Summary of the invention
Based on this, it is necessary to problem that cannot be compatible for the cutting of existing diamond wire and conventional soda acid process for etching, carry
Diamond wire cutting and the follow-up silicon chip using conventional soda acid making herbs into wool is used for a kind of.
A kind of silicon chip, the facet of described silicon chip has the some cut channel patterns arranged in the first direction;Described cut channel
Pattern is connected by the bending of some strias or interconnection forms.
Above-mentioned silicon chip, owing to its cut channel pattern is connected or interconnection by the bending of some strias, through conventional soda acid
After process for etching, could be formed with the light trapping structure of effect, so that diamond wire cutting technique is held concurrently with conventional soda acid process for etching
Hold.
Wherein in an embodiment, the facet of described silicon chip is additionally provided with gully the most spaced apart;
Described gully extends in a second direction, and described second direction is vertical with described first direction;Stria at described gully is parallel.
Wherein in an embodiment, the degree of depth in described gully is 5~50 μm;The width in described gully be 0.1~
1.5mm。
Present invention also offers the preparation method of a kind of silicon chip.
The preparation method of a kind of silicon chip, comprises the steps:
Silicon crystal diamond wire is carried out line cutting;
In described line cutting process, the corundum on described diamond wire is made to vibrate in the first direction, to form cut channel figure
Case.
The preparation method of above-mentioned silicon chip, the follow-up soda acid process for etching that can directly use routine carrys out making herbs into wool, makes diamond wire
Cutting technique is mutually compatible with conventional soda acid process for etching, and then reduces the cost of manufacture of photovoltaic cell.
Wherein in an embodiment, it is additionally included in described line cutting process, makes the corundum on described diamond wire only
Move in a second direction, to form gully.
Present invention also offers a kind of silicon slice wire cutting apparatus.
A kind of silicon slice wire cutting apparatus, including:
Two guide wheels, be arranged in parallel;At least one in said two guide wheel is non-circular guide wheel, described non-circular guide wheel
Surface each point be a to the maximum difference of the distance of the rotary shaft of described non-circular guide wheel, 0 < a < 1mm;
And diamond wire, it is tensioned between two guide wheels, and moves under the drive of guide wheel.
Above-mentioned silicon slice wire cutting apparatus, owing to special guide wheel is arranged, can make corundum on diamond wire along the
While one direction is moved, vibrate the most in a second direction, thus form the cut channel pattern of the present invention at silicon chip surface, make Buddha's warrior attendant
Wire cutting technology can be compatible with conventional soda acid process for etching, and then reduces the cost of manufacture of photovoltaic cell.
Wherein in an embodiment, said two guide wheel is all in regular polygon.
Wherein in an embodiment, described guide wheel includes rounded base wheel and scalable is connected to described base wheel
Surface on some projections.
Wherein in an embodiment, the metal base undulate of described diamond wire.
Wherein in an embodiment, the corundum of described diamond wire includes the first corundum and the second corundum, institute
The ratio stating the first corundum and described second corundum is 9:1~1:1.
Detailed description of the invention
In order to make the purpose of the present invention, technical scheme and advantage clearer, below in conjunction with detailed description of the invention, right
The present invention is further elaborated.Should be appreciated that detailed description of the invention described herein only in order to explain the present invention,
It is not intended to limit the present invention.
It should be noted that when element is referred to as " being fixed on " another element, and it can be directly on another element
Or element placed in the middle can also be there is.When an element is considered as " connection " another element, and it can be to be directly connected to
To another element or may be simultaneously present centering elements.
Unless otherwise defined, all of technology used herein and scientific terminology and the technical field belonging to the present invention
The implication that technical staff is generally understood that is identical.The term used the most in the description of the invention is intended merely to describe tool
The purpose of the embodiment of body, it is not intended that in limiting the present invention.Term as used herein " and/or " include one or more phase
Arbitrary and all of combination of the Listed Items closed.
The silicon chip of existing diamond wire cutting, after conventional soda acid process for etching, its battery efficiency does not promotes
Decline on the contrary.The present inventor finds through research, sees Fig. 1, the silicon chip 100 ' of existing diamond wire cutting, cuts shape
The stria 101 ' of a plurality of parallel arrangement become, the spacing between these strias 101 ' is about 1.6 μm, and stria 101 ' it
Between there is the silicon chip surface of similar mirror portion.After conventional soda acid process for etching, owing to soda acid making herbs into wool utilizes soda acid
Corrosion anisotropy on crystal orientation, adds these stria 101 ' parallel arrangements, and the facet of the silicon chip after making herbs into wool becomes on the contrary
Smooth, do not form light trapping structure.The reason that this namely diamond wire cutting is incompatible with conventional soda acid process for etching.
See Fig. 2, the silicon chip 100 of an embodiment of the present invention, diamond wire cutting form, it has facet.This is cut
There is on face some cut channel patterns 110.Cut channel pattern 110 (namely the Y-direction in Fig. 2) periodic arrangement in the first direction.
Cut channel pattern 110 is made up of diamond wire cutting stria in cutting process.
The cut channel pattern 110 of the present invention is in " non-linear ", namely cut channel pattern 110 is connected by the bending of some strias or intersected
It is formed by connecting.The mutually continued access such as such as " it ", " mutually ", " work ", " witch ", X-shaped, worm shape forms.The cut channel pattern of the present invention,
After conventional soda acid process for etching, form the light trapping structure of surface rule change.
Usually, the damage of cut channel pattern 110 is in Nano/micron level, after conventional soda acid process for etching, corresponding
Ground light trapping structure is also Nano/micron level.
In order to optimize the performance of silicon chip 100 further, the silicon chip 100 of present embodiment, its facet is additionally provided with along
The gully 104 that one direction is spaced apart;Gully, gully 104 extends in a second direction, and second direction is vertical with first direction
Direction (namely the X-direction in second direction Fig. 2).Stria at gully 104 is parallel.
Specifically, the position in gully 104 and quantity, position and quantity according to the main gate line of photovoltaic cell are designed.Example
As, the bar number in gully is 2,3,4,5 ... 18 etc..
Owing to gully 104 is correspondingly arranged up and down with main gate line, the stria at gully 104 is parallel (i.e. with existing diamond wire
The stria of cutting is the same), after conventional soda acid process for etching, become more smooth, so can reduce reduction main
Recombination-rate surface under grid line and reduction main gate line resistance, thus promote photovoltaic cell electricity conversion.
Preferably, the degree of depth in gully 104 is 5~50 μm;The width in gully 104 is 0.1~1.5mm.
In the present embodiment, the number in gully is 4, and the degree of depth in gully is 15 μm, and the width in gully is 0.8mm.
It is, of course, understood that in some cases, the present invention can also be not provided with gully 104.
Silicon chip provided by the present invention, owing to its cut channel pattern is connected by the bending of some strias or intersected to form, is passing through
After conventional soda acid process for etching, could be formed with the light trapping structure of effect, so that diamond wire cutting technique and conventional soda acid
Process for etching is compatible, and then reduces the cost of manufacture of photovoltaic cell.
Present invention also offers the preparation method of a kind of silicon chip.
The preparation method of a kind of silicon chip, carries out line cutting including by silicon crystal diamond wire.
Wherein, diamond wire includes metal base and the corundum being fixedly arranged on metal base;During cutting on line, make
Corundum (Y-direction in figure) in the first direction vibrates, to form cut channel pattern.
Owing to corundum is while moving in X direction, also vibrate along Y-direction, so each corundum is at silicon chip surface
The stria generated not is a straight line in X direction, after the stria superposition of different corundum, i.e. forms some strias curved
Folding connects or cross-coupled cut channel pattern.
In order to optimize the performance of silicon chip further, during cutting on line, also include making corundum only move in a second direction
Dynamic, stria now is the stria at gully.I.e. when needs form gully, in certain period of time, only control corundum
Move along Y-direction.
Specifically, gully can be come by the method that constant cutting position repeats to cut or constant cutting tension force repeats to cut
Realize.
The preparation method of above-mentioned silicon chip, the follow-up soda acid process for etching that can directly use routine carrys out making herbs into wool, makes diamond wire
Cutting technique is mutually compatible with conventional soda acid process for etching.It addition, the preparation method of the silicon chip of the present invention, be applicable to monocrystalline and
This efficiency cutting of polycrystalline manufactures.
Present invention also offers a kind of silicon wafer cutting device for preparing above-mentioned silicon chip.
Seeing Fig. 3, silicon wafer cutting device 1000 includes two guide wheels 310,320, and diamond wire 400.
Wherein, the Main Function of two guide wheels 310,320 is, by diamond wire 400 tensioning, and drives diamond wire 400 basic
X-direction along figure is moved.Specifically, two guide wheels 310,320 be arranged in parallel, and are spaced a distance so that by silicon wafer
Body 200 is placed between two guide wheels 310,320.
Seeing Fig. 4, diamond wire 400 includes metal base 410 and corundum 420, and corundum 420 is fixedly arranged at metal base
On 410.The Main Function of metal base 410 is, as the carrier of corundum.Metal base 410 does not the most produce dissection,
Play dissection is the corundum being fixedly arranged on metal base 410.
In cutting process, the run-in synchronism of two guide wheels 310,320, drive diamond wire 400 high-speed motion simultaneously, so that
Corundum 420 high-speed motion, produces cutting to silicon crystal 200.
It is, of course, understood that usually, silicon wafer cutting device 1000 also includes spray coolant device (not shown)
And silicon crystal hold-down devices (not shown) etc..These devices all can use structure known in those skilled in the art,
This repeats no more.
In the present invention, at least one in two guide wheels 310,320 is non-circular guide wheel, i.e. two guide wheels 310,320
In at least one be non-circular.The surface each point of non-circular guide wheel is a to the maximum difference of the distance of rotary shaft, 0 < a < 1mm.
It is, a be in non-circular guide pulley surface distance rotary shaft point furthest in distance and the non-circular guide pulley surface of rotary shaft
The distance nearest point of rotary shaft is to the difference of the distance of rotary shaft.So owing to each point is apart from the distance not phase of the rotary shaft of guide wheel
With, diamond wire is in motor process, while corundum 420 moves the most only along an X, also has and vibrates along Y-direction, and Y side
To vibration control within certain amplitude, thus on the facet of silicon chip, form the cut channel pattern of the present invention, and avoid
The phenomenon that in prior art, diamond wire cutting stria is parallel.
It is highly preferred that span 3~17 μm of a.So can promote the performance of silicon chip further.
In a preferred embodiment, two guide wheels are all in regular polygon.It is of course also possible to be simply a guide wheel in just
Polygon.
The operation principle of the silicon wafer cutting device of the present invention is described with the guide wheel of positive 300 limit shapes below.
Two guide wheels in silicon wafer cutting device are identical, a length of 200mm in its footpath, and the spacing between two guide wheels is 400mm.
Owing to guide wheel is positive 300 limit shapes.The most positive 300 Xing Zhong summits, limit are 100mm to the distance of rotary shaft, in positive 300 Xing Zhong limits, limit
Point is 99.995mm to the distance of rotary shaft.It is, the distance of rotary shaft is arrived at positive 300 Xing Zhong summits, limit and midpoint, limit respectively
Difference a be 5 μm.
Two guide wheels are controlled by electric rotating machine, and synchronous rotary.Guide wheel drives diamond wire to move with the X-direction of 17m/s.
Owing to positive 300 Xing Zhong summits, limit are different from the distance that rotary shaft is arrived at midpoint, limit respectively, cause the corundum on diamond wire in X side
While motion, there is again periodic Y-direction motion (vibration the most in the Y direction).
It is computed, owing to guide wheel is that positive 300 limit shapes, i.e. guide wheel are often revolved and turned around, has the Y-direction in 300 cycles to move.
The difference of the distance arriving rotary shaft respectively due to positive 300 Xing Zhong summits, limit and midpoint, limit is 5 μm.It is to say, along with 17m/
The X-direction motion of s, corundum amplitude in the Y direction is 5 μm.
As a example by silicon chip width is as 156mm, then corundum length every about 500 μm in silicon chip X-direction makees one
Individual amplitude is the stria of 5 μm.By the stria of different corundum, finally form cut channel pattern on the surface of silicon chip.
It is it is, of course, understood that guide wheel is not limited to regular polygon, it is also possible to be other shape, such as oval,
Also the partial arc section or on the circumference of guide wheel, straightway or arc section by one or more are (bent with the arc section being replaced
Rate is different) or oval segmental arc or other geometrical curve replace.Replacement can be the uniform replacement kept at a certain distance away, also or
Irregular replacement.
It is, of course, also possible to be guide wheel include rounded base wheel and scalable be connected on base wheel surface some convex
Rise.When this projection stretches out the periphery of base wheel, the corundum on diamond wire, while X-direction moves, vibrates in the Y direction,
Now can form the cut channel pattern of the present invention.When this projection is retracted in the periphery of base wheel, now guide wheel recovers periphery,
Corundum on diamond wire only moves in X-direction, now can form the stria at gully.
Preferably, metal base 410 is in wavy, namely " non-linear ".In the present invention, metal base 410 can be plane
Interior wave, can also be three-dimensional spatially spiral wave.
Use the metal base 410 of wave design, the obstruction in X-Y direction can be buffered, it is simple to " self adaptation " walks around silicon
Hard spot on crystal 200, is conducive to improving cutting speed, and avoids the hard spot disconnection problem that existing diamond wire cuts, from
And the beneficially yield of output silicon chip, cost and production capacity.Meanwhile, wave design combines with the design of guide wheel of the present invention, makes
Cutting movement spatial alternation, and then form regular surface damage and making herbs into wool effect, promote power conversion efficiency (pce) further.
In the present embodiment, the wavelength of metal base 410 is 3mm, and the difference in height between trough and crest is 7 μm.
Preferably, corundum 420 on metal base 410 in non-uniform Distribution, at crest, the trough of metal base 410
Place is simultaneously or optionally one distribution is closeer.In the present embodiment, corundum 420 density at crest, trough is higher.
In the present embodiment, corundum 420 includes the first corundum 421 and the second corundum 422, the first corundum
421 and second corundum 422 be the corundum of two kinds of different sizes.Specifically, the particle diameter of the first corundum 421 is less than the second gold medal
The particle diameter of emery 422.
It is highly preferred that the ratio of the first corundum 421 and the second corundum 422 is 9:1~1:1.
Above-mentioned silicon slice wire cutting apparatus, owing to special guide wheel is arranged, can make corundum on diamond wire along the
While one direction is moved, vibrate the most in a second direction, thus form the cut channel pattern of the present invention at silicon chip surface, make Buddha's warrior attendant
Wire cutting technology can be compatible with conventional soda acid process for etching, and then reduces the cost of manufacture of photovoltaic cell.
Each technical characteristic of the above embodiment can combine arbitrarily, for making description succinct, not to above-mentioned
The all possible combination of each technical characteristic in embodiment is all described, but, if the combination of these technical characteristics
There is not contradiction, be all considered to be the scope that this specification is recorded.
The above embodiment only have expressed the several embodiments of the present invention, and it describes more concrete and detailed, but
Can not therefore be construed as limiting the scope of the patent.It should be pointed out that, for those of ordinary skill in the art
For, without departing from the inventive concept of the premise, it is also possible to make some deformation and improvement, these broadly fall into the guarantor of the present invention
Protect scope.Therefore, the protection domain of patent of the present invention should be as the criterion with claims.