201040995 六、發明說明 【發明所屬之技術領域】 本發明係有關於，對鋁板進行電解蝕刻的電解電容器 用鋁電極板之製造方法。 【先前技術】 近年來，隨著個人電腦或資訊機器等電子機器的數位 〇 化、高頻化之演進，對於固體鋁電解電容器，除了要求低 背化、低阻抗化、低ESR，還要求高電容量化。 在製造固體鋁電解電容器時，先前係如圖7(a)所示， 在鋁箔l〇x的全面，進行電解蝕刻後，進行陽極氧化，然 後，如圖7(b)、（c)所示，將鋁箔10x藉由沖壓等進行沖 孔而獲得陽極15x。在陽極15x係在要形成陰極（未圖示） 的部分151x與端子19之連接部分15 2x之間，設有遮蔽 材18。在所述的陽極15x中，要形成陰極（未圖示）的部分 Ο 151X、及端子19之連接部分152X，兩者均爲呈海綿狀的 蝕刻部位1 3。 另一方面，爲了確保鋁箔的強度之目的，在蝕刻之 際，在鋁箔的表面，先設置具備用來規定蝕刻領域之開孔 部的遮蔽材之技術，已被揭露（專利文獻1)。 使用專利文獻1所記載之方法來製造固體鋁電解電容 器時，如圖8(a)所示，在蝕刻前的鋁箔15y之表面，在端 子19之連接部分15 2y等設有遮罩30y之狀態下，進行電 解蝕刻。接下來，在對鋁箔10y進行陽極氧化後，去除遮 -5- 201040995 罩30y，然後，如圖8(b)、（c)所示，將鋁箔10y藉由沖壓 等進行沖孔而獲得陽極15y。於所述之陽極15y中，要形 成陰極之部分151y係爲海綿狀的蝕刻部位13，但是端子 19之連接部分152y係爲未蝕刻部位12。 [先前技術文獻] [專利文獻] [專利文獻1]日本特開昭60-31217號公報 【發明內容】 [發明所欲解決之課題] 然而，圖7及圖8所示的方法中，係有以下之問題 點。首先，在圖7所示的形態中，由於端子19之連接部 分15 2x也是海綿狀的蝕刻部位13，因此會有容易發生端 子19之連接不良的問題點。又，由於就連端子19之連接 部分1 5 2x等這類沒有必要蝕刻的領域都被電解蝕刻，因 此會有發生浪費之用電量的問題點。再者，就連沒有必要 鈾刻的領域都被電解蝕刻所帶來的後果是，導致蝕刻液中 的鋁濃度在短時間內就上升等蝕刻液容易劣化之問題點。 相對於此，在圖8所示的形態中，電解蝕刻之際，電 流集中到遮罩30y附近的結果，會沿著遮罩30y而發生過 蝕刻部位1 3 s，導致靜電容量降低之問題點。 有鑑於以上問題點，本發明的課題在於提供一種，不 會發生因電流集中所導致的過蝕刻部位，可對必要之領域 選擇性地進行蝕刻的電解電容器用鋁電極板之製造方法。 -6- 201040995 [用以解決課題之手段] 爲了解決上記課題，在本發明中，係在蝕刻液中被對 向配置之第1電極與第2電極之間使前記第1電極及前記 第2電極呈對向之方式而配置了鋁板之狀態下，對前記鋁 板進行電解鈾刻的電解電容器用鋁電極板之製造方法中， 其特徵爲，在進行前記電解蝕刻時，在前記鋁板之兩面， Q 設置第1遮罩，其係具備用來規定對該當鋁板之鈾刻領域 的複數第1開孔部，並且在前記第1電極及前記第2電極 中對向於前記鋁板的面，設置前記第1開孔部所投影之領 域是成爲第2開孔部的第2遮罩；將前記第2開孔部之面 積，設成前記第1開孔部之面積的0.7倍至1 .1 5倍。 在本發明中，係在進行電解蝕刻之際，於鋁板上，沒 有必要蝕刻的領域係以第1遮罩加以覆蓋，因此於鋁板 上，在被第1遮罩變成未蝕刻部位的領域中，可連接端 〇 子。因此，由於電解電容器用鋁電極板與端子可確實地連 接，所以端子連接部分的信賴性高。又，因爲對於沒有必 要蝕刻的領域係不進行電解蝕刻，因此不會發生浪費的用 電量。甚至，由於不會對蝕刻液中發生浪費的鋁溶解，因 此可抑制蝕刻液的劣化。又，在第1電極及第2電極係設 有第2遮罩，所述之第2遮罩，係在第1開孔部所投影之 領域中，具備第2開孔部。因此，第2開孔部係與第1開 孔部爲相同形狀。而且，第2開孔部之面積係被限定成， 第1開孔部之面積的0.7倍至1.15倍。因此，由於在在 201040995 鋁板中被第1開孔部所露出的領域，和在第1電極及第2 電極中被第2開孔部所露出之領域之間’係形成適當的電 位分布，所以在鋁板上較難發生過蝕刻部位或蝕刻不足部 位。亦即，當第2開孔部之面積是不到第1開孔部之面積 的0.7倍時，在鋁板中被第1開孔部所露出的領域的端部 係會發生蝕刻不足部位，導致電解電容器用鋁電極板的靜 電容量降低。相對於此，當第2開孔部之面積是超過第1 開孔部之面積的1.1 5倍時，在鋁板中被第1開孔部所露 出的領域的端部係會發生過蝕刻部位，導致電解電容器用 鋁電極板的靜電容量降低。然而在本發明中，由於第2開 孔部與第1開孔部的面積比是被適當設計，因此不會發生 鈾刻不足部位或過蝕刻部位。因此，可製造靜電容量高的 電解電容器用鋁電極板。 於本發明中，於前記第1遮罩中被前記第1開孔部所 夾住的部分，係含有寬度寸法爲1mm以上的帶狀部分， 較爲理想。若依據所述構成，則可將寬度寸法爲1mm以 上的未蝕刻部位，形成在鋁板，可在所述的未蝕刻部位， 連接端子。 於本發明中，前記第1遮罩的厚度是0.1mm以下， 較爲理想。若依據所述構成，則在蝕刻之際，氣泡就不會 被起因於第1遮罩之落差所牽引而覆蓋鋁板表面。因此， 於鋁板中’可防止對於第1開孔部所露出之領域的電流密 度隨著銘板表面之氣泡而變動。 於本發明中可採用以下構成：前記第1遮罩，係由被 -8- 201040995 固著在前記鋁板之兩面的樹脂製遮蔽材所成。 於本發明中，前記第1開孔部係爲將四角形之角部切 削成圓弧狀之形狀’或者是圓形，較爲理想。當第1開孔 部是四角形時，在蝕刻之際，在四角形的角落部分，會有 電流集中而較容易進行蝕刻之傾向，但若第1開孔部是將 四角形之角部切削成圓弧狀之形狀或是圓形時，則可防止 此種電流集中。於本發明中，四角形係可爲正方形或長方 0 形之任一種形狀。又’圓形係可爲正圓、扁圓、橢圓之任 —種形狀。 於本發明中，前記電解蝕刻係爲交流蝕刻，進行前記 電解蝕刻，以使得前記鋁板上的蝕刻部位之厚度是每單面 相當於75 μιη以上，較爲理想。若依據本發明，則因爲不 發生電流集中，所以不會發生過飩刻部位，可達成每單面 相當於75μιη以上之深度位置的蝕刻。因此，可獲得靜電 容量高的電解電容器用鋁電極板》 〇 適用了本發明的電解電容器用鋁電極板，是被當作電 解質採用機能性高分子的鋁電解電容器的陽極來使用。亦 即，適用了本發明的電解電容器用鋁電極板，係在表面形 成介電體膜，在該當介電體膜上形成機能性高分子層，而 被用於電解電容器。 [發明效果] 在本發明中，係在進行電解鈾刻之際，於鋁板上，沒 有必要蝕刻的領域係以第1遮罩加以覆蓋，因此於鋁板 -9- 201040995 上，在被第1遮罩變成未蝕: 子。因此，電解電容器用鋁電 賴性較高。又，因爲對於沒有 解蝕刻，因此不會發生浪費的 鈾刻液中發生浪費的鋁溶解， 又，由於第2開孔部之面積係 的〇 . 7倍至1 . 1 5倍，因此在 或蝕刻不足部位。因此，可製 用鋁電極板。 紐部位的領域中，可連接端 極板與端子的連接部分的信 必要蝕刻的領域係不進行電 用電量。甚至，由於不會對 因此可抑制蝕刻液的劣化。 被限定成第1開孔部之面積 鋁板上較難發生過蝕刻部位 造靜電容量高的電解電容器 【實施方式】 以下，作爲本發明的實施 電解電容器用鋁電極板（蝕刻 置。 形態，說明適用了本發明之 板）的製造方法、及製造裝 〔蝕刻裝置的說明〕 圖1係適用了本發明之電 裝置（蝕刻裝置）中的鋁板及 1(a)、（b)係相當於從2個電極 及從另一方側觀看的斜視圖。 電容器用鋁電極板之製造方法 的說明圖。 如圖1所示，適用了本發 的製造裝置（以下稱作蝕刻裝唇 解電容器用鋁電極板的製造 電極之構成的說明圖，圖 當中之一方側觀看的斜視圖 圖2係適用了本發明之電解 中，形成在鋁板的第1遮罩 明之電解電容器用鋁電極板 | 100)，係具有：儲留著鹽 -10- 201040995 酸系之蝕刻液90的蝕刻槽（未圖示）、在蝕刻液90中對向 配置的複數電極20、和電源裝置80。電極20，係由碳、 鉑等在蝕刻液中不會發生電解溶解的導電體所成，在蝕刻 液90中彼此對向配置。以下的說明中，將對向的2個電 極20當中之一方稱作第1電極2 0a，另一方稱作第2電 極20b來說明。 在第1電極2 0a與第2電極2 0b之間，係配置有用來 0 製造電解電容器用鋁電極板所需的鋁板ίο，鋁板ίο與第 1電極20a之間隔、及鋁板10與第2電極20b之間隔， 係爲25mm以下，理想係爲20mm以下。在以下的說明 中，於鋁板10中將與第1電極20a對向的面稱作第1面 l〇a，將與第2電極20b對向的面稱作第2面10b來說 明。 鋁板10，係爲可形成複數後述之固體鋁電解電容器 用陽極的尺寸，圖2中被虛線L1包圍的領域是藉由沖壓 〇 等進行沖孔而當作固體鋁電解電容器用的陽極15使用。 (遮罩的說明） 如圖1及圖2所示，在本形態中，係在進行電解蝕刻 時，在於鋁板10中與第1電極20a對向的第！面10a， 係設有第1遮罩3 0a，其係具備複數用來規定對鋁板10 之鈾刻領域用的四角形之第1開孔部3 1 a。又，在於鋁板 10中與第2電極2 0b對向的第2面l〇b上也是和第1面 10a同樣地，設有第1遮罩3 0b，其係具備複數用來規定 -11 - 201040995 對鋁板10之蝕刻領域用的四角形之第1開孔部31b。第1 遮罩3 0a與第1遮罩30b係被形成爲平面來看係爲重疊， 第1開孔部3 1 a與第1開孔部3 1 b係具有相同形狀及相同 寸法。 又，在本形態中，係如圖1所示，於第1電極20a 中，鋁板10的第1面l〇a所對向的電極面21a，係設有 第2遮罩40a，於第2遮罩40a中，與第1遮罩30a之第 1開孔部3 1 a對向的領域，係形成有四角形的第2開孔部 41a。又，於第2電極2 0b中，在與鋁板10的第2面10b 對向的電極面21b上也是和電極面21a同樣地，設置有第 2遮罩40b，於第2遮罩40b中，與第1遮罩30b之第1 開孔部3 1 b對向的領域，係形成有四角形的第2開孔部 41b ° 第2開孔部41a，係被形成在將第1開孔部31a帶著 所定倍率而朝電極面2 1 a垂直投影而成之領域，第2開孔 部4 1 a與第1開孔部3 1 a係具有相似形狀而彼此對向。 又，第2開孔部41 b也是和第2開孔部41 a同樣地，被形 成在將第1開孔部31b朝電極面21b垂直投影而成之領 域，第2開孔部4 1 b與第1開孔部3 1 b係具有相似形狀而 彼此對向。 此處，第2開孔部41 a與第2開孔部41 b係爲等面 積。又，第2開孔部41a、41b之面積，係爲第1開孔部 31a、31b之面積的0.7倍至1.15倍。因此，第2開孔部 41a、41b係被形成在’將第1開孔部31a、31b朝著電極 -12- 201040995 面21b帶有0.7倍至1.15倍之縮放比例而垂直投 之領域。 於第1遮罩30a、30b中，被第1開孔部31a、 夾住的部分，係含有寬度寸法爲1mm以上的帶 32a、32b。在本形態中，第1遮罩30a、30b係由 在鋁板10之兩面的樹脂製遮蔽材所成，厚度係爲 以下。所述之第1遮罩30a、30b，係可採用，將 ^ 脂、聚醋樹脂、砂樹脂等之樹脂材料，以塗佈法或 刷等進行塗佈後，.令其固化之構成。 至於第2遮罩40a、40b係可採用，例如，使 1電極20a及第2電極20b之電極面21a、21b予 的樹脂板，在所述之樹脂板上設置用來作爲第2 41a、41b的孔之構成。 此外，關於第2遮罩40a、40b也是和第 30a、3 0b同樣地，可使用被固著在第1電極20a Q 電極20b的環氧樹脂、聚酯樹脂、矽樹脂等這類樹 蔽材。又，關於第1遮罩30a、30b也是和第 40a、40b同樣地，可採用使用將第1面l〇a及第2 覆蓋的樹脂板，在所述的樹脂板上設置用來作爲第 部3 1 a、3 1 b的孔之構成。 (電解電容器用鋁電極板的說明） 圖3係使用適用了本發明之電解電容器用鋁電 固體鋁電解電容器用的陽極的模式性圖示之說明圖 影所成 3 1b所 狀部分 被固著 0.1mm 環氧樹 網版印 用將第 以覆蓋 開孔部 1遮罩 及第2 脂製遮 2遮罩 面1 Ob 1開孔 極板的 。使用 -13- 201040995 參照圖1所說明過的蝕刻裝置100來製造電解電容器用銘 電極板時，首先，藉由電源裝置80在第1電極20a與第 2電極20b之間，施加交流電流。其結果係如圖2所示， 在鋁板10的第1面l〇a及第2面10b中，從第1遮罩 3 0a、30b的第1開孔部31a、31b所露出的部分，係被交 流蝕刻、廣面化而成爲蝕刻部位1 3。又，被第1遮罩 30a、30b所覆蓋的部分係成爲未蝕刻部位12。如此— 來，獲得電解電容器用鋁電極（鈾刻板14)。 接下來，對蝕刻板14進行陽極氧化後，去除第1遮 罩3 0a、3 0b。接下來，以進行過陽極氧化的蝕刻板14來 進行沖壓等之方法，將虛線L1所示的領域予以切下，獲 得圖3所示的固體鋁電解電容器用之陽極15。 圖3所示的陽極15中，在要形成陰極（未圖示）的部 分151與端子19之連接部分152之間形成遮蔽材18，在 位於遮蔽材1 8之一方側的端部（連接部分1 5 2)，藉由點狀 熔接等方法，而連接上端子19。此處，端子19之連接部 分152，係爲被第1遮罩30a、30b的帶狀部分32a、32b 所覆蓋的領域，係爲未蝕刻部位1 2。 接下來，在固體鋁電解電容器用的陽極15上，進行 過陽極氧化的蝕刻板14之表面當中，對蝕刻部位13，依 照公知方法而含浸了聚吡咯以形成機能性高分子層後，在 機能性高分子層的表面，使用碳糊等或銀糊等來形成陰 極。在含浸聚吡咯時是例如，對蝕刻部位1 3滴下了吡咯 單體的乙醇溶液後，滴下過硫酸銨及2-萘酸鈉水溶液， -14- 201040995 以使吡咯單體發生化學聚合，形成由聚啦略所成之預鍍 層。接著，將鈾刻板14浸漬在含有吡咯單體及2 -萘酸鈉 的乙腈電解液中，使之前形成的化學聚合聚吡咯層的一部 分接觸至不鏽鋼線而成爲陽極，另一方面，將不鏽鋼板當 作陰極而進行電解聚合，形成要當作機能性高分子層的電 解聚合聚吡咯。此外，亦可取代聚吡咯，改用聚噻吩。然 後，將陰極形成爲覆蓋機能性高分子層，則完成了固體鋁 0 電解電容器。 (蝕刻板14的詳細構成） 於本實施形態中，蝕刻板14若厚達150 μιη以上，則 蝕刻部位13的厚度會被蝕刻到兩面合計1 50μχη以上深度 的位置。更具體而言，蝕刻部位1 3係被蝕刻到單面深度 75μιη以上、或者ΙΟΟμηχ以上、甚至120μιη以上之位置。 即使如此，在蝕刻板14的厚度方向的中央，係殘留有蕊 ❹ 部16。 又，在本實施形態中，鋁板10的鋁純度係爲99.98 質量％以上。因此，鈾刻板14係韌性較高，在製造固體 鋁電解電容器之際的操作上較爲容易。此處，若鋁板10 的鋁純度未達下限値，則硬度增加韌性降低，操作中會有 裂開等損傷之疑慮，並不理想。又，雖然鋁板10的厚度 是隨著目的而可設定爲各種厚度，但是使用例如150μπι 至1mm，一般係採用300〜400μιη者。 在本實施形態中，作爲對鋁板1 〇的蝕刻工程，係爲 -15- 201040995 至少進行使鋁板10產生蝕刻凹坑的蝕刻工程（以下稱作第 1飩刻工程）、使飩刻凹坑進行成長的蝕刻工程（以下稱作 第2蝕刻工程）之情形，也有在第1蝕刻工程與第2蝕刻 工程之間進行輔助性蝕刻工程之情形。甚至，也有藉由1 次蝕刻工程’就進行了蝕刻凹坑之產生與蝕刻凹坑之成長 兩者的情形。 當蝕刻工程進行複數次的情況下，任一蝕刻工程中， 均如參照圖1所說明，是先在鋁板10形成第1遮罩 30a、30b，並在第1電極20a及第2電極20b形成第2遮 罩 4 0a、4 0 b ° 若作爲對鋁板1 0的蝕刻工程是進行第1蝕刻工程與 第2蝕刻工程的情況下，則在第1蝕刻工程（一次電解處 理）中，以低濃度鹽酸水溶液實施交流蝕刻。又，作爲前 處理可將鋁板進行脫脂洗淨或是輕度的蝕刻，以實施表面 氧化膜之去除，較爲理想。於一次電解處理中，作爲蝕刻 液所使用的低濃度鹽酸水溶液，係例如，比例上是含有 1.5〜3.0莫耳/升之鹽酸與〇.〇5〜0.5莫耳/升之硫酸的水 溶液，液體溫度是40〜5 5 °C。作爲交流蝕刻條件，係使 用頻率1 0〜5 0Hz的交流波形，所述的交流波形係可使用 正弦波形、四角形波形、交直重疊波形等。此時的電流密 度係爲0.4〜0.5 A/cm2，若依照所述的蝕刻之條件，則可 在鋁板10表面鑽孔產生多數凹坑。 在實施一次電解處理後，在第2蝕刻工程（主電解處 理）中，使凹坑成長成海綿狀同時促進蝕刻進行。該主電 -16- 201040995 解處理中所使用的蝕刻液係爲，例如比例上是含有4〜7 莫耳/升之鹽酸與0.05〜0.5莫耳/升之硫酸的水溶液中， 液體溫度係低於一次處理的溫度而爲25 °C以下，較理想 係爲1 5〜25 °C。作爲交流蝕刻條件，係使用頻率20〜 6 0Hz的交流波形，所述的交流波形係可使用正弦波形、 四角形波形、交直重疊波形等。此時的電流密度係低於一 次電解處理而爲0.2〜0.3 A/cm2，處理時間係設定成可處 ¢) 理至所定的蝕刻部位厚度的時間，將一次電解處理中所鑽 孔出來的凹坑更進一步進行鑽孔。 進行過一次電解處理後，在進行主電解處理之前，爲 了使主電解處理確實被進行，亦可使用交直重疊波形，促 使一次電解處理中所鑽孔之凹坑表面活化，然後才進行主 電解處理。所述之處理中，係以負載比（duty ratio)係爲約 0_7〜0.9 ’電流密度係爲0_ 1 2〜0· 1 7A/cm2之條件，進行 6 0秒左右的蝕刻處理。 Ο 若以如此條件來進行蝕刻，則蝕刻部位1 3的整體比 重係爲0.6〜1_2，可形成具有以下說明之凹坑口徑或凹坑 數的蝕刻部位1 3。關於凹坑口徑或數量，係可藉由影像 解析裝置來測定。又，將已被鈾刻之表面，在深度方向上 每次保持所定間隔進行硏磨後，以影像解析裝置測定各硏 磨面的孔徑與數目，算出凹坑徑爲0.01〜Ιμιηφ之凹坑數 的佔有比率後，就可測定各層的特定尺寸口徑之凹坑的佔 有比率。於所述判定中，蝕刻板1 4係於蝕刻部位1 3之各 平面剖面中’ 〇·〇 1〜1 μιη φ的凹坑數佔全凹坑數的70%以 -17- 201040995 上、理想爲存在75%以上，較爲理想。若將如此的蝕刻板 1 4進行陽極氧化而當作陽極1 5使用，則可實現靜電容量 大且 ESR低的固體鋁電解電容器。此外，由於未滿 Ο.ΟΟΙμιηφ的凹坑係對靜電容量之提升沒有貢獻，因此影 像解析裝置所測定的口徑係設定爲0.001 μηι φ以上。 