CN106181748A - There is the abrasive wheel design that elongated tooth is arranged - Google Patents

Abstract

The invention provides and there is the abrasive wheel design that elongated tooth is arranged.Abrasive wheel include basal disc and protrude from basal disc surface outside multiple teeth.Multiple teeth alignment is around the elongated ring at the center of abrasive wheel.

Description

There is the abrasive wheel design that elongated tooth is arranged

Cross-Reference to Related Applications

The application was the continuation-in-part application of following commonly assigned patent application: in 2011 11 The Shen of No. 13/290,879 entitled " End Point Detection in Grinding " that the moon 7 was submitted to Please, entire contents is hereby expressly incorporated by ginseng.

Technical field

The present invention relates to that there is the abrasive wheel design that elongated tooth is arranged.

Background technology

In the fabrication of integrated circuits, grinding is a kind of conventional technology.In grinding technics, grind Wheel is placed on above wafer.Abrasive wheel and wafer all rotate, so owing to abrasive wheel goes desurfacing and Reduce the thickness of wafer.

In the manufacture of device wafers, grind and can be used for such as during the formation of silicon through hole (TSV) In the thinning back side of silicon substrate.There are other techniques that can use grinding technique.Seal in fan-out chip-scale In the formation of piece installing, can cutting device wafer, and select known good tube core and be attached to carry On body, it is known that good die is spaced apart from each other.Known good tube core includes for forming fan-out connector Copper post.Then moulding compound is filled between known good tube core and in the space of top to form fan-out Wafer.After curing mold plastics, grinding technics can be implemented to remove on part and the copper post of moulding compound Other dielectric materials of side.After exposing copper post, electrical connector can be made to be connected to copper post, so make Must extend in the area bigger than the area of known good tube core to the connector of fan-out wafer.

Because the layer standing to grind is usually thin layer, so stopping grinding work at correct temporally precise Skill is most important to the yield rate of integrated manufacturing technology.Such as, in the manufacture of fan-out wafer, when complete When entirely exposing the copper post in the essentially all of known good tube core in whole fan-out wafer, need to stop Only grind, and substantially without grinding occurred.In existing grinding technique, gauge is for grinding The gross thickness of fan-out wafer is detected during technique.When gross thickness is decreased to predetermined value, it is believed that the most sudden and the most violent Expose copper post.But, this detection method is inaccurate, and may result in yield loss.

Summary of the invention

For solving problems of the prior art, according to an aspect of the invention, it is provided a kind of Device, including:

Abrasive wheel, including:

Basal disc；And

Multiple teeth, protrude from outside the surface of described basal disc, and wherein, the plurality of tooth alignment encloses Elongated ring around the center of described abrasive wheel.

According to one embodiment of present invention, the first tooth in the plurality of tooth has apart from described center The first distance, the second tooth in the plurality of tooth has the second distance apart from described center, and Described first distance is more than described second distance, and the amount that described first distance is bigger than described second distance is big Width in described tooth.

According to one embodiment of present invention, the first tooth in the plurality of tooth has apart from described center The first distance, the second tooth in the plurality of tooth has the second distance apart from described center, and, Described first distance is more than described second distance, and the amount that described first distance is bigger than described second distance is big In about 1mm.

According to one embodiment of present invention, described first distance with between about 2mm to about 9mm it Between difference more than described second distance.

According to one embodiment of present invention, described basal disc includes forming first circular and the second circle respectively The outward flange of shape and inward flange, and, the center of described abrasive wheel is described first circular and described The center of two circles.

According to one embodiment of present invention, described abrasive wheel is configured to raised and declines, and Described device also includes:

Rotating disk, is configured to pivot；And

Chuck, is positioned at above described rotating disk and is configured to rotate together with described rotating disk, wherein, and institute State an abrasive wheel part towards described chuck.

According to one embodiment of present invention, the plurality of tooth is formed by abrasive material.

According to a further aspect in the invention, it is provided that a kind of device, including:

Abrasive wheel, is configured to rotate around the first axle, and described abrasive wheel includes:

Basal disc, has the center being directed at described first axle；And

Multiple teeth, protrude from outside the surface of described basal disc, and wherein, the plurality of tooth includes:

First tooth, has the first distance apart from the center of described basal disc；And

Second tooth, has a second distance at center apart from described basal disc, described second away from From more than described first distance.

According to one embodiment of present invention, also include:

Chuck；And

Rotating disk, is positioned at below described chuck, and wherein, described rotating disk is configured to rotate around the second axle, Described second axle deviates described first axle.

According to one embodiment of present invention, the plurality of tooth also includes having with the center of described basal disc 3rd tooth of the 3rd distance, described 3rd distance is more than described first distance and less than described second distance.

According to one embodiment of present invention, described first distance be to the plurality of tooth center Big distance, and the minimum range that described second distance is the center to the plurality of tooth, and wherein, Gradually the tooth away from described first tooth and near described second tooth becomes big gradually with the distance at described center.

According to one embodiment of present invention, the plurality of tooth alignment has the ring of ellipse.

According to one embodiment of present invention, the difference between described first distance and described second distance More than the width of a tooth in the plurality of tooth and described along pointing to from the center of described basal disc Width described in the orientation measurement of the one tooth in multiple teeth.

According to one embodiment of present invention, the difference between described first distance and described second distance Greater than about 1mm.

According to another aspect of the invention, it is provided that a kind of method, including:

Select the target reflectivity of grinding wafer technique；

Wafer is implemented grinding technics, and along with the carrying out of described grinding technics, measures from described crystalline substance The reflectance value of the light of the surface reflection of circle；And

Record reflectance value in described reflectance value equals to or more than described target reflectivity Time, stop described grinding technics.

According to one embodiment of present invention, also include: when reaching described target reflectivity, implement Extension is ground to remove the layer with predetermined thickness of described wafer, wherein, grinds completing described extension Implement to stop the step of described grinding technics during mill.

According to one embodiment of present invention, also include: when reaching described target reflectivity, in advance Implement extension in the section of fixing time to grind, and wherein, implement to stop institute when completing described extension and grinding State the step of grinding technics.

According to one embodiment of present invention, described wafer includes:

Multiple component pipe cores；And

Moulding compound, be arranged between the plurality of component pipe core and the plurality of component pipe core above sky In between.

According to one embodiment of present invention, the step of described target reflectivity is selected to include:

Grind, with described wafer, there is mutually isostructural sample wafer；

During grinding the step of described sample wafer, monitor the reflectance of the end face of described sample wafer Value；

Periodically survey described sample wafer to determine the optimal end points of described grinding technics；And

The reflectance value corresponding with described optimal end points in described reflectance value is recorded as described mesh Mark reflectance.

According to one embodiment of present invention, noncontact gauge is used to measure described reflectance.

Accompanying drawing explanation

When reading in conjunction with the accompanying drawings, by following detailed description, the disclosure be may be better understood Each side.It is emphasized that according to the standard practices in industry, be not necessarily to scale various Parts.It practice, in order to clearly discuss, the size of various parts can be at random increased or decreased.

Fig. 1 shows and includes component pipe core and the cross section of wafer of the moulding compound for moulded device tube core Figure, wherein, implements grinding technics, and measures wheel load wafer；

Fig. 2 graphically shows the wheel electric current in time dependent grinding technics；

Fig. 3 shows the sectional view of a part for wafer shown in Fig. 1, its, employ different moulds Formula represents the stage in grinding technics；

Fig. 4 graphically shows the copper exposure rate of the copper post in grinding technics along with wheel curent change；

Fig. 5 shows and includes component pipe core and the cross section of wafer of the moulding compound for moulded device tube core Figure, wherein, implements grinding technics to wafer, and measures the reflectance of wafer；

Fig. 6 shows and sends light on wafer for measuring reflectance, wherein, and rotating wafer；

Fig. 7 graphically shows the light intensity of the light of the wafer reflection changed over time in grinding technics Degree；

The thickness that Fig. 8 shows the sample wafer along with milling time change and the reflection light received Intensity；

Fig. 9 to Figure 16 show some embodiments according to the disclosure in the formation of packaging part in Between the sectional view in stage, wherein, implement grinding technics；

Figure 17 shows the top view of the abrasive wheel according to some embodiments, wherein, the tooth of abrasive wheel with Elongated ring is directed at；

Figure 18 to Figure 20 is the top view of the grinding technics according to some embodiments；And

Figure 21 shows the top view of the grinding technics using abrasive wheel, and the tooth of abrasive wheel is to quasi-circular.

Detailed description of the invention

Following disclosure provides multiple different embodiments or the reality of the different characteristic for realizing the present invention Example.The particular instance of assembly explained below and layout is to simplify the present invention.Certainly, these are only real Example and be not intended to limit the present invention.Such as, in the following description, above second component or on shape Become first component can include the embodiment that first component directly contacts with second component, it is also possible to include Miscellaneous part can be formed between first component and second component and make first component and second component not The directly embodiment of contact.It addition, the present invention can in multiple examples repeated reference symbol and/or word Symbol.This being recycled and reused for simplifies and clear, and itself does not indicates that the plurality of embodiment and/or join Relation between putting.

Additionally, this can use such as " ... under ", " ... below ", " following ", " ... on Face " and the spatial relationship term of " above " etc., readily to describe as illustrated in the drawing one Individual element or parts and another element (multiple element) or the relation of parts (multiple parts).Except figure Shown in orientation outside, spatial relationship term will include using or the various differences of device in operation Orientation.Device can otherwise position (90-degree rotation or in other orientation), and passes through Spatial relation description as used herein symbol is correspondingly explained.

According to various embodiments, it is provided that a kind of detect the method for end points in grinding technics.Discuss reality Execute the change of example.Running through various view and illustrative embodiment, identical reference character user refers to phase Same element.Although it should be appreciated that the fan-out wafer of chip scale package (CSP) is used as example, But the end-point detecting method according to embodiment can be additionally used in grind other kinds of grinding wafer other The wafer of type detects end points in (such as, device wafers).

