TWI412073B - Wafer cutting method for contact image sensing unit - Google Patents

Abstract

Disclosed is a wafer cutting method for contact image sensing unit, which provides a wafer containing a plurality of rectangular chips. The distance between adjacent chps' short sides is the wide cutting pathway, while the distance between adjacent chips' long sides is the long cutting pathway. The cutting method uses blades to cut along the wide cutting pathway while laser is applied to cut along the long cutting pathway.

Description

接觸式影像感測單元之晶圓切割方法 Wafer cutting method of contact image sensing unit

本發明係與晶圓切割方法有關，特別係與切割接觸式影像感測單元(CIS)晶圓之技術有關。 The present invention relates to wafer dicing methods, and in particular to techniques for cutting contact image sensing unit (CIS) wafers.

按，傳統上用於接觸式影像感測單元(Contact Image Sensor,CIS)之晶片係採用鑽石刀具來進行晶圓之切割，如第一圖所示，晶圓切割刀12一般係由一圓形的鑽石刀片所構成，藉由鑽石刀片的高速旋轉而對表面已製作有電路層的晶圓1加以切割，其中，為便於進行晶圓1的切割，於晶圓1表面通常設有多道相互縱橫交錯的切割道11，將晶圓1界定出複數個晶片10。 According to the conventional method, the contact image sensor (CIS) chip uses a diamond cutter for wafer cutting. As shown in the first figure, the wafer cutter 12 is generally a circular shape. The diamond blade is formed by cutting the wafer 1 on which the circuit layer has been formed by the high-speed rotation of the diamond blade. In order to facilitate the cutting of the wafer 1, a plurality of mutual surfaces are usually provided on the surface of the wafer 1. The wafer 1 defines a plurality of wafers 10 in a crisscrossing scribe line 11.

為降低成本，業界無不力求於每片晶圓1上獲致最多的晶片10數量，因而晶片10間之切割道11距離要求越來越窄，相對應地，晶圓切割刀12的寬度亦需越來越薄；當刀片越薄，刀片的使用壽命亦隨之降低；且切割道11變窄後，切割的產能與良率亦降低，導致每一晶片的成本反較以前增加而不符所需。 In order to reduce the cost, the industry has no desire to obtain the largest number of wafers 10 per wafer 1. Therefore, the distance between the scribe lines 11 of the wafers 10 is narrower and narrower, and correspondingly, the width of the wafer dicing blade 12 is also required. Thinner and thinner; the thinner the blade, the longer the life of the blade; and the narrower the cutting lane 11, the cutting capacity and yield are also reduced, resulting in a lower cost per wafer than the previous increase .

請參第二圖，為現行具有多個矩形的接觸式影像感測單元晶片20之晶圓2，為於每片晶圓2上獲致最多晶片20之數量，其相鄰晶片20間之切割道21已甚小；其中，相鄰晶片20之短邊201的間距係為寬切割道211，而相鄰晶片20之長邊202的間距係為長切割道212。 Referring to FIG. 2, the wafer 2 of the current contact image sensing unit wafer 20 having a plurality of rectangles has a maximum number of wafers 20 per wafer 2, and a dicing street between adjacent wafers 20 21 is very small; wherein the short sides 201 of adjacent wafers 20 are spaced apart by a wide scribe line 211, and the long sides 202 of adjacent wafers 20 are spaced apart by a long scribe line 212.

請參第三圖A以及第三圖B，當以晶圓切割刀12進行 切割道21之切割時，部份寬切割道2111以及部份長切割道2121切割時會被晶圓切割刀12切除而損失，切割後，晶片20之側邊僅留些微的邊緣，有些甚至會切割至晶片20，故經晶圓切割刀12切割該切割道21後甚常造成晶片20之不良。 Please refer to the third figure A and the third figure B, when using the wafer cutter 12 When the cutting path 21 is cut, a part of the wide cutting track 2111 and a part of the long cutting path 2112 are cut by the wafer cutting blade 12 and are lost. After cutting, only a slight edge is left on the side of the wafer 20, and some may even The wafer 20 is diced, so that the wafer 20 is cut by the wafer dicing blade 12 and the wafer 20 is often defective.

近幾年由於雷射之內部切割(Stealth Dicing)技術係透過雷射改變矽的晶體結構以於晶圓內部產生應力，使所欲切割之晶片分開，因有切割道可趨近零損失之特點，切割道可以做到甚小且具有良好之切割品質，故業界陸續導入以雷射來進行晶圓之切割。 In recent years, due to the laser's internal cutting (Stealth Dicing) technology, the crystal structure of the crucible is changed by laser to generate stress inside the wafer, so that the wafer to be cut is separated, and the cutting track can be close to zero loss. The cutting track can be made very small and has good cutting quality. Therefore, the industry has introduced laser cutting for laser cutting.