關於蝕刻部位13的厚度，理想係爲兩面合計是 150μιη以上，至少形成單面從表面起算往深度方向是 75μιη以上，理想係爲ΙΟΟμιη以上，更理想則爲120μιη以 上的蝕刻部位1 3，較佳。若蝕刻部位1 3的厚度未達上記 數値，則無法獲得充分的靜電容量，因此不能期待固體鋁 電解電容器之小型化或電極層積片數的削減。 又，凹坑徑爲〇.〇1〜Ιμηιφ之凹坑數的佔有比率係很 重要。凹坑徑超過1 μπι φ的凹坑若有多數存在，則會使靜 電容量降低。理想係爲〇 _ 1 μηι φ以下。此種尺寸的凹坑之 存在量係於各面達到全凹坑數的70%以上、理想爲75 %以 上，藉此就可製作靜電容量高而ESR低的電解電容器》 上記尺寸之凹坑的存在量若是8 0%以上則更爲理想。凹坑 尺寸的測定位置，若太靠近表面則在電解蝕刻時對表面積 擴大不會有所貢獻而溶解，使凹坑與凹坑彼此連結而徒然 導致凹坑徑擴大，因此是設定在從表面起算20 μιη之深度 的位置。又，由於蝕刻部位13與蕊部16的交界面係有凹 凸而非一定，因此將蝕刻深度設定成從固定位置（蝕刻部 位13與蕊部16之交界）起往表面10 μπι淺的位置。 又，本發明中所使用的鋁板10，係鋁純度爲99.98質 -18- 201040995 量％以上所成，粒徑以相當於球狀而論而爲0.1〜1 · 0 μιη 0 的含鐵金屬間化合物的數目係爲含有ΙχΙΟ7〜1 〇1()/cm3 者，較爲理想。若依據所述構成，則可提高特定尺寸口徑 的凹坑的佔有比率，並且可製作ESR更低的電容器。其 原因可想成’因爲金屬間化合物越多則粒徑越小，所以化 成皮膜在凹坑表面以均等厚度而被形成，使固體電解質變 得更容易被含浸的緣故。 0 鋁純度爲99.98質量％以上而成的鋁板1〇，除了 A1 以外的兀素’係例如Fe爲5〜50ppm、Cu爲30ppm未滿 者較爲理想，Si則爲60ppm以下、理想係40ppm以下即 可。若Fe、Si超過上限値，則會產生含Fe、Si的粗大之 金屬間化合物的結晶物及析出物，導致漏電流變大。Si 的情況下則也會產生單體Si，因此基於同樣的理由也不 理想。若Cu超過上限値則基質的腐蝕電位會大幅往高價 偏移，因此會有無法良好蝕刻之疑慮。 Q 相對於此，Fe的5〜50ppm之含量，以周知的値可促 進產生 AlmFe、AUFe、AhFe、Al-Fe-Si、Al-(Fe、M)-S i (M係其他金屬）等之金屬間化合物，容易變成交流蝕刻 的凹坑起點，因此較爲理想。Cu的未滿3 Oppm之含量， 係因爲Fe的存在而可使基質的腐鈾電位穩定化，使得特 定尺寸的凹坑變得容易被鑽孔出現，而較爲理想。Cu的 理想含量係爲25ppm以下’下限係2ppm以上’更理想係 爲3ppm以上。若未達下限値，則在蝕刻板的加熱工程 中，結晶粒會異常成長而降低機械強度。相對於此，若 -19- 201040995[Technical Field] The present invention relates to a method for producing an aluminum electrode plate for an electrolytic capacitor which is electrolytically etched on an aluminum plate. [Prior Art] In recent years, with the evolution of digital and high-frequency electronic devices such as personal computers and information devices, solid aluminum electrolytic capacitors are required to have low back, low impedance, and low ESR. Capacitance quantification. In the manufacture of a solid aluminum electrolytic capacitor, as shown in Fig. 7(a), anodization is performed after the electrolytic etching of the aluminum foil 10x, and then, as shown in Figs. 7(b) and (c). The aluminum foil 10x is punched by punching or the like to obtain an anode 15x. A shield 18 is provided between the portion 15x of the anode 15x where the cathode (not shown) is to be formed and the connection portion 15 2x of the terminal 19. In the anode 15x, a portion Ο 151X of a cathode (not shown) and a connecting portion 152X of a terminal 19 are formed, and both of them are sponge-like etched portions 13 . On the other hand, in order to secure the strength of the aluminum foil, a technique of providing a masking material for defining an opening portion in the etching field on the surface of the aluminum foil has been disclosed (Patent Document 1). When the solid aluminum electrolytic capacitor is manufactured by the method described in Patent Document 1, as shown in Fig. 8(a), the surface of the aluminum foil 15y before the etching is provided with the mask 30y at the connection portion 15 2y of the terminal 19 or the like. Next, electrolytic etching is performed. Next, after the aluminum foil 10y is anodized, the cover-5-201040995 cover 30y is removed, and then, as shown in Figs. 8(b) and (c), the aluminum foil 10y is punched by punching or the like to obtain an anode 15y. . In the anode 15y, the portion 151y where the cathode is formed is a sponge-like etching portion 13, but the connecting portion 152y of the terminal 19 is the unetched portion 12. [Prior Art Document] [Patent Document 1] [Patent Document 1] JP-A-60-31217 SUMMARY OF INVENTION [Problems to be Solved by the Invention] However, in the methods shown in Figs. 7 and 8, The following questions are points. First, in the embodiment shown in Fig. 7, since the connecting portion 15 2x of the terminal 19 is also a sponge-like etching portion 13, there is a problem that connection failure of the terminal 19 is likely to occur. Further, since such a field in which the connection portion 1 5 2x of the terminal 19 is not required to be etched is electrolytically etched, there is a problem that wasteful power consumption occurs. Further, even if the field in which the uranium engraving is not required is electrolytically etched, the effect is that the concentration of aluminum in the etching liquid rises in a short time, and the etching liquid is likely to be deteriorated. On the other hand, in the embodiment shown in FIG. 8, when the current is concentrated in the vicinity of the mask 30y during the electrolytic etching, the over-etched portion 1 3 s occurs along the mask 30y, causing a problem that the electrostatic capacitance is lowered. . In view of the above problems, an object of the present invention is to provide a method for producing an aluminum electrode plate for an electrolytic capacitor which can be selectively etched in a necessary field without causing an over-etched portion due to current concentration. -6- 201040995 [Means for Solving the Problem] In order to solve the above problem, in the present invention, the first electrode and the second electrode are placed between the first electrode and the second electrode which are opposed to each other in the etching liquid. In the method of manufacturing an aluminum electrode plate for electrolytic capacitors in which an electrode is subjected to electrolytic uranium engraving in a state in which an electrode is disposed in an opposing manner, the electrode is formed on both sides of the aluminum plate before the electrolytic etching. Q: The first mask is provided, and the first opening portion for defining the uranium engraving area of the aluminum plate is provided, and the surface of the first electrode and the second electrode facing the front aluminum plate is provided in the front surface. The area projected by the first opening portion is the second mask that serves as the second opening portion; and the area of the second opening portion is set to be 0.7 times the area of the first opening portion to 1.15. Times. In the present invention, in the case of performing electrolytic etching, the field which is not required to be etched on the aluminum plate is covered with the first mask, and therefore, in the field in which the first mask becomes an unetched portion on the aluminum plate, It can be connected to the terminal. Therefore, since the aluminum electrode plate for the electrolytic capacitor can be reliably connected to the terminal, the reliability of the terminal connection portion is high. Further, since the electrolytic etching is not performed in the field where etching is not necessary, wasteful power consumption does not occur. Further, since the waste aluminum is not dissolved in the etching liquid, deterioration of the etching liquid can be suppressed. Further, the first electrode and the second electrode are provided with a second mask, and the second mask includes a second opening portion in a field in which the first opening portion is projected. Therefore, the second opening portion has the same shape as the first opening portion. Further, the area of the second opening portion is limited to 0.7 times to 1.15 times the area of the first opening portion. Therefore, in the field of being exposed by the first opening portion in the 201040995 aluminum plate, and the region where the first opening and the second electrode are exposed by the second opening portion, an appropriate potential distribution is formed. It is difficult to have an etched portion or an under-etched portion on an aluminum plate. In other words, when the area of the second opening portion is less than 0.7 times the area of the first opening portion, the portion of the aluminum plate that is exposed by the first opening portion is insufficiently etched. The electrostatic capacity of the aluminum electrode plate for electrolytic capacitors is lowered. On the other hand, when the area of the second opening portion is more than 1.15 times the area of the first opening portion, an over-etched