頭B是包含有絕緣性之基板9 1。在該基板 ，疊層形成有由玻璃所構成之釉面層92、發熱電阻體 、電極94及保護膜96。保護膜96是由以玻璃爲主成 之材料所形成。依據該熱印頭B執行印字處理時，在使 熱紙等之記錄紙抵接於保護膜96上之狀態下予以相對 動。此時，在發熱電阻體93所發生之熱傳達至記錄紙 φ ，執行所欲之印字。 在上述構成之熱印頭中，電極94是可藉由例如A1 Cu、Au等之導電性優良之金屬材料所形成。其中An 化學性安定之材料，耐蝕性優良。因此，若以A u製造 極94時，則可以避免因電極之腐蝕而產生通電不良。 者，Au比起A1等，電阻（抵抗率）爲小。因此’當 Au形成電極94時，比起使用A1之時，電壓下降量變 ，可以降低電力消耗。 以Au製造電極，雖然可取得上述之優點’但是另 明 有 11 y 上 93 分 感 移 上 是 電 再 以 小 -4- (2) 1270476 面則產生下述般之不良狀況。即是，Au比起其他良導電 性金屬’與形成保護膜之玻璃的密著性差。因此，有可能 發生保護膜自電極94剝離，該關係到降低熱印頭之耐久 性。再者，藉由電極和保護膜之熱膨脹率之差，雖然在保 護膜產生應力，但是該應力助長保護膜剝離。 [專利文獻1]日本特開2002-673 67 【發明內容】 本發明是鑒於上述事態所創造出者。在此，本發明之 課題是以提供提高Au製之電極和保護膜之密著性的熱印 頭。並且，本發明之另外課題是以提供如此之熱印頭之製 造方法。 爲了解決上述課題，本發明是想出下述之技術性手段 〇 藉由本發明之第1觀點所提供之熱印頭，是具備有基 板、釉面層（glaze layer )、發熱電阻體、用以對該發熱 電阻體進行通電之以Au爲主成分的電極，和覆蓋上述發 熱電阻體及電極之保護膜。在上述電極之表面形成有多數 凹部。 若依據如此之構成，則可以提高上述電極和上述保護 膜之密著力。具體而言，由於在電極表面形成多數凹部’ 覆蓋電極之保護膜之一部分則陷入至凹部內。其結果’可 以藉由所謂之定錨（anchor )效果提昇密著力。再者’保 護膜上由於電極和保護膜之熱膨脹率之差’在沿著該些境 (3) 1270476 界面之方向上產生比較大之應力。若依據本發明，難以產 生沿著上述境界面之方向的偏移，由該方面來看對於抑制 保護膜之剝離也爲佳。 上述多數凹部是藉由使上述電極表面之中心線平均粗 度Ra設爲0.1〜0.5//m而所形成爲最佳。若依據如此之 構成，則可適當發揮上述之定錨（anchor)效果。 上述多數凹部是藉由貫通於上述電極之厚度的多數貫 通部所形成爲佳。上述貫通部即使形成具有圓形剖面亦可 。此時，上述貫通孔之直徑爲例如1〜1 0 μ m。再者，本 發明中即使取代圓形剖面，使成爲矩形剖面地形成上述貫 通部亦可。此時，該矩形爲具有短邊及長邊，短邊之長度 (矩形之寬度）爲例如1〜10//Π1。若依據如此之構成， 進入至貫通部之保護膜之一部分與形成在電極之下層側之 釉面層或發熱電阻體直接緊密接著。因釉面層或是發熱電 阻體對保護膜之密著性，比電極對保護膜之密著性優，故 藉由確保保護膜和釉面層或發熱電阻體之密著區域，則可 以提昇保護膜之密著力，抑制保護膜之剝離。 本發明之熱印頭是又具備有被形成在上述電極之下層 側之絕緣膜爲佳。絕緣膜對保護膜之密性，比起電極對保 護膜之密著性還優。因此，依據如此之構成，由於進入至 上述貫通部之保護膜的一部分與絕緣膜直接密著，提昇了 保護膜之密著力，適合用於謀求抑制保護膜之剝離。 藉由本發明之第2觀點所提供之熱印頭具備有基板、 釉面層（g】aze layer)、發熱電阻體、用以對該發熱電阻 -6 - (4) 1270476 體進行通電之以Αιι爲主成分的電極，和覆蓋上述發熱電 阻體及電極之保護膜。在上述電極上形成有含有Ni、Cr 及Ti中之至少1種的金屬薄膜。 若依據如此之構成，則與本發明之第1觀點相同，可 以提高電極和保護膜之密著力。即是，Ni、Cr、Ti等之 金屬與保護膜之密著性比起Au與保護膜之密著性還優。 因此，可以抑制保護膜之剝離。再者，因上述金屬與An 之附著力優良，故也不會發生金屬薄膜從電極剝離之不良 狀況。 若依據本發明之第3觀點，則是提供熱印頭之製造方 法。該製造方法是具有在基板上形成釉面層之工程、在上 述釉面層上形成以Au爲主成分之電極的工程、形成發熱 電阻體之工程，和形成覆蓋上述發熱電阻體及電極之工程 。並且若依據該製造方法，於形成上述電極之工程後，設 置有將上述基板予以熱處理之工程。 若依據如此之製造方法，被形成在電極下層之釉面層 之玻璃成分是擴散至電極之表面附近。因玻璃對保護膜之 密著性，比Au對保護膜之密著性還優，故擴散至電極之 表面附近之釉面層之玻璃成分當作接著劑發揮功能，提昇 保護膜之密著性。其結果，可以謀求熱印頭之耐久性。 本發明之製造方法是又具有在上述釉面層和上述電極 之間，形成包含有Ni、Cr及Ti中之至少1種的金屬膜的 工程爲佳。若依此，金屬膜之上述金屬成分擴散至電極之 表面附近。因上述金屬對保護膜之密著性，比Au對保護 (5) 1270476 膜之密著性還優，故擴散至電極比面附近之上述金屬成分 當作接著劑而發揮功能，提昇保護膜之密著力。 本發明之其他特徵及優點，藉由參照圖面如下述般予 以詳細說明明顯可知。 【實施方式】 以下，針對本發明之最佳實施例，參照圖面予以具體 φ 說明。 第1圖至第3圖是表示根據本發明之第】實施例之熱 印頭A1。熱印頭A1是具備有基板1、釉面層2、發熱電 阻體3、共同電極41、多數之個別電極42、金屬薄膜5 及保護膜6 (參照第2圖A )。 基板1爲俯視觀看時呈矩形之平板狀，由例如氧化鋁 陶瓷等之絕緣體所構成，在基板1上疊層形成有釉面層2 、發熱電阻體3、電極層4(各電極41、42)、金屬薄膜 φ 5及保護膜6。釉面層2是發揮當作蓄熱層之功用。並且 ，釉面層2是提供適合形成共同電極3或個別電極4之平 滑表面。若依據該構成，印刷塗佈玻璃漿糊之後，藉由燒 結同漿糊而所形成。釉面層2包含有隆起部21，同隆起 部具有圓弧狀之外面。發熱電阻體3是藉由CVD法或是 濺鍍法形成例如Ta Si 02之膜，形成至少覆蓋釉面層2之 隆起部21。發熱電阻體3之厚度例如爲0.2〜2.0//m。電 極層4是被疊層於發熱電阻體3之上層側，藉由濺鍍法形 成例如以Αιι爲主成分之金屬材料的膜。電極層4之厚度 (6) 1270476 例如爲0.3〜2.0//m。電極層4是藉由例如光微影法選擇 性蝕刻一部分，藉此形成共同電極4 1、個別電極42。 共同電極4 1是由共同線部4 1 A及多數延伸部4 1 B所 構成。如第1圖A所示般，共同線部41A是包含沿著基 板1之長邊方向之部分（主部分），和由該兩端部延伸至 基板1之短邊方向之部分（副部）。上述各延伸部4 1 B是 由共同線部41A之主部向基板1之短邊方向突出。共同 線部4 1 A爲用以自圖外之端子部對後述之發熱電阻部31 一起流動電流之部分，且爲具有大面積之構成。 如第2圖A所示般，各個別電極42是在釉面層2之 隆起部21之頂上面附近，使發熱電阻體3之一部分予以 露出，該一端是與各延伸部41B隔著間隔而被形成。各個 別電極42之另一端是電性連接於驅動IC7。驅動1C 7是 用以根據自外部被發送出之列印用之畫像資料，控制通電 者，被搭載在基板1上。當藉由驅動IC7選擇性對個別電 極42通電時，發熱電阻體3中，個別電極42和與此相對 之延伸部4 1之間的露出部分當作發熱電阻部3 1發揮功能 ，以形成1個發熱點之方式加以構成。 如第2圖B所示般，在共同電極之延伸部41B及個 別電極42之表面41Ba、42a上形成有多數凹部，該些多 數凹部是藉由使表面41Ba、42a設成凹凸狀之粗面而所形 成。表面41Ba、42a之中心線平均粗度Ra爲〇· 1〜0.5 #ηι。如此之凹凸狀可以藉由乾蝕刻等之表面處理手法而 形成。 -9- (7) 1270476 金屬薄膜5是被疊層於共同線部4 1 A之上層側，藉 由鍍層處理或是濺鍍法形成包含Ni、Cr、Ti中之至少1 種的金屬膜。金屬薄膜5之厚度是被設定爲例如〇·2〜2· 0 A m。在共同線部4 1 Α及金屬薄膜5上形成有俯視呈圓形 (剖面爲圓形）之多數貫通孔h，以作爲貫通至下層側之 釉面層2或是發熱電阻體之貫通部。貫通孔h之直徑最佳 爲1〜1 0 // m。貫通孔h是可以藉由例如利用玻璃罩幕之 蝕刻而形成。並且，就以貫通部而言，即使如第1圖B， 形成剖面爲長矩形狀之縫隙S，取代貫通孔h亦可。各縫 隙S具有短邊和長邊。 保護膜6是被形成覆蓋共同電極4 1及個別電極42， 例如由Si02、SiN等所構成。保護膜6之厚度是被設定成 例如3〜10/ζιη。由第2圖及第3圖明顯可知，保護膜6 之一部分是進入貫通孔h，直接與釉面層2或發熱電阻體 3緊密接著。 接著，針對具有上述構成之熱印頭A之作用予以說 明。 於本實施例之熱印頭A中，在共同電極4之延伸部 41B及個別電極42之表面41Ba、42a上，形成有多數凹 部。因此，保護膜6(被形成在電極層4之上層側）之一 部分進入表面41Ba、42a，藉由所謂的定錨效果，可以謀 求提昇保護膜6之密著力。因此，可以抑制保護膜6之剝 離，謀求提昇熱印頭A1之耐久性。並且，於本實施例中 ，表面41 Ba、42a之中心線平均粗度Ra設爲0.1〜0.5 -10- (8) 1270476 # m時，適當發揮上述定錨效果，適合用於抑制保護膜6 ' 之剝離。 ' 再者，在保護膜6上，由於構成電極層4之Au和構 成保護膜6之剝離之熱膨脹率之差，於沿著該些境界面之 方向上產生比較大之應力。但是若依據本實施例，則難以 產生沿著上述境界面之方向的偏移，適合用於抑制保護膜 之剝離。 φ 因在共同電極4 1之共同線部4 1 A之上層側上，形成 有包含Ni、Cr、Ti中之任一者之金屬薄膜5，故可以提 局保護膜6之密著力。具體而言，Ni、Cr、Ti等之金屬 因比起Au，離子化傾向大且不安定，故容易在表面形成 氧化膜，藉由該氧化膜之存在，可確保與玻璃之密著性。 因此，藉由使金屬薄膜5介於電極層4(本實施例中爲共 同線部4 1 A )和保護膜6之間，則可以抑制保護膜6之剝 離，提昇熱印頭之耐久性。再者，上述金屬因與Au之附 φ 著力優良，故也不會產生金屬薄膜從電極層4剝離之不良 狀況。 在共同線部41A及金屬薄膜5上，形成貫通至共同 部41A之下面的多數貫通孔h。在此，被形成在共同線部 41A之上層側之保護膜6,是該一部分進入至貫通孔h， 與被形成在共同線部4 1 A之下層側之釉面層2或發熱電 阻體3直接密著。因釉面層2或是發熱電阻體3對保護膜 6之密著性，比電極層4對保護膜6之密著性良好，故藉 由確保保護膜6和釉面層2或發熱電阻體3之密著區域， -11 - (9) 1270476 則提昇與保護膜6之密著力，其結果可以抑制保護膜6之 剝離。再者，因保護膜6之一部分進入至貫通孔h ’故即 使在保護膜6發生沿著該下層之境界面的應力，也難產生 沿著該境界面之方向的偏移。因此，適合用於抑制保護膜 6之剝離。並且，貫通孔h之直徑被設爲1〜1 〇 # m時， 保護膜6之一部分被適當充塡至貫通孔h內，另外可以迴 避共同線部4 1 A之截面積極端縮小。