然，以雷射切割晶圓時，晶片需重新佈設以縮小切割道，且其相關製程之設備亦需配合調整；故此過渡期間仍需在原晶圓上進行晶片之切割；另一方面為提升切割品質以提升產能及良率，導入雷射切割技術亦為刻不容緩，因此有於原晶圓上以雷射進行切割晶片之考量。 However, when the wafer is laser-cut, the wafer needs to be re-routed to reduce the scribe line, and the equipment of the related process needs to be adjusted; therefore, the wafer is still cut on the original wafer during the transition; Quality to improve productivity and yield, the introduction of laser cutting technology is also an urgent task, so there are lasers on the original wafer to cut the wafer.

因此，為使多個晶片緊密排列時可獲取連續性之掃描影像，晶片切割時需將晶片之部分寬切割道切除，以於晶片之短邊僅留些微的邊緣。惟，以雷射於原晶圓上進行晶片之切割時，由於雷射不損失切割道，切割後晶片之側邊仍保留其完整之邊緣，應用於接觸式影像感測單元(Contact Image Sensor,CIS)之晶片時，因晶片之短邊有限定的邊緣距離以緊密排列多個晶片，進而獲取高解析度之掃描影像，故以雷射切割原晶圓之寬切割道顯不符所需。 Therefore, in order to obtain a continuous scan image when a plurality of wafers are closely arranged, a part of the wide scribe line of the wafer is cut during wafer cutting to leave only a slight edge on the short side of the wafer. However, when laser cutting is performed on the original wafer, since the laser does not lose the dicing road, the side of the wafer remains intact after cutting, and is applied to the contact image sensing unit (Contact Image Sensor, In the case of a wafer of CIS), since the short side of the wafer has a defined edge distance to closely arrange a plurality of wafers, thereby obtaining a high-resolution scan image, the wide cut track of the original wafer by laser cutting is not required.

請參第四圖A以及第四圖B，係為以雷射22切割之另 一種方式，於原晶圓2上，相鄰晶片20之長邊202的長切割道212上係以一道雷射切割，另於相鄰晶片20之短邊201的寬切割道211上予以二道雷射切割，冀藉由二道雷射之切割以移除部份寬切割道2111；然，由於相鄰晶片20之短邊201的部分寬切割道2111距離過小(僅約0.02mm)，經雷射22切割後易附著於二側晶片20之短邊201上而難以單獨分離移除。 Please refer to Figure 4A and Figure 4B for the other In one manner, on the original wafer 2, the long scribe line 212 of the long side 202 of the adjacent wafer 20 is cut by a laser, and the second tang 211 of the short side 201 of the adjacent wafer 20 is applied. Laser cutting, 冀 cutting by two lasers to remove a portion of the wide scribe line 2111; however, since the distance of the portion of the wide scribe line 2111 of the short side 201 of the adjacent wafer 20 is too small (only about 0.02 mm), The laser 22 is easily attached to the short side 201 of the two-sided wafer 20 after being cut, and is difficult to separate and remove.

因此，如何克服當前技術之種種缺失，實為目前亟待解決之課題。 Therefore, how to overcome the various shortcomings of current technology is a problem that needs to be solved urgently.

本發明之主要目的，在原晶圓不改變晶圓切割道距離之狀況下，提供一種接觸式影像感測單元之晶圓切割方法，係以晶圓切割刀切割矩形晶片之短邊間的寬切割道，以切除部分寬切割道，俾使多個晶片緊密排列時可獲取高解析度之掃描影像。 The main purpose of the present invention is to provide a wafer cutting method for a contact image sensing unit in which the original wafer does not change the distance of the wafer scribe line, and the wafer cutting blade is used to cut the wide cut between the short sides of the rectangular wafer. In order to remove a part of the wide scribe line, a high-resolution scan image can be obtained when a plurality of wafers are closely arranged.

本發明之另一目的，在原晶圓不改變晶圓切割道距離之狀況下，提供一種接觸式影像感測單元之晶圓切割方法，係以雷射切割矩形晶片之長邊間的長切割道，以保持切割晶片長邊之切割品質，進而增加晶片之產能及良率。 Another object of the present invention is to provide a wafer cutting method for a contact image sensing unit by laser cutting a long cutting path between long sides of a rectangular wafer without changing the distance of the wafer scribe line. In order to maintain the cutting quality of the long side of the cut wafer, thereby increasing the throughput and yield of the wafer.

