JP6450964B2 - Individual piece manufacturing method - Google Patents

Description

  The present invention relates to an individual piece manufacturing method.

  A plate-like member such as a semiconductor wafer (hereinafter sometimes abbreviated as “wafer”) has a diameter of 300 mm so that a thickness of 200 mm is 725 μm, for example, according to SEMI (Semiconductor Equipment and Materials International) standards. The thing is specified to have a thickness of 775 μm. Since such a wafer is formed with a large number of electronic circuits such as ICs and LSIs (hereinafter sometimes abbreviated as circuits), it is ground to, for example, about 50 μm to form semiconductor chips (individual pieces). More than 90% of them will be thrown away.

  Patent Document 1 discloses a step of diffusