200928286 九、發明說明： 【發明所屬之技術領域】 本發明係關於一種覆晶基板上雷射微孔之檢測方法及其 檢測系統’其係一種能辨識印刷電路板上鑽孔之多種尺寸 的檢測方法及其檢測系統。 【先前技術】 隨著電子產品需求之驅動，印刷電路板在形態上漸趨輕 薄短小’在功能上則要求性能穩定、多功能及高速化。相 φ 對地’其製程技術的發展則越來越困難，亦即要滿足輕量 化、薄形化、細線化及小孔化等高密度設計的需求。目前 極受重視的球拇陣列（Ball Grid Array ; BGA)或覆晶（flip chip)基板及使用量日增的可攜式產品之電路基板，例如大 哥大、電腦中央處理器、電子辭典、PCMCIA卡等，將會 使用大量的高密度（High Density Integration ; HDI)基板， 傳統基板鑒於其密度不夠，雖然在製造上不斷改良如鑽孔 Q 機、蝕刻機等製程設備，但仍只能做到4密爾（mil)線距與 6密爾直控之通孔’如此無法達到上述需求以及未來窄腳距 電子構裝設計的限制。因此具有細線、小孔的高密度基板 便應運而生，希望能取代傳統多層壓合基板或印刷電路板 的製程。 相對地，增層（build-up)法基板製程配合雷射鑽孔技術將 可有效減少通孔佔用面積，而容易達成細線、小孔的高密 度要求，其在傳統基板結構内加上一至數層的細線層，是 一種經濟又有效的基板製造方法。此類型基板的中間層可 200928286 為傳統之FR-4或ABF基板，然後逐層疊加上介電層與銅 箔，此疊加上的線路與孔徑均比傳統的基板細小，而層間 厚度也相對縮小，如此密度增加且厚度變薄，故基板面積 將可變小。 ' 尤其對覆晶基板高密度電路板而言，無論是半成品或成 品之品質檢測工作都變的非常重要，特別是關於線寬、孔 ^孔垂直度、孔真圓度及銅墊尺寸等都需要進行量測及 ❹200928286 IX. Description of the Invention: [Technical Field] The present invention relates to a method for detecting laser microholes on a flip chip substrate and a detection system thereof, which are capable of identifying various sizes of drilled holes on a printed circuit board Method and its detection system. [Prior Art] With the demand for electronic products, printed circuit boards are becoming lighter and shorter in form. In terms of functions, performance is required to be stable, versatile, and high-speed. It is increasingly difficult to develop the process technology of phase φ to ground, that is, to meet the needs of high-density designs such as lightweight, thinning, thinning and small holes. Currentlyadays, Ball Grid Array (BGA) or flip chip substrates and circuit boards for portable products with increasing usage, such as Big Brother, Computer Central Processing Unit, Electronic Dictionary, PCMCIA Cards, etc., will use a large number of high-density (HDI) substrates. In view of the insufficient density of conventional substrates, although manufacturing processes such as drilling Q machines and etching machines are constantly being improved, they can only be achieved. The 4 mil line spacing and the 6 mil direct control via hole are so unable to meet the above requirements and the limitations of future narrow pitch electronic assembly designs. Therefore, a high-density substrate having fine lines and small holes has emerged, and it is desired to replace the conventional multi-layered substrate or printed circuit board process. In contrast, the build-up substrate process combined with the laser drilling technology can effectively reduce the area occupied by the via holes, and it is easy to achieve the high density requirements of thin wires and small holes, which add one to several in the conventional substrate structure. The thin layer of the layer is an economical and effective method of manufacturing the substrate. The intermediate layer of this type of substrate can be 200928286 as a traditional FR-4 or ABF substrate, and then the dielectric layer and the copper foil are laminated one by one. The superimposed lines and apertures are smaller than the conventional substrate, and the interlayer thickness is relatively small. As the density increases and the thickness becomes thin, the substrate area can be made small. Especially for high-density circuit boards with flip-chip substrates, the quality inspection work of semi-finished products or finished products becomes very important, especially regarding line width, hole hole verticality, hole roundness and copper pad size. Need to measure and ❹