portion is formed at the end portion of the aluminum plate which is exposed by the first opening portion. The electrostatic capacity of the aluminum electrode plate for electrolytic capacitors is lowered. However, in the present invention, since the area ratio of the second opening portion to the first opening portion is appropriately designed, the uranium-inserted portion or the over-etched portion does not occur. Therefore, an aluminum electrode plate for an electrolytic capacitor having a high electrostatic capacitance can be manufactured. In the present invention, it is preferable that the portion of the first mask which is sandwiched by the first opening portion is a strip-shaped portion having a width of 1 mm or more. According to the above configuration, the unetched portion having a width of 1 mm or more can be formed on the aluminum plate, and the terminal can be connected to the unetched portion. In the present invention, the thickness of the first mask is preferably 0.1 mm or less. According to the above configuration, at the time of etching, the air bubbles are not pulled by the drop of the first mask to cover the surface of the aluminum plate. Therefore, it is possible to prevent the current density in the field exposed by the first opening portion from fluctuating with the bubble on the surface of the nameplate in the aluminum plate. In the present invention, the first configuration may be adopted. The first mask is made of a resin masking material which is fixed to both sides of the aluminum sheet by the -8-201040995. In the present invention, it is preferable that the first opening portion is a shape in which a corner portion of a square is cut into an arc shape or a circle. When the first opening portion has a square shape, in the corner portion of the square shape, current concentrates and tends to be easily etched. However, when the first opening portion is formed, the corner portion of the square is cut into an arc. When the shape is round or round, this current concentration can be prevented. In the present invention, the quadrilateral shape may be any of a square shape or a rectangular shape. Further, the circular shape may be a shape of a perfect circle, an oblate shape, or an ellipse. In the present invention, the electrolytic etching is performed by alternating current etching, and pre-electrolytic etching is performed so that the thickness of the etching portion on the aluminum sheet is preferably 75 μm or more per one surface. According to the present invention, since current concentration does not occur, the etched portion does not occur, and etching at a depth of 75 μm or more per one-sided surface can be achieved. Therefore, an aluminum electrode plate for an electrolytic capacitor having a high electrostatic capacitance can be obtained. 铝 The aluminum electrode plate for an electrolytic capacitor of the present invention is used as an anode of an aluminum electrolytic capacitor using a functional polymer as an electrolyte. In other words, the aluminum electrode plate for an electrolytic capacitor of the present invention is applied to a surface of a dielectric film, and a functional polymer layer is formed on the dielectric film to be used for an electrolytic capacitor. [Effect of the Invention] In the present invention, in the case of performing electrolytic uranium engraving, the field which is not required to be etched on the aluminum plate is covered with the first mask, so that it is covered by the first cover on the aluminum plate -9-201040995. The cover becomes unetched: child. Therefore, aluminum for electrolytic capacitors has high electrical dependency. Further, since there is no etch-etching, wasteful aluminum dissolution does not occur in the wasteed uranium etchant, and since the area of the second opening portion is 7. 7 times to 1.15 times, Under-etched parts. Therefore, an aluminum electrode plate can be used. In the field of the new part, the area where the connection between the terminal plate and the terminal can be connected is not required to be used for electric power. Even if it is not correct, deterioration of the etching liquid can be suppressed. An electrolytic capacitor having a high electrostatic capacitance is formed in an aluminum plate which is limited to an area of the first opening portion. [Embodiment] Hereinafter, an aluminum electrode plate for an electrolytic capacitor according to the present invention is applied (etched. [Manufacturing method of the board of the present invention] and manufacturing apparatus [Description of etching apparatus] Fig. 1 is an aluminum plate to which the electric device (etching apparatus) of the present invention is applied, and 1(a) and (b) are equivalent to 2 Electrodes and oblique views from the other side. Description of the method for producing an aluminum electrode plate for a capacitor. As shown in Fig. 1, an explanatory view of a manufacturing apparatus of the present invention (hereinafter referred to as a manufacturing electrode of an aluminum electrode plate for etching a lip-removing capacitor) is applied, and one side of the drawing is a perspective view of FIG. In the electrolysis of the invention, the aluminum electrode plate | 100) for the electrolytic capacitor formed in the first mask of the aluminum plate has an etching bath (not shown) in which the salt--10-201040995 acid-based etching liquid 90 is stored, The plurality of electrodes 20 disposed opposite to each other in the etching liquid 90 and the power supply device 80. The electrode 20 is made of a conductor which does not cause electrolytic dissolution in an etching liquid such as carbon or platinum, and is disposed to face each other in the etching liquid 90. In the following description, one of the two opposing electrodes 20 will be referred to as a first electrode 20a, and the other as a second electrode 20b. Between the first electrode 20a and the second electrode 20b, an aluminum plate for manufacturing an aluminum electrode plate for an electrolytic capacitor, an aluminum plate ίο and a first electrode 20a, and an aluminum plate 10 and a second electrode are disposed. The interval of 20b is 25 mm or less, and the ideal is 20 mm or less. In the following description, the surface facing the first electrode 20a in the aluminum plate 10 is referred to as a first surface 10a, and the surface facing the second electrode 20b is referred to as a second surface 10b. The aluminum plate 10 is a size for forming an anode for a plurality of solid aluminum electrolytic capacitors to be described later, and the field surrounded by a broken line L1 in Fig. 2 is used as an anode 15 for a solid aluminum electrolytic capacitor by punching a punch or the like. (Description of the mask) As shown in Fig. 1 and Fig. 2, in the present embodiment, in the case of performing electrolytic etching, the aluminum plate 10 is opposed to the first electrode 20a! The surface 10a is provided with a first mask 30a, which is provided with a plurality of first opening portions 3 1 a for defining a square shape for the uranium engraving field of the aluminum plate 10. Further, in the second surface 10b opposed to the second electrode 20b in the aluminum plate 10, the first mask 30b is provided in the same manner as the first surface 10a, and the plural number is used to define -11 - 201040995 A first opening portion 31b having a square shape for the etching of the aluminum plate 10. The first mask 30a and the first mask 30b are formed so as to overlap each other in plan view, and the first opening portion 3 1 a and the first opening portion 3 1 b have the same shape and the same size. Further, in the present embodiment, as shown in FIG. 1, in the first electrode 20a, the second mask 40a is provided on the electrode surface 21a facing the first surface 10a of the aluminum plate 10, and the second mask 40a is provided. In the mask 40a, a quadrangular opening portion 41a is formed in a region facing the first opening portion 31a of the first mask 30a. Further, in the second electrode 20b, the second mask 40b is provided on the electrode surface 21b opposed to the second surface 10b of the aluminum plate 10, similarly to the electrode surface 21a, and the second mask 40b is provided in the second mask 40b. In the field facing the first opening portion 3 1 b of the first mask 30b, a quadrangular opening portion 41b is formed in the second opening portion 41a, and the first opening portion 31a is formed in the first opening portion 31a. The second opening portion 4 1 a and the first opening portion 3 1 a have similar shapes and are opposed to each other in a region in which the electrode surface 21 1 a is vertically projected with a predetermined magnification. Further, similarly to the second opening portion 41a, the second opening portion 41b is formed in a field in which the first opening portion 31b is vertically projected toward the electrode surface 21b, and the second opening portion 4 1 b is formed. The first opening portion 3 1 b has a similar shape and faces each other. Here, the second opening portion 41a and the second opening portion 41b are in an equal area. Further, the area of the second opening portions 41a and 41b is 0.7 times to 1.15 times the area of the first opening portions 31a and 31b. Therefore, the second opening portions 41a and 41b are formed in a field in which the first opening portions 31a and 31b are placed vertically at a scale of 0.7 times to 1.15 times toward the electrode -12-201040995 surface 21b. In the first masks 30a and 30b, the portions that are sandwiched by the first opening portions 31a include the belts 32a and 32b having a width of 1 mm or more. In the present embodiment, the first masks 30a and 30b are made of a resin masking material on both surfaces of the aluminum plate 10, and have a thickness of the following. The first masks 30a and 30b may be formed by applying a resin material such as a grease, a polyester resin or a sand resin to a coating method or a brush to cure the resin. For the second masks 40a and 40b, for example, a resin plate for preposing the electrode faces 21a and 21b of the first electrode 20a and the second electrode 20b is provided on the resin plate as the second 41a, 41b. The composition of the hole. In addition, as for the second masks 40a and 40b, similarly to the 30th and 30b, it is possible to use a tree material such as an epoxy resin, a polyester resin or a silicone resin which is fixed to the first electrode 20a and the Q electrode 20b. . In addition, as for the first masks 30a and 30b, similarly to the 40th and 40th, a resin plate having the first surface 10a and the second cover may be used, and the resin plate may be used as the first portion. The composition of the holes of 3 1 a, 3 1 b. (Description of Aluminum Electrode Plate for Electrolytic Capacitor) FIG. 3 is a schematic diagram showing the use of an anode for an aluminum-electric solid aluminum electrolytic capacitor for electrolytic capacitors to which the present invention is applied. The 0.1mm epoxy tree screen printing will cover the opening 1 cover and the 2nd cover 2 Ob 1 open plate. When the electrode plate for an electrolytic capacitor is manufactured by using the etching apparatus 100 described with reference to Fig. 1, first, an alternating current is applied between the first electrode 20a and the second electrode 20b by the power supply device 80. As a result, as shown in FIG. 2, in the first surface 10a and the second surface 10b of the aluminum plate 10, the portions exposed from the first opening portions 31a and 31b of the first masks 30a and 30b are It is etched and etched to form an etched portion 13 . Further, the portion covered by the first masks 30a and 30b is the unetched portion 12. In this way, an aluminum electrode (uranium plate 14) for electrolytic capacitors is obtained. Next, after the etched plate 14 is anodized, the first masks 30a and 30b are removed. Then, the field shown by the broken line L1 is cut by a method such as pressing the etched plate 14 which has been anodized, and the anode 15 for the solid aluminum electrolytic capacitor shown in Fig. 3 is obtained. In the anode 15 shown in Fig. 3, a masking member 18 is formed between a portion 151 where a cathode (not shown) is to be formed and a connecting portion 152 of the terminal 19, at an end portion (connecting portion) on one side of the masking member 18. 1 5 2), the upper terminal 19 is connected by a method such as spot welding. Here, the connection portion 152 of the terminal 19 is a region covered by the strip portions 32a and 32b of the first masks 30a and 30b, and is an unetched portion 12. Next, in the anode 15 for a solid aluminum electrolytic capacitor, among the surfaces of the etched plate 14 subjected to anodization, the etched portion 13 is impregnated with polypyrrole to form a functional polymer layer according to a known method, and then functions. The surface of the polymer layer is formed by using a carbon paste or the like or a silver paste. In the case of impregnating the polypyrrole, for example, after dropping an ethanol solution of the pyrrole monomer to the etching site 13 , an aqueous solution of ammonium persulphate and sodium 2-naphthate is added dropwise, and -14 to 201040995 to chemically polymerize the pyrrole monomer. The pre-plated layer formed by the poly. Next, the uranium plate 14 is immersed in an acetonitrile electrolyte containing a pyrrole monomer and sodium 2-naphthate, and a part of the previously formed chemically polymerized polypyrrole layer is brought into contact with a stainless steel wire to become an anode, and on the other hand, a stainless steel plate is used. Electrolytic polymerization is carried out as a cathode to form an electrolytically polymerized polypyrrole to be used as a functional polymer layer. In addition, it is also possible to replace polypyrrole and switch to polythiophene. Then, the cathode was formed to cover the functional polymer layer, and a solid aluminum 0 electrolytic capacitor was completed. (Detailed configuration of the etched plate 14) In the present embodiment, when the thickness of the etched plate 14 is 150 μm or more, the thickness of the etched portion 13 is etched to a position at a depth of 1 50 μm or more on both sides. More specifically, the etching portion 13 is etched to a position having a single-face depth of 75 μm or more, or ΙΟΟμηχ or more, or even 120 μm or more. Even in this case, the core portion 16 remains in the center of the thickness direction of the etching plate 14. Further, in the present embodiment, the aluminum purity of the aluminum plate 10 is 99.98 mass% or more. Therefore, the uranium engraving plate 14 has high toughness and is easy to handle when manufacturing a solid aluminum electrolytic capacitor. Here, if the aluminum purity of the aluminum plate 10 is less than the lower limit 値, the hardness increase toughness is lowered, and there is a fear of cracking or the like during the operation, which is not preferable. Further, although the thickness of the aluminum plate 10 can be set to various thicknesses depending on the purpose, for example, 150 μm to 1 mm is used, and generally 300 to 400 μm is used. In the present embodiment, as an etching process for the aluminum plate 1 ,, at least -15 to 201040995, an etching process for causing etching of the aluminum plate 10 (hereinafter referred to as a first etching process) is performed, and the etch pit is performed. In the case of a growing etching process (hereinafter referred to as a second etching process), there