Further it is provided that abrasive wheel, wherein, the tooth lapping in abrasive wheel has elongated layout, so Make the wafer being ground produced have surface evenly, and designed by elongated tooth lapping The inhomogeneities in grinding can be reduced.

Fig. 1 shows the sectional view of wafer 20, and such as, this wafer 20 could be for forming fan-out The fan-out wafer of connector.Wafer 20 includes tube core 22.In one embodiment, tube core 22 is bag Include the component pipe core of the such as active device of transistor (not shown).Tube core 22 can pass through binding agent 42 are bonded on carrier 40.The end face of metal column (such as, it can be copper post) adjacent die 22, Metal column can be previously formed in tube core 22, and may be electrically connected to the active device in tube core 22. In certain embodiments, can be that the polymeric layer 28 of aramid layer is formed on copper post 26.Moulding compound 30 be filled between tube core 22 and tube core 22 above space in.It should be noted that the material of wafer 20 Material and structure are the examples of the design explaining embodiment, and can use the end-point detection according to embodiment Method grinds the wafer with different materials and structure.According to exemplary embodiment, grinding technics is used for Remove moulding compound 30 and the part of polymeric layer 28, and expose metal column 26, so can be formed It is electrically connected to the fan-out connector of metal column 26.

Milling tool 44 grinding crystal wafer 20, milling tool 44 includes abrasive wheel 46, and it has for grinding The coarse sand of the end face of mill wafer 20.In grinding technics, abrasive wheel 46 and wafer 20 all rotate.Grind Grinder tool 44 also includes the control unit of the action for controlling grinding technics and control abrasive wheel 46 48.During grinding technics, control unit 48 can detect the surface being ground, and correspondingly adjusts The wheel load of whole grinding technics.In certain embodiments, milling tool 44 adjusts to drive abrasive wheel The wheel electric current of 46, therefore according to exemplary embodiment, wheel electric current can be used for representing wheel load.Wheel electric current Can be used as showing what the exemplary abrasive instrument of wheel load included being manufactured by Disco Corporation DGP8761.In alternative embodiments, other parameters are used can to represent resistance and/or the wheel of lapped face Load.

Fig. 2 graphically shows in the exemplary abrasive technique of sample wafer along with milling time becomes The wheel electric current changed.In grinding technics, if wheel load includes stem portion, it includes corresponding respectively to grind 50A, 50B and 50C of the molding compound of this wafer of grind away, aramid layer and layers of copper.Fig. 2 illustrates For different material, wheel electric current (wheel load) is different.

Along with the carrying out of grinding technics, remove upper strata, and expose and grind following layer.Fig. 3 shows Having gone out the sectional view of a part for structure in Fig. 1, this part includes metal column 26, polymeric layer 28 With moulding compound 30.If the stage that Fig. 3 graphically shows grinding technics is represented by dry model, i.e. Mode A, Mode B, pattern C and pattern O.During Mode A, at lap plastics 30 with poly- The most non-abrasive metal post 26 while compound layer 28.During Mode B, expose and grind whole Some in the metal column 26 of individual wafer 20, and the metal column 26 that exposes can have and be ground Tip, and the lower part with bigger vertical view area may not be ground.In pattern C, base This exposure and grind whole metal columns 26, and substantially without the metal occurred whole wafer 20 Crossing of post 26 is ground.In pattern O, there is grinding.Optimal situation is the Optimum End ground Point is positioned at pattern C or at least in Mode B, but Mode A and pattern O are undesirable, and can For failure mode.

Because the wheel load grinding different materials is different (as shown in Figure 2), so Mode A, pattern Wheel load in B and pattern C is different.By grind sample wafer can find corresponding to Mode A, Mode B and pattern C wheel load, and periodically survey during grinding technics sample wafer with Association between discovery mode and respective wheel load.The most this association can be used for determining grinding technics Optimal end points, and grinding technics has mutually isostructural production wafer for grinding with sample wafer.

Fig. 4 shows the experimental result obtained by the grinding technics of sample fan-out wafer, wherein, shows Go out (copper post 26) the copper exposure changed along with wheel load (it is represented as taking turns electric current).Point 52A, 52B, 52C and 52D are the points checking sample fan-out wafer.Point 52A is corresponding to 8.8amp Wheel electric current, in this time, in 937 tube cores, Mode A, Mode B, pattern C and pattern Number of die in O is respectively 936,0,0 and 1.Point 52B corresponds to the wheel electric current of 9.1amp, Number of die in this time, Mode A, Mode B, pattern C and pattern O is respectively 666, 265,2 and 1.Point 52C is corresponding to the wheel electric current of 9.4amp, in this time, Mode A, Mode B, Number of die in pattern C and pattern O is respectively 150,711,73 and 1.Point 52D corresponds to The wheel electric current of 10amp, in this time, in 937 tube cores, Mode A, Mode B, pattern C It is respectively 9,501,424 and 1 with the number of die in pattern O.It can be seen that at a 52D, Only 9 tube cores are still in Mode A, and 925 in 937 tube cores are in Mode B or pattern C In.After some 52D, in order to more tube core is brought in pattern C from Mode A and Mode B, Implement further to grind (the wheel electric current of use 10amp), to remove the extra play of wafer 20, to be somebody's turn to do The thickness of extra play is equal to about 1.1 μm.Therefore, Mode A, Mode B, pattern C and pattern O In number of die be respectively 0,16,918 and 1.This equates the copper exposure (Fig. 4) of 99.7%. The wheel load of these experimental results explanation such as wheel electric current can be used as determining the index of optimal end points.

Generally, according to embodiment, such as by sample wafer implement grinding technics can find corresponding to The target wheel of optimal end points loads and finds that target wheel loads the (electricity of the 10amp in such as Fig. 4 Stream).On the production wafer with the structure identical with sample wafer, optimal end points can be to reach To target wheel load time.In other embodiments, end points is so determined: load it reaching target wheel After, implement extension and grind the thickness of wafer to be reduced predetermined grinding thickness (such as, shown in Fig. 4 1.1 μm in example).Predetermined grinding thickness also can be between about 1 μm and about 5 μm. It should be appreciated that predetermined grinding thickness is an example, and can be to grind different wafers with sudden and violent Reveal different parts and change.In other embodiments, end points is so determined: reach target wheel load Afterwards, implement extension the milling time cycle extended to grind.In the exemplary embodiment, implement The time that extension is ground can be between about 10 seconds and about 50 seconds.Can find what extension was ground by experiment The optimal persistent period.In certain embodiments, target wheel can reached such as the milling tool 44 in Fig. 1 Automatically implement extension after load to grind, then stop grinding technics.In other embodiments, can hands Dynamic enforcement extends grinding technics.

Fig. 5 to Fig. 7 shows the method for the end points of the determination grinding technics according to alternate embodiment.Remove It is used as to determine Optimum End by the reflectance that recorded by the surface being ground of wafer rather than wheel load Beyond the standard of point, these embodiments are similar to the embodiment shown in Fig. 1 to Fig. 4.Unless otherwise tool Body illustrates, otherwise in these embodiments, material and the forming method of assembly are essentially identical with similar component, By the same reference character representation in the embodiment shown in Fig. 1 to Fig. 4.

With reference to Fig. 5, luminous/receipts light gauge 60 is used for measuring reflectance, wherein, luminous/to receive light gauge 60 can include the luminous gauge 60A for launching the light 62 and receipts light gauge 60B of reception reflection light 64. Luminous/receipts light gauge 60 is the noncontact gauge not contacted with wafer 20 during grinding technics.Luminous / receive the part that light gauge 60 can be reflectance measurement tool, this reflectance measurement tool is configured to survey Amount is launched the reflectance of light 62, is measured the intensity of reflection light and calculate reflectance.Because light 64 can Reflected from surface and also can be reflected from the internal part of wafer 20, so reflectance can be surface Material and be buried in the function of material of lower face of wafer 20.Reflectance can be also in wafer 20 The function of the topological structure of parts.

With reference to Fig. 6, during grinding technics, the light 62 launched by luminous/receipts light gauge 60 is incident upon On the point 68 (it is actually formed circle along with the rotation of wafer 20) of wafer 20.It should be appreciated that Even if light 62 can project on fixed-direction, and (figure on a metal column 26 can be projected every time 1), but being as the rotation of wafer 20, at different time points, light 62 can be projected onto wafer Moulding compound 30 (Fig. 5) on miscellaneous part on 20, between such as tube core 22.It is therefore possible for the detected that Reflectance be from circular 68 average results obtained.

Fig. 7 graphically shows the reflection light 64 changed over time in exemplary abrasive technique (Fig. 5) intensity.Because the incident illumination of Fig. 5 62 can have fixing intensity, reflection light 64 Intensity may also indicate that reflectance, because the intensity by reflection light 64 can divided by the intensity of incident illumination 62 Calculate reflectance.In grinding technics, it is shown that if light intensity include stem portion, including 70A, 70B and 70C, they the most corresponding lap plastic layers, aramid layer and layers of copper.Fig. 7 shows For different materials, the intensity of reflection light 64 is different, and therefore reflectance is different.Therefore, Reflectance can be used as determining the index of the optimal end points of grinding technics.

Fig. 8 shows the experimental result obtained by the grinding technics of sample fan-out wafer, wherein, shows Go out the thickness of the sample wafer along with milling time change and reflected the intensity of light.Left Y-axis shows Wafer thickness, and corresponding to line 82 and 84.Right Y-axis shows light intensity, and corresponding to ripple Shape 86.Line 82 represents along with the thickness (Fig. 1) of moulding compound 30 of milling time change, and line 84 Expression is along with the thickness (Fig. 1) of the silicon substrate 24 of milling time change.As shown in Figure 8, along with grinding The carrying out of grinding process, the thickness of moulding compound 30 reduces.Meanwhile, because such as polymeric layer 28 Can be exposed along with the carrying out ground with the miscellaneous part of copper post, As time goes on, light intensity (waveform 86) strengthens.Moulding compound 30, polymeric layer 28, metal column 26 and silicon substrate 24 are ground The region of mill is also shown in region 88A, 88B, 88C and 88D.When metal column 26 and polymer Layer 28 may select optimal end points when being all ground.Therefore, time point T0 can be selected as exemplary Good end points, and light intensity I0 is used for calculating target reflectivity accordingly.