規格判讀。圖1 (a)係一習知覆晶基板丨〇上鑽孔之量測示意 圖。在上層絕緣層U中有微孔15，且有一内部銅線路層之 銅墊（pad)12設於該微孔15底部之下層絕緣層13上。該微 孔15 —般係由雷射（c〇2雷射或uv雷射）加工產生，因此 孔壁111(或孔徑）相對於上表s 112ι現漸擴。#量測之照 明光線80由兩側斜向照射微孔15時，因孔壁η〗和上表 面112均為同一材質而顏色相同，所以上方攝影機（圖未示） 擷取影像中微孔15之上孔徑往往無法清楚呈現。圖吵） 糸微孔之’像示‘5圖。圖中A部分係較清楚之銅墊12影 像’ B部分及C部分則分別為孔壁111和上表面112之界 線混淆的影像。 由於缺乏正確之上孔徑將無法確認鑽孔之品質，亦即傳 統之檢測方法或檢測'系統將無法滿足高密度覆晶基板製造 上更精密之需求。 【發明内容】 、本發月之目的係、提供—種覆晶基板上雷射微孔之檢測方 法及其m % ’係針對鐵孔結構中之不同材料的顏色而 200928286 扠射不同波長之光線，藉此可辨識出鑽孔結構中各區域之 幾何尺寸，並進一步得到顯示鑽孔品質之數據。 為達上述目的，本發明揭示一種覆晶基板上雷射微孔之 檢測方法，其係投射第一波長之光線於一覆晶基板上至少 一個鑽孔。藉由該第一波長之光線與該鑽孔之第一區域的 顏色相近似，且該第一區域可以反射該第一波長之光線， 一攝影機可清楚擷取該第一區域之影像。接著，再投射第 ❹ 一波長之光線於該覆晶基板上鑽孔。藉由該第二波長之光 線與該鑽孔之第二區域的顏色相近似，且該第二區域可以 反射該第二波長之光線，該攝影機可清楚擷取該第二區域 之影像。 本發明另揭7F -種覆晶基板上雷射微孔之檢測系統，包 含一光源裝置及一一視覺取像模組。該光源裝置可分別產 生第一波長之光線及第二波長之光線，並依序照射該覆晶 基板。該視覺取像模組可根據該第一波長之光線及該第二 〇 波長之光線分別擷取該覆晶基板上鑽孔的第一影像及第二 影像，其中該第-影像中該鑽孔之第一區域的亮度較其他 區域偏高，又該第二影像中該鑽孔之第二區域的亮度較其 他區域偏高。 【實施方式】 圖2 (a)係本發明覆晶基板上雷射微孔之檢測系統的示意 圖。自動光學檢測系統2 0係包含一可固定待檢測物之平： 24、-視覺取像模組25及—光源裝置23。視覺取像模細 25至少包括收集反射光線之倍率鏡帛2卜及將光學訊號轉 200928286 換為電氣訊號之訊號接收器22。光源裝置23會產生至少兩 種不同波長之第一波長光線30及第二波長光線3〇|(參見如 2(b)) ’並且分別以該兩種波長之光線3〇及3〇，照射覆晶基 板10上鑽孔15。為了使銅墊12之影像清楚形成於視覺取 像模組25内，建議光源裝置23發出之第一波長光線3〇係 垂直於上表面112。再者，為了使孔壁之反射光不影響上表 面Π2之影像能清楚形成於視覺取像模組25内，甚至使得 上表面112之孔邊界（上孔徑）難辨識，建議光源裝置23發 出之第一波長光線30’係斜射至上表面112，因此能避免同 材質之斜面孔壁111的反射光使得孔邊界難以辨識。 圖3係光源裝置發出兩種不同波長之光線的頻譜圖。為 了使鑽孔15内銅墊12之邊界（下孔徑）影像清楚可辨識，因 此選擇採取和銅墊12之咖啡色（或稱銅之暗紅色）相近之紅 色光31照射覆晶基板1〇，如此銅墊12可以將紅色光η 反射至視覺取像模組25而形成良好且明亮之影像A1，如 φ 圖4(a)所示。又因為孔壁111和上表面112之顏色偏灰白 色’所以對於紅色光31之反射率較差，從而於影像A1之 外環分別形成亮度較暗之影像B1及C1。亦即下孔徑之尺 寸清晰可辨識’相較亮度明顯偏暗之影像B1及ci則顯得 十分容易讀取。 為了使鑽孔15上表面112之孔邊界（上孔徑）影像清楚可 辨識，因此可選擇採取和上表面112呈現灰白色相近之藍 色光32垂直照射覆晶基板1〇,如此上表面112可以將藍色 光32反射至視覺取像模組25而形成良好且明亮之影像 200928286 C2 ’如圖4(b)所示。又因為斜面之孔壁lu無法將垂直之 藍色光32有效反射至視覺取像模組25，且底部之銅塾12 對於藍色光32之反射率較差，從而於影像C2之内部分別 形成亮度較暗之影像A2及B2。亦即上孔徑之尺寸清晰可 辨識，相較於亮度明顯偏暗之影像A2及B2則顯得十分容 易讀取。 本發明之技術内容及技術特點已揭示如上，然而熟悉本 ❹項技術之人士仍可能基於本發明之教示及揭示而作種種不 背離本發明精神之替換及修飾。因此，本發明之保護範圍 應不限於實施例所揭示者，而應包括各種不背離本發明之 替換及修飾，並為以下之申請專利範圍所涵蓋。 【圖式簡單說明】 圖1(a)係一習知覆晶基板上鑽孔之量測示意圖； 圖1(b)係微孔之影像示意圖； 圖2(a)〜2(b)係本發明覆晶基板上鑽孔之檢測系統的示 意圖； 圖3係本發明光源裝置發出兩種不同波長之光線的頻譜 圖； 圖4(a)係本發明微孔之影像示意圖；以及 圖4(b)係本發明微孔之影像示意圖。 【主要元件符號說明】 10 覆晶基板 11 上層 絕緣層 12 銅墊 13 下層 絕緣層 15 微孔 20 檢測 系統 200928286 23 光源裝置 24 25 視覺取像模組 30 30' 第二波長光線 31 32 藍色光 80 111 孔壁 112 A、 B、C、Al、B1、 Cl、A2 平臺 第一波長光線 紅色光 光線 上表面 B2、C2 影像Specification interpretation. Fig. 1(a) is a schematic view showing the measurement of a hole in a conventional flip-chip substrate. A micro hole 15 is formed in the upper insulating layer U, and a pad 12 having an inner copper wiring layer is provided on the insulating layer 13 under the bottom of the micro hole 15. The microholes 15 are generally produced by laser (c〇2 laser or uv laser) processing, so that the hole walls 111 (or apertures) are gradually enlarged relative to the upper table s 112. When the illumination light 80 is irradiated obliquely to the micro-holes 15 from both sides, since the hole wall η and the upper surface 112 are the same material and the colors are the same, the upper camera (not shown) captures the micro-holes in the image 15 The upper aperture is often not clearly presented. Figure noisy) 糸 micro hole's image shows ‘5 picture. Part A of the figure is a clear image of the copper pad 12 image. The B portion and the C portion are images of the boundary between the hole wall 111 and the upper surface 112, respectively. The lack of a correct upper aperture will not confirm the quality of the borehole, ie