為達成上述之目的，本發明係提供一種接觸式影像感測單元之晶圓切割方法，包括提供一包含有複數個矩形晶片之晶圓，相鄰晶片短邊之間距係為寬切割道，而相鄰晶片長邊之間距係為長切割道；其切割之方式係以晶圓切割刀切割該等寬切割道，而以雷射切割該等長切割道。 To achieve the above object, the present invention provides a wafer dicing method for a contact image sensing unit, comprising providing a wafer including a plurality of rectangular wafers, wherein the distance between the short sides of adjacent wafers is a wide scribe line, and The distance between the long sides of adjacent wafers is a long scribe line; the cutting is performed by cutting the equal scribe lines with a wafer dicing cutter and cutting the equal length scribe lines by laser.

本發明所揭露之晶圓切割方法，係可運用於各式晶圓之切割製程中。然，因使用晶圓切割刀切割晶圓之方式會損失切割道，故特別適用於晶片間之切割道具有寬切割道且晶片之間距有特別要求之晶圓切割，如接觸式影像感測單元(Contact Image Sensor,CIS)之晶片；由於應用接觸式影像感測單元時，係以多個晶片緊密排列以獲取連續性之掃描影像，因此，矩形晶片之短邊的邊緣有要求一定的距離，而晶片之長邊間之距離則無特殊之要求，所以晶片長邊的邊緣距離不限。 The wafer cutting method disclosed in the present invention can be applied to a cutting process of various wafers. However, because the wafer cutting blade is used to cut the wafer, the cutting channel is lost. Therefore, it is particularly suitable for wafer cutting with wide cutting lanes between wafers and special requirements between wafers, such as contact image sensing unit. (Contact Image Sensor, CIS) wafer; since the contact image sensing unit is applied, a plurality of wafers are closely arranged to obtain a continuous scanned image, and therefore, the edge of the short side of the rectangular wafer requires a certain distance. There is no special requirement for the distance between the long sides of the wafer, so the edge distance of the long side of the wafer is not limited.

首請參閱第五圖A，本發明接觸式影像感測單元之晶圓切割方法，包括提供一晶圓3，該晶圓3包含有複數個晶片30，該等複數個晶片30係為呈矩形之接觸式影像感測單元晶片(實際實施時亦可切割不同形狀之晶片型態)，相鄰晶片30之間係為切割道31，該等切割道31係可區分為寬切割道311以及長切割道312，其中，寬切割道311係為該晶片30之短邊301間的間距，而長切割道312係為該晶片30之長邊302間的間距；切割該晶圓3時，係沿該等切割道31而使晶圓3分割為複數個晶片30，利用本發明之切割晶圓方法時，係以傳統之晶圓切割刀12切割寬切割道311，並以雷射22之內部切割(Stealth Dicing)方式切割長切割道312，最後再施加拉力於長切割道312兩側，即可沿切割道31而使該晶圓30分割為複數個晶片30。 Referring to FIG. 5A, a wafer cutting method of the contact image sensing unit of the present invention includes providing a wafer 3, the wafer 3 including a plurality of wafers 30, and the plurality of wafers 30 are rectangular. The contact image sensing unit wafer (which can also be cut in different shapes) can be cut between the adjacent wafers 30, and the cutting channels 31 can be divided into wide cutting paths 311 and long. The scribe line 312, wherein the wide scribe line 311 is the pitch between the short sides 301 of the wafer 30, and the long scribe line 312 is the spacing between the long sides 302 of the wafer 30; when the wafer 3 is cut, the edge is cut The dicing lines 31 divide the wafer 3 into a plurality of wafers 30. When the dicing wafer method of the present invention is used, the wide dicing streets 311 are cut by a conventional wafer dicing blade 12, and the inside of the laser 22 is cut. The (Stealth Dicing) method cuts the long cutting track 312 and finally applies a pulling force to both sides of the long cutting path 312, so that the wafer 30 can be divided into a plurality of wafers 30 along the cutting path 31.