Generally, according to embodiment, such as by sample wafer is implemented grinding technics, implementation cycle property Ground check and calculate target reflectivity (such as by Fig. 8 moderate strength class I0) can find corresponding to The target reflectivity of optimal end points.About having the production wafer of the structure identical with sample wafer, Good end points is when reaching target reflectivity.In other embodiments, optimal end points is so determined: After realizing target reflectivity, within the milling time cycle extended, implement extension grind, or implement to expand Exhibition is ground in order to the thickness of wafer 20 is decreased to predetermined value.Extension can be found through experiments grind The good time.

Fig. 9 to Figure 16 shows the cross section in the interstage manufacturing packaging part according to some embodiments Figure.Fig. 9 shows the releasing layer 41 above carrier 40, carrier 40 and the pipe above releasing layer 41 Core adhesive film (DAF) 42.Carrier 40 can be glass carrier, ceramic monolith etc..Carrier 40 can There is the plan view shape of circle and can have the size of Silicon Wafer.Such as, carrier 40 can have 8 English Very little diameter, the diameter etc. of 12 inches.Releasing layer 41 can be by polymer-based material (such as, photo-thermal Conversion (LTHC) material) formed, it can be together with carrier 40 from upper by formed subsequent step Face structure is removed.According to some embodiments of the present invention, releasing layer 41 is discharged by epoxy resin-matrix heat Material is formed, and it will be decomposed under light and heat condition.According to other embodiments of the invention, releasing layer 41 are formed by ultraviolet (UV) glue.Releasing layer 41 can be also the laminated film being laminated on carrier 40.Release The end face putting layer 41 is smooth and has height coplanarity.DAF layer 42 is laminated to releasing layer 41 Top, and for allowing the tube core 22 (Figure 10) of follow-up placement to be attached to carrier 40.

Figure 10 shows the placement of component pipe core 22, and it is bonded to DAF 42.Component pipe core 42 can For logical device tube core, in it, include logic transistor.Some exemplary enforcements according to the present invention Example, component pipe core 22 aims at Mobile solution design.Such as, component pipe core 22 can be power management collection Become circuit (PMIC) tube core, transceiver (TRX) tube core etc..

According to some exemplary embodiments of the present invention, at the end face of component pipe core 22, it is pre-formed gold Belonging to post 26 (such as, copper post), wherein, metal column 26 is electrically connected to IC-components, such as Transistor in component pipe core 22.According to some embodiments of the present invention, (it can for top dielectric layer 28 For polymeric layer) fill the gap between adjacent metal post 26.According to some embodiments, push up dielectric layer 40 can be formed by polybenzoxazoles (PBO), polyamide or other polymer.

Then, moulding material 30 is encapsulated on component pipe core 22 by moulding technology.Figure 11 shows The structure produced.The gap between adjacent devices tube core 22 filled by moulding material 30.Moulding material 30 Moulding compound, molding underfilling, epoxy resin or resin can be included.The end face of moulding material 30 is high Top in metal column 26.In whole description, carrier 40 and include component pipe core 22 and mold member The above structure of material 30 is collectively known as composite wafer 100.

Then, enforcement grinding steps is with thinning moulding material 30, until exposing metal column 26.Figure Corresponding grinding technics it is also shown in 11.Owing to grinding, the top of metal column 26 and moulding material The end face of 30 is substantially co-planar.

With reference to Figure 11, it is shown that for the milling tool 44 of grinding technics.Milling tool 44 includes card Dish 102 and rotating disk 104.Composite wafer 100 is placed on above chuck 102.According to the present invention one A little exemplary embodiments, composite wafer 100 is fixed thereon by chuck 102 by vacuum.Chuck 102 It is positioned at above rotating disk 104 with composite wafer 100.Milling tool 44 also includes being configured to around axle 106 The mechanism of rotary turnplate 104 (such as, motor, controller etc., not shown).Therefore, wafer 100 also rotate around axle 106.

Milling tool 44 includes abrasive wheel 46, wherein, abrasive wheel 46 contact during grinding technics and Polishing composite wafer 100.Abrasive wheel 46 includes basal disc 110, and it has in the top view of abrasive wheel 46 Have round-shaped.Outside abrasive wheel 46 also includes protruding from the bottom surface of basal disc 110 (under) multiple Tooth lapping 112.Making to be shown in broken lines some tooth lappings 112, because as shown, these tooth lappings do not exist On same plane.