the conventional inspection method or test 'system will not meet the more sophisticated requirements for high-density flip-chip substrate manufacturing. SUMMARY OF THE INVENTION The purpose of this month is to provide a method for detecting laser micropores on a flip chip substrate and the color of the different materials in the iron hole structure and the length of the light of different materials in the iron hole structure 200928286 Thereby, the geometrical dimensions of the various regions in the drilling structure can be identified, and further data showing the quality of the drilling can be obtained. In order to achieve the above object, the present invention discloses a method for detecting a laser micropore on a flip chip substrate, which is to project at least one hole of light of a first wavelength onto a flip chip substrate. The light of the first wavelength is similar to the color of the first region of the borehole, and the first region can reflect the light of the first wavelength, and a camera can clearly capture the image of the first region. Then, the light of the first wavelength is projected to be drilled on the flip chip. The light of the second wavelength is approximated by the color of the second region of the borehole, and the second region can reflect the light of the second wavelength, and the camera can clearly capture the image of the second region. According to another aspect of the invention, a detection system for a laser microhole on a flip chip substrate comprises a light source device and a visual image capturing module. The light source device generates light of a first wavelength and light of a second wavelength, respectively, and sequentially illuminates the flip chip. The visual image capturing module can respectively capture the first image and the second image of the hole drilled on the flip chip according to the light of the first wavelength and the light of the second wavelength, wherein the hole in the first image The brightness of the first area is higher than other areas, and the brightness of the second area of the second image is higher than other areas. [Embodiment] Fig. 2 (a) is a schematic view showing a detection system of laser micropores on a flip chip of the present invention. The automatic optical detection system 20 includes a flat that can fix the object to be detected: 24, a visual image capturing module 25, and a light source device 23. The visual image capturing module 25 includes at least a magnification mirror for collecting reflected light and a signal receiver 22 for converting the optical signal to 200928286 for electrical signals. The light source device 23 generates at least two different wavelengths of the first wavelength light 30 and the second wavelength light 3〇| (see, eg, 2(b))' and respectively illuminates the light with the light of the two wavelengths 3〇 and 3〇, respectively. A hole 15 is drilled in the crystal substrate 10. In order to clearly form the image of the copper pad 12 in the visual imaging module 25, it is recommended that the first wavelength light 3 emitted by the light source means 23 is perpendicular to the upper surface 112. Moreover, in order to make the image reflected by the wall of the hole not affect the upper surface Π2, the image can be clearly formed in the visual image capturing module 25, and even the hole boundary (upper aperture) of the upper surface 112 is