請同參閱第五B圖，以本發明接觸式影像感測單元之晶圓切割方法切割該晶圓3時，該晶片30之短邊301的寬切割道311經由晶圓切割刀切割後，將損失晶片30之短邊301間之部分寬切割道3111；而該晶片30之長邊302的長切割道312係以雷射方式進行切割；切割後，將多個該些晶片30緊密排列時，由於部分寬切割道3111之損失，晶片30之短邊301僅留些微的邊緣，故可緊密排列多個晶片30；另由於以雷射22切割時可保持晶片30之長邊312的切割品質，該晶片30之長邊312時幾乎無損失切割道311，故甚少造成該晶片30之不良。 Referring to FIG. 5B, when the wafer 3 is diced by the wafer dicing method of the contact image sensing unit of the present invention, the wide scribe line 311 of the short side 301 of the wafer 30 is cut by a wafer dicing blade, and Loss of a portion of the wide scribe line 3111 between the short sides 301 of the wafer 30; and the long scribe line 312 of the long side 302 of the wafer 30 is laser-cut; after dicing, when a plurality of the wafers 30 are closely arranged, Due to the loss of the partial wide scribe line 3111, the short side 301 of the wafer 30 leaves only a slight edge, so that the plurality of wafers 30 can be closely arranged; and because the cutting quality of the long side 312 of the wafer 30 can be maintained when the laser 22 is cut, The long side 312 of the wafer 30 has almost no loss of the scribe line 311, so that the wafer 30 is less likely to be defective.

請參閱第六圖，係為本發明接觸式影像感測單元之晶圓切割方法一實施例之流程圖，其步驟包括： Please refer to FIG. 6 , which is a flowchart of an embodiment of a wafer cutting method of the contact image sensing unit of the present invention, and the steps thereof include:

(a)提供一晶圓，該晶圓係包含有複數個晶片，其相鄰晶片之間係為切割道，且該等晶片短邊之間距係為寬切割道，而其長邊之間距係為長切割道。 (a) providing a wafer comprising a plurality of wafers, the adjacent wafers being diced between the adjacent wafers, and the distance between the short sides of the wafers being a wide scribe line and the distance between the long sides thereof For long cutting roads.

(b)以晶圓切割刀切割該等寬切割道。 (b) cutting the equal width cuts with a wafer cutter.

(c)以雷射切割該等長切割道。 (c) cutting the equal length cutting track by laser.

上述方法中，該步驟(c)亦可於步驟(b)前進行，亦即，以雷射切割該等長切割道之步驟係可於以晶圓切割刀切割該等寬切割道之步驟前進行；其中，雷射切割之方法係為內部切割(Stealth Dicing)，而複數個晶片係為呈矩形之接觸式影像感測單元晶片，且其長邊之間距係為長切割道，而其短邊之間距係為寬切割道；最後，施加拉力於該等長切割道之兩側，可使該晶圓分割為複數個晶片。 In the above method, the step (c) may also be performed before the step (b), that is, the step of cutting the equal length of the dicing line by laser is performed before the step of cutting the equal scribe line by the wafer dicing knife The laser cutting method is Stealth Dicing, and the plurality of wafers are rectangular contact image sensing unit wafers, and the long side distance is a long cutting path, and the short length thereof is short. The distance between the sides is a wide scribe line; finally, applying a pulling force to both sides of the equal scribe line allows the wafer to be divided into a plurality of wafers.

請參第七圖，係為本發明接觸式影像感測單元之晶片使用示意圖。完成切割後，複數個表面具電路之接觸式影像感測單元晶片30係等間距地緊密排列於一具有控制電路41之基板4，設置晶片30於基板4時，晶片30與晶片30間之間距需符合一定之距離以獲取高解析度之掃描影像。 Please refer to the seventh figure, which is a schematic diagram of the use of the wafer of the contact image sensing unit of the present invention. After the dicing is completed, the plurality of surface-mounting contact image sensing unit wafers 30 are closely arranged at equal intervals on a substrate 4 having the control circuit 41, and the distance between the wafer 30 and the wafer 30 is set when the wafer 30 is disposed on the substrate 4. A certain distance is required to obtain a high-resolution scanned image.

綜上所述，本發明接觸式影像感測單元之晶圓切割方法，係以晶圓切割刀切割晶片間之寬切割道，以及以雷射切割晶片間之長切割道，以保持排列於基板時晶片間一定之間距，且可提升產能及晶片之良率。 In summary, the wafer cutting method of the contact image sensing unit of the present invention cuts the wide scribe line between the wafers by a wafer dicing blade, and cuts the long scribe lines between the wafers by laser to keep the substrates arranged on the substrate. When there is a certain distance between the wafers, the productivity and the yield of the wafer can be improved.

惟以上所述僅為本發明之較佳可行實施例，非因此即拘限本發明之專利範圍，故舉凡運用本發明說明書及圖式內容所為之等效結構變化，均同理皆包含於本發明之範圍內，合予陳明。 However, the above description is only a preferred embodiment of the present invention, and thus the scope of the present invention is not limited thereto, and the equivalent structural changes of the present specification and the contents of the drawings are all included in the present invention. Within the scope of the invention, it is given to Chen Ming.