is a case where an auxiliary etching process is performed between the first etching process and the second etching process. In addition, there is a case where both the generation of the etching pit and the growth of the etching pit are performed by one etching process. When the etching process is performed plural times, in any etching process, as described with reference to FIG. 1, the first masks 30a and 30b are formed on the aluminum plate 10, and the first electrode 20a and the second electrode 20b are formed. When the first etching process and the second etching process are performed on the etching process of the aluminum plate 10, the second masks 40a and 40b are lower in the first etching process (primary electrolytic process). The concentrated hydrochloric acid aqueous solution was subjected to alternating etching. Further, as the pretreatment, the aluminum plate may be subjected to degreasing washing or light etching to remove the surface oxide film, which is preferable. In a single electrolytic treatment, the low-concentration hydrochloric acid aqueous solution used as the etching liquid is, for example, an aqueous solution containing 1.5 to 3.0 mol/liter of hydrochloric acid and 〇.〇5 to 0.5 mol/liter of sulfuric acid, liquid. The temperature is 40 to 5 5 °C. As the alternating current etching condition, an alternating current waveform having a frequency of 10 to 50 Hz is used, and the alternating current waveform can be a sinusoidal waveform, a quadrangular waveform, an intersecting superimposed waveform, or the like. The current density at this time is 0.4 to 0.5 A/cm2, and according to the etching conditions described above, a large number of pits can be formed in the surface of the aluminum plate 10. After the primary electrolytic treatment is performed, in the second etching process (main electrolytic treatment), the pits are grown into a sponge shape and the etching progress is promoted. The etchant used in the treatment of the main electricity-16-201040995 is, for example, an aqueous solution containing 4 to 7 mol/liter of hydrochloric acid and 0.05 to 0.5 mol/liter of sulfuric acid in a ratio, and the liquid temperature is low. It is 25 ° C or less at a temperature of one treatment, and preferably 15 to 25 ° C. As the alternating current etching conditions, an alternating current waveform having a frequency of 20 to 60 Hz is used, and the alternating current waveform can be a sinusoidal waveform, a quadrangular waveform, an intersecting superimposed waveform, or the like. The current density at this time is 0.2 to 0.3 A/cm 2 lower than the primary electrolytic treatment, and the treatment time is set to a time at which the thickness of the etched portion can be determined, and the hole drilled in the primary electrolytic treatment is recessed. The pit is further drilled. After performing one electrolytic treatment, in order to make the main electrolysis process be carried out before the main electrolysis process, the cross-overlap waveform may be used to promote the activation of the pit surface of the drilled hole in one electrolysis process, and then the main electrolysis process is performed. . In the above-described treatment, the etching treatment is performed for about 60 seconds under the condition that the duty ratio is about 0_7 to 0.9 Ω and the current density is 0_1 2 to 0·1 7 A/cm 2 . Ο If the etching is performed under such conditions, the overall specific gravity of the etching portion 13 is 0.6 to 1_2, and the etching portion 13 having the pit diameter or the number of pits described below can be formed. The size or number of pits can be determined by an image analysis device. Further, after the surface which has been engraved by urethane is honed at a predetermined interval in the depth direction, the aperture and number of each honing surface are measured by an image analyzing device, and the number of pits having a pit diameter of 0.01 to Ιμιηφ is calculated. After occupying the ratio, the ratio of the pits of the specific size caliber of each layer can be measured. In the above determination, the etching plate 14 is in the plane cross section of the etching portion 13, and the number of pits of '〇·〇1 to 1 μηη φ is 70% of the total number of pits to -17-201040995. It is ideal for more than 75%. When such an etching plate 14 is anodized and used as the anode 15, a solid aluminum electrolytic capacitor having a large electrostatic capacity and a low ESR can be realized. Further, since the pits which are less than Ο.ΟΟΙιηφ do not contribute to the improvement of the electrostatic capacity, the aperture measured by the image analyzing device is set to 0.001 μηι φ or more. The thickness of the etched portion 13 is preferably 150 μm or more in total of both surfaces, and is preferably at least 75 μm or more in the depth direction from the surface, and is preferably ΙΟΟμηη or more, more preferably 120 μm or more. . If the thickness of the etched portion 13 is less than the upper limit 値, a sufficient electrostatic capacitance cannot be obtained. Therefore, it is not expected to reduce the size of the solid aluminum electrolytic capacitor or the number of electrode laminates. Further, it is important that the pit diameter is the ratio of the number of pits of 〇.〇1 to Ιμηιφ. If there are many pits with a pit diameter of more than 1 μm φ, the electrostatic capacity is lowered. The ideal system is 〇 _ 1 μηι φ or less. The amount of pits of such a size is such that each surface reaches 70% or more, and preferably 75% or more of the total number of pits, whereby an electrolytic capacitor having a high electrostatic capacitance and a low ESR can be produced. It is more desirable if the amount is more than 80%. When the measurement position of the pit size is too close to the surface, it does not contribute to the surface area expansion during electrolytic etching, and the pit and the pit are connected to each other, which in turn causes the pit diameter to expand, so it is set from the surface. The position of the depth of 20 μιη. Further, since the interface between the etching portion 13 and the core portion 16 is concave rather than constant, the etching depth is set to a position 10 μπι from the fixed position (the boundary between the etching portion 13 and the core portion 16) to the surface. Further, the aluminum plate 10 used in the present invention is formed by an aluminum purity of 99.98 mass -18 - 201040995 or more, and the particle diameter is 0.1 to 1 · 0 μιη 0 in the ferrous metal equivalent of a spherical shape. The number of the compounds is preferably from ΙχΙΟ7 to 1 〇1 ()/cm3. According to the above configuration, the ratio of the pits of the specific size caliber can be increased, and a capacitor having a lower ESR can be produced. The reason for this is that the smaller the particle size, the smaller the particle size, so that the film is formed at a uniform thickness on the surface of the pit, and the solid electrolyte is more easily impregnated. 0. Aluminum plate having an aluminum purity of 99.98% by mass or more, except for A1, such as Fe is 5 to 50 ppm, Cu is 30 ppm or less, and Si is 60 ppm or less, and preferably 40 ppm or less. Just fine. When Fe and Si exceed the upper limit 値, crystals and precipitates of a coarse intermetallic compound containing Fe and Si are generated, and leakage current is increased. In the case of Si, monomer Si is also generated, and therefore it is not preferable for the same reason. If Cu exceeds the upper limit, the corrosion potential of the substrate will be greatly shifted to a high price, so there is a concern that the etching cannot be performed well. Q is based on the fact that the content of 5 to 50 ppm of Fe promotes the production of AlmFe, AUFe, AhFe, Al-Fe-Si, Al-(Fe, M)-S i (other metal of M), etc. by well-known ruthenium. It is preferable that the intermetallic compound easily becomes the starting point of the pit for the AC etching. The content of Cu of less than 3 Oppm is stabilized by the presence of Fe, which stabilizes the uranium potential of the substrate, making it possible for pits of a specific size to be easily drilled. The ideal content of Cu is 25 ppm or less, and the lower limit is 2 ppm or more, and more preferably 3 ppm or more. If the lower limit 値 is not reached, the crystal grains will grow abnormally and the mechanical strength will be lowered in the heating process of the etched plate. In contrast, if -19- 201040995
