TW201803428A - Method of manufacturing glass substrate that has through hole, method of forming through hole in glass substrate and system for manufacturing glass substrate that has through hole - Google Patents

Abstract

A method of manufacturing a glass substrate that has a through hole, includes (1) forming an initial hole in a glass substrate by irradiating laser light from a first surface side of the glass substrate; (2) performing a first etching process using a first etching solution to form, from the initial hole, a first through hole that extends from a first opening formed at a first surface to a second opening formed at a second surface, and to make a ratio "d1/Rt1" of a thickness "d1" of the glass substrate with respect to a diameter "Rt1" of the first opening to be within a range between 10 to 20; and (3) performing a second etching process to enlarge the first through hole using a second etching solution, whose etching rate with respect to the glass substrate is faster than that of the first etching solution.

Description

Method for producing glass substrate having through holes and method for forming through holes in glass substrate

The present invention relates to a method of producing a glass substrate having a through hole and a method of forming a through hole in the glass substrate.

In the prior art, a technique of forming one or two or more through holes in a glass substrate by irradiating laser light generated from a laser light source onto a glass substrate is known (for example, Patent Document 1). Such a glass substrate having a through hole is used, for example, in a glass interposer in which a through hole is filled with a conductive filler. [Prior Art Document] [Patent Document] [Patent Document 1] Japanese Patent Laid-Open Publication No. 2003-226551

[Problems to be Solved by the Invention] Generally, the glass substrate having the through-holes is manufactured by the following processes: (1) preparing a glass substrate having first and second surfaces; (2) by first from the glass substrate The side of the surface is irradiated with the laser light to form a through hole penetrating from the first opening of the first surface of the glass substrate to the second opening of the second surface of the glass substrate; and (3) by wet etching the glass substrate The through hole is enlarged to the required size. Here, in the process of the process (3), there is a problem in that a narrow portion is formed in a substantially central portion of the through hole along the entire longitudinal direction of the through hole. The reason for this is that, in general, the through hole formed by the process of (2) has a relatively small diameter compared to the thickness of the glass substrate. That is, in the case where the "fine" through-hole is subjected to the wet etching treatment in the process of (3), the concentration of the etching solution is not sufficiently diffused inside the through-hole, and the etching reaction is generated. The object stagnates in the through hole. As a result, it is difficult to sufficiently carry out the etching reaction inside the through hole, and a narrow portion is generated. In particular, in the field of the glass interposer, a very fine through hole is formed in the process of (2). Therefore, in the manufacturing process of the glass interposer, there is a problem that such a narrow portion is more likely to occur in the through hole. An object of the present invention is to provide a method for producing a glass substrate having through holes having a relatively uniform shape. Further, it is an object of the present invention to provide a method of forming a through hole having a relatively uniform shape on a glass substrate. Further, an object of the present invention is to provide a manufacturing system for a glass substrate in which a through hole having a relatively uniform shape is formed on a glass substrate. [Technical means for solving the problem] The present invention provides a manufacturing method of a glass substrate having a through-hole, which has the following processes: (1) by using a glass substrate having first and second surfaces facing each other The side of the first surface is irradiated with laser light to form an initial hole on the glass substrate; (2) the first etching process is performed on the glass substrate by the first etching solution, and the initial hole is formed from the initial hole When the first opening of the first surface extends to the first through hole formed in the second opening of the second surface, when the thickness of the glass substrate is d ₁ and the diameter of the first opening is R _t1 a ratio of d ₁ /R _t1 is in the range of 10 to 20; and (3) after the process of the above (2), using a second etching solution having a larger etching rate than the first etching solution for the glass substrate, The glass substrate is subjected to a second etching treatment to expand the first through hole. Further, the present invention provides a method of forming a through hole in a glass substrate, which has the following process: (1) by the side of the first surface of the glass substrate having the first and second surfaces facing each other Irradiating the laser light to form an initial hole on the glass substrate; (2) performing the first etching treatment on the glass substrate by the first etching solution, and forming the first opening formed in the first surface from the initial hole 2 is formed to extend to the first opening of the first through hole of said second surface, the thickness of the glass substrate ₁ to be set to D, the diameter of the opening of the first set when R _t1, ratio d ₁ / R _t1 is a range of 10 to 20; and (3) after the process of the above (2), the second etching solution having a larger etching rate than the first etching solution for the glass substrate is used to perform the second etching on the glass substrate. The etching process increases the first through hole. [Effect of the Invention] According to the present invention, a method of manufacturing a glass substrate having through holes having a relatively uniform shape can be provided. Further, according to the present invention, a method of forming a through hole having a relatively uniform shape on a glass substrate can be provided. Moreover, according to the present invention, it is possible to provide a manufacturing system of a glass substrate in which a glass substrate is formed with a through hole having a relatively uniform shape.

_t0 ，第2開口24之直徑為

_b0 。 繼而，於製程S30中，為了將貫通孔20之直徑擴張至所需之尺寸，而將玻璃基板10進行濕式蝕刻處理。 此處，於由製程S20所形成之貫通孔20之第1開口22之直徑

_t0 (或第2開口24之直徑

_b0 )足夠大之情形時，在濕式蝕刻處理時，可將蝕刻溶液沿貫通孔20之全長均勻且充分地供給。因此，貫通孔20被相對均勻地蝕刻。 然而，若第1開口22之直徑

_t0 及第2開口24之直徑

_b0 變小，則濕式蝕刻處理時，於此種微細之貫通孔20之內部中，難以使蝕刻反應充分進行。其原因在於：於貫通孔20之內部，蝕刻溶液之濃度擴散未充分進行，又，蝕刻反應之生成物易停滯於貫通孔20內。又，於此種微細之貫通孔20中，亦有向貫通孔20之內部充分供給蝕刻溶液本身變得困難之情形。 因此，貫通孔20係第1及第2開口22、24以及其附近被選擇性地蝕刻。換言之，於貫通孔20之內部，難以對貫通孔20進行充分之蝕刻處理。 結果，製程S30後，如圖2(c)所示，形成剖面為所謂「砂鐘型」之擴張貫通孔30。即，所形成之擴張貫通孔30於第1開口32及第2開口34之側獲得特定之尺寸，但於貫通孔30之內部，具有不滿足特定之尺寸之狹窄部36。 如此，於先前之製造方法中，尤其存在如下問題，即，若貫通孔20之直徑(