Milling tool 44 includes being configured to when not implementing to grind raise abrasive wheel 46 and reduce grinding Wheel 46 is in order to the mechanism's (such as, conduction band, motor etc., not shown) ground.Milling tool 44 Also include the mechanism's (such as, motor, controller etc., not shown) around axle 114 spin finishing wheel 46, Axle 114 deviates from axle 106.According to some embodiments of the present invention, axle 106 and the position of axle 114 It is fixing, and composite wafer 100 and abrasive wheel 46 rotate simultaneously so that grinding of abrasive wheel 46 Roll flute 112 is polished composite wafer 100.According to some embodiments of the present invention, tooth 112 by diamond, Carborundum, silicon nitride or other kinds of abrasive material are formed.Tooth 112 has grinding composite wafer 100 Applicable roughness and hardness.

Figure 18 shows the some parts of top view of the structure shown in Figure 11, wherein, it is shown that multiple Synthetic circle 100 and abrasive wheel 46.Although it should be noted that Figure 18 shows tooth lapping 112, but Tooth lapping 112 is actually hidden in after basal disc 110.Composite wafer 100 and abrasive wheel 46 are grinding Can counter-rotating (or rotating in the same direction) during technique.Such as, as shown in figure 18, compound Wafer 100 can rotate in the clockwise direction around axle 106, and abrasive wheel 46 can be around axle 114 inverse Rotate on clockwise.By composite wafer 100 and the rotation of abrasive wheel 46, by abrasive wheel 46 Grind the whole end face of composite wafer 100.

Although it should be appreciated that composite wafer 100 is with being described grinding technics and corresponding milling tool 44 Example, but such as other integrated circuits of Silicon Wafer, package substrate, plug-in unit etc. are used as grinding Grinder tool 44 is ground.

After grinding technics, expose component pipe core 22 and corresponding metal column 26, as shown in figure 12. Then, as shown in figure 13, rewiring layer (RDL) 116 and dielectric layer 118 are formed.Such as, as Shown in Figure 13, RDL 116 is formed on the end face of moulding material 30 and metal column 26.According to this Some bright embodiments, the formation of RDL 116 include deposit metal level (such as, aluminum, aluminum bronze, nickel, Tungsten or their alloy), and by etch process patterned metal layer.Replacing according to the present invention For embodiment, forming RDL 116 in electroplating technology, wherein, each RDL 116 includes crystal seed layer (not shown) and be positioned at the electroplating metal material above crystal seed layer.

Figure 13 also show dielectric layer 118, and it covers the some parts of RDL 116, and stays Other parts are uncovered.According to some embodiments of the present invention, dielectric layer 118 by such as PBO, The polymer of polyamide etc. is formed.According to the alternate embodiment of the present invention, dielectric layer 118 by silicon nitride, Silicon oxide or their multilamellar are formed.Opening 120 is formed in dielectric layer 118 to expose RDL The pad of 116.The formation of opening 120 can be implemented by photoetching process.

Figure 14 shows the formation of the electrical connector 122 according to some exemplary embodiments.Electrical connector The formation of 122 can include being placed on by solder ball on the expose portion of RDL 116, is then refluxed for solder Ball.According to the alternate embodiment of the present invention, the formation of electrical connector 122 include implement plating step with Above RDL 116, form solder areas be then refluxed for solder areas.Electrical connector 122 may also include metal Post and include solder cap alternatively, it is formed also by plating.Can before forming electrical connector 122 Formed and maybe can be formed without underbump metallization layer (UBM, not shown).The formation of UBM can include Deposition and patterning.

Then, the part above releasing layer 41 that is positioned at of composite wafer 100 separates with carrier 40.Multiple The remainder (not including carrier 40 and releasing layer 41) of synthetic circle 100 is referred to as packaging part 124, It is illustrated in fig .15.By the light of such as UV light or laser is incident upon on releasing layer 41 with Decompose releasing layer 41 can implement to separate.

In subsequent step, as shown in figure 15, packaging part 124 is placed in cutting belt 126, cutting Band 126 is fixed on framework 128.Implement die separation step to cut into multiple by packaging part 124 Packaging part 130 (Figure 16), each packaging part includes component pipe core 22.

Figure 17 shows the upward view of the abrasive wheel 46 according to some embodiments of the present invention.Abrasive wheel 46 include basal disc 110, and basal disc 110 is formed and includes outward flange 110A and the annular of inward flange 110B. Abrasive wheel 46 has center 132.According to some embodiments of the present invention, outward flange 110A and inner edge Each in edge 110B forms circle, great majority in circle (or the most all, except some contract Enter) point there is the equidistance to center 132.According to some exemplary embodiments, outward flange 110A There is the diameter of about 300mm.

Tooth lapping 112 is positioned on the side (shown bottom side as an example) of basal disc 110, and dashes forward Outside surface for basal disc 110, so make in grinding technics, such as, as shown in figure 11, Tooth lapping 112 contacts with surface to be ground, and basal disc 110 is away from surface to be ground simultaneously.