其結果，抑制共同 線部41A中之電壓下降量的增加，爲最適合。並且，如 上述般，即使於形成有縫隙S (第1圖B)當作貫通部之 時，藉由進入至縫隙S之保護膜6之一部分，與釉面層2 或發熱電阻體3直接密著，則可以抑制保護膜6之剝離。 在此，縫隙S是形成沿著對共同線部4 1A之寬度方向呈 略正交之方向爲佳，縫隙S之寬度（短邊之長度）爲1〜 1 〇 // m爲佳。此時，共同線部4 1 A之截面積不會極端變小 ，抑制共同線4 1 A之電壓下降量的增加。 共同電極41之共同線部41A爲對各發熱電阻部31 一起流動電流’且被形成爲具有大面積。 第4圖是說明根據本實施例之熱印頭之改變例的截面 圖（相當於第3圖）。第4圖所示之熱印頭Ala是在共同 線部4 1 A之下層側形成有絕緣膜8。絕緣膜8是適當選擇 使用對保護膜6之構成材料（例如，；5i〇2、siN等）密著 性優良之材料’例如以Τ^〇5所構成。因絕緣膜8對保護 膜6之密著性’比電極層4對保護膜6之密著性優，故在 熱印頭Ala中，藉由保護膜6之一部分進入至貫通孔h， -12- (10) 1270476 與絕緣膜8直接密著，則可以提昇保護膜6之密著力，抑 制保護膜6之剝離。再者，絕緣膜8對保護膜6之密著性 ，也比釉面層2或發熱電阻體3對保護膜6之密著性優。 依此，熱印頭A 1 a即使在不形成絕緣膜8上之電極層4之 範圍，亦可以比上述熱印頭A1，提昇保護膜6之密著力 。因此，若依據熱印頭A 1 a，則更有效果抑制保護膜6之 剝離。 第5圖及第6圖是表示根據本發明之第2實施例的熱 印頭A2。並且，在第5圖以後之圖面中，對於與第1實 施例相同或類似之要素，賦予與第1實施例相同之符號。 熱印頭A2是具備有基板1、釉面層2、發熱電阻體3 、共同電極410、多數個別電極420及保護膜6。並且， 於第5圖中，省略保護膜6。 於基板1上，依序疊層釉面層2、電極層4、發熱電 阻體3及保護膜6而予以形成。釉面層2是具有外面隆起 成略圓弧狀之隆起部21。電極層4是被疊層於釉面層2 之上層側。電極層4是選擇性被蝕刻一部分，藉由施予後 述之熱處理，形成有共同電極410、個別電極420。 共同電極4 1 0是與第1實施形例相同，具有共同線部 4 1 0A和多數之延伸部41 0B。但是，在共同線部41 0A不 形成貫通孔，針對該點與第1實施例中之共同電極41之 形狀不同。各個別電極420是在釉面層之隆起部21之頂 上面附近，被形成使隆起部21之一部份露出，與各延伸 部41 0B隔著間隔。於共同電極410及個別電極420中， •13· (11) 1270476 下層側之釉面層2之玻璃成分擴散至該些表面附近。第6 * 圖及第7圖至第1〇圖中，擴散至電極表面附近之玻璃成 * 分是模式性以點表示。如此之玻璃成分之擴散是藉由施予 後述之熱處理所達成。 發熱電阻體3是被疊層於電極層4之上層側。發熱電 阻體3是覆蓋釉面層之隆起部21之露出部分，並且形成 跨過延伸部41 0B之一端部和個別電極420之一端部。發 φ 熱電阻體3之中，延伸部41 0B和與此相向之個別電極 420之間的露出部分是當作發熱電阻部3 1發揮功能，構 成能夠形成1個發熱點。因此，於本實施例中，發熱電阻 體3被形成於電極層4之上層側之點，及不形成金屬薄膜 5之點，是與第1實施例的疊層構造有所不同。. 接著，參照第7圖至第9圖說明上述熱印頭A2之製 造方法。 首先’如弟7圖A所不般’在基板1上，使具有外 φ 面隆起成略圓弧狀之隆起部21地形成釉面層2。釉面層2 之形成是藉由印刷、燒結玻璃漿糊而執行。接著，如第7 圖B所示般，在釉面層2上形成電極層4。電極層4之形 成，是藉由印刷；燒結以Αχι爲主要成分之金屬漿糊而執 行。接著，藉由光微影法等選擇性蝕刻電極層4之一部分 ，如第7圖C所示般，玻璃成分形成未擴散之共同電極 410’、個別電極420’。 接著，基板1是經過1小時施予80(TC〜900°C之熱 處理。電極之主成分的Au是具有雜質容易擴散之性質。 -14- (12) 1270476 因此，如第7圖D所示般，釉面層2之玻璃成分擴散至 共同電極410’、個別電極420,之內部，在該些表面附近 • 形成包含有玻璃成分之共同電極411、個別電極420。 接著，如第8圖A所示般，形成發熱電阻體層3，。 發熱電阻體層3 ’之形成是藉由c V D法或濺鑛法形成例如 TaSi〇2之膜而執行。接著，藉由蝕刻除去發熱電阻體層 3 ’之不用部分，如第8B圖所示般，形成發熱電阻體3。 φ 接著’如第9圖所示般，形成保護膜6。保護膜6之 形成，例如’藉由CVD法或是濺鑛法形成例如Si〇2或是 SiN之膜。 若依據本實施例，釉面層2之玻璃成分擴散至共同電 極4 1〇及個別電極420之表面附近。玻璃對保護膜6之密 著性比Au對保護膜6之密著性優，故擴散到共同電極 410及個別電極420之表面附近之玻璃成分當作接著劑發 揮功能，提昇保護膜6之密著力。因此，可以謀求熱印頭 φ A2之耐久性。 第1 〇圖是說明根據第2實施例之熱印頭之改變例的 剖面圖。第10圖所示之熱印頭A2 a是具有藉由濺鍍法在 釉面層2和電極層4之間形成金屬膜9之構成。金屬膜9 之形成是依據在釉面層2上，藉由濺鍍法形成含有例如 Ni、Cr、Ti中之任一者之金屬的膜而執行。在該熱印頭 A2a中，如上述般於電極形成後藉由施予熱處理，而成爲 金屬膜9所含的上述金屬成分擴散至表面附近之共同電極 4 1 1、個別電極42 1。因上述金屬對保護膜6之密著性， •15- (13) 1270476 比Au對保護膜6之密著性優，故擴散至共同電極4 1 1及 * 個別電極421之表面附近之上述金屬成分當作接著劑發揮 ' 功能，提昇保護膜6之密著力。再者，由於保護膜6之種 類不同，也有金屬膜9之金屬成分對保護膜6之密著性， 比釉面層2之玻璃成分對保護膜6之密著性優良之情形， 於此時熱印頭A2a爲最適合。並且，藉由將金屬膜9設爲 特定厚度以下之薄膜，即使於熱印頭A2a中，亦可以期待 φ 釉面層2之玻璃成分擴散至共同電極411、個別電極42 1 之表面附近。 本發明並不定於上述實施例。例如，被形成電極之凹 部並不限定於藉由蝕刻所形成者，即使爲藉由噴沙法或利 用縮小投影露光裝置等之其他手法而形成者亦可。 於上述第1實施例中，藉由光蝕刻之凹部形成即使僅 對電極一部份執行亦可，即使對全體電極執行亦可。同樣 的，金屬薄膜5或是貫通孔h之形成，即使僅對電極之一 φ 部分執行亦可，即使對全體電極執行亦可。 於本發明中，貫通部並不限定於俯視呈圓形之貫通孔 或是俯視呈長矩形狀之縫隙，貫通部之形狀、數量及配置 等亦可適當設定。 保護膜並不限定於上述各實施例中之單層構造者。例 如，保護膜即使爲具備有由耐磨損層等之2層以上所構成 之疊層構造亦可。再者，本發明之熱印頭即使爲薄膜型亦 可，即使爲厚膜型亦可。 -16- (14) 1270476 【圖式簡單說明】 第1圖A是槪略表示根據本發明之第1實施例 印頭的重要部位之平面圖，第1圖B是表示共同電極 變例的部分平面圖。 第2圖A是表示第1實施例之熱印頭之剖面圖， 圖B是模式性表示共同電極及個別電極之表面狀態之 圖。 第3圖是沿著第1圖之III 一 III線之剖面圖。 第4圖是表示第1實施例之熱印頭之改變例的剖 〇 第5圖是槪略性表示根據本發明之第2實施例之 頭之重要部位的平面圖。 ' 第6圖是表示第2實施例之熱印頭之剖面圖。 第7圖A〜D是用以說明製造第2實施例之熱印 方法的剖面圖。 第8圖A〜B是用以說明接續第7圖所示之工程 程之剖面圖。 第9圖是用以說明接續第8圖所示之工程的工程 面圖。 第1 〇圖是表示第2實施例之熱印頭之改變例的 圖。 第1 1圖是表示作爲本發明之關連技術之熱印頭 例的剖面圖。 之熱 之改 第2 剖面 面圖 熱印 頭之 的工 之剖 剖面 之一 -17- (15) (15)1270476 【主要元件符號說明】 1 :基板 2 :釉面層 3 :發熱電阻體 4 :電極 5 :金屬薄膜 6 :保護膜 41 :共同電極 4 2 :個別電極 4 1 A ·共问線部 4 1 B :延伸部 A1 :熱印頭 h :貫通孔 5 :縫隙1270476 (1) Nine, the invention description - [Technical field to which the invention pertains] k The present invention relates to a thermal head used in a thermal printer. Furthermore, this is a method of manufacturing a thermal head. [Prior Art] Conventionally, a device for performing printing on a recording paper of a thermal paper has been proposed, and various thermal heads have been proposed (for example, refer to Patent Document 1 below). The first figure of the present invention is an example of a thermal head showing the related art of the present invention. Specifically, the illustrated thermal head B is an insulating substrate 9 1 . On the substrate, a glazed layer 92 made of glass, a heating resistor, an electrode 94, and a protective film 96 are laminated. The protective film 96 is formed of a material mainly composed of glass. When the printing process is performed in accordance with the thermal head B, the recording paper such as thermal paper is moved in contact with the protective film 96. At this time, the heat generated in the heating resistor 93 is transmitted to the recording paper φ, and the desired printing is performed. In the thermal head having the above configuration, the electrode 94 can be formed of a metal material having excellent conductivity such as A1 Cu or Au. Among them, An chemically stable material has excellent corrosion resistance. Therefore, when the electrode 94 is made of A u , it is possible to avoid the occurrence of power failure due to corrosion of the electrode. The Au (resistance rate) is small compared to A1 and the like. Therefore, when Au is formed into the electrode 94, the amount of voltage drop becomes smaller than when A1 is used, and power consumption can be reduced. The electrode is made of Au, although the above advantages can be obtained', but it is also obvious that there is a defect of 93 points on the 11th and a small on the -4-(2) 1270476 side. That is, Au is inferior in adhesion to the other conductive metal as the glass forming the protective film. Therefore, it is possible that the protective film is peeled off from the electrode 94, which is related to lowering the durability of the thermal head. Further, the stress is generated in the protective film by the difference in thermal expansion coefficient between the electrode and the protective film, but the stress promotes peeling of the protective film. [Patent Document 1] JP-A-2002-673 67 SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances. Here, an object of the present invention is to provide a thermal head which improves the adhesion between an electrode made of Au and a protective film. Further, another object of the present invention is to provide a method of manufacturing such a thermal head. In order to solve the above problems, the present invention is directed to the following technical means. The thermal head provided by the first aspect of the present invention includes a substrate, a glaze layer, and a heating resistor. An electrode mainly composed of Au and a protective film covering the heating resistor and the electrode are energized to the heating resistor. A plurality of recesses are formed on the surface of the above electrode. According to such a configuration, the adhesion between the electrode and the protective film can be improved. Specifically, since a part of the protective film covering the electrode is formed on the surface of the electrode, a large number of recesses are trapped into the recess. As a result, the adhesion can be enhanced by the so-called anchor effect. Further, the difference in thermal expansion coefficient between the electrode and the protective film on the protective film produces a relatively large stress in the direction along the interface of the environment (3) 1270476. According to the present invention, it is difficult to cause a deviation in the direction along the above-described interface, and in this respect, it is also preferable to suppress the peeling of the protective film. Most of the above-mentioned concave portions are formed by setting the center line average roughness Ra of the electrode surface to 0.1 to 0.5 / / m. According to such a configuration, the above-described anchor effect can be appropriately exerted. Most of the above-mentioned recesses are preferably formed by a plurality of through portions penetrating through the thickness of the electrodes. The through portion may have a circular cross section. At this time, the diameter of the through hole is, for example, 1 to 10 μm. Further, in the present invention, even if the circular cross section is replaced, the above-mentioned through portion may be formed in a rectangular cross section. At this time, the rectangle has a short side and a long side, and the length of the short side (the width of the rectangle) is, for example, 1 to 10//Π1. According to this configuration, a part of the protective film that has entered the through portion is directly closely connected to the glazed layer or the heating resistor formed on the lower layer side of the electrode. Since the adhesion of the glaze layer or the heating resistor to the protective film is superior to that of the electrode to the protective film, it can be improved by ensuring the adhesion region between the protective film and the glaze layer or the heating resistor. The adhesion of the protective film suppresses the peeling of the protective film. The thermal head of the present invention is preferably provided with an insulating film formed on the lower layer side of the above electrode. The tightness of the insulating film to the protective film is superior to the adhesion of the electrode to the protective film. Therefore, according to such a configuration, a part of the protective film that has entered the penetration portion is directly adhered to the insulating film, thereby enhancing the adhesion of the protective film, and is suitable for suppressing peeling of the protective film. The thermal head provided by the second aspect of the present invention includes a substrate, a glazed layer (g) aze layer, a heating resistor, and a heating element for energizing the heating resistor -6 - (4) 1270476. An electrode as a main component, and a protective film covering the heating resistor and the electrode. A metal thin film containing at least one of Ni, Cr, and Ti is formed on the electrode. According to the first aspect of the present invention, the adhesion between the electrode and the protective film can be improved. That is, the adhesion between the metal such as Ni, Cr, Ti, and the protective film is superior to that of the Au and the protective film. Therefore, peeling of the protective film can be suppressed. Further, since the adhesion between the metal and An is excellent, the problem that the metal thin film is peeled off from the electrode does not occur. According to the third aspect of the present invention, there is provided a method of manufacturing a thermal head. This manufacturing method is a process of forming a glazed layer on a substrate, a process of forming an electrode containing Au as a main component on the glazed layer, a process of forming a heating resistor, and a process of forming the heating resistor and the electrode. . Further, according to the manufacturing method, after the process of forming the electrode, a process of heat-treating the substrate is provided. According to such a manufacturing method, the glass component of the glaze layer formed under the electrode layer is diffused to the vicinity of the surface of the electrode. Since the adhesion of the glass to the protective film is better than the adhesion of the Au to the protective film, the glass component of the glazed layer which spreads to the vicinity of the surface of the electrode functions as an adhesive to enhance the adhesion of the protective film. . As a result, the durability of the thermal head can be achieved. Further, in the production method of the present invention, it is preferable to form a metal film containing at least one of Ni, Cr and Ti between the glaze layer and the electrode. According to this, the metal component of the metal film diffuses to the vicinity of the surface of the electrode. Since the adhesion of the metal to the protective film is superior to that of Au (5) 1270476 film, the metal component diffused to the vicinity of the electrode surface functions as an adhesive, and the protective film is lifted. Confidence. Other features and advantages of the present invention will be apparent from the description and appended claims. [Embodiment] Hereinafter, a preferred embodiment of the present invention will be specifically described with reference to the drawings. Figs. 1 to 3 are views showing a thermal head A1 according to a first embodiment of the present invention. The thermal head A1 includes a substrate 1, a glaze layer 2, a heating resistor 3, a common electrode 41, a plurality of individual electrodes 42, a metal thin film 5, and a protective film 6 (see Fig. 2A). The substrate 1 has a rectangular plate shape in plan view, and is made of an insulator such as alumina ceramic. The glazed layer 2, the heating resistor 3, and the electrode layer 4 are laminated on the substrate 1 (each electrode 41, 42) ), metal film φ 5 and protective film 6. The glaze layer 2 functions as a heat storage layer. Also, the glaze layer 2 is provided with a smooth surface suitable for forming the common electrode 3 or the individual electrodes 4. According to this configuration, after the glass paste is printed and applied, it is formed by sintering the same paste. The glaze layer 2 includes a ridge portion 21 having an arcuate outer surface. The heating resistor 3 is formed of a film of, for example, Ta Si 02 by a CVD method or a sputtering method to form a ridge portion 21 covering at least the glaze layer 2. The thickness of the heating resistor 3 is, for example, 0.2 to 2.0/m. The electrode layer 4 is laminated on the upper layer side of the heating resistor 3, and a film of a metal material containing, for example, Αι is mainly formed by sputtering. The thickness of the electrode layer 4 (6) 1270476 is, for example, 0.3 to 2.0//m. The electrode layer 4 is selectively etched by, for example, photolithography, thereby forming the common electrode 41 and the individual electrode 42. The common electrode 4 1 is composed of a common line portion 4 1 A and a plurality of extension portions 4 1 B. As shown in FIG. 1A, the common line portion 41A is a portion (main portion) including a longitudinal direction along the substrate 