_t0 、

_b0 )相對於玻璃基板10之厚度相對變小，則擴張貫通孔30具有顯著之狹窄部36。 (具有本發明之一實施形態之貫通孔之玻璃基板之製造方法) 繼而，參照圖3～圖7，對具有本發明之一實施形態之貫通孔之玻璃基板之製造方法之一例進行說明。 圖3概略地表示具有本發明之一實施形態之貫通孔之玻璃基板之製造方法之流程的一例。又，圖4～圖7模式性地表示具有本發明之一實施形態之貫通孔之玻璃基板之製造方法中之各製程的態樣。 如圖3所示，具有本發明之一實施形態之貫通孔之玻璃基板之製造方法(以下稱為「第1製造方法」)具有： (0)準備具有相互對向之第1及第2表面之玻璃基板的製程(製程S110)； (1)藉由自上述玻璃基板之上述第1表面之側照射雷射光，而於上述玻璃基板上形成初始孔的製程(製程S120)； (2)利用第1蝕刻溶液，對上述初始孔進行第1蝕刻處理， 藉此，於上述玻璃基板形成自第1開口延伸至第2開口之第1貫通孔， 於將上述(2)之製程後之玻璃基板之厚度設為d₁ 、將上述第1貫通孔之上述第1開口之直徑設為R_t1 時，比d₁ /R_t1 為10～20之範圍的製程(製程S130)；及 (3)利用第2蝕刻溶液，對上述第1貫通孔進行第2蝕刻處理的製程(製程S140)。 以下，參照圖4～圖7，對各製程進行詳細說明。 (步驟S110) 首先，準備具有圖4所示之剖面形狀之玻璃基板110。玻璃基板110具有相互對向之第1表面112及第2表面114。又，玻璃基板110具有初始厚度d₀ 。 初始厚度d₀ 例如較佳為0.1 mm～0.7 mm，更佳為0.2 mm～0.5 mm，尤佳為0.3 mm～0.5 mm。若初始厚度d₀ 低於0.3 mm，則即便於先前之製造方法中，亦存在難以形成上述砂鐘型之擴張貫通孔之情況。 玻璃基板110之組成並無特別限定。玻璃基板110可為例如鈉鈣玻璃、及無鹼玻璃等。 (步驟S120) 繼而，藉由自玻璃基板110之第1表面112之側照射雷射光，而於玻璃基板110上形成1個或2個以上之初始孔。 只要能夠於玻璃基板110上形成初始孔，則雷射光之種類及照射條件並無限定。雷射光可為例如CO₂ 雷射、UV雷射等。又，雷射光亦可為自短脈衝雷射(例如微微秒雷射、飛秒雷射)振盪之雷射光。 再者，初始孔之形態並無特別限定，初始孔可為貫通孔，亦可為非貫通孔。又，初始孔亦可為沿玻璃基板110之厚度方向排列之由複數個孔隙構成之孔隙行。於使用短脈衝雷射之情形時，易形成孔隙行作為初始孔。 圖5表示於玻璃基板110上形成初始孔120之狀態。再者，於圖5所表示之例中，初始孔120為貫通孔，此處稱為「初始貫通孔」120。 如圖5所示，初始貫通孔120係自形成於玻璃基板110之第1表面112之第1初始開口122延伸至形成於玻璃基板110之第2表面114之第2初始開口124。於初始貫通孔120中，將第1初始開口122之直徑稱為R_t0 ，將第2初始開口124之直徑稱為R_b0 。 此處，該階段中之玻璃基板110之厚度d₀ 與第1初始開口122之直徑R_t0 之比即d₀ /R_t0 為例如25以上。比d₀ /R_t0 較佳為30以上。於比d₀ /R_t0 為25以上之情形時，藉由將先前之製造方法變更為第1製造方法，可獲得較大之效果。即，於比d₀ /R_t0 為25以上之情形時，就先前之製造方法而言，會因蝕刻製程而於貫通孔內產生較大之狹窄部。然而，利用第1製造方法，可有意義地抑制該狹窄部。 第1初始開口122之直徑R_t0 為例如15 μm以下，亦可為13 μm以下。 再者，圖5所表示之例中，為了簡化，以初始貫通孔120之第1初始開口122之直徑R_t0 與第2初始開口124之直徑R_b0 實質上相等之方式而表示。然而，必須注意利用雷射光照射而形成之初始貫通孔120實際上成為直徑自第1初始開口122向第2初始開口124逐漸變小之錐形之形態的情況較多。因此，通常R_t0 ＞R_b0 。 再者，圖5僅表示單一之初始貫通孔120，但亦可於玻璃基板110上形成複數個初始貫通孔120。 (步驟S130) 繼而，為了擴大初始貫通孔120之直徑，而利用第1蝕刻溶液對初始貫通孔120進行蝕刻處理(以下稱為「第1蝕刻處理」或「第1蝕刻製程」)。 第1蝕刻溶液只要能夠對初始貫通孔120適當地進行蝕刻，則其種類並無特別限定。例如，第1蝕刻溶液可為包含氫氟酸之酸溶液。又，第1蝕刻溶液亦可為除氫氟酸之外，包含至少1種其他酸之混酸溶液。例如，第1蝕刻溶液亦可為氫氟酸與鹽酸之混酸溶液或氫氟酸與硝酸之混酸溶液。 第1蝕刻處理中之第1蝕刻溶液之針對玻璃基板110之蝕刻速率V₁ 為例如0.5 μm/min以下，較佳為0.2 μm/min以下，更佳為0.02 μm/min以下。 第1蝕刻製程可於任意適當之溫度下實施，處理溫度可為例如室溫。 第1蝕刻製程可藉由例如向初始貫通孔120內選擇性地供給第1蝕刻溶液而實施(以下將此種方法稱為「局部蝕刻處理(方法)」)。藉由局部蝕刻處理方法，可不使玻璃基板110之厚度變化地擴張初始貫通孔120之直徑。例如，以不阻塞初始貫通孔120之方式貼上蝕刻保護膜進行蝕刻即可。 或者，第1蝕刻製程亦可藉由使玻璃基板110整體暴露於第1蝕刻溶液中而實施(以下將此種方法稱為「整體蝕刻處理(方法)」)。例如，第1蝕刻製程亦可藉由使具有初始貫通孔120之玻璃基板110浸漬於收容有第1蝕刻溶液之浴槽內(浸漬方式)而實施。或者，第1蝕刻製程亦可為將第1蝕刻溶液直接澆淋玻璃基板之方式(噴淋式)。於整體蝕刻處理方法之情形時，玻璃基板110之厚度本身亦自d₀ 變化(減少)為d₁ 。 又，於第1蝕刻製程中，亦可對玻璃基板110施加超音波、或使玻璃基板110振動、或使蝕刻溶液起泡。藉此能夠進行更均勻之蝕刻。 以下，作為一例，對利用整體蝕刻處理方法而實施第1蝕刻製程之情況進行說明。 圖6模式性地表示利用整體蝕刻處理方法之第1蝕刻製程後之玻璃基板110之剖面。 如圖6所示，藉由第1蝕刻製程，玻璃基板110變化成厚度d₁ 。即，玻璃基板110具有第1新生表面113及第2新生表面115。 又，初始貫通孔120變成第1貫通孔130。第1貫通孔130自形成於第1新生表面113之第1開口132延伸至形成於第2新生表面115之第2開口134。 此處，第1製造方法具有以下特徵：將第1開口132之直徑設為R_t1 時，比d₁ /R_t1 為10～20之範圍。比d₁ /R_t1 更佳為10～15之範圍。 藉由將比d₁ /R_t1 設定為此種範圍內，於以後之製程S140中，可顯著抑制可能形成於貫通孔之狹窄部。 即，藉由於第1蝕刻製程中以比d₁ /R_t1 為20以下之方式擴張初始貫通孔120，可於第2蝕刻製程中抑制在已擴張之第1貫通孔130內產生顯著之狹窄部。 再者，將比d₁ /R_t1 設為10以上之原因在於：即便實施第1蝕刻製程直至比d₁ /R_t1 未達10，第2蝕刻製程中亦幾乎不產生變化。即，藉由將比d₁ /R_t1 設為10以上，可縮短第1蝕刻製程之處理時間。 再者，有將如上所述之利用整體蝕刻處理方法所獲得之玻璃基板之第1新生表面113尤其稱為「與玻璃基板之第1表面對應之表面」之情形。同樣地，有將第2新生表面115尤其稱為「與玻璃基板之第2表面對應之表面」之情形。 (步驟S140) 繼而，為了將第1貫通孔130之直徑進一步擴大，即，為了將貫通孔擴張至所需之直徑，而利用第2蝕刻溶液對第1貫通孔130進行蝕刻處理(以下稱為「第2蝕刻處理」或「第2蝕刻製程」)。 第2蝕刻製程與上述第1蝕刻製程之情況相同，可利用局部蝕刻處理方法或整體蝕刻處理方法而實施。又，第2蝕刻製程可為與第1蝕刻製程相同之處理方法(方式)，亦可為不同之處理方法(方式)。例如，第1蝕刻製程可設為浸漬方式，第2蝕刻製程可設為噴淋方式。第1蝕刻製程由於處理時間容易變長，故而就生產性(成本)方面而言較佳為浸漬方式。第2蝕刻製程由於一面抑制玻璃基板之厚度之減少一面易於調整孔徑，故較佳為噴淋方式。 此處，以利用整體蝕刻處理方法實施第2蝕刻製程之情況為例進行說明。 於整體蝕刻處理方法中，第2蝕刻製程可藉由例如使具有第1貫通孔130之玻璃基板110浸漬於收容有第2蝕刻溶液之浴槽內而實施。藉此，玻璃基板110之厚度自d₁ 變化(減少)為d₂ 。 第2蝕刻溶液可為例如包含氫氟酸之酸溶液。又，第2蝕刻溶液亦可為除氫氟酸以外還包含至少1種其他酸之混酸溶液。混酸溶液亦可與第1蝕刻溶液相同。第2蝕刻製程可於任意適當之溫度下實施，處理溫度可為例如室溫。 此處，第2蝕刻溶液係自針對玻璃基板110之蝕刻速率能較上述第1蝕刻溶液更大者中選定。 例如，第2蝕刻處理中之第2蝕刻溶液之針對玻璃基板110之蝕刻速率V₂ 可為上述第1蝕刻溶液之針對玻璃基板110之蝕刻速率V₁ 的3倍以上，較佳為10倍以上，更佳為100倍以上。例如，第2蝕刻溶液之針對玻璃基板110之蝕刻速率V₂ 為5.0 μm/min以下，較佳為2.0 μm/min以下，更佳為1.5 μm/min以下。蝕刻速率V₂ 可為例如1.0 μm/min～1.5 μm/min之範圍。 圖7模式性地表示第2蝕刻製程後之玻璃基板110之剖面。 如圖7所示，藉由第2蝕刻製程，玻璃基板110變化成厚度d₂ 。即，玻璃基板110具有第3新生表面117及第4新生表面119。 又，第1貫通孔130變化成第2貫通孔140。第2貫通孔140自形成於第3新生表面117之第3開口142延伸至形成於第4新生表面119之第4開口144。 經由以上之製程，可製造形成有具有所需之尺寸之第2貫通孔140之玻璃基板110。 此處，於第1製造方法中，經由第1蝕刻製程及第2蝕刻製程之至少2個階段之蝕刻製程而形成貫通孔(第2貫通孔140)。 其中，於第1蝕刻製程中，利用蝕刻速率V₁ 相對較小之第1蝕刻溶液蝕刻初始貫通孔120。 第1蝕刻溶液由於蝕刻速率V₁ 相對較小，故蝕刻處理需要相應之時間。因此，於初始貫通孔120內之第1蝕刻溶液之濃度擴散相對迅速發生。即，第1蝕刻溶液由於針對玻璃基板110之蝕刻速率V₁ 相對較小，故與初始貫通孔120之第1初始開口122或第2初始開口124附近之玻璃基板110被蝕刻相比，第1蝕刻溶液相對較快地擴散至初始貫通孔120內。