difficult to recognize, it is recommended that the light source device 23 emits The first wavelength ray 30' is obliquely incident on the upper surface 112, so that the reflected light of the oblique wall 111 of the same material can be avoided to make the hole boundary difficult to recognize. Figure 3 is a spectrogram of a light source device emitting light of two different wavelengths. In order to make the boundary (lower aperture) image of the copper pad 12 in the bore 15 clear and identifiable, the red light 31 which is similar to the brown color of the copper pad 12 (or dark red of copper) is selected to illuminate the flip chip 1 〇, such copper The pad 12 can reflect the red light η to the visual image capturing module 25 to form a good and bright image A1, as shown in Fig. 4(a). Further, since the color of the hole wall 111 and the upper surface 112 is grayish white, the reflectance to the red light 31 is inferior, so that the images B1 and C1 having darkness are formed on the outer ring of the image A1, respectively. That is, the size of the lower aperture is clearly identifiable. The images B1 and ci which are significantly darker than the brightness are very easy to read. In order to make the hole boundary (upper aperture) image of the upper surface 112 of the drill hole 15 clearly identifiable, the blue light 32 similar to the upper surface 112 may be selected to be vertically irradiated with the blue crystal 32, so that the upper surface 112 may be blue. The colored light 32 is reflected to the visual imaging module 25 to form a good and bright image 200928286 C2 ' as shown in Figure 4(b). Moreover, since the vertical wall 32 of the inclined surface cannot effectively reflect the vertical blue light 32 to the visual image capturing module 25, and the bottom copper yoke 12 has a poor reflectivity to the blue light 32, respectively, a darkness is formed inside the image C2. Images A2 and B2. That is, the size of the upper aperture is clearly identifiable, and the images A2 and B2 which are significantly darker than the brightness are very easy to read. The technical contents and technical features of the present invention have been disclosed as above, and those skilled in the art can still make various substitutions and modifications without departing from the spirit and scope of the invention. Therefore, the scope of the present invention should be construed as being limited by the scope of the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1(a) is a schematic view showing the measurement of the borehole on a conventional flip-chip substrate; Fig. 1(b) is a schematic view of the micropore; Fig. 2(a)~2(b) BRIEF DESCRIPTION OF THE DRAWINGS FIG. 3 is a schematic diagram of a light source of the present invention for emitting light of two different wavelengths; FIG. 4(a) is a schematic view of an image of a microhole of the present invention; and FIG. 4(b) Is a schematic image of the micropores of the present invention. [Main component symbol description] 10 Flip-chip substrate 11 Upper insulating layer 12 Copper pad 13 Lower insulating layer 15 Micro hole 20 Detection system 200928286 23 Light source device 24 25 Visual imaging module 30 30' Second wavelength light 31 32 Blue light 80 111 hole wall 112 A, B, C, Al, B1, Cl, A2 platform first wavelength light red light ray upper surface B2, C2 image
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