TWI231533B - Method for grinding a backside of a wafer including protruding components on its active surface - Google Patents

Abstract

A method for grinding backside of a wafer including protruding components on its active surface is disclosed. A plurality of protruding components, such as passive components, are mounted on an active surface of a wafer, a spacer tape having a plurality of openings is attached to the active surface of the wafer. The openings are aligned with the passive components without contact. A grinding tape is adhered to the spacer tape to seal the protruding components inside the openings. Thus, a back surface of the wafer can be grinded without damaging the wafer or the protruding components.

Description

1231533 V. Description of the invention (1) [Technical field to which the invention belongs] · The present invention relates to a wafer back grinding method for a wafer, and more particularly to a wafer back grinding method in which the active surface of a wafer is joined with protruding elements. [Previous technology] In order to improve the electrical function of the semiconductor package and reduce the thickness of the semiconductor package =, passive components or various large lifting components are often set on the active surface of the wafer (wafer) and the back of the wafer (wafer) A polishing and thinning process is applied, depending on the process steps. 'Passive parts can be set on the active surface of the wafer before or after wafer back grinding, or 70 passive parts can be set after the wafer is cut into wafers. It is arranged on a wafer. One of the process steps of placing passive components or various protruding components on the active surface of a wafer (wafer) is to first grind a wafer, then cut the wafer into a plurality of wafers, and then place the wafers. It is adhered to a plurality of substrates or lead frames, and then a solder paste or a flux is formed on the active surfaces of the wafers, and then a plurality of passive components or other protruding components are set on the active surfaces of the wafers, and then Carry out a wire bonding process ... to complete a plurality of semiconductor packages, but since the above process is to attach individual wafers to the substrates or lead frames, The solder paste or flux connected to the passive components cannot be formed on the wafers that have been separated and adhered to the substrates by a faster printing method. Instead, the solder paste or flux must be applied on the spot of the dispenser. The active surfaces of these individual wafers cannot be increased in operating speed. In addition, in order to set passive components on individual wafers after sticking the crystals, the wafers should still have an appropriate thickness for bonding passive components. The thickness will not be effectively reduced. Another method is to provide passive components in the semiconductor package.

1231533 V. Description of the invention (2) It is to grind one of the wafers before mounting and cutting the wire-bonded part, but after that, the rapid lift-up process or soldering is performed on the crystal plane. This may result in solder paste yield, flux, and back grinding. Therefore, passive wafers are formed on the surface. Passive wafers are formed or soldered on the wafer back. Multiple steps are performed on the back of the wafer. There are ... etc., The thickness of the rounder is used as a passive element for grinding, but the passive component of the crystal is rounded down due to the back grinding, so the speed is still set according to the previous system. When set in advance, 'the thickness of the non-circle reaches the active surface, and the wafer is then connected into multiple halves. The crystal can not be polished. The old and passive printing methods cannot be used to place the active and passive components on the wafer. Then, the printing method of the step of conducting the conductor encapsulation circle in sequence is performed. In order to form the active surface of the solder paste, and then the wafer is actively used for polishing, a passive component is set in advance on the active surface of the wafer before the wafer back grinding process is performed. Surface, ^ sequentially carry out general packaging processes such as grinding wafers, dicing wafers, wire bonding processes, sealing processes, etc. to complete a plurality of semiconductor packages, because-before grinding wafers, these passive components are first carried out Surface bonding process, so that the active surface of the wafer can be printed with tin or flux to increase the production capacity. However, referring to FIG. 1, one of the active surfaces 11 of a wafer i 0 is provided with a plurality of Passive components 13 and an abrasive tape _ 20 is attached to the active surface 11 of the wafer 10, because the passive components 13 are previously set on the active surface 11, and the conventionally known abrasive tape 2 〇 Only 0.2 to 0.3 mm thick ', so that the abrasive tape 20 is unevenly placed on the active surface of the wafer 10, and then the unevenness