Cu含量超過30ppm，則會異常促進蝕刻時的溶解，並不 理想。其他的元素則是，Ni、Ti、Zr分別在〗〇PPm以 下、理想係3ppm以下即可。甚至，其他雜質係在3ppm 以下，較爲理想。藉此，由於在前記的交流蝕刻方法成爲 了凹坑的起點，因此容易鑽孔出特定尺寸之口徑的凹坑成 爲海綿狀。 此種高純度的鋁係將電解初級金屬加以精製而製造。 作爲此時所用的精製方法，三層式電解法或結晶分別法係 被廣泛採用，藉由這些精製法，可將鋁以外的元素，大半 加以去除。然而，關於Fe及Cu，係不視爲雜質而是可視 爲微量合金元素來利用，因此當測定精製後各元素之含 量，Fe及Cu之含量未達所定量時，可在扁塊（slab)鑄造 時，在熔湯中添加 Al_Fe、Al- Cu母合金等，以調節Fe 或Cu的含量。 要獲得前記的含有粒徑以相當於球狀而論而爲〇.〇1〜 Ι.Ομιηφ之含Fe金屬間化合物之數目爲ΙχΙΟ7〜101G/Cm3 的鋁板10，可例示以下之方法。首先，半連續鑄造鋁純 度足99.98質量％以上、調整過Fe含量之鋁熔湯，而獲得 扁塊。接下來，將扁塊以53(TC以上之溫度進行均質化處 理，將板溫度領域通過相當於易於析出含Fe金屬間化合 物之範圍（3 00〜400°C)之通過次數設成3次以上，或是保 持30分鐘以上60分鐘以下而獲得熱延壓板，將所述之熱 延壓板僅用冷延壓而作成所定之厚度。若將前述組成的鋁 熔湯如前述般地鑄造、延壓，則可容易獲得理想大小、且 -20- 201040995 含所定數量Fe的金屬間化合物。含Fe之金屬間化合物的 大小與數目，係可用影像解析裝置來測定。 含Fe金屬間化合物之粒徑以相當於球狀而論而爲未 滿Ο.ΟΙμιηφ ，在公知方法下會有難以成爲鈾刻凹坑之核 的傾向。又，若超過Ι.Ομηιφ則在組裝固體鋁電解電容器 時，容易對漏電流造成影響。又，粒徑以相當於球狀而論 而爲0.01〜Ι.Ομιηφ的含Fe金屬間化合物之數目若未滿1 0 X 1 07/cm3，則特定尺寸的凹坑之佔有比率會變少，若超過 lxl01()/Cm3則會發生較多的過剩溶解。 (蝕刻結果） 首先，鋁純度爲99.99質量％以上、含鐵30Ppm、含 砂40PPm、殘部係其他不可避免之雜質所成的扁塊，經過 所定的延壓，獲得厚度〇.4〇mm的鋁板10。 接下來，對該鋁板10用以下之條件 〇 第1階段蝕刻（第1蝕刻工程） 蝕刻液組成：3莫耳/升鹽酸+0.5莫耳/升硫酸的 混合水溶液 蝕刻液溫度：50t 電解波形：正弦波交流、頻率5 0Hz 電流密度：〇.5A/cm2 電解時間：7 5秒 第2階段蝕刻（第2蝕刻工程） 蝕刻液組成：7莫耳/升鹽酸+0.5莫耳/升硫酸的 -21 - 201040995When the Cu content exceeds 30 ppm, the dissolution at the time of etching is abnormally promoted, which is not preferable. In other elements, Ni, Ti, and Zr may be below 〇 〇 PPm and ideally below 3 ppm. Even other impurities are preferably 3 ppm or less. Thereby, since the alternating etching method described above becomes the starting point of the pit, it is easy to drill a pit having a diameter of a specific size into a sponge shape. Such high-purity aluminum is produced by refining an electrolytic primary metal. As a purification method used at this time, a three-layer electrolysis method or a crystal separation method is widely used, and by these refining methods, most elements other than aluminum can be removed. However, regarding Fe and Cu, it is not considered as an impurity but can be regarded as a trace alloy element. Therefore, when the content of each element after the purification and the content of Fe and Cu are not determined to be quantitative, it can be used in a flat block (slab). At the time of casting, Al_Fe, an Al-Cu master alloy or the like is added to the melt to adjust the content of Fe or Cu. The following method can be exemplified to obtain the aluminum plate 10 having the number of Fe-containing intermetallic compounds having a particle diameter of 〇.〇1 to Ι.Ομηηφ as 前7 to 101 G/cm3. First, a semi-continuous casting of an aluminum melt having an aluminum purity of 99.98 mass% or more and adjusting the Fe content is obtained to obtain a flat block. Next, the flat block is homogenized at a temperature of 53 (TC or higher, and the plate temperature range is set to 3 or more times by the number of passes corresponding to a range in which the Fe-containing intermetallic compound is easily precipitated (300 to 400 ° C). Or maintaining the hot-rolling plate for 30 minutes or more and 60 minutes or less, and forming the heat-expanding plate into a predetermined thickness by cold-pressing only. If the aluminum melt of the above composition is cast and stretched as described above, , the ideal size and -20- 201040995 intermetallic compounds containing a certain amount of Fe can be easily obtained. The size and number of Fe-containing intermetallic compounds can be determined by an image analysis device. The particle size of the Fe-containing intermetallic compound is It is equivalent to a spherical shape and is not full. ΟΙμιηφ, under the known method, there is a tendency to become a nucleus of uranium pits. Moreover, if it exceeds Ι.Ομηιφ, it is easy to leak when assembling a solid aluminum electrolytic capacitor. The influence of the current is also affected. Further, if the number of the Fe-containing intermetallic compounds having a particle diameter of 0.01 to Ι.Ομηηφ is less than 10 0 1 07/cm 3 , the ratio of the pits of a specific size is occupied. meeting When it exceeds lxl01()/Cm3, excessive excess dissolution occurs. (Etching result) First, aluminum purity is 99.99% by mass, iron is 30 Ppm, sand is contained at 40 ppm, and other unavoidable impurities are formed. The flat block is subjected to a predetermined pressure to obtain an aluminum plate 10 having a thickness of 〇4 〇 mm. Next, the aluminum plate 10 is subjected to the following conditions: first stage etching (first etching process) etching liquid composition: 3 moles /L of hydrochloric acid +0.5 mol / liter of sulfuric acid mixed aqueous solution etching solution temperature: 50t Electrolytic waveform: sine wave AC, frequency 5 0Hz Current density: 〇.5A/cm2 Electrolysis time: 7 5 seconds 2nd stage etching (2nd etching Engineering) Etching liquid composition: 7 mol / liter of hydrochloric acid + 0.5 mol / liter of sulfuric acid - 21 - 201040995
混合水溶液 鈾刻液溫度：1 7 °C 電解波形：正弦波交流、頻率2 0Hz 電流密度：〇·3 A/cm2 電解時間：2700秒 來進行交流蝕刻，獲得蝕刻板1 4。 此時，於第1蝕刻工程及第2蝕刻工程之任一工程 中’均如參照圖1所說明，是先在鋁板10形成第1遮罩 30a、3 0b’並在第1電極20a及第2電極20b形成第2遮 罩4 0a、40b。此處，係將第2開孔部41a、41b之面積， 變化成第1開孔部3 1 a、3 1 b之面積的1.2 0倍（比較例 1)、1.15倍（實施例1)、ΐ·〇〇倍（實施例2)、0.70倍（實施 例3)、0.65倍（比較例2)、0·50倍（比較例3)而進行蝕 刻。此外’作爲參考例，也以在鋁板1 〇有形成第1遮罩 30a、30b’但在第1電極20a及第2電極20b並未形成第 2遮罩4〇a、40b之條件，來進行之。 接下來，在己二酸銨中對蝕刻板14以6V的化成電 壓進行陽極氧化，測定靜電容量。靜電容量之測定結果示 於表1。靜電容量及皮膜耐電壓之測定係以依照EIAJ規 定之方法而進行。 -22- 201040995 [表l] 面積比* 靜電容量 μΡ/cm2 皮膜耐電壓 V CV積 pFV/cm2 備考 1.20 712 6.0 4272 比較例1 1.15 762 6.0 4572 實施例1 1.00 798 6.1 4868 實施例2 0.70 759 6.0 4554 實施例3 0.65 719 6.1 4386 比較例2 0.50 660 6.3 4158 比較例3 Αητ 無 689 6.0 4134 參考例 第2開孔部41a, 41b之面積 第1開孔部31a,31b之面i 又，令第2開孔部4 1 a、4 1 b對第1開孔部3 1 a、3 1 b 的面積比爲橫軸，令靜電容量値（CV積）爲縱軸來作圖的 結果，示於圖4。又，在圖5中係模式性圖示了，各試料 的平面構成與剖面構成之關係。此外，圖5(a)係比較例1 q 所述的蝕刻板的平面圖及A-A’剖面圖之說明圖，圖5(b) 係實施例2所述的蝕刻板的平面圖及B-B1剖面圖之說明 圖，圖5(c)係參考例所述的蝕刻板的平面圖及C-C1剖面 圖之說明圖。 如表1及圖4所示，若將第2開孔部41a、41b之面 積，設定成第1開孔部31a、31b之面積的1.15倍（實施 例1)，1.00倍（實施例2)、0.70倍（實施例3)，則與參考 例相比較，可將靜電容量（CV積）提高約10%以上。 相對於此，若將第2開孔部41a、41b之面積，設定 成第1開孔部31a、31b之面積的1.20倍（比較例1)、 -23- 201040995 〇·65倍（比較例2)、0.50倍（比較例3)的情況下，與 例相比較時的靜電容量（CV積）之增加率係未滿6%。 由係如以下所述。 首先，若將第2開孔部41a、41b之面積設成第 孔部31a、31b之面積的1.25倍（比較例1)，則因爲 於第1開孔部31a、31b之面積，第2開孔部41a、4 面積會過廣，所以如圖5(a)所示，在第1開孔部3 31b外露之部分的端部（第1遮罩30a、3 0b之附近）， 生過蝕刻部位13s，無法提升靜電容量。又，若將第 孔部41a、41b之面積設成第1開孔部31a、31b之面 0.5 〇倍（比較例3 )，則因爲相較於第1開孔部3 1 a、3 面積’第2開孔部41a、41b之面積會過窄，所以如B 所示在第1開孔部3 1 a、3 1 b外露之部分會發生蝕刻 部位13t，無法提升靜電容量。 相對於此，若將第2開孔部41a、41b之面積設 1開孔部31a、31b之面積的1.00倍（實施例3)，則 5(b)所示，不會發生過蝕刻部位13s或蝕刻不足 1 3t ’因此可以提升靜電容量。此外還確認到，若將 開孔部4 1 a、4 1 b之面積設成第1開孔部3 1 a、3 1 b之 的0 · 7倍至1 .1 5倍，則不會發生過鈾刻部位1 3 s或餓 足部位13t。因此，關於第2開孔部41a、41b之面積 設成第1開孔部31a、31b之面積的0.7倍至1.15倍 爲理想。 參考 其理 1開 相較 lb之 ί 1 a、 會發 2開 積的 lb之 B 5(c) 不足 成第 如圖 部位 第2 面積 刻不 ，係 ，較 -24- 201040995 (本形態的主要效果） 如以上說明，在本形態中，係在進行電解蝕刻之際， 於鋁板1 〇上，沒有必要蝕刻的領域係以第1遮罩30a、 3〇b加以覆蓋，因此於鋁板10上，在被第1遮罩30a、 3〇b變成未鈾刻部位12的連接領域512中，可連接端子 19。因此，電解電容器用鋁電極板（蝕刻板14)與端子19 的連接部分的信賴性較高。 0 又，因爲對於沒有必要蝕刻的領域係不進行電解蝕 刻，因此不會發生浪費的用電量。甚至，由於不會對蝕刻 液中發生浪費的鋁溶解，因此可抑制蝕刻液的劣化。 又，在第1電極20a及第2電極20b係設有第2遮罩 4 0a、40b ’所述之第2遮罩40a、40b，係在第1開孔部 31a、31b的垂直投影之領域中，具備第2開孔部41a、 41b。因此，第2開孔部41a、41b係與第1開孔部31a、 31b爲相同形狀。而且，第2開孔部41a、41b之面積係 Q 被限定爲第1開孔部31a、31b之面積的0.7倍至1.15 倍。因此，在在鋁板10中被第1開孔部31a、31b所露出 的領域，和在第1電極20a及第2電極20b中被第2開孔 部4 1 a、4 1 b所露出之領域之間，係形成適當的電位分 布，所以在鋁板10上不會發生過蝕刻部位13s或鈾刻不 足部位1 3 t。