因此，第1初始開口122或第2初始開口124附近之玻璃基板110被蝕刻之程度與於初始貫通孔120中心部玻璃基板110被蝕刻之程度的差變小。藉此，由蝕刻反應所產生之生成物容易自初始貫通孔120之內部擴散至外部，從而顯著抑制停滯於初始貫通孔120之內部之情況。 因此，藉由第1蝕刻製程，可於抑制初始貫通孔內之狹窄部之顯著產生之狀態下，將初始貫通孔擴張至充分之直徑。 繼而，於第2蝕刻製程中，使用蝕刻速率V₂ 相對較大之第2蝕刻溶液。 但是，藉由第1蝕刻製程，初始貫通孔120已經充分擴張。因此，於第2蝕刻製程中，可使第2蝕刻溶液相對迅速且均勻地分佈於第1貫通孔130。又，由蝕刻反應所產生之生成物自第1貫通孔130之內部快速移動，從而顯著抑制停滯於第1貫通孔130之內部之情況。 因此，第1貫通孔130被相對均勻地蝕刻，即便於第2蝕刻製程中，第1貫通孔130內亦難以產生顯著之狹窄部。 以上之結果為，藉由第1製造方法，與如先前之僅利用單一之蝕刻製程而擴張初始貫通孔之情形相比，可顯著抑制狹窄部之形成，能夠形成形狀相對整齊之貫通孔。 本發明之一實施形態之方法尤其於使用UV雷射或短脈衝雷射之情形等、形成縱橫比相對較高之初始孔(孔隙行)之情形時有效。其原因在於：若初始孔之縱橫比較高，則蝕刻溶液之濃度擴散更難進行，或更難向初始孔內部供給蝕刻溶液。 以上，參照圖3～圖7對具有本發明之一實施形態之貫通孔之玻璃基板之製造方法之一例進行了說明。但是，業者應當明白，上述記載僅為一例，本發明亦可藉由其他態樣而實施。 例如，於上述記載中，製程S120所形成之初始孔為初始貫通孔120。然而，初始孔亦可為非貫通孔、及沿玻璃基板之厚度方向排列之由複數個孔隙構成之孔隙行。於此情形時，於第1蝕刻製程後形成貫通孔，藉由第2蝕刻製程擴張此種貫通孔。 又，第1製造方法具有2個階段之蝕刻製程。然而，於具有本發明之一實施形態之貫通孔之玻璃基板之製造方法中，蝕刻製程亦可分3個階段以上而實施。於此情形時，可於第1蝕刻製程中，使用蝕刻速率相對較小之第1蝕刻溶液，於第2蝕刻製程中，使用蝕刻速率為中速程度之第2蝕刻溶液，於第3蝕刻製程中，使用蝕刻速率相對較大之第3蝕刻溶液。 進而，具有上述貫通孔之玻璃基板之製造方法亦可應用於在玻璃基板形成貫通孔之方法。 (具有本發明之另一實施形態之貫通孔之玻璃基板之製造方法) 具有本發明之另一實施形態之貫通孔之玻璃基板之製造方法係如下製造方法，其係具有貫通孔之玻璃基板之製造方法，具有如下製程： (1)藉由自具有相互對向之第1及第2表面之玻璃基板之第1表面之側照射雷射光，而於玻璃基板上形成初始孔； (2)利用第1蝕刻溶液，對初始孔進行第1濕式蝕刻處理， 藉此，形成自玻璃基板之第1表面或與該第1表面對應之表面延伸至玻璃基板之第2表面或與該第2表面對應之表面之第1貫通孔；及 (3)利用第2蝕刻溶液，對第1貫通孔進行第2濕式蝕刻處理， 藉此，形成第1貫通孔被蝕刻而成之第2貫通孔， 第2蝕刻溶液具有針對玻璃基板而言較第1蝕刻溶液更大之蝕刻速率。 如上所述，藉由使第2蝕刻溶液具有針對玻璃基板而言較第1蝕刻溶液更大之蝕刻速率，可形成形狀相對整齊之貫通孔。尤其是於使用UV雷射或短脈衝雷射之情形時形成縱橫比相對較高之初始孔，故而若使用本實施形態之製造方法則屬有效。 具有上述貫通孔之玻璃基板之製造方法亦可應用於在玻璃基板上形成貫通孔之方法。 本實施形態可將參照上述圖3～圖7之一實施形態之構成進行適當組合。再者，具體構成之說明可適用上述一實施形態之說明，故而省略。 (製造具有本發明之另一實施形態之貫通孔之玻璃基板之系統) 製造具有本發明之另一實施形態之貫通孔之玻璃基板之系統係如下系統，其係製造具有貫通孔之玻璃基板之系統，具備： 雷射加工系統，其係藉由向玻璃基板照射雷射光，而於上述玻璃基板上形成初始孔；及 蝕刻系統，其係針對上述玻璃基板，藉由蝕刻初始孔而形成貫通孔； 上述蝕刻系統係 具有第1蝕刻系統及第2蝕刻系統， 上述第1蝕刻系統係進行使用第1蝕刻溶液之第1蝕刻處理之系統， 上述第2蝕刻系統係進行使用具有針對上述玻璃基板而言較上述第1蝕刻溶液更大之蝕刻速率之第2蝕刻溶液之第2蝕刻處理之系統， 上述蝕刻系統構成為於藉由上述第1蝕刻系統進行上述玻璃基板之處理後，藉由上述第2蝕刻系統進行上述玻璃基板之處理。 雷射加工系統較佳為具備UV雷射。又，雷射加工系統亦可具備微微秒雷射或飛秒雷射等短脈衝雷射。 如上所述，藉由使用具有針對玻璃基板而言較第1蝕刻溶液更大之蝕刻速率之蝕刻溶液作為第2蝕刻溶液，可形成形狀相對整齊之貫通孔。尤其是於使用UV雷射或短脈衝雷射之情形時形成相對縱橫比較高之初始孔，故而若使用本實施形態之系統形成具有貫通孔之玻璃基板則有效。 蝕刻系統較佳為進而具有洗淨系統。較佳為於利用第1蝕刻系統之第1蝕刻處理與利用第2蝕刻系統之第2蝕刻處理間，進行利用洗淨系統之洗淨處理。由於第1蝕刻處理與第2蝕刻處理中所使用之蝕刻溶液之濃度不同，故而較佳為預先於兩次處理間進行洗淨。洗淨處理使用例如純水。 上述系統亦可應用於在玻璃基板上形成貫通孔之方法。 本實施形態可將上述實施形態之構成進行適當組合。再者，具體構成之說明可適用上述實施形態之說明，故而省略。 [實施例] 以下，對本發明之實施例進行說明。再者，以下之記載中，例1～例4為實施例，例5為比較例。 (例1) 利用以下之方法，製造具有特定之尺寸之貫通孔之玻璃基板。 (雷射光照射) 首先，準備縱50 mm×橫50 mm×厚度(d₀ )400 μm之玻璃基板(無鹼玻璃基板)。 繼而，自該玻璃基板之第1表面(縱50 mm×橫50 mm之一表面)之側照射UV雷射光，形成初始貫通孔。初始貫通孔之第1初始開口(第1表面側之開口)之直徑R_t0 約為13 μm，相反側之第2表面上之第2初始開口之直徑R_b0 約為3 μm。因此，於該玻璃基板中，比d₀ /R_t0 約為30.8。 (第1蝕刻製程) 繼而，對所獲得之玻璃基板進行第1蝕刻處理。 第1蝕刻溶液設為0.4 wt%之氫氟酸溶液。第1蝕刻處理係藉由使玻璃基板於該氫氟酸溶液中浸漬80分鐘而實施。處理溫度為室溫。再者，玻璃基板於靜止狀態(即不負擔振動之狀態)下進行蝕刻。 藉此，初始貫通孔被蝕刻而獲得第1貫通孔。再者，玻璃基板本身亦被蝕刻，變成厚度d₁ ＝390 μm。 玻璃基板之第1表面側之第1貫通孔之第1開口之直徑R_t1 為25.1 μm，第2表面側之第2開口之直徑R_b1 為10.4 μm。因此，比d₁ /R_t1 約為15.6。 (第2蝕刻製程) 繼而，對玻璃基板進行第2蝕刻處理。 第2蝕刻溶液設為2 wt%之氫氟酸溶液。第2蝕刻處理係藉由使玻璃基板於該氫氟酸溶液中浸漬25分鐘而實施。處理溫度為室溫。再者，玻璃基板於靜止狀態(即不負擔振動之狀態)下進行蝕刻。第2蝕刻溶液之蝕刻速率V₂ 為第1蝕刻溶液之蝕刻速率V₁ 之大約10倍。 藉此，第1貫通孔被蝕刻而獲得第2貫通孔。再者，玻璃基板本身亦被蝕刻，變成厚度d₂ ＝360 μm。 玻璃基板之第1表面側之第2貫通孔之第3開口之直徑R_t2 為46.3 μm，第2表面側之第4開口之直徑R_b2 為33.8 μm。因此，比d₂ /R_t2 約為7.8。 (例2) 利用與例1相同之方法，製造具有特定之尺寸之貫通孔之玻璃基板。 但是，於例2中，第1蝕刻製程中，將利用第1蝕刻溶液進行之蝕刻時間設為120分鐘。又，第2蝕刻製程中，將利用第2蝕刻溶液進行之蝕刻時間設為21分鐘。 第1蝕刻製程後之玻璃基板之厚度d₁ ＝385 μm。又，玻璃基板之第1表面側之第1貫通孔的第1開口之直徑R_t1 為28.7 μm，第2表面上之第2開口之直徑R_b1 為15.6 μm。因此，比d₁ /R_t1 約為13.4。 另一方面，第2蝕刻製程後之玻璃基板之厚度d₂ ＝360 μm。玻璃基板之第1表面側之第2貫通孔的第3開口之直徑R_t2 為46.0 μm，第2表面側之第4開口之直徑R_b2 為34.3 μm。因此，比d₂ /R_t2 約為7.8。 (例3) 利用與例1相同之方法，製造具有特定之尺寸之貫通孔之玻璃基板。 但是，於該例3中，第1蝕刻製程中，將利用第1蝕刻溶液進行之蝕刻時間設為210分鐘。又，第2蝕刻製程中，將利用第2蝕刻溶液進行之蝕刻時間設為8分鐘。 第1蝕刻製程後之玻璃基板之厚度d₁ ＝370 μm。又，玻璃基板之第1表面側之第1貫通孔的第1開口之直徑R_t1 為36.8 μm，第2表面側之第2開口之直徑R_b1 為23.1 μm。因此，比d₁ /R_t1 約為10。 另一方面，第2蝕刻製程後之玻璃基板之厚度d₂ ＝360 μm。玻璃基板之第1表面側之第2貫通孔的第3開口之直徑R_t2 為46.4 μm，第2表面側之第4開口之直徑R_b2 為33.3 μm。因此，比d₂ /R_t2 約為7.8。 (例4) 利用與例1相同之方法，製造具有特定之尺寸之貫通孔之玻璃基板。 但是，於該例4中，第1蝕刻製程中，將利用第1蝕刻溶液進行之蝕刻時間設為40分鐘。又，第2蝕刻製程中，將利用第2蝕刻溶液進行之蝕刻時間設為30分鐘。 第1蝕刻製程後之玻璃基板之厚度d₁ 約為395 μm。又，玻璃基板之第1表面側之第1貫通孔的第1開口之直徑R_t1 為18.9 μm，第2表面側之第2開口之直徑R_b1 為7.6 μm。因此，比d₁ /R_t1 約為20.9。 另一方面，第2蝕刻製程後之玻璃基板之厚度d₂ ＝360 μm。又，玻璃基板之第1表面側之第2貫通孔的第3開口之直徑R_t2 為45.6 μm，第2表面側之第4開口之直徑R_b2 為34.0 μm。因此，比d₂ /R_t2 約為7.9。 (例5) 利用與例1相同之方法，製造具有特定之尺寸之貫通孔之玻璃基板。 但是，該例5中未實施第1蝕刻製程。即，照射UV雷射光，於玻璃基板上形成初始貫通孔後，對該玻璃基板僅實施第2蝕刻製程。於第2蝕刻製程中，將利用第2蝕刻溶液進行之蝕刻時間設為33分鐘。 第2蝕刻製程後之玻璃基板之厚度d₂ ＝360 μm。又，玻璃基板之第1表面側之第2貫通孔的第3開口之直徑R_t2 為45.6 μm，第2表面側之第4開口之直徑R_b2 為32.7 μm。因此，比d₂ /R_t2 約為7.9。 以下之表1中彙總表示有製造例1～例5中之玻璃基板時各製程中之玻璃基板之厚度、及貫通孔之開口之直徑等。 [表1]

