CN201235584Y - Silicon slice wire cutting apparatus - Google Patents

Abstract

The utility model discloses a wire cutting device for silicon wafers, which mainly comprises a guide wheel with wire slots and a steel wire mesh wound on the guide wheel. Slot pitch, the unequal slot pitch starts from the steel wire winding guide wheel, and decreases sequentially along the length direction of the guide wheel. The reduced groove pitch is compatible with the wear of the steel wire during the cutting process. Due to the reduced groove pitch, the number of wire grooves is increased under the condition that the groove length of the existing guide wheel remains the same, and the corresponding winding The steel wire mesh on the guide wheel is dense, which increases the number of silicon wafers cut by one knife, and the economic benefit is remarkable.

Description

Wafer wire cutting device

technical field

The utility model relates to a silicon chip wire cutting device which uses a wire cutting system to process silicon slices for silicon single crystal rods.

Background technique

At present, most of the small-diameter silicon single crystal rods are still cut by an internal slicer. Its blade is inlaid on the inner circumference of the circular thin metal substrate, and the outer circle of the blade is fixed on the rotating shaft. Compared with the outer circular blade slicer adopted in the early stage, it can use a thinner blade (according to the diameter of the required processing, the appropriate cutter head and blade are selected, for example, cutting a silicon single crystal rod with a diameter of 200mm requires a 34in cutter head, the thickness of the blade is about 380μm, and the thickness of the metal substrate of the knife is less than 200μm), so it can cut thinner wafers with relatively small cutting consumption, small processing allowance and high precision.

With the continuous development of IC technology and technology, in order to improve the processing accuracy of silicon slices, reduce the loss of incision materials and improve production efficiency, at present, in the processing of silicon slices with a diameter greater than 100mm, especially for silicon slices with a diameter greater than 200mm In single crystal rod slicing processing, wire cutting system has been widely used to process silicon slices.

Wire cutting technology refers to the use of a steel wire (typically 120 μm) on the wire cutting device to form a "steel wire mesh" (the guide wheel is engraved with precise wire grooves) and wound 2 or 4 guide wheels in sequence. The mortar nozzles on both sides of the single crystal rod spray the mortar cutting fluid on the "steel wire mesh", and the high-speed rotation of the guide wheel drives the "steel wire mesh" to bring the mortar into the single crystal rod, and the steel wire tightly presses the abrasive sand on the single crystal rod. Abrasive cutting is carried out on the surface of the ingot, and the single crystal ingot is pushed down through the "steel wire mesh" while moving down at a slow speed. After several hours of grinding and cutting, the silicon single crystal ingot can be cut once It is cut into many silicon wafers of equal thickness.

As shown in Figure 1, Figure 2 and Figure 3, the wire cutting device mainly includes a guide wheel 1 engraved with a wire groove, a steel wire mesh 2 wound on the guide wheel 1, a workbench 3 carrying a silicon single crystal rod 5, and a mortar nozzle 4.

The use of wire cutting technology for slicing has high production efficiency, small slit loss, small surface damage, and high surface processing accuracy (warp can reach Warp<10μm), so it is more suitable for slicing large-diameter silicon single crystals.

Taking silicon single crystal processing with a diameter of 200mm as an example, the slice thickness is 800μm, and the output per kilogram of single crystal is about 13.4 pieces. The cutting cost is about $1.51 per piece, and the output of the wire cutting machine is about 5 times that of the inner circle cutting machine. The cutting operating cost of the wire cutting machine will be lower than the operating cost of the inner circle cutting machine by more than 20%.

However, the grooves engraved on the guide wheel of the above-mentioned wire cutting system are evenly distributed, which determines that the steel wire mesh wound on the guide wheel is also evenly distributed, and the distance between the steel wires is constant. In this way, during the silicon wafer wire cutting process, due to the continuous wear and tear of the steel wire, the diameter of the steel wire gradually becomes smaller. Generally, after one silicon single crystal ingot is cut with one knife at a time, the diameter of the steel wire should be reduced by at least 20 μm. Due to the reduction of the diameter of the steel wire, the loss of the slit becomes smaller, and the less cut part is added to the thickness of the slice. Compared with the slice, the thickness of the slice must gradually decrease with the gradual reduction of the wire diameter Increase, because the steel wire becomes thinner and the slit becomes smaller, the saved material is not used, but is wasted on the thickness of the slice, and the thickness of each slice cut by one knife is not the same, and there is a large The thickness deviation of the silicon wafer is also fixed.

Therefore, the silicon wafer wire cutting device needs to be improved.

In view of this, the utility model is proposed.

Utility model content

The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art, and provide an improved silicon wafer wire cutting device, which can reduce the diameter of the steel wire and make the groove pitch smaller through the guide wheel, so as to ensure that the silicon single crystal rod One knife is cut into several silicon wafers with the same thickness at one time, increasing the number of slices and increasing economic benefits.

In order to solve the above-mentioned technical problems, the basic idea of the technical solution adopted by the utility model is: a silicon wafer wire cutting device, which mainly includes a guide wheel with a wire groove, and a steel wire mesh wound on the guide wheel, which is characterized in that: The groove pitch on the guide wheel is an unequal slot pitch, and the unequal slot pitch starts from the steel wire winding the guide wheel and decreases sequentially along the length direction of the guide wheel.

The slot pitches on the guide wheel are not equal, and along the length direction of the guide wheel, starting from the first slot where the steel wire is wound on the guide wheel, the slot pitches of the two adjacent slots decrease sequentially. Small, the reduced groove pitch is adapted to the diameter of the steel wire after its previous groove wears. or,

The groove pitches on the guide wheel are unequal, and along the length direction of the guide wheel, unequal groove pitches are arranged in segments, and the number of segments is more than two, and there are several slots in each segment The distance between the slots is equal, and the distance between the slots on the two adjacent sections decreases sequentially from the first section where the steel wire is wound on the guide wheel. Adapt to the diameter after a period of wear.

The groove pitches on the guide wheel are unequal, and are divided into 3 unequal groove pitches along the length direction of the guide wheel. The first section on the wheel begins to decrease in turn, and there are several wire slots with equal groove spacing on each section.

The groove pitches on the guide wheel are unequal, and are divided into 8 unequal slot pitches along the length direction of the guide wheel. The first segment on the wheel begins to decrease in turn, and there are several wire slots with equal groove spacing on each segment.

After adopting the above technical solution, the utility model has the following beneficial effects compared with the prior art.

The utility model is a wire cutting device for silicon wafers. Due to the principle that the diameter becomes smaller due to the wear of the steel wire during the cutting process, the wire groove on the guide wheel is changed to an unequal slot distance. Decrease along the length direction of the guide wheel, so that under the condition that the groove length of the guide wheel remains unchanged, due to the decrease of the groove pitch, the number of wire grooves increases, and the density of the wire mesh wound on the guide wheel increases. It also increases thereupon, adopting this encrypted steel wire mesh to implement wire cutting obviously increases the number of cut silicon wafers compared with the prior art, and increases economic benefits while improving output. Due to the improvement of the slot pitch on the guide wheel, the gradually reduced slot pitch is adapted to the wear amount of the steel wire, that is to say, the densification amount of the steel wire mesh compensates for the decrease in the diameter of the steel wire after wear. The increase in the thickness of the sliced silicon wafers can not only increase the number of slices, increase economic benefits, but also improve the quality of slices, so that silicon single crystal rods can be cut into several silicon wafers with the same thickness at one time.

For example, using the applicant's existing 2 Swiss MEYER BURGER DS265 type wire cutting machines, since the silicon chip cutting groove distance of the guide wheel is improved, the groove distance is divided into 3 sections and successively reduced, and each machine can cut 6 more pieces at a time. Each slice is calculated at 58 yuan, and the number of extra-cut silicon slices per month is 1080, which can increase the total income by 62,640 yuan.

Using the applicant's existing 12 sets of Swiss MEYER BURGER DS264 wire cutting machines, the groove distance of the guide wheel is divided into 8 sections to reduce successively, and each machine can cut 26 more pieces with one knife, and each piece is calculated at 58 yuan, more than a month The number of silicon slices is 28,080, which can increase the total income by 1,628,640 yuan.

In a word, the silicon wafer wire cutting device of the utility model improves the slot pitch of the guide wheel by changing the original equal slot pitch to an unequal slot pitch, and the slot pitch decreases sequentially along the length direction of the guide wheel, so that the wire The number of grooves increases, and the encryption of the wire grooves on the guide wheel correspondingly increases the density of the steel wire mesh wound on the guide wheel. The wire cutting device for silicon wafers with this steel wire mesh encryption is used to wire-cut silicon single crystal rods. Compared with the existing technology, the quantity and quality of slices are obviously improved, and the economic benefits are very significant.

The utility model will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Description of drawings

Fig. 1 is the schematic diagram of prior art steel wire cutting silicon single crystal rod;

Fig. 2 is a schematic diagram before cutting of a silicon wafer cutting device in the prior art;

Fig. 3 is a schematic diagram after cutting by a silicon wafer cutting device in the prior art;

Fig. 4 is a schematic diagram of an embodiment of improving the groove pitch of the silicon wafer cutting guide wheel of the present invention;

Fig. 5 is a schematic diagram of another embodiment of the improved groove pitch of the silicon wafer cutting guide wheel of the present invention.

Detailed ways

As shown in Fig. 1, Fig. 2, Fig. 3, Fig. 4 and Fig. 5, a silicon wafer wire cutting device of the present invention is based on the existing device, and the diameter becomes smaller by using the abrasion of the steel wire during the wire cutting process. Based on the principle, the guide wheel is mainly improved to meet the requirements of steel wire mesh densification. The device mainly includes a guide wheel 1 with a wire groove, and a steel wire mesh 2 wound on the guide wheel 1. The groove distance on the guide wheel 1 is originally equidistant. The main feature of the utility model is that the guide wheel 1 The slotting pitch on wheel 1 is changed to an unequal slotting pitch, and the unequal slotting pitch starts from the wire winding guide wheel and decreases sequentially along the length direction of the guide wheel, so that the winding on the The steel wire mesh on the wire groove of the guide wheel is gradually dense, which is used to compensate for the increase in the thickness of the silicon wafer to be cut due to the reduction in the diameter of the steel wire after wear. There are two ways to implement the unequal groove pitch on the guide wheel as follows:

In the first embodiment, the unequal groove pitch on the guide wheel 1 is along the length direction of the guide wheel, starting from the first wire slot where the steel wire is wound on the guide wheel 1, two adjacent wire slots The groove pitch of the groove decreases successively, and the reduced groove distance is adapted to the diameter of the steel wire after its previous wire groove is worn.

In the second embodiment, the unequal slotting pitches on the guide wheel 1 are unequal slotting pitches arranged in sections along the length direction of the guide wheel, and the number of subsections is more than two sections. There are several slots with the same slot pitch, and the slot pitches on two adjacent sections decrease sequentially from the first section where the steel wire is wound on the guide wheel 1, and the slot pitch of each section decreases Adapt to the diameter of the steel wire after its previous section has been worn. The second implementation mode is the preferred technical solution of the utility model.

In the second embodiment, unequal groove pitches are arranged on the guide wheel in sections, and there are two specific examples as follows to further illustrate the improvement and the pitch of the guide wheel in the wire cutting device for silicon wafers. Beneficial effect.

Embodiment one

As shown in Figure 4, the groove pitches on the guide wheel 1 are unequal, and are divided into three unequal groove pitches along the length direction of the guide wheel. , starting from the first section where the steel wire winds on the guide wheel 1 decreases successively, and there are several slots with equal slot pitches on each section. As shown in Figure 4, in the length direction of the guide wheel 1, according to the slot length L1, it is divided into three sections with unequal slot pitches, that is, the slot pitch of the first section A > the slot section of the second section B Slot pitch>Slot pitch of the third segment C. The groove pitches on the first section A, the second section B, and the third section C are respectively equal.

According to the above-mentioned technical characteristics, the applicant has made improvements on the following types of wire cutting devices for silicon wafers:

A. The groove pitch structure of the existing Swiss MEYER BURGER DS265 machine guide wheel:

Grooving length L1=310mm, the total number of grooves is 925, and the groove pitch is 0.335mm.

B. Increase the number of groove pitches after improvement

Using the Swiss MEYER BURGER DS265 machine, under the condition of the slotting length L1 = 310mm, the slotting method is divided into 3 sections, and the slot spacing on each section is equal, and the slot spacing of the first section A is 0.335mm , The groove pitch of the second paragraph B is 0.333mm, and the groove distance of the third paragraph C is 0.33mm. Since the groove pitch is successively reduced in three stages, the number of bus slots is increased to 932, the number of slot pitches is increased by 6, and the number of slices is increased by 6. Slice thickness deviations are correspondingly reduced.

C. Economic benefits

Using a Swiss MEYER BURGER DS265 wire cutting machine, the number of silicon wafers cut by one cut is 6 more than the number of silicon wafers, and the extra piece increases the benefit by 58 yuan, that is, the increased benefit by one cut is 348 yuan, and the monthly increase in benefit is at least 31320 yuan.

According to the applicant's existing two Swiss MEYER BURGER DS265 wire cutting machines, 1080 more pieces can be cut out every month, and the total income will increase by 62640 yuan per month.

Embodiment two

As shown in Figure 5, the groove pitches on the guide wheel 1 are unequal, and are divided into 8 unequal groove pitches along the length direction of the guide wheel, and the groove pitches on two adjacent sections are unequal. , starting from the first section where the steel wire is wound on the guide wheel 1, decreases successively, and there are several wire grooves with equal groove spacing on each section.

According to the above-mentioned technical characteristics, the applicant has made improvements on the following types of wire cutting devices for silicon wafers:

A. The groove pitch structure of the existing Swiss MEYER BURGER DS264 machine guide wheel:

Grooving length L2 = 820mm, the total number of grooves is 2448, and the groove pitch is 0.335mm.

B. Increase the number of groove pitches after improvement:

Using the Swiss MEYER BURGER DS264 machine, under the condition that the slot length L2=820mm, refer to Figure 5, the slotting method is divided into 8 sections, and the slot spacing of each section is equal, and the slot spacing of the first section A is 0.335mm, the slot pitch of the second segment B is 0.334mm, the slot pitch of the third segment C is 0.333mm, the slot pitch of the fourth segment D is 0.332mm, and the slot pitch of the fifth segment E is 0.331 mm, the pitch of the F slot in the 6th section is 0.33mm, the slot pitch of the G slot in the 7th section is 0.329mm, and the slot pitch of the H slot in the 8th section is 0.328mm. Since the groove pitch is successively reduced in 8 sections, the number of bus slots is increased to 2475, the number of slot pitches is increased by 26, and the number of slices is increased by 26. Slice thickness deviations are correspondingly reduced.

C. Economic benefits

Using a Swiss MEYER BURGER DS264 wire cutting machine, the number of silicon wafers cut by one cut is 26 more than the number of silicon wafers, and the extra piece increases the benefit by 58 yuan, that is, the profit is increased by 1,508 yuan per cut, and the monthly income can be increased by at least 135,720 Yuan.

Based on the applicant's existing 12 Swiss MEYER BURGER DS264 machines, the number of extra-cut silicon wafers per month is 28,080, and the total income increased per month is 1,628,640 yuan.

In a word, the silicon wafer wire cutting device of the utility model mentioned above, under the condition that the groove length of the existing guide wheel remains unchanged, the structure of the slot pitch of the guide wheel is improved by using the wear of the steel wire during the cutting process. The principle of diameter reduction is changed from the evenly distributed equidistant slot pitch on the guide wheel in the prior art to the unevenly distributed unequal slot pitch, and the slot pitch is sequentially arranged along the length direction of the guide wheel The number of wire grooves increases, and the encryption of wire grooves on the guide wheel correspondingly increases the density of the steel wire mesh wound on the guide wheel. Using this silicon wafer wire cutting device with gradually denser steel wire mesh, silicon single crystal ingots are processed Wire cutting effectively improves the quantity and quality of slices, and significantly improves economic benefits.

Claims (5)

1. A wire cutting device for silicon wafers, mainly comprising a guide wheel (1) with a wire groove, and a steel wire mesh (2) wound on the guide wheel (1), characterized in that: the guide wheel (1) is The slotting pitch is unequal slotting pitch, and the unequal slotting pitch starts from the steel wire winding guide wheel, and decreases sequentially along the length direction of the guide wheel. 2. A silicon wafer wire cutting device according to claim 1, characterized in that: the groove pitches on the guide wheel (1) are unequal, and are wound from the steel wire on the guide wheel along the length direction of the guide wheel. The first wire groove on the wheel (1) starts, and the groove pitch of two adjacent wire grooves decreases successively, and the groove pitch of this reduction adapts to the diameter of the steel wire after its previous wire groove wears. 3. A silicon wafer wire-cutting device according to claim 1, characterized in that: the groove pitches on the guide wheel (1) are unequal, and are set unequal in sections along the length direction of the guide wheel Slotted slot distance, the number of segments is more than two sections, there are several slots with equal slotted slot spacing on each section, and the slotted slot distance on two adjacent sections is wound from the steel wire on the guide wheel (1 ) on the first section starts to decrease in turn, and the groove pitch of each section is reduced to adapt to the diameter of the steel wire after its previous section is worn. 4. A silicon wafer wire cutting device according to claim 1 or 3, characterized in that: the groove pitches on the guide wheel (1) are not equal, and are divided into three sections along the length direction of the guide wheel. Equal groove pitch, the groove pitch on two adjacent sections decreases sequentially from the first section where the steel wire is wound on the guide wheel (1), and there are several slots with the same pitch on each section of wire slots. 5. A silicon wafer wire cutting device according to claim 1 or 3, characterized in that: the groove pitches on the guide wheel (1) are unequal, and are divided into 8 sections along the length direction of the guide wheel. Equal groove pitch, the groove pitch on two adjacent sections decreases sequentially from the first section where the steel wire is wound on the guide wheel (1), and there are several slots with equal slot pitch on each section of wire slots.

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