Page 7 1231533 V. Description of the invention (3) The wafer 10 of the flat abrasive tape 20 is set on a polishing table (not shown in the figure) to grind one of the wafers 10 back surface 2 but if As mentioned above, because the conventional polishing tape 30 is only 0.2 to 0.3 mm thick, it cannot provide a flat bonding plane in the process of polishing wafers, and the stress during wafer back grinding will be concentrated on these passive components. In this way, the wafer or the passive component 13 is peeled off during the development. [Summary of the Invention] The main purpose of the present invention is to provide a method for polishing a backside of a protruding element on the active surface of a wafer by attaching a padding tape to one active surface of a wafer. The padding tape has a plurality of Openings to avoid a plurality of passive components or other protruding components not placed on the active surface, so that the second / second padding tape can be flatly attached to the active surface of the wafer to avoid grinding the wafer One of the wafers was broken on the back side. The second objective of this month is to provide a method for polishing the backside of a protruding element on the active surface of a wafer. After the step of attaching a padding tape to an active surface of a wafer, a polishing tape is provided on the wafer. On the padding tape, the tape is provided with a plurality of openings to avoid avoiding a plurality of passive components provided on the f-moving surface, and the abrasive tape is used to seal the passive components. The upper openings are formed to avoid grinding water or other pollutants into the openings to contaminate the active surface of the wafer when grinding one of the back surfaces of the wafer. Firstly, the method of polishing the backside of the protruding element on the active surface of the wafer. The wafer of the Department of Science and Technology has an active surface and a back surface, and laments a plurality of passive components or other protruding components on the active surface. , Then post

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V. Description of the invention (4) A first pad of tape is placed on the wafer, and it has a plurality of openings, so that the first pad on the surface of the library is an abrasive tape on the first cooked pad. Jiaomu μ—People who were picked up by the warrior, and placed in some openings: L main: ΐ straps, to seal the passive components in the band to the sergeant. Also set-the second padding adhesive with a plurality of openings should avoid the 4b passive component ;; the openings of the padding tape are opposed to each other, and the polishing tape is attached to the second padding surface _ i 4 θ grind the back of the wafer to avoid breaking the wafer when grinding the back of the wafer. [Embodiment] With reference to the drawings, the present invention will be described by the following embodiments. According to a first specific embodiment of the present invention, a method for polishing a backside of a protruding element on an active surface of a wafer is provided. First, referring to the figure, a wafer is provided. The wafer 110 has an active surface lu and a back surface. 112. A plurality of active surfaces 丨 u formed on the wafer 丨 丨 are formed on the dry pad 11 3. The wafer 丨 10 has a first thickness between the active surface 111 and the back surface 112. In this embodiment, it is about tens of mils; please refer to FIG. 2β again, and a plurality of bonding agents 1 2 0 are formed on the zinc pads 11 3 by printing. The bonding agents 120 may be solder paste. Or flux; please refer to FIG. 2C again, and then set a plurality of protruding elements on the active surface 111. In this embodiment, the protruding elements are exemplified by a plurality of passive elements 1 30, and the bonding agents are used. 12 0 connects the passive components 130 and the solder pads 1 13; please refer to FIG. 2D again, a first padding tape 140 is attached to the active surface 111 of the wafer 110, and the first padding tape 140 is There are a plurality of openings 141 to correspondingly avoid the passive elements 130 so that the first cushioning tape 1 40 It may be flat on the wafer 110

Page 9 1231533 5. The active surface 111 of the description of the invention (5) may not contact the passive elements 130. In the present embodiment, the height of the passive elements 130 is higher than the first cushion tape South degree of 14 (); please refer to FIG. 2E again, set a second padding tape 15 on the first padding tape 140, the second padding tape 50 has a plurality of openings 151, these The size of the openings 151 may not be in contact with the passive components 丨 30, preferably it may be the same size as the openings 141 to correspond to avoid the passive components 130; please refer to again In FIG. 2F, an abrasive tape 160 is attached to the second padding tape 150 to seal the passive components 130 to the openings 151 of the second padding tape 150 and the first padding tape. In the openings 141 of 140, in this embodiment, it is not limited to the first 塾 nanto tape 140, and the second high tape 150 is not required. When the height of the passive components 130 is low, At the height of the first padding tape 140, the abrasive tape 160 is directly adhered to the first padding tape 140, The passive components 130 are sealed in the openings 141 without the step of setting the second tape 150. Preferably, the first padding tape ho and the abrasive tape 1 60 can It is integrally formed in the same step. If the height of the passive components 130 is still higher than the second height-adjusting tape, 50, then a third height-adjusting tape may be set until the height of the height-adjusting tapes is higher than the passive heights. The height of the element 130 enables the polishing tape 160 to be attached to the outermost padding tape and has a flat outer surface 161 for the adsorption and fixing of the polishing stage (not shown). Preferably, the polishing tape The adhesive tape 160 does not contact the passive components 130, so as to avoid leaving adhesive residue on the passive components 130 when the abrasive tape 160 is removed; please refer to FIG. 2G again to polish the wafer 11 Back surface 11 2 to the required wafer thickness, so that the wafer 11 is formed to a second thickness