1, and a portion (sub-portion) extending from the both end portions to the short side direction of the substrate 1. . Each of the extending portions 4 1 B protrudes from the main portion of the common line portion 41A toward the short side direction of the substrate 1. The common line portion 4 1 A is a portion for flowing a current together with the heat generating resistor portion 31 to be described later from the terminal portion outside the drawing, and has a large area. As shown in FIG. 2A, the respective electrodes 42 are exposed in the vicinity of the top surface of the ridge portion 21 of the glazed layer 2, and one end of the heating resistor 3 is exposed, and the one end is spaced apart from each of the extending portions 41B. Was formed. The other end of each of the electrodes 42 is electrically connected to the drive IC 7. The drive 1C 7 is for controlling the energizer based on the image data for printing which is sent from the outside, and is mounted on the substrate 1. When the individual electrodes 42 are selectively energized by the driving IC 7, the exposed portion between the individual electrodes 42 and the extending portion 41 opposed to the heating resistor 3 functions as the heating resistor portion 31 to form a The way of heating points is constructed. As shown in FIG. 2B, a plurality of concave portions are formed on the surfaces 41Ba and 42a of the common electrode extension portion 41B and the individual electrode 42, and the plurality of concave portions are formed by roughening the surfaces 41Ba and 42a. And formed. The center line average roughness Ra of the surfaces 41Ba and 42a is 〇·1 to 0.5 #ηι. Such unevenness can be formed by a surface treatment method such as dry etching. -9- (7) 1270476 The metal thin film 5 is laminated on the layer side of the common line portion 4 1 A, and a metal film containing at least one of Ni, Cr, and Ti is formed by plating treatment or sputtering. The thickness of the metal thin film 5 is set to, for example, 〇·2 to 2·0 A m. A plurality of through holes h having a circular shape (a circular cross section) are formed in the common line portion 4 1 Α and the metal thin film 5 as a through portion penetrating the glazed layer 2 on the lower layer side or the heating resistor. The diameter of the through hole h is preferably 1 to 1 0 // m. The through hole h can be formed by etching using, for example, a glass mask. Further, in the penetrating portion, even if the slit S having a long rectangular cross section is formed as in the first drawing B, the through hole h may be replaced. Each slit S has a short side and a long side. The protective film 6 is formed to cover the common electrode 41 and the individual electrode 42, and is made of, for example, SiO 2 , SiN or the like. The thickness of the protective film 6 is set to, for example, 3 to 10/ζι. As is apparent from Figs. 2 and 3, a part of the protective film 6 enters the through hole h and is directly adhered to the glaze layer 2 or the heating resistor 3. Next, the action of the thermal head A having the above configuration will be explained. In the thermal head A of the present embodiment, a plurality of concave portions are formed on the extending portions 41B of the common electrode 4 and the surfaces 41Ba, 42a of the individual electrodes 42. Therefore, a part of the protective film 6 (formed on the upper layer side of the electrode layer 4) enters the surfaces 41Ba, 42a, and the adhesion of the protective film 6 can be improved by the so-called anchoring effect. Therefore, peeling of the protective film 6 can be suppressed, and the durability of the thermal head A1 can be improved. Further, in the present embodiment, when the center line average roughness Ra of the surfaces 41 Ba and 42a is 0.1 to 0.5 -10- (8) 1270476 # m, the above anchoring effect is appropriately exerted, and it is suitable for suppressing the protective film 6 'The stripping.' Further, on the protective film 6, due to the difference in thermal expansion ratio between Au constituting the electrode layer 4 and peeling of the protective film 6, a relatively large stress is generated in the direction along the interface. However, according to the present embodiment, it is difficult to generate a shift in the direction along the above-described interface, and it is suitable for suppressing peeling of the protective film. φ Since the metal thin film 5 including any of Ni, Cr, and Ti is formed on the layer side of the common line portion 4 1 A of the common electrode 4 1 , the adhesion of the protective film 6 can be improved. Specifically, since the metal such as Ni, Cr, or Ti has a large ionization tendency and is unstable