亦即，當第2開孔部4 1 a、4 1 b之面積是不到 第1開孔部31a、31b之面積的0.7倍時，在鋁板10中被 第1開孔部3 1 a、3 1 b所露出的領域的端部係會發生蝕刻 不足部位13t，導致電解電容器用鋁電極板的靜電容量降 -25- 201040995 低。相對於此’當第2開孔部41a、41b之面積是超過第 1開孔部31a、31b之面積的1.15倍時’在鋁板10中被第 1開孔部31a、31b所露出的領域的端部係會發生過蝕刻 部位13s，導致電解電容器用鋁電極板的靜電容量降低。 因此在本形態中’由於是將第2開孔部41a、41b與第1 開孔部31a、31b之面積比作了最佳化’因此可製造靜電 容量高的電解電容器用鋁電極板。 尤其是當進行電解蝕刻進行到深達使得鋁板1 〇中的 鈾刻部位13之厚度是每單面爲75μιη以上的情況下，一 旦電位分布紊亂而發生電流集中，則很容易發生過蝕刻部 位1 3 s，但是若依據本形態，則難以發生所述之電流集 中。因此，電解蝕刻沒有進行到那麼深，所換來的是，可 製造靜電容量高的電解電容器用鋁電極板。 又，於第1遮罩30a、30b中，被第1開孔部3la、 31b所夾住的部分，係含有寬度寸法爲lmm以上的帶狀 部分32a、3 2b。因此，可形成寬度寸法爲1mm以上的帶 狀未蝕刻部位1 2，若爲所述的帶狀未蝕刻部位1 2，則可 確實地連接端子19。 又，因爲第1遮罩30a、30b的厚度是0.1mm以下， 所以在蝕刻之際，蝕刻中所產生的氣泡，不會被起因於第 1遮罩30a、30b之落差所牽引而覆蓋到鋁板1〇表面。因 此，於鋁板1 〇中，可防止對於第1開孔部3 1 a、3 1 b所露 出之領域的電流密度隨著鋁板10表面之氣泡而變動。 -26- 201040995 (其他實施形態） 圖6係本發明的其他實施形態的說明圖。於上記實施 形態中，雖然第1開孔部3 1 a、3 1 b之形狀是四角形，但 如圖6(a)所示，第1開孔部31a、31b之形狀係爲，將四 角形之角部切削成圓弧狀之形狀，較爲理想。又，如圖 6(b)所示，第1開孔部3 1a、3 1b之形狀係爲正圓、扁 圓、橢圓等圓形，較爲理想。當第1開孔部31a、31b是 0 四角形時，在蝕刻之際，在四角形的角落部分，會有電流 集中而較容易進行蝕刻之傾向，但若第1開孔部31a、 31b是將四角形之角部切削成圓弧狀之形狀或是圓形時， 則可防止此種電流集中。因此，可穩定地製造靜電容量高 的蝕刻板1 4。此外，採用所述形狀的情況下也是只要將 虛線L 1所示的四角形領域藉由沖壓等進行沖孔，就可獲 得四角形的陽極1 5。 〇 [產業上利用之可能性] 在本發明中，係在進行電解蝕刻之際，於鋁板上，沒 有必要蝕刻的領域係以第1遮罩加以覆蓋，因此於鋁板 上，在被第1遮罩變成未蝕刻部位的領域中，可連接端 子。因此，電解電容器用鋁電極板與端子的連接部分的信 賴性較高。又，因爲對於沒有必要蝕刻的領域係不進行電 解蝕刻，因此不會發生浪費的用電量。甚至，由於不會對 蝕刻液中發生浪費的鋁溶解，因此可抑制蝕刻液的劣化。 又，由於第2開孔部之面積係被限定成第1開孔部之面積 -27- 201040995 的0.7倍至1.15倍，因此在鋁板上不會發生過蝕刻部位 或蝕刻不足部位。因此，可製造靜電容量高的電解電容器 用銘電極板。 【圖式簡單說明】 [圖1]適用了本發明之電解電容器用鋁電極板之製造 裝置的說明圖。 [圖2]適用了本發明之電解電容器用鋁電極板之製造 方法中，形成在鋁板的遮罩的說明圖。 [圖3]使用適用了本發明之電解電容器用鋁電極板的 固體鋁電解電容器用的陽極的模式性圖示之說明圖。 [圖4]適用了本發明之電解電容器用鋁電極板之製造 方法中，第1開孔部與第2開孔部之面積比，與靜電容量 値之關係的圖形。 [圖5]本發明之實施例及比較例所述之電解電容器用 銘電極板的平面構成及剖面構成的說明圖。 [圖6]本發明的其他實施形態的說明圖。 [圖7]先前之電解電容器用鋁電極板的說明圖。 [圖8]參考例所述之電解電容器用鋁電極板的說明 圖。 【主要元件符號說明】 10 :鋁板 1 2 :未蝕刻部位 -28- 201040995 1 3 :鈾刻部位 1 3 :過蝕刻部位 13t :蝕刻不足部位 1 4 :鈾刻板 1 5 :陽極 20a、20b ：電極 30a、30b ：第1遮罩 0 3 1 a、3 1 b :第1開孔部 40a、40b :第2遮罩 4 1 a、4 1 b :第2開孔部 〇 -29Mixed aqueous solution Uranium engraving temperature: 1 7 °C Electrolytic waveform: sinusoidal alternating current, frequency 2 0 Hz Current density: 〇·3 A/cm2 Electrolysis time: 2700 seconds AC etching is performed to obtain an etched plate 14 . At this time, in any of the first etching process and the second etching process, as described with reference to FIG. 1, the first masks 30a and 30b' are formed on the aluminum plate 10, and the first electrodes 20a and the first electrodes are formed. The second electrode 20b forms the second masks 40a and 40b. Here, the area of the second opening portions 41a and 41b is changed to 1.20 times (Comparative Example 1) and 1.15 times (Example 1) of the area of the first opening portions 3 1 a and 3 1 b. Etching was carried out by using ΐ·〇〇 times (Example 2), 0.70 times (Example 3), 0.65 times (Comparative Example 2), and 0.50 times (Comparative Example 3). In addition, as a reference example, the first masks 30a and 30b' are formed on the aluminum plate 1 but the second masks 4a and 40b are not formed on the first electrode 20a and the second electrode 20b. It. Next, the etching plate 14 was anodized with a chemical conversion voltage of 6 V in ammonium adipate, and the electrostatic capacity was measured. The measurement results of the electrostatic capacity are shown in Table 1. The measurement of the electrostatic capacity and the withstand voltage of the film was carried out in accordance with the method specified in EIAJ. -22- 201040995 [Table l] Area ratio * Electrostatic capacity μΡ/cm2 Film withstand voltage V CV product pFV/cm2 Remarks 1.20 712 6.0 4272 Comparative Example 1 1.15 762 6.0 4572 Example 1 1.00 798 6.1 4868 Example 2 0.70 759 6.0 4554 Example 3 0.65 719 6.1 4386 Comparative Example 2 0.50 660 6.3 4158 Comparative Example 3 Αητ No 689 6.0 4134 Reference Example Second opening portion 41a, 41b Area First opening portion 31a, 31b surface i again, order 2 The result of plotting the area ratio of the opening portions 4 1 a and 4 1 b to the first opening portions 3 1 a and 3 1 b as the horizontal axis and the capacitance 値 (CV product) as the vertical axis is shown in FIG. Figure 4. Further, in Fig. 5, the relationship between the planar configuration of each sample and the cross-sectional configuration is schematically illustrated. 5(a) is a plan view and an A-A' cross-sectional view of the etched plate described in Comparative Example 1q, and FIG. 5(b) is a plan view and a B-B1 of the etched plate described in Embodiment 2. FIG. 5(c) is a plan view of the etched plate and an explanatory view of a C-C1 cross-sectional view of the reference example. As shown in Table 1 and FIG. 4, the area of the second opening portions 41a and 41b is set to 1.15 times the area of the first opening portions 31a and 31b (Example 1) and 1.00 times (Example 2). When the ratio is 0.70 times (Example 3), the electrostatic capacity (CV product) can be increased by about 10% or more as compared with the reference example. On the other hand, the area of the second opening portions 41a and 41b is set to 1.20 times (Comparative Example 1) and -23 to 201040995 〇·65 times the area of the first opening portions 31a and 31b (Comparative Example 2) In the case of 0.50 times (Comparative Example 3), the increase rate of the electrostatic capacitance (CV product) when compared with the example was less than 6%. It is as follows. First, when the area of the second opening portions 41a and 41b is 1.25 times the area of the first hole portions 31a and 31b (Comparative Example 1), the area of the first opening portions 31a and 31b is second. Since the area of the hole portions 41a and 4 is excessively wide, as shown in Fig. 5(a), the end portion of the portion (the vicinity of the first masks 30a and 30b) exposed by the first opening portion 31b is etched. At 13 s, the electrostatic capacity cannot be increased. Further, when the areas of the first hole portions 41a and 41b are set to be 0.5 times the surface of the first opening portions 31a and 31b (Comparative Example 3), the area is larger than the first opening portion 3 1 a, 3 Since the area of the second opening portions 41a and 41b is too narrow, the portion to be exposed is exposed in the portions of the first opening portions 3 1 a and 3 1 b as indicated by B, and the electrostatic capacitance cannot be increased. On the other hand, when the area of the second opening portions 41a and 41b is set to 1.00 times the area of the opening portions 31a and 31b (Example 3), the over-etched portion 13s does not occur as indicated by 5(b). Or etch less than 13t' so it can increase the electrostatic capacity. Further, it has been confirmed that the area of the opening portions 4 1 a and 4 1 b is not set to 0. 