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Degree h2 'The second thickness h2 is smaller than the first thickness hi, for example, it can be as small as 6 to 15 mils. In addition, the passive components 30 are accommodated in the openings 44 without being polished. The adhesive tape 160 is in adhesive contact, so when the back surface 112 of the wafer 110 is polished, the stress acting on the first padding tape 140, the second padding tape 150, and the abrasive tape 160 will not cause stress concentration on the The passive components 130 are to prevent the passive components 130 from being damaged and the wafer 11 0 being broken. In this embodiment, the openings 14 of the first padding tape 1 40 are in position. The number and the number can correspond to the passive elements 1 3 0, so that each passive element 130 is contained in each corresponding opening 141 'of the first padding tape 4o, so that the first padding tape / Or the second padding tape 50 has a better bonding support area with the L abrasive tape 160; please refer to FIG. 2H again, f after removing the abrasive tape 160, the second padding tape 150 and the first pad High | Adhesive tape 1 4 0, after that, the back of the wafer 丨 丨 〇 丨 2 is attached to a dicing adhesive 70 Further step of cutting the wafer Shushu square, the wafer to form a plurality of 114,130 with a passive element. I

Therefore, in the present invention, the first padding tape 140 with the openings 41 is attached to the active surface of the wafer 110, and the openings 41 of the first padding tape 40 are correspondingly avoided. The passive components 130 disposed on the active surface 111 are opened, so that the first padding tape 4o can be flatly attached to the active surface 111 of the wafer 110, and the abrasive tape 160 is disposed on the first A pad of adhesive tape 140 'and the abrasive tape 160 has the flat outer surface 16] [, so as to avoid grinding stress concentrated on the passive components 13 when the back surface of the wafer 110 is polished i 2 〇The wafer is broken. In addition, the grinding tape 160 is used to seal the passive components 丨 3 〇 in the openings 141 to avoid

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When grinding the back surface 112 of the wafer 110, the polishing slurry (not shown), or other > dyeable materials enter the openings i 4 i to contaminate the wafer 丨 0 0 In the first embodiment of the present invention, a method for polishing a backside of a protruding element on a moving surface of a wafer is applicable to those having other protruding elements.

First, referring to FIG. 3A, a wafer 2 丨 〇 is provided. The wafer 2 丨 has an active surface 211 and a back surface 212. The active surface 211 is provided with a plurality of protrusions το 21 3, that is, The wafer 21 0 is a wafer having various active elements on the active surface and the active surface is uneven. The protruding elements 213 are one of bumps and solder balls or other elements; please refer to 3B, a first padding tape 2 20 is attached to the active surface 211 of the wafer 210. The first padding tape 220 has a plurality of openings 22 1 to avoid the protruding elements 21 3. In the embodiment, the heights of the protruding elements 2 1 3 are lower than the height of the first padding tape 220; please refer to FIG. 3C again, and set an abrasive tape 230 on the first padding tape 220 to seal The protruding elements 21 3 are in the openings 221 of the first cushioning tape 220 so that the abrasive tape 230 adheres to the first cushioning tape 220 and has a flat outer surface 231. Preferably, The abrasive tape 230 is not in contact with the protruding elements 213. When the height of the protruding elements 213 is higher than the The height of the height-adhesive tape 220 'can be provided with a second height-adhesive tape 220 on the first height-adhesive tape 220 (not shown), until the height of the protruding elements 21 3 is lower than the height-adhesive tapes. Height ', and then the abrasive tape 2 3 0 is adhered to the second Taonan tape and set on the first padding tape 220 to seal the protruding elements 21, 3 on the first padding tape 2 20 The openings 221; please refer to FIG. 3D again

Page 121231533 V. Description of the invention (8) The back side 2 1 2 of the wafer 2 1 0 to the required wafer thickness, since the protruding elements 2 1 3 are avoided in the openings 221, When the back surface 212 of the wafer 21 0 is ground, the stress acting on the first padding tape 2 20 and the grinding tape 230 will not cause stress to be concentrated on the protruding elements 213 to avoid damage and The wafer 210 is broken. The scope of this Ξ :: Γ 当 is subject to the definition of the scope of the attached patent application. Any changes made within the scope of this technology should be understood and ^ = deviate from the spirit and scope of this book. The protection scope of the present invention.

1231533 Brief description of the drawings [Simplified description of the drawings] Figure 1: A cross-sectional schematic diagram of a conventional abrasive tape attached to a wafer provided with a plurality of passive elements; Figures 2 A to 2 Figures: According to the present invention The first specific embodiment is an old grinding method of a protruding element on the active surface of a wafer, a schematic cross-sectional view of a wafer during manufacturing; and FIGS. 3A to 3D: According to a second specific embodiment of the present invention, a A wafer back grinding method of a protruding element on the active surface of a wafer, a schematic cross-sectional view of a wafer during manufacturing.