(評估) 於以上述方式所製造之各玻璃基板中，觀察第2貫通孔之形態。更具體而言，於第2貫通孔中，測定與延伸方向垂直之剖面最小之狹窄部之直徑R_c 。 將結果彙總並示於表2。再者，例1～例5中任一玻璃基板中，第2貫通孔之狹窄部均存在於貫通孔之全長之大致中央部分。 [表2]

由該結果可知，於例5中，第2貫通孔之狹窄部之直徑R_c 極小，比R_c /R_t2 低於0.4。可知於例4中，第2貫通孔之狹窄部之直徑R_c 較例5而擴張。進而，可知於例1至例3中，第2貫通孔之狹窄部之直徑R_c 被顯著擴張，比R_c /R_t2 至少超過0.5。 如此，藉由實施2個階段之蝕刻製程，可抑制貫通孔之狹窄部之顯著產生。進而，確認到藉由實施2個階段之蝕刻製程，並且將第1蝕刻製程後之玻璃基板之厚度d₁ 與第1貫通孔之第1開口之直徑R_t1 之比d₁ /R_t1 設為10～20之範圍，可形成形狀相對整齊之貫通孔。Hereinafter, an embodiment of the present invention will be described with reference to the drawings. (Method of Manufacturing Glass Substrate Having Previous Through Holes) First, in order to better understand the features of the present invention, a method of manufacturing a glass substrate having a prior through hole will be briefly described with reference to FIGS. 1 to 2 . Fig. 1 schematically shows a flow of a method of manufacturing a glass substrate having a prior through hole (hereinafter simply referred to as "previous manufacturing method"). Further, Fig. 2 schematically shows one of the processes of the prior art shown in Fig. 1. As shown in FIG. 1, the prior manufacturing method has a process of preparing a glass substrate (process S10), a process of irradiating a glass substrate with laser light to form a through hole (process S20), and performing wet processing on a glass substrate having a through hole. The process of expanding the through hole to a desired size by etching (process S30). In the process S10, the glass substrate 10 having the first surface 12 and the second surface 14 as shown in FIG. 2(a) is prepared. Then, in the process S20, as shown in FIG. 2(b), the through hole 20 is formed in the glass substrate 10. The through hole 20 is formed by irradiating laser light (not shown) from the side of the first surface 12 of the glass substrate 10. The through hole 20 has a first opening 22 on the first surface 12 of the glass substrate 10 and a second opening 24 on the second surface 14 . The diameter of the first opening 22 is