1‧‧‧晶圓 1‧‧‧ wafer

10‧‧‧晶片 10‧‧‧ wafer

11‧‧‧切割道 11‧‧‧ cutting road

12‧‧‧晶圓切割刀 12‧‧‧ Wafer Cutting Knife

2‧‧‧晶圓 2‧‧‧ wafer

20、30‧‧‧晶片 20, 30‧‧‧ wafer

201、301‧‧‧短邊 201, 301‧‧‧ Short side

202、302‧‧‧長邊 202, 302‧‧‧ long side

21、31‧‧‧切割道 21, 31‧‧ ‧ cutting road

211、311‧‧‧寬切割道 211, 311‧‧‧ wide cutting

2111、3111‧‧‧部分寬切割道 2111, 3111‧‧‧ part of wide cutting

212、312‧‧‧長切割道 212, 312‧‧ long cutting road

2121‧‧‧部分長切割道 2121‧‧‧Some long cutting roads

4‧‧‧基板 4‧‧‧Substrate

41‧‧‧控制電路 41‧‧‧Control circuit

a~c‧‧‧步驟 a~c‧‧‧step

第一圖 係為習知以切割刀進行晶圓切割之示意圖。 The first figure is a schematic diagram of conventional wafer cutting with a cutting blade.

第二圖 係為晶圓切割道之局部放大圖。 The second figure is a partial enlarged view of the wafer dicing street.

第三圖A 係為以晶圓切割刀切割晶圓之切割道示意圖。 The third figure A is a schematic diagram of a dicing road for cutting a wafer with a wafer dicing blade.

第三圖B 係為第三圖A切割後之示意圖。 The third figure B is a schematic view after cutting in the third figure A.

第四圖A 係為以雷射切割晶圓之切割道示意圖。 The fourth figure A is a schematic diagram of a cutting path for laser cutting a wafer.

第四圖B 係為第四圖A切割後之示意圖。 The fourth figure B is a schematic view after cutting in the fourth figure A.

第五圖A 係為本發明以晶圓切割刀切割晶圓之寬切 割道，以雷射切割晶圓之長切割道之示意圖。 Figure 5 is a wide cut of the wafer cut by the wafer dicing blade of the present invention. A slash, a schematic diagram of a long cut of a wafer that is laser cut.

第五圖B 係為第五圖A切割後之示意圖。 Figure 5B is a schematic view of the fifth figure A after cutting.

第六圖 係本發明接觸式影像感測單元之晶圓切割方法之流程圖。 Figure 6 is a flow chart of a wafer cutting method of the contact image sensing unit of the present invention.

第七圖 係本發明接觸式影像感測單元之晶圓切割方法之晶片使用示意圖。 The seventh figure is a schematic diagram of the use of the wafer of the wafer cutting method of the contact image sensing unit of the present invention.

a~c‧‧‧步驟 a~c‧‧‧step

Claims (3)

一種接觸式影像感測單元之晶圓切割方法，其包括：(a)提供一晶圓，該晶圓係包含有複數個矩形晶片，該些晶片係為接觸式影像感測單元晶片，其相鄰晶片間係為切割道，且該等晶片短邊之間距係為寬切割道，而其長邊之間距係為長切割道；(b)以晶圓切割刀切割該等寬切割道，以切除部分寬切割道；以及(c)以雷射切割該等長切割道，以保持切割晶片長邊之切割品質。 A wafer cutting method for a contact image sensing unit, comprising: (a) providing a wafer, the wafer comprising a plurality of rectangular wafers, wherein the wafers are contact image sensing unit wafers, and the phases thereof Between the adjacent wafers is a dicing street, and the distance between the short sides of the wafers is a wide scribe line, and the distance between the long sides thereof is a long scribe line; (b) cutting the width scribe lines with a wafer dicing cutter to Cutting a portion of the wide scribe line; and (c) cutting the equal length scribe line with a laser to maintain the cut quality of the long side of the dicing wafer. 如申請專利範圍第1項所述之接觸式影像感測單元之晶圓切割方法，其中(c)步驟係於(b)步驟前進行。 The wafer cutting method of the contact image sensing unit according to claim 1, wherein the step (c) is performed before the step (b). 如申請專利範圍第1項所述之接觸式影像感測單元之晶圓切割方法，其中該雷射切割之方法係為內部切割(Stealth Dicing)。 The wafer cutting method of the contact image sensing unit according to claim 1, wherein the laser cutting method is Stealth Dicing.