compared to Au, it is easy to form an oxide film on the surface, and the adhesion to the glass can be ensured by the presence of the oxide film. Therefore, by interposing the metal thin film 5 between the electrode layer 4 (the common line portion 4 1 A in the present embodiment) and the protective film 6, the peeling of the protective film 6 can be suppressed, and the durability of the thermal head can be improved. Further, since the above-mentioned metal is excellent in adhesion to Au, φ does not cause a problem that the metal thin film is peeled off from the electrode layer 4. In the common line portion 41A and the metal thin film 5, a plurality of through holes h penetrating to the lower surface of the common portion 41A are formed. Here, the protective film 6 formed on the upper layer side of the common line portion 41A enters the through hole h and the glazed layer 2 or the heating resistor 3 formed on the layer side below the common line portion 4 1 A. Directly close. Since the adhesion of the glaze layer 2 or the heating resistor 3 to the protective film 6 is better than that of the electrode layer 4 to the protective film 6, the protective film 6 and the glaze layer 2 or the heating resistor are ensured. In the adhesion region of 3, -11 - (9) 1270476 enhances the adhesion with the protective film 6, and as a result, peeling of the protective film 6 can be suppressed. Further, since one portion of the protective film 6 enters the through hole h', even if the protective film 6 is subjected to stress along the interface of the lower layer, it is difficult to cause a shift along the direction of the interface. Therefore, it is suitable for suppressing peeling of the protective film 6. Further, when the diameter of the through hole h is 1 to 1 〇 #m, one portion of the protective film 6 is appropriately filled into the through hole h, and the cross-sectional positive end of the common line portion 4 1 A can be prevented from being reduced. As a result, it is most suitable to suppress an increase in the amount of voltage drop in the common line portion 41A. Further, as described above, even when the slit S (Fig. 1B) is formed as the penetration portion, the portion of the protective film 6 that has entered the slit S is directly bonded to the glaze layer 2 or the heating resistor 3 Then, peeling of the protective film 6 can be suppressed. Here, the slit S is preferably formed in a direction orthogonal to the width direction of the common line portion 41A, and the width of the slit S (the length of the short side) is preferably 1 to 1 〇 // m. At this time, the cross-sectional area of the common line portion 4 1 A does not become extremely small, and the increase in the amount of voltage drop of the common line 4 1 A is suppressed. The common line portion 41A of the common electrode 41 flows current 'to each of the heat generating resistor portions 31' and is formed to have a large area. Fig. 4 is a cross-sectional view (corresponding to Fig. 3) for explaining a modified example of the thermal head according to the embodiment. The thermal head Ala shown in Fig. 4 is formed with an insulating film 8 on the layer side below the common line portion 4 1 A. The insulating film 8 is appropriately selected and used, for example, a material having excellent adhesion to a constituent material (e.g., 5i2, siN, etc.) of the protective film 6, for example, Τ^〇5. Since the adhesion of the insulating film 8 to the protective film 6 is superior to that of the protective layer 6 by the electrode layer 4, in the thermal head Ala, a portion of the protective film 6 enters the through hole h, -12 - (10) When 1270476 is directly adhered to the insulating film 8, the adhesion of the protective film 6 can be increased, and the peeling of the protective film 6 can be suppressed. Further, the adhesion of the insulating film 8 to the protective film 6 is also superior to that of the glaze layer 2 or the heating resistor 3 to the protective film 6. Accordingly, the thermal head A 1 a can raise the adhesion of the protective film 6 than the thermal head A1 even in the range where the electrode layer 4 on the insulating film 8 is not formed. Therefore, if the thermal head A 1 a is used, it is more effective to suppress the peeling of the protective film 6. Fig. 5 and Fig. 6 show a thermal head A2 according to a second embodiment of the present invention. In the drawings, the same or similar elements as those of the first embodiment are denoted by the same reference numerals as in the first embodiment. The thermal head A2 includes a substrate 1, a glaze layer 2, a heating resistor 3, a common electrode 410, a plurality of individual electrodes 