Simple explanation of component symbols: 10 wafers 11 13 passive components 20 abrasive tapes 11 0 wafers iii 113 soldering pads 114 1 2 0 bonding agent 1 3 0 protruding elements 140 first padding tape 141 150 second padding tape 151 160 polishing Tape ι61 170 cutting tape hi first thickness h2 21 0 wafer 211

Active surface 12 Back Active surface 112 Back Wafer Opening Opening Outer surface Second thickness Active surface 212 Back

Page 14 1231533 Brief description of the drawing 2 1 3 Protruding element 220 First cushioning tape 221 Opening 230 Abrasive tape 231 Outer surface ❿

Page 15

Claims (1)

! 231533 6. Scope of patent application [Scope of patent application], a method for polishing the backside of a protruding element on the active surface of a wafer, including: providing a wafer; the wafer has an active surface and a back surface, and a plurality of pads; It is formed on the active surface of the wafer; forming a plurality of bonding agents on the welding surfaces; setting a plurality of passive components on the active surface, and connecting the passive components and the bonding pads with the bonding agents; Combine a first padding tape on the active surface of the wafer. The first padding tape has a plurality of openings to avoid the passive components. An abrasive tape is provided on the first padding tape to seal the driven elements in the openings; and the back surface of the wafer is polished. 2. The method of polishing the back of a protruding element on the active surface of a wafer as described in item 1 of the scope of the patent application, wherein the height of the passive elements is lower than the height of the first padding tape. 3. The method of polishing the back of a protruding element on the active surface of a wafer according to item 1 of the scope of the patent application, wherein the height of the passive elements is higher than the height of the cushion tape. 4. The method for polishing a protruding element on a wafer backside as described in item 3 of the scope of the patent application, further comprising: setting a second padding tape surface and a padding tape, the second padding tape has Multiple openings 1 = openings of the first padding tape to avoid the passive components. Ten should be in 5. The method for grinding the protruding element on the crystal back as described in item 丨 of the patent application scope, wherein the abrasive tape does not contact the surface & beryllium Page 16 1231533 6. Scope of patent application. 6. If applying for the special back grinding method in the same step -7. For applying one of the back grinding methods, and 8, for a protrusion, provide a protrusion element, which is the first method, in which the body The first method of setting the formation range, wherein the printed component is on the wafer circle, the wafer is set on the main bonding, a first padding tape, and the tape is set up from the component research 9 and the Ruzhijing backing pad 10 , Ruzhijing back glutinous rubber 11, Ruianzhijing, the first has the first set of multiple grinding grinding the crystals for the application of the special high-grinding square belt application high-specific application of the high-grinding square polishing pad application An opening, abrasive tape in the opening; and the eighth method of rounding the back surface, where the degree. The eighth method of profit range, which is the degree. The tenth method of the utility model, which is additionally provided, the protruding element described in the first item on the wafer active-side first padding tape and the abrasive tape is the protruding element described in the zero item on the active surface of the wafer. It is selected from solder paste and flux formed on the pads of the wafer. An active surface polishing method includes: an active surface and a back surface, a plurality of moving surfaces; on the active surface of the wafer, the first pad is raised to avoid the protruding elements; the first tape is high The height of the protruding elements on the active surface of the wafer to seal the protruding elements described above is lower than the height of the protruding elements on the active surface of the wafer of the protruding element described in the first item. One of the protruding elements on the wafer actively includes: a second padding tape is provided on the second padding tape system having a plurality of opening pairs Page 17 1231533 VI. Scope of patent application ^ t _ _ .. ^ ^ Avoid these protruding elements. Should be at the opening of the first pad surface, with the surface 19 a made of ice * ... 1 $ The protruding elements described in the wafer are active 12, such as the patent application scope No. 8 ☆ Du Sun, s Grinding method, wherein 70 pieces of these protrusions are selected from bumps and solder balls 1 Q,. ^ ≪ said protruding elements on the active surface of the wafer 1 3, as described in the 8th patent application scope .. Crystal back grinding method, # 中 此 研 # "is not in contact with some of the protruding elements 4 Η0Η, ^ ^ The protruding elements described on the active surface of the wafer <» I Patent No. 8 high potential tape and the The abrasive tape is used in the back-grinding method, in which the first part is integrally formed in the same step. Φ