7 times to 1.15 times of the first opening portions 3 1 a and 3 1 b, and does not occur. Pass the uranium engraved part for 13 s or the hungry foot part 13t. Therefore, the area of the second opening portions 41a and 41b is preferably 0.7 times to 1.15 times the area of the first opening portions 31a and 31b. Referring to the reason 1 open phase compared to lb ί 1 a, will be 2 open product lb B 5 (c) is not enough to the second part of the picture as the area is not, the system, compared with -24- 201040995 (the main form of this form (Effects) As described above, in the present embodiment, when the electrolytic etching is performed, the areas where the etching is not required on the aluminum plate 1 are covered by the first masks 30a and 3b, so that the aluminum plate 10 is placed on the aluminum plate 10. The terminal 19 can be connected to the connection region 512 in which the first masks 30a and 3b become the uranium-imprinted portion 12. Therefore, the reliability of the connection portion of the aluminum electrode plate (etching plate 14) for the electrolytic capacitor and the terminal 19 is high. 0 Also, since there is no electrolytic etching in the field where etching is not necessary, wasteful power consumption does not occur. Further, since the wasteful aluminum is not dissolved in the etching liquid, deterioration of the etching liquid can be suppressed. Further, the first masks 40a and 40b described in the second masks 40a and 40b' are provided in the first electrode 20a and the second electrode 20b, and are in the field of vertical projection of the first opening portions 31a and 31b. The second opening portions 41a and 41b are provided. Therefore, the second opening portions 41a and 41b have the same shape as the first opening portions 31a and 31b. Further, the area Q of the second opening portions 41a and 41b is limited to 0.7 times to 1.15 times the area of the first opening portions 31a and 31b. Therefore, the area exposed by the first opening portions 31a and 31b in the aluminum plate 10 and the areas exposed by the second opening portions 4 1 a and 4 1 b in the first electrode 20a and the second electrode 20b are exposed. Since an appropriate potential distribution is formed between them, the over-etched portion 13s or the uranium-inserted portion 1 3 t does not occur on the aluminum plate 10. In other words, when the area of the second opening portions 4 1 a and 4 1 b is less than 0.7 times the area of the first opening portions 31a and 31b, the first opening portion 3 1 a is formed in the aluminum plate 10 . The end portion of the exposed area of 3 1 b will have an under-etched portion 13t, resulting in a low electrostatic capacitance drop of -25,040,995 for the aluminum electrode plate for electrolytic capacitors. In contrast, when the area of the second opening portions 41a and 41b is 1.15 times larger than the area of the first opening portions 31a and 31b, the area of the aluminum plate 10 exposed by the first opening portions 31a and 31b is The etched portion 13s occurs at the end portion, resulting in a decrease in the electrostatic capacity of the aluminum electrode plate for the electrolytic capacitor. Therefore, in the present embodiment, the area ratio of the second opening portions 41a and 41b to the first opening portions 31a and 31b is optimized. Therefore, an aluminum electrode plate for an electrolytic capacitor having a high electrostatic capacitance can be produced. In particular, when electrolytic etching is performed until the thickness of the uranium engraved portion 13 in the aluminum plate 1 is 75 μm or more per one side, once the potential distribution is disordered and current concentration occurs, the overetched portion 1 easily occurs. 3 s, but according to this aspect, it is difficult to cause the current concentration to occur. Therefore, the electrolytic etching is not so deep, and in return, an aluminum electrode plate for an electrolytic capacitor having a high electrostatic capacitance can be produced. Further, in the first masks 30a and 30b, the portions sandwiched by the first opening portions 31a and 31b include strip portions 32a and 32b having a width of 1 mm or more. Therefore, a strip-shaped unetched portion 1 2 having a width of 1 mm or more can be formed, and if it is the strip-shaped unetched portion 1 2 described above, the terminal 19 can be surely connected. Further, since the thickness of the first masks 30a and 30b is 0.1 mm or less, the bubbles generated during the etching are not pulled by the gaps of the first masks 30a and 30b to cover the aluminum sheets during the etching. 1 〇 surface. Therefore, in the aluminum plate 1 , the current density in the region exposed by the first opening portions 3 1 a and 3 1 b can be prevented from fluctuating with the bubbles on the surface of the aluminum plate 10. -26- 201040995 (Other Embodiments) Fig. 6 is an explanatory view showing another embodiment of the present invention. In the above embodiment, the shape of the first opening portions 3 1 a and 3 1 b is a square shape. However, as shown in FIG. 6( a ), the shapes of the first opening portions 31 a and 31 b are quadrangular. It is preferable that the corner portion is cut into an arc shape. Further, as shown in Fig. 6(b), the shape of the first opening portions 3 1a and 31b is preferably a circle such as a perfect circle, a flat circle or an ellipse. When the first opening portions 31a and 31b are in a square shape of 0, when the etching is performed, current concentrates in the corner portions of the square shape and tends to be easily etched. However, the first opening portions 31a and 31b have a square shape. When the corner portion is cut into an arc shape or a circular shape, such current concentration can be prevented. Therefore, the etching plate 14 having a high electrostatic capacitance can be stably produced. Further, in the case of adopting the above shape, the quadrilateral anode 15 can be obtained by punching a square-shaped field indicated by a broken line L1 by punching or the like. 〇 [Probability of industrial use] In the present invention, in the case of performing electrolytic etching, the field which is not required to be etched on the aluminum plate is covered with the first mask, so that the aluminum plate is covered by the first cover. In the field where the cover becomes an unetched portion, the terminal can be connected. Therefore, the reliability of the connection portion between the aluminum electrode plate and the terminal for the electrolytic capacitor is high. Further, since the electroless etching is not performed in the field where etching is not necessary, wasteful power consumption does not occur. Further, since the aluminum which is wasted in the etching liquid is not dissolved, deterioration of the etching liquid can be suppressed. Further, since the area of the second opening portion is limited to 0.7 times to 1.15 times the area of the first opening portion -27 - 201040995, the over-etched portion or the under-etched portion does not occur on the aluminum plate. Therefore, it is possible to manufacture an electrode plate for an electrolytic capacitor having a high electrostatic capacitance. [Brief Description of the Drawings] [Fig. 1] An explanatory view of a manufacturing apparatus for an aluminum electrode plate for an electrolytic capacitor of the present invention. Fig. 2 is an explanatory view of a mask formed on an aluminum plate in the method for producing an aluminum electrode plate for an electrolytic capacitor of the present invention. Fig. 3 is an explanatory view showing a schematic diagram of an anode for a solid aluminum electrolytic capacitor to which an aluminum electrode plate for an electrolytic capacitor of the present invention is applied. [Fig. 4] A graph showing the relationship between the area ratio of the first opening portion and the second opening portion and the capacitance 値 in the method for producing an aluminum electrode plate for an electrolytic capacitor of the present invention. Fig. 5 is an explanatory view showing a plan configuration and a cross-sectional configuration of an electrode plate for an electrolytic capacitor according to an embodiment of the present invention and a comparative example. Fig. 6 is an explanatory view showing another embodiment of the present invention. Fig. 7 is an explanatory view of a prior art aluminum electrode plate for an electrolytic capacitor. Fig. 8 is an explanatory view of an aluminum electrode plate for an electrolytic capacitor described in Reference Example. [Main component symbol description] 10 : Aluminum plate 1 2 : Unetched portion -28- 201040995 1 3 : Uranium engraved portion 13: Over-etched portion 13t: Under-etched portion 1 4: Uranium plate 1 5 : Anode 20a, 20b: Electrode 30a, 30b: first mask 0 3 1 a, 3 1 b : first opening portions 40a, 40b: second mask 4 1 a, 4 1 b : second opening portion 〇-29