420, and a protective film 6. Further, in the fifth drawing, the protective film 6 is omitted. On the substrate 1, the glaze layer 2, the electrode layer 4, the heat generating resistor 3, and the protective film 6 are laminated in this order. The glaze layer 2 is a ridge portion 21 having an outer ridge which is slightly arcuate. The electrode layer 4 is laminated on the upper layer side of the glaze layer 2. The electrode layer 4 is selectively etched and a common electrode 410 and an individual electrode 420 are formed by applying a heat treatment to be described later. The common electrode 401 is the same as the first embodiment, and has a common line portion 4 1 0A and a plurality of extension portions 41 0B. However, the through hole is not formed in the common line portion 41 0A, and the point is different from the shape of the common electrode 41 in the first embodiment. Each of the individual electrodes 420 is formed in the vicinity of the top surface of the raised portion 21 of the glazed layer, and a portion of the raised portion 21 is formed to be spaced apart from each of the extending portions 41 0B. In the common electrode 410 and the individual electrode 420, the glass component of the glaze layer 2 on the lower layer side of the 13·(11) 1270476 is diffused to the vicinity of the surfaces. In Fig. 6* and Fig. 7 to Fig. 1, the glass diffusion into the vicinity of the electrode surface is schematically indicated by dots. The diffusion of such a glass component is achieved by applying a heat treatment described later. The heating resistor 3 is laminated on the upper layer side of the electrode layer 4. The heat-generating resistor body 3 is an exposed portion covering the ridge portion 21 of the glaze layer, and is formed to extend across one end portion of the extension portion 406B and one end portion of the individual electrode 420. Among the φ thermistors 3, the exposed portion between the extending portion 41 0B and the individual electrode 420 opposed thereto functions as the heat generating resistor portion 31, and is configured to form one heat generating point. Therefore, in the present embodiment, the heating resistor 3 is formed on the upper layer side of the electrode layer 4, and the metal thin film 5 is not formed, which is different from the laminated structure of the first embodiment. Next, a method of manufacturing the above-described thermal head A2 will be described with reference to Figs. 7 to 9. First, the glaze layer 2 is formed on the substrate 1 by the ridges 21 having the outer φ faces raised in a slightly arc shape on the substrate 1. The formation of the glaze layer 2 is performed by printing and sintering a glass paste. Next, as shown in Fig. 7B, the electrode layer 4 is formed on the glaze layer 2. The formation of the electrode layer 4 is performed by printing; sintering a metal paste containing Αχ as a main component. Then, a portion of the electrode layer 4 is selectively etched by photolithography or the like. As shown in Fig. 7C, the glass component forms an undiffused common electrode 410' and an individual electrode 420'. Next, the substrate 1 is subjected to a heat treatment of 80 (TC to 900 ° C) for 1 hour. Au, which is a main component of the electrode, has a property of easily diffusing impurities. -14- (12) 1270476 Therefore, as shown in Fig. 7D In general, the glass component of the glaze layer 2 is diffused to the inside of the common electrode 410' and the individual electrode 420, and in the vicinity of the surfaces, a common electrode 411 including a glass component and an individual electrode 420 are formed. Next, as shown in Fig. 8 As shown, the heating resistor layer 3 is formed. The formation of the heating resistor layer 3' is performed by forming a film of, for example, TaSi 2 by a c VD method or a sputtering method. Then, the heating resistor layer 3' is removed by etching. In the unnecessary portion, as shown in Fig. 8B, the heating resistor 3 is formed. φ Next, as shown in Fig. 9, a protective film 6 is formed. The formation of the protective film 6, for example, by CVD or sputtering A film such as Si〇2 or SiN is formed. According to the present embodiment, the glass component of the glaze layer 2 is diffused to the vicinity of the surface of the common electrode 4 1〇 and the individual electrode 420. The adhesion of the glass to the protective film 6 is higher than that of Au. The adhesion to the protective film 6 is excellent, so that it spreads to the common electrode 410 The glass component in the vicinity of the surface of the individual electrode 420 functions as an adhesive to increase the adhesion of the protective film 6. Therefore, the