_T0 , the diameter of the second opening 24 is

_B0 . Then, in the process S30, the glass substrate 10 is subjected to a wet etching treatment in order to expand the diameter of the through hole 20 to a desired size. Here, the diameter of the first opening 22 of the through hole 20 formed by the process S20

_T0 (or the diameter of the second opening 24)

_{When b0} ) is sufficiently large, the etching solution can be uniformly and sufficiently supplied along the entire length of the through hole 20 during the wet etching treatment. Therefore, the through holes 20 are relatively uniformly etched. However, if the diameter of the first opening 22 is

The diameter of _t0 and the second opening 24

_{When b0} is small, it is difficult to sufficiently perform the etching reaction in the inside of such fine through-holes 20 during the wet etching treatment. This is because the concentration of the etching solution is not sufficiently diffused inside the through hole 20, and the product of the etching reaction is likely to be stagnant in the through hole 20. Further, in such a fine through hole 20, it is difficult to sufficiently supply the etching solution itself to the inside of the through hole 20. Therefore, the through holes 20 are selectively etched by the first and second openings 22 and 24 and their vicinity. In other words, it is difficult to perform sufficient etching treatment on the through hole 20 inside the through hole 20. As a result, after the process S30, as shown in FIG. 2(c), the expanded through hole 30 having a cross section of a so-called "sand bell type" is formed. In other words, the formed expanded through hole 30 has a specific size on the side of the first opening 32 and the second opening 34, but has a narrow portion 36 that does not satisfy a specific size inside the through hole 30. Thus, in the prior manufacturing method, there is particularly a problem that if the diameter of the through hole 20 (