Tooth lapping 112 includes the multiple discrete tooth being spaced apart from each other.Such as, the sum of tooth lapping 112 The scope of amount between about 20 to about 60, and can use more or less of tooth lapping 112. Being distributed multiple tooth lapping 112 along ring 134, they are around center 132.Some according to the present invention are real Executing example, ring 134 has major axis 136 and short axle 138.Along the ring 134 measured by major axis 136 Size is referred to as length L1, and is referred to as width along the size of the ring 134 measured by short axle 138 W1, width W1 are less than length L1.Therefore, ring 134 hereinafter referred to as elongated ring.From grinding The outward flange of tooth 112 measures length L1 and width W1.

Ring 134 can have ellipse or any other is regular or irregularly shaped.Such as, Figure 17 illustrates Ellipse, wherein, center 132 is oval symmetrical centre.Therefore, when drawing any passing During the straight line at center 132, straight line would span across two points of the ring 134 on the opposite side at center 132, And center 132 is equidistant by have to the two point.Additionally, when at major axis 136 Shang Cong center When the point of 132 to ring 134 measures, distance is equal to D1, and it is equal to (L1) according to some embodiments /2.Illustrating alternatively, the farthest tooth 112 of distance center 132 has distance D1.When at short axle 138 When the point of Shang Cong center 132 to ring 134 measures, distance is equal to D2, according to some embodiments, D2 is equal to (W1)/2.Illustrating alternatively, the nearest tooth 112 of distance center 132 has distance D2. In whole description of the invention, distance D1 and distance D2 are hereinafter referred to as ring 134 distance center 132 Ultimate range and minimum range.The distance between other points any on center 132 and ring 134 is situated between Between D1 and D2.According to some exemplary embodiments, gradually away from major axis 136 and adjacent to short The distance at the Chi Yu center 132 of axle 138 gradually diminishes.Such as, distance D4 is less than distance D3, Distance D3 be by measure than have the tooth pitch of distance D4 from major axis 136 closer to tooth 112 in one Individual gained.

According to some embodiments of the present invention, wittingly design ultimate range D1 and minimum range D2 it Between difference (D1-D2), and this difference at least above by the manufacture of abrasive wheel 46 unintentionally The difference that technique change may cause.Such as, difference (D1-D2) is greater than about 1mm.At abrasive wheel 46 or tooth 112 have in large-sized embodiment, difference (D1-D2) also can increase.According to some Embodiment, the scope of difference (D1-D2) also can be between about 2mm to about 9mm.Additionally, work as When tooth lapping 112 has width W2, difference (D1-D2) can more than width W2 to disperse grinding, Such as the discussion that will be given in subsequent paragraph.

Figure 18 and Figure 19 shows the wafer 100 in grinding technics and the top view of abrasive wheel 46.Root According to some embodiments of the present invention, as shown in figure 18, the center 132 of abrasive wheel 46 and axle 114 weight Folded, abrasive wheel 46 rotates around axle 114.Wafer 100 rotates around axle 106.Figure 18 shows axle 106 With the connecting line 139 of 114, wherein, connecting line 139 is marked as pointing to axle 106 from center 132 Arrow.At any time, can have the tooth 112 of alignment (be bordering on most) connecting line 139.Should Noting, it is most that the part of this tooth neighbouring of wafer 100 is ground, and most probable is crossed and ground.

Figure 18 shows the moment when the major axis of ring 134 is directed at connecting line 139.According to the present invention's Some embodiments, in this moment, it is internal that axle 106 is positioned at ring 134.In Figure 18, labelling point 140 is to show Go out the solstics that tooth 112 can reach up in the side of arrow 139.

Figure 19 shows the moment when the short axle of ring 134 is directed at connecting line 139.According to the present invention's Some embodiments, in this moment, axle 106 also is located at the inside of ring 134.Figure 19 marks a little 142 to illustrate the nearest point that tooth 112 reaches up in the side of 139 labellings of arrow.

Relatively Figure 18 and Figure 19 understands, and along with the rotation of abrasive wheel 46, tooth 112 is one by one Through connecting line 139.Because ring 134 is elongated, so different teeth 112 may pass through connecting line The difference of 139 rather than the fixing point through connecting line 139.In a word, when through connecting line 139 Time, tooth 112 is positioned at being in a little on position in the range of 140 and 142.The most advantageously reduce Crossing of the center of wafer 100 is ground.For example, referring to showing Figure 21 of prior art, In this scenario, ring 134 ' (being directed at by tooth 112 ') is circular, and all of tooth 112 ' has To rotary shaft 114 and the same distance at abrasive wheel center 132.In figure 21, all of tooth 112 ' By the identical point through connecting line 139, and identical zonule 144 will be ground.Therefore, wafer This part can by cross be ground.But, as shown in figure 19, when tooth 122 point 140 and point 142 it Between swing position on through connecting line 139 time, cross abrasive areas 146 have than the region in Figure 21 The area that the area of 144 is big.Illustrate alternatively, cross to grind and disperseed, therefore in wafer 100 Heart region is ground without departing from crossing of allowing in this specification.

Additionally, by making the difference (D1-D2) (Figure 17) the width W2 more than tooth 112, alignment figure The tooth of the connecting line 139 shown in 18 will completely offset from the tooth of connecting line 139 in alignment Figure 19.So Also enhanced the dispersion of abrasive areas.

Figure 20 shows another embodiment, wherein, when short axle 138 is overlapping with connecting line 139 Moment, axle 106 is positioned at the outside of ring 134.Illustrate alternatively, along with abrasive wheel 46 is from Figure 18 Shown position rotates to the position shown in Figure 20, and the tooth 112 of alignment connecting line 139 retreats through axle 106.This means to disperse further abrasive areas.

Embodiments of the invention have some features.By designing the right with elongated circle of abrasive wheel Accurate tooth, reduces crossing of wafer and grinds.Test result indicate that the elongated alignment by using tooth lapping, Crossing of the central area of wafer 100 grinds (Figure 11) in the range of this specification.By comparison, remove The tooth lapping wafer to using identical grinding condition to grind beyond quasi-circular can have quilt during grinding The metal column 26 removed the most completely, thus cause the invalid of the center tube core in wafer.

According to some embodiments of the present invention, abrasive wheel includes basal disc and protrudes from the surface of basal disc Multiple teeth.Multiple teeth alignment is around the elongated ring at the center of abrasive wheel.

According to the alternate embodiment of the present invention, a kind of device includes the abrasive wheel being configured to pivot. Abrasive wheel includes the basal disc with the center being directed at the first axle, and the surface protruding from basal disc is many Individual tooth.Multiple teeth include first tooth with first distance at the center of distance basal disc and have distance base Second tooth of the second distance at the center of dish, and second distance is more than the first distance.

According to the alternate embodiment of the present invention, a kind of method includes that the target selecting grinding wafer technique is anti- Penetrate rate, and wafer is implemented grinding technics.Along with the carrying out of grinding technics, record the table from wafer The reflectance value of the light of face reflection.The reflectance value recorded equals to or more than target reflectivity, institute To stop grinding technics.

The parts of some embodiment are discussed above so that those skilled in the art can be more preferably geographical Solve various aspects of the disclosure.It should be appreciated by those skilled in the art, can be used this easily Design or change other based on Gong Kai for reaching the purpose identical with embodiment described herein And/or realize technique and the structure of same advantage.Those skilled in the art is it should also be appreciated that this Equivalent constructions is without departing from the spirit and scope of the disclosure, and without departing substantially from the spirit of the disclosure and model In the case of enclosing, multiple change can be carried out, change and change.

Claims (10)

1. a device, including:

Abrasive wheel, including:

Basal disc；And

Multiple teeth, protrude from outside the surface of described basal disc, and wherein, the plurality of tooth alignment encloses Elongated ring around the center of described abrasive wheel.

Device the most according to claim 1, wherein, the first tooth in the plurality of tooth have away from From first distance at described center, the second tooth in the plurality of tooth has second apart from described center Distance, and described first distance is more than described second distance, described first distance than described second away from The width of described tooth it is more than from big amount.

Device the most according to claim 1, wherein, the first tooth in the plurality of tooth have away from From first distance at described center, the second tooth in the plurality of tooth has second apart from described center Distance, and, described first distance is more than described second distance, described first distance ratio described second It is greater than about 1mm apart from big amount.

Device the most according to claim 3, wherein, described first distance is with between about 2mm Difference between about 9mm is more than described second distance.

Device the most according to claim 1, wherein, described basal disc includes forming the first circle respectively Shape and the outward flange of the second circle and inward flange, and, the center of described abrasive wheel is described first circle Shape and the center of described second circle.

Device the most according to claim 1, described abrasive wheel is configured to raised and declines, And described device also includes:

Rotating disk, is configured to pivot；And

Chuck, is positioned at above described rotating disk and is configured to rotate together with described rotating disk, wherein, and institute State an abrasive wheel part towards described chuck.

Device the most according to claim 1, wherein, the plurality of tooth is formed by abrasive material.

8. a device, including:

Abrasive wheel, is configured to rotate around the first axle, and described abrasive wheel includes:

Basal disc, has the center being directed at described first axle；And

Multiple teeth, protrude from outside the surface of described basal disc, and wherein, the plurality of tooth includes:

First tooth, has the first distance apart from the center of described basal disc；And

Second tooth, has a second distance at center apart from described basal disc, described second away from From more than described first distance.

Device the most according to claim 8, also includes:

Chuck；And

Rotating disk, is positioned at below described chuck, and wherein, described rotating disk is configured to rotate around the second axle, Described second axle deviates described first axle.

10. a method, including:

Select the target reflectivity of grinding wafer technique；

Wafer is implemented grinding technics, and along with the carrying out of described grinding technics, measures from described crystalline substance The reflectance value of the light of the surface reflection of circle；And

Record reflectance value in described reflectance value equals to or more than described target reflectivity Time, stop described grinding technics.