durability of the thermal head φ A2 can be achieved. Fig. 1 is a view showing the heat according to the second embodiment. A cross-sectional view of a modified example of the printing head. The thermal head A2a shown in Fig. 10 has a configuration in which a metal film 9 is formed between the glaze layer 2 and the electrode layer 4 by sputtering. This is performed by forming a film containing a metal such as Ni, Cr, or Ti on the glaze layer 2 by sputtering. In the thermal head A2a, the electrode is formed after the electrode formation as described above. By the heat treatment, the metal component contained in the metal film 9 is diffused to the common electrode 4 1 1 and the individual electrode 42 1 in the vicinity of the surface. Due to the adhesion of the metal to the protective film 6, • 15-(13) 1270476 is superior to Au in the adhesion of the protective film 6, so that the above-mentioned metal component which is diffused to the vicinity of the surface of the common electrode 4 1 1 and the individual electrode 421 functions as an adhesive to enhance the adhesion of the protective film 6. Since the type of the protective film 6 is different, there is also a metal of the metal film 9. The adhesion of the component to the protective film 6 is superior to the adhesion of the glass component of the glaze layer 2 to the protective film 6, and the thermal head A2a is most suitable at this time. In the film of a specific thickness or less, even in the thermal head A2a, the glass component of the φ glaze layer 2 can be expected to diffuse near the surface of the common electrode 411 and the individual electrode 42 1 . The present invention is not limited to the above embodiment. The recessed portion of the formed electrode is not limited to being formed by etching, and may be formed by a sandblasting method or another method using a reduced projection exposure device or the like. In the first embodiment described above, the recessed portion formed by photolithography may be formed only for a part of the electrode, even if it is performed on the entire electrode. Similarly, the formation of the metal thin film 5 or the through hole h may be performed only on one of the electrodes φ, even if it is performed on the entire electrode. In the present invention, the penetration portion is not limited to a through hole having a circular shape in plan view or a slit having a long rectangular shape in plan view, and the shape, number, arrangement, and the like of the penetration portion may be appropriately set. The protective film is not limited to the single layer structure in the above embodiments. For example, the protective film may have a laminated structure including two or more layers of a wear-resistant layer or the like. Further, the thermal head of the present invention may be of a film type, and may be of a thick film type. -16- (14) 1270476 BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1A is a plan view schematically showing an important part of a printing head according to a first embodiment of the present invention, and Fig. 1B is a partial plan view showing a common electrode modification. . Fig. 2A is a cross-sectional view showing the thermal head of the first embodiment, and Fig. B is a view schematically showing the state of the surface of the common electrode and the individual electrodes. Fig. 3 is a cross-sectional view taken along line III-III of Fig. 1. Fig. 4 is a cross-sectional view showing a modification of the thermal head of the first embodiment. Fig. 5 is a plan view schematically showing an important part of the head according to the second embodiment of the present invention. Fig. 6 is a cross-sectional view showing the thermal head of the second embodiment. Figs. 7A to 7D are cross-sectional views for explaining the method of manufacturing the thermal printing of the second embodiment. Figs. 8A to 8B are cross-sectional views for explaining the construction process shown in Fig. 7. Fig. 9 is a plan view showing the construction of the work shown in Fig. 8. Fig. 1 is a view showing a modified example of the thermal head of the second embodiment. Fig. 1 is a cross-sectional view showing an example of a thermal head which is a related art of the present invention. One of the cross-sections of the hot stamping head of the second section -17- (15) (15) 1270476 [Description of main components] 1 : Substrate 2: glazed layer 3: heating resistor 4 : Electrode 5 : Metal film 6 : Protective film 41 : Common electrode 4 2 : Individual electrode 4 1 A · Common line portion 4 1 B : Extension portion A1 : Thermal head h : Through hole 5 : Gap
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