_T0 ,

_B0 ) The thickness of the glass substrate 10 is relatively small, and the expanded through hole 30 has a conspicuous narrow portion 36. (Manufacturing Method of Glass Substrate Having Through Hole in an Embodiment of the Present Invention) Next, an example of a method of manufacturing a glass substrate having a through hole according to an embodiment of the present invention will be described with reference to Figs. 3 to 7 . Fig. 3 is a view schematically showing an example of a flow of a method for producing a glass substrate having a through hole according to an embodiment of the present invention. 4 to 7 schematically show aspects of each process in the method of manufacturing a glass substrate having through-holes according to an embodiment of the present invention. As shown in Fig. 3, a method for producing a glass substrate having a through-hole according to an embodiment of the present invention (hereinafter referred to as "first manufacturing method") has: (0) preparing first and second surfaces facing each other (Processing of the glass substrate (Process S110); (1) a process of forming an initial hole on the glass substrate by irradiating the laser light from the side of the first surface of the glass substrate (Process S120); (2) utilizing The first etching solution is subjected to a first etching treatment on the initial hole, whereby a first through hole extending from the first opening to the second opening is formed in the glass substrate, and the glass substrate after the process of the above (2) is formed. when the thickness is indicated as d _1, the said first diameter of the opening of the first through-hole of the set R _t1, ratio d ₁ / R _t1 is in the range of 10 to 20. the process (process S130); and (3) using The second etching solution performs a second etching process on the first through holes (process S140). Hereinafter, each process will be described in detail with reference to FIGS. 4 to 7. (Step S110) First, the glass substrate 110 having the cross-sectional shape shown in Fig. 4 is prepared. The glass substrate 110 has a first surface 112 and a second surface 114 that face each other. Further, the glass substrate 110 has an initial thickness d ₀ . The initial thickness d _{0 is,} for example, preferably 0.1 mm to 0.7 mm, more preferably 0.2 mm to 0.5 mm, and particularly preferably 0.3 mm to 0.5 mm. When the initial thickness d _{0 is} less than 0.3 mm, even in the prior manufacturing method, it is difficult to form the above-mentioned sand bell type expanded through hole. The composition of the glass substrate 110 is not particularly limited. The glass substrate 110 may be, for example, soda lime glass, alkali-free glass, or the like. (Step S120) Then, one or two or more initial holes are formed on the glass substrate 110 by irradiating the laser light from the side of the first surface 112 of the glass substrate 110. The type of the laser light and the irradiation conditions are not limited as long as the initial holes can be formed on the glass substrate 110. The laser light can be, for example, a CO ₂ laser, a UV laser, or the like. Also, the laser light may be a laser that oscillates from a short pulsed laser (eg, a picosecond laser, a femtosecond laser). Further, the form of the initial hole is not particularly limited, and the initial hole may be a through hole or a non-through hole. Further, the initial holes may be pore rows composed of a plurality of pores arranged in the thickness direction of the glass substrate 110. In the case of using a short pulse laser, it is easy to form a pore row as an initial hole. FIG. 5 shows a state in which the initial hole 120 is formed on the glass substrate 110. Furthermore, in the example shown in FIG. 5, the initial hole 120 is a through hole, and is referred to as an "initial through hole" 120 herein. As shown in FIG. 5 , the initial through hole 120 extends from the first initial opening 122 formed on the first surface 112 of the glass substrate 110 to the second initial opening 124 formed on the second surface 114 of the glass substrate 110 . In the initial through hole 120, the diameter of the first initial opening 122 is referred to as R _t0 , and the diameter of the second initial opening 124 is referred to as R _b0 . Here, the ratio d ₀ /R _t0 of the thickness d ₀ of the glass substrate 110 and the diameter R _t0 of the first initial opening 122 in this stage is, for example, 25 or more. The ratio d ₀ /R _{t0 is} preferably 30 or more. When the ratio d ₀ /R _t0 is 25 or more, a large effect can be obtained by changing the previous manufacturing method to the first manufacturing method. That is, when the ratio d ₀ /R _t0 is 25 or more, in the conventional manufacturing method, a large narrow portion is generated in the through hole due to the etching process. However, with the first manufacturing method, the narrowed portion can be significantly suppressed. The diameter R _t0 of the first initial opening 122 is, for example, 15 μm or less, and may be 13 μm or less. In the example shown in FIG. 5, for the sake of simplicity, the diameter R _t0 of the first initial opening 122 of the initial through hole 120 and the diameter R _{b0 of} the second initial opening 124 are substantially equal. However, it is necessary to pay attention to the fact that the initial through hole 120 formed by the irradiation of the laser light is actually in a shape in which the diameter gradually decreases from the first initial opening 122 to the second initial opening 124. Therefore, usually R _t0 >R _b0 . 5 shows only a single initial through hole 120, but a plurality of initial through holes 120 may be formed on the glass substrate 110. (Step S130) Then, in order to enlarge the diameter of the initial through hole 120, the initial through hole 120 is etched by the first etching solution (hereinafter referred to as "first etching process" or "first etching process"). The type of the first etching solution is not particularly limited as long as it can be appropriately etched into the initial through hole 120. For example, the first etching solution may be an acid solution containing hydrofluoric acid. Further, the first etching solution may be a mixed acid solution containing at least one other acid in addition to hydrofluoric acid. For example, the first etching solution may be a mixed acid solution of hydrofluoric acid and hydrochloric acid or a mixed acid solution of hydrofluoric acid and nitric acid. The etching rate V ₁ of the first etching solution in the first etching treatment with respect to the glass substrate 110 is, for example, 0.5 μm/min or less, preferably 0.2 μm/min or less, and more preferably 0.02 μm/min or less. The first etching process can be carried out at any suitable temperature, and the processing temperature can be, for example, room temperature. The first etching process can be performed by, for example, selectively supplying the first etching solution into the initial through holes 120 (hereinafter, this method is referred to as "local etching process (method)"). By the local etching treatment method, the diameter of the initial through hole 120 can be expanded without changing the thickness of the glass substrate 110. For example, etching may be performed by affixing an etching resist film so as not to block the initial through holes 120. Alternatively, the first etching process may be performed by exposing the entire glass substrate 110 to the first etching solution (hereinafter, this method is referred to as "total etching process (method)"). For example, the first etching process may be performed by immersing the glass substrate 110 having the initial through holes 120 in a bath in which the first etching solution is accommodated (immersion method). Alternatively, the first etching process may be a method in which the first etching solution is directly poured onto the glass substrate (spray type). In the case of the overall etching treatment method, the thickness of the glass substrate 110 itself also changes (decreases) from d ₀ to d ₁ . Further, in the first etching process, ultrasonic waves may be applied to the glass substrate 110, or the glass substrate 110 may be vibrated or the etching solution may be foamed. Thereby a more uniform etching can be performed. Hereinafter, a case where the first etching process is performed by the entire etching processing method will be described as an example. FIG. 6 schematically shows a cross section of the glass substrate 110 after the first etching process using the bulk etching process. As shown in FIG. 6, the glass substrate 110 is changed to a thickness d ₁ by the first etching process. That is, the glass substrate 110 has the first new surface 113 and the second new surface 115. Further, the initial through hole 120 becomes the first through hole 130. The first through hole 130 extends from the first opening 132 formed in the first new surface 113 to the second opening 134 formed in the second new surface 115 . Here, in the first manufacturing method, when the diameter of the first opening 132 is R _t1 , the ratio d ₁ /R _t1 is in the range of 10 to 20. It is more preferably in the range of 10 to 15 than d ₁ /R _t1 . By setting the ratio d ₁ /R _t1 to such a range, in the subsequent process S140, the narrow portion which may be formed in the through hole can be remarkably suppressed. In other words, in the first etching process, the initial through hole 120 is expanded to be _equal to or less than d ₁ /R _t1 , so that a significant narrow portion can be prevented from being generated in the expanded first through hole 130 in the second etching process. . Further, the reason why the ratio d ₁ /R _{t1 is} 10 or more is that even if the first etching process is performed until the ratio d ₁ /R _{t1 is} less than 10, almost no change occurs in the second etching process. That is, by setting the ratio d ₁ /R _t1 to 10 or more, the processing time of the first etching process can be shortened. In addition, the first new surface 113 of the glass substrate obtained by the overall etching treatment method as described above is particularly referred to as "the surface corresponding to the first surface of the glass substrate". Similarly, the second new surface 115 is particularly referred to as "the surface corresponding to the second surface of the glass substrate". (Step S140) Then, in order to further enlarge the diameter of the first through hole 130, that is, to expand the through hole to a desired diameter, the first through hole 130 is etched by the second etching solution (hereinafter referred to as "Second etching process" or "Second etching process"). The second etching process is the same as in the case of the first etching process described above, and can be carried out by a local etching process or a bulk etching process. Further, the second etching process may be the same processing method (method) as the first etching process, or may be a different processing method (method). For example, the first etching process may be an immersion method, and the second etching process may be a shower method. Since the first etching process tends to be long in processing time, the immersion method is preferable in terms of productivity (cost). The second etching process is preferably a shower method because it is easy to adjust the aperture while suppressing the decrease in the thickness of the glass substrate. Here, a case where the second etching process is performed by the entire etching processing method will be described as an example. In the overall etching treatment method, the second etching process can be performed by, for example, immersing the glass substrate 110 having the first through holes 130 in a bath in which the second etching solution is accommodated. Thereby, the thickness of the glass substrate 110 is changed (decreased) from d ₁ to d ₂ . The second etching solution may be, for example, an acid solution containing hydrofluoric acid. Further, the second etching solution may be a mixed acid solution containing at least one other acid in addition to hydrofluoric acid. The mixed acid solution may be the same as the first etching solution. The second etching process can be carried out at any suitable temperature, and the processing temperature can be, for example, room temperature. Here, the second etching solution is selected from the case where the etching rate for the glass substrate 110 can be larger than that of the first etching solution. For example, the etching rate V ₂ of the second etching solution in the second etching treatment for the glass substrate 110 may be three times or more, preferably 10 times or more, the etching rate V ₁ of the first etching solution for the glass substrate 110. More preferably 100 times or more. For example, the etching rate V ₂ of the second etching solution with respect to the glass substrate 110 is 5.0 μm/min or less, preferably 2.0 μm/min or less, and more preferably 1.5 μm/min or less. The etching rate V ₂ may be, for example, in the range of 1.0 μm/min to 1.5 μm/min. FIG. 7 schematically shows a cross section of the glass substrate 110 after the second etching process. As shown in FIG. 7, the glass substrate 110 is changed to a thickness d ₂ by a second etching process. That is, the glass substrate 110 has the third new surface 117 and the fourth new surface 119. Further, the first through hole 130 is changed to the second through hole 140. The second through hole 140 extends from the third opening 142 formed in the third new surface 117 to the fourth opening 144 formed in the fourth new surface 119. Through the above process, the glass substrate 110 on which the second through holes 140 having the desired dimensions are formed can be manufactured. Here, in the first manufacturing method, the through hole (the second through hole 140) is formed through an etching process of at least two stages of the first etching process and the second etching process. In the first etching process, the initial through holes 120 are etched by the first etching solution having a relatively small etching rate V ₁ . Since the etching rate V _{1 of the} first etching solution is relatively small, the etching process requires a corresponding time. Therefore, the concentration diffusion of the first etching solution in the initial through hole 120 relatively quickly occurs. In other words, since the first etching solution has a relatively small etching rate V ₁ for the glass substrate 110, the first initial opening 122 of the initial through hole 120 or the glass substrate 110 in the vicinity of the second initial opening 124 is etched. The etching solution diffuses into the initial through hole 120 relatively quickly. Therefore, the difference between the degree of etching of the glass substrate 110 in the vicinity of the first initial opening 122 or the second initial opening 124 and the extent to which the glass substrate 110 is etched in the central portion of the initial through hole 120 is small. Thereby, the product generated by the etching reaction is easily diffused from the inside of the initial through hole 120 to the outside, and the stagnation inside the initial through hole 120 is remarkably suppressed. Therefore, in the first etching process, the initial through hole can be expanded to a sufficient diameter while suppressing the occurrence of a significant portion of the narrow portion in the initial through hole. Then, in the second etching process, the second etching solution having a relatively large etching rate V ₂ is used. However, the initial through hole 120 has been sufficiently expanded by the first etching process. Therefore, in the second etching process, the second etching solution can be relatively quickly and uniformly distributed in the first through holes 130. In addition, the product generated by the etching reaction rapidly moves from the inside of the first through hole 130, and the stagnation inside the first through hole 130 is remarkably suppressed. Therefore, the first through holes 130 are relatively uniformly etched, and even in the second etching process, it is difficult to form a significant narrow portion in the first through holes 130. As a result of the above, the first manufacturing method can significantly suppress the formation of the narrow portion as compared with the case where the initial through hole is expanded by a single etching process as before, and a through hole having a relatively uniform shape can be formed. The method of one embodiment of the present invention is effective especially in the case of forming an initial hole (pore row) having a relatively high aspect ratio using a case of a UV laser or a short pulse laser. The reason for this is that if the vertical and horizontal directions of the initial holes are relatively high, the concentration diffusion of the etching solution is more difficult to perform, or it is more difficult to supply the etching solution to the inside of the initial holes. Hereinabove, an example of a method of manufacturing a glass substrate having a through hole according to an embodiment of the present invention has been described with reference to Figs. 3 to 7 . However, it should be understood by those skilled in the art that the above description is only an example, and the present invention can also be implemented by other aspects. For example, in the above description, the initial hole formed by the process S120 is the initial through hole 120. However, the initial holes may be non-through holes, and pore rows composed of a plurality of pores arranged in the thickness direction of the glass substrate. In this case, a through hole is formed after the first etching process, and the through hole is expanded by the second etching process. Further, the first manufacturing method has a two-stage etching process. However, in the method of manufacturing a glass substrate having through-holes according to an embodiment of the present invention, the etching process may be carried out in three or more stages. In this case, a first etching solution having a relatively small etching rate may be used in the first etching process, and a second etching solution having a medium etching rate in the second etching process may be used in the third etching process. Among them, a third etching solution having a relatively large etching rate is used. Further, the method for producing a glass substrate having the above-described through holes can also be applied to a method of forming a through hole in a glass substrate. (Manufacturing Method of Glass Substrate Having Through Hole in Another Embodiment of the Present Invention) A method of producing a glass substrate having a through hole according to another embodiment of the present invention is a method of manufacturing a glass substrate having a through hole The manufacturing method has the following processes: (1) forming an initial hole on the glass substrate by irradiating the side of the first surface of the glass substrate having the first and second surfaces facing each other; (2) utilizing The first etching solution is subjected to a first wet etching treatment on the initial hole, thereby forming a surface extending from the first surface of the glass substrate or the surface corresponding to the first surface to the second surface of the glass substrate or the second surface a first through hole corresponding to the surface; and (3) performing a second wet etching treatment on the first through hole by the second etching solution, thereby forming a second through hole in which the first through hole is etched. The second etching solution has a larger etching rate for the glass substrate than the first etching solution. As described above, by providing the second etching solution with an etching rate larger than that of the first etching solution for the glass substrate, a through hole having a relatively uniform shape can be formed. In particular, when a UV laser or a short pulse laser is used, an initial hole having a relatively high aspect ratio is formed. Therefore, it is effective to use the manufacturing method of the present embodiment. The method for producing a glass substrate having the above-described through holes can also be applied to a method of forming through holes in a glass substrate. In the present embodiment, a configuration of an embodiment of the above-described Figs. 3 to 7 can be appropriately combined. In addition, the description of the specific configuration can be applied to the description of the above embodiment, and therefore will not be described. (System for producing a glass substrate having a through-hole according to another embodiment of the present invention) A system for producing a glass substrate having a through-hole according to another embodiment of the present invention is a system for manufacturing a glass substrate having a through-hole The system includes: a laser processing system that forms an initial hole on the glass substrate by irradiating the glass substrate with laser light; and an etching system that forms a through hole by etching the initial hole for the glass substrate The etching system includes a first etching system and a second etching system, wherein the first etching system performs a first etching process using a first etching solution, and the second etching system is used for the glass substrate. a second etching process of the second etching solution having a larger etching rate than the first etching solution, wherein the etching system is configured to perform the processing on the glass substrate by the first etching system, 2 etching system performs the processing of the above glass substrate. The laser processing system preferably has a UV laser. In addition, the laser processing system can also have short-pulse lasers such as picosecond lasers or femtosecond lasers. As described above, by using an etching solution having a larger etching rate than the first etching solution for the glass substrate as the second etching solution, a through hole having a relatively uniform shape can be formed. In particular, when a UV laser or a short pulse laser is used, an initial hole having a relatively high aspect ratio is formed. Therefore, it is effective to form a glass substrate having a through hole by using the system of the present embodiment. The etching system preferably has a cleaning system. Preferably, the cleaning process by the cleaning system is performed between the first etching process using the first etching system and the second etching process using the second etching system. Since the concentration of the etching solution used in the first etching treatment and the second etching treatment is different, it is preferable to wash the coating between the two treatments in advance. The washing treatment uses, for example, pure water. The above system can also be applied to a method of forming a through hole in a glass substrate. In the present embodiment, the configurations of the above-described embodiments can be combined as appropriate. In addition, the description of the specific configuration can be applied to the description of the above embodiment, and therefore will not be described. [Examples] Hereinafter, examples of the invention will be described. In the following description, Examples 1 to 4 are examples, and Example 5 is a comparative example. (Example 1) A glass substrate having through holes having a specific size was produced by the following method. (Laser light irradiation) First, a glass substrate (alkali-free glass substrate) having a length of 50 mm × a width of 50 mm × a thickness (d ₀ ) of 400 μm was prepared. Then, UV laser light is irradiated from the side of the first surface (50 mm in length × 50 mm in width) of the glass substrate to form an initial through hole. The diameter R _t0 of the first initial opening (opening on the first surface side) of the initial through hole is about 13 μm, and the diameter R _b0 of the second initial opening on the second surface on the opposite side is about 3 μm. Therefore, in the glass substrate, the ratio d ₀ /R _t0 is about 30.8. (First etching process) Next, the obtained glass substrate was subjected to a first etching treatment. The first etching solution was set to a 0.4 wt% hydrofluoric acid solution. The first etching treatment was carried out by immersing the glass substrate in the hydrofluoric acid solution for 80 minutes. The treatment temperature is room temperature. Further, the glass substrate is etched in a stationary state (that is, in a state where vibration is not burdened). Thereby, the initial through hole is etched to obtain the first through hole. Furthermore, the glass substrate itself was also etched to have a thickness d ₁ = 390 μm. The diameter R _t1 of the first opening of the first through hole on the first surface side of the glass substrate was 25.1 μm, and the diameter R _b1 of the second opening on the second surface side was 10.4 μm. Therefore, the ratio d ₁ /R _t1 is about 15.6. (Second Etching Process) Next, the glass substrate is subjected to a second etching process. The second etching solution was set to a 2 wt% hydrofluoric acid solution. The second etching treatment was carried out by immersing the glass substrate in the hydrofluoric acid solution for 25 minutes. The treatment temperature is room temperature. Further, the glass substrate is etched in a stationary state (that is, in a state where vibration is not burdened). The etching rate V ₂ of the second etching solution is about 10 times the etching rate V ₁ of the first etching solution. Thereby, the first through holes are etched to obtain the second through holes. Further, the glass substrate itself was also etched to have a thickness d ₂ = 360 μm. The diameter R _t2 of the third opening of the second through hole on the first surface side of the glass substrate is 46.3 μm, and the diameter R _b2 of the fourth opening on the second surface side is 33.8 μm. Therefore, the ratio d ₂ /R _t2 is about 7.8. (Example 2) A glass substrate having through holes having a specific size was produced in the same manner as in Example 1. However, in Example 2, in the first etching process, the etching time by the first etching solution was set to 120 minutes. Further, in the second etching process, the etching time by the second etching solution was 21 minutes. The thickness of the glass substrate after the first etching process is d ₁ = 385 μm. Further, the diameter R _t1 of the first opening of the first through hole on the first surface side of the glass substrate was 28.7 μm, and the diameter R _b1 of the second opening on the second surface was 15.6 μm. Therefore, the ratio d ₁ /R _t1 is about 13.4. On the other hand, the thickness of the glass substrate after the second etching process is d ₂ = 360 μm. The diameter R _t2 of the third opening of the second through hole on the first surface side of the glass substrate was 46.0 μm, and the diameter R _b2 of the fourth opening on the second surface side was 34.3 μm. Therefore, the ratio d ₂ /R _t2 is about 7.8. (Example 3) A glass substrate having through holes having a specific size was produced in the same manner as in Example 1. However, in the third example, in the first etching process, the etching time by the first etching solution was 210 minutes. Further, in the second etching process, the etching time by the second etching solution was set to 8 minutes. The thickness of the glass substrate after the first etching process is d ₁ = 370 μm. Further, the diameter R _t1 of the first opening of the first through hole on the first surface side of the glass substrate was 36.8 μm, and the diameter R _b1 of the second opening on the second surface side was 23.1 μm. Therefore, the ratio d ₁ /R _t1 is about 10. On the other hand, the thickness of the glass substrate after the second etching process is d ₂ = 360 μm. The diameter R _t2 of the third opening of the second through hole on the first surface side of the glass substrate was 46.4 μm, and the diameter R _b2 of the fourth opening on the second surface side was 33.3 μm. Therefore, the ratio d ₂ /R _t2 is about 7.8. (Example 4) A glass substrate having through holes having a specific size was produced in the same manner as in Example 1. However, in the fourth example, in the first etching process, the etching time by the first etching solution was 40 minutes. Further, in the second etching process, the etching time by the second etching solution was set to 30 minutes. The thickness d ₁ of the glass substrate after the first etching process is about 395 μm. Further, the diameter R _t1 of the first opening of the first through hole on the first surface side of the glass substrate was 18.9 μm, and the diameter R _b1 of the second opening on the second surface side was 7.6 μm. Therefore, the ratio d ₁ /R _t1 is about 20.9. On the other hand, the thickness of the glass substrate after the second etching process is d ₂ = 360 μm. Further, the diameter R _t2 of the third opening of the second through hole on the first surface side of the glass substrate was 45.6 μm, and the diameter R _b2 of the fourth opening on the second surface side was 34.0 μm. Therefore, the ratio d ₂ /R _t2 is about 7.9. (Example 5) A glass substrate having through holes having a specific size was produced in the same manner as in Example 1. However, in the fifth example, the first etching process was not performed. That is, after the UV laser light is irradiated and an initial through hole is formed on the glass substrate, only the second etching process is performed on the glass substrate. In the second etching process, the etching time by the second etching solution was set to 33 minutes. The thickness of the glass substrate after the second etching process is d ₂ = 360 μm. Further, the diameter R _t2 of the third opening of the second through hole on the first surface side of the glass substrate was 45.6 μm, and the diameter R _b2 of the fourth opening on the second surface side was 32.7 μm. Therefore, the ratio d ₂ /R _t2 is about 7.9. Table 1 below shows the thickness of the glass substrate and the diameter of the opening of the through hole in each of the processes in the production of the glass substrates in Production Examples 1 to 5. [Table 1]

(Evaluation) The shape of the second through hole was observed in each of the glass substrates manufactured as described above. More specifically, in the second through hole, the diameter R _c of the narrow portion having the smallest cross section perpendicular to the extending direction is measured. The results are summarized and shown in Table 2. Further, in any of the glass substrates of Examples 1 to 5, the narrow portion of the second through hole is present in a substantially central portion of the entire length of the through hole. [Table 2]

From the results, in Example 5, the diameter R _c of the narrow portion of the second through hole was extremely small, and the ratio R _c /R _{t2 was} less than 0.4. In Example 4, the diameter R _c of the narrow portion of the second through hole was expanded as compared with Example 5. Further, in Examples 1 to 3, the diameter R _c of the narrow portion of the second through hole was significantly expanded, and the ratio R _c /R _{t2 was} at least 0.5. Thus, by performing the etching process of two stages, the remarkable occurrence of the narrow portion of the through hole can be suppressed. Further, it was confirmed that the ratio d ₁ /R _t1 of the thickness d ₁ of the glass substrate after the first etching process and the diameter R _t1 of the first opening of the first through hole was set by performing the etching process of two stages. In the range of 10 to 20, a through hole having a relatively uniform shape can be formed.

_t0‧‧‧直徑

_b0‧‧‧直徑10‧‧‧ glass substrate
12‧‧‧ first surface
14‧‧‧ second surface
20‧‧‧through holes
22‧‧‧ first opening
24‧‧‧2nd opening
30‧‧‧Expanding through holes
32‧‧‧1st opening
34‧‧‧2nd opening
36‧‧‧Sarrow
110‧‧‧ glass substrate
112‧‧‧ first surface
113‧‧‧1st new surface
114‧‧‧2nd surface
115‧‧‧2nd new surface
117‧‧‧3rd new surface
119‧‧‧4th fresh surface
120‧‧‧ initial through hole
122‧‧‧1st initial opening
124‧‧‧2nd initial opening
130‧‧‧1st through hole
132‧‧‧1st opening
134‧‧‧2nd opening
140‧‧‧2nd through hole
142‧‧‧3rd opening
144‧‧‧4th opening
d ₀ ‧‧‧thickness
d ₁ ‧‧‧thickness
d ₂ ‧‧‧thickness
R _t0 ‧‧‧diameter
R _t1 ‧‧‧diameter
R _t2 ‧‧‧diameter
R _b0 ‧‧‧diameter
R _b1 ‧‧‧diameter
R _b2 ‧‧‧diameter
S110‧‧‧Process
S120‧‧‧Process
S130‧‧‧Process
S140‧‧‧Process

_T0 ‧‧‧diameter

_b0 ‧‧‧ diameter

Fig. 1 is a flow chart schematically showing a method of manufacturing a glass substrate having a prior through hole. 2(a) to 2(c) are diagrams schematically showing one of the processes of the method for producing a glass substrate having the previous through hole shown in Fig. 1. Fig. 3 is a view schematically showing an example of a flow of a method for producing a glass substrate having a through hole according to an embodiment of the present invention. Fig. 4 is a view schematically showing a process in a method of manufacturing a glass substrate having a through-hole according to an embodiment of the present invention shown in Fig. 3. Fig. 5 is a view schematically showing a process of a method for producing a glass substrate having a through-hole according to an embodiment of the present invention shown in Fig. 3; Fig. 6 is a view schematically showing a process of a method for producing a glass substrate having a through-hole according to an embodiment of the present invention shown in Fig. 3; Fig. 7 is a view schematically showing a process in a method of manufacturing a glass substrate having a through-hole according to an embodiment of the present invention shown in Fig. 3;

S110‧‧‧Process

S120‧‧‧Process

S130‧‧‧Process

S140‧‧‧Process

Claims (15)

A method for producing a glass substrate having a through hole, wherein the manufacturing method has the following steps: (1) irradiating laser light from a side of the first surface of the glass substrate having the first and second surfaces facing each other Forming an initial hole on the glass substrate; (2) performing the first etching treatment on the glass substrate by the first etching solution, and forming the initial hole from the first opening formed on the first surface to be formed in the above In the first through hole of the second opening of the second surface, when the thickness of the glass substrate is d ₁ and the diameter of the first opening is R _t1 , the ratio d ₁ /R _t1 is 10 to 20. And (3) after the process of the above (2), the second etching solution having a larger etching rate than the first etching solution for the glass substrate is used to perform the second etching treatment on the glass substrate to expand The first through hole. The method of claim 1, wherein the ratio V ₂ /V ₁ of the etching rate V ₂ of the second etching solution to the etching rate V ₁ of the first etching solution is 3 or more. The manufacturing method of claim 1 or 2, wherein the etching rate V ₁ of the first etching solution is 0.5 μm/min or less. The manufacturing method according to any one of claims 1 to 3, wherein the etching rate V ₂ of the second etching solution is in a range of from 1 μm/min to 5 μm/min. The manufacturing method according to any one of claims 1 to 4, wherein the thickness d _{1 is} smaller than the thickness d ₀ . The manufacturing method according to any one of claims 1 to 5, wherein the thickness d ₀ is 0.3 mm or more. The manufacturing method according to any one of claims 1 to 6, wherein the thickness d ₀ is 0.5 mm or less. The manufacturing method according to any one of claims 1 to 7, wherein, when the diameter of the opening on the first surface of the initial hole formed in the process of the above (1) is R _t0 , the ratio d ₀ / R _t0 is 25 or more. The manufacturing method according to any one of claims 1 to 7, wherein the initial hole formed by the process of (1) above is a through hole or a row of pores. A method of forming a through hole in a glass substrate, the method having the following steps: (1) irradiating the side of the first surface of the glass substrate having the first and second surfaces facing each other with laser light, Forming an initial hole on the glass substrate; (2) performing the first etching treatment on the glass substrate by the first etching solution, and forming the initial hole from the first opening formed on the first surface to forming the second surface In the first through hole of the second opening of the surface, when the thickness of the glass substrate is d ₁ and the diameter of the first opening is R _t1 , the ratio d ₁ /R _t1 is 10 to 20; (3) After the process of the above (2), the second etching solution having a larger etching rate than the first etching solution for the glass substrate is used, and the glass substrate is subjected to a second etching treatment to expand the first 1 through hole. The method of claim 10, wherein the etching rate V ₂ of the second etching solution is in a range of 1 μm/min to 5 μm/min. A system for manufacturing a glass substrate having a through hole, the system comprising: a laser processing system for forming an initial hole on the glass substrate by irradiating laser light to the glass substrate; and an etching system for the glass a substrate is formed by etching an initial hole; the etching system includes a first etching system and a second etching system, and the first etching system is a system using a first etching process using a first etching solution, 2 etching system is a system using a second etching process having a second etching solution having a larger etching rate than the first etching solution for the glass substrate, wherein the etching system is configured by the first etching After the system performs the processing on the glass substrate, the glass substrate is processed by the second etching system. The system of claim 12, wherein the etching system further includes a cleaning system, and the cleaning process is performed by the cleaning system between the first etching process and the second etching process. The system of claim 12 or 13, wherein said laser processing system has a short pulse laser selected from the group consisting of a picosecond laser or a femtosecond laser. The system of claim 12 or 13, wherein the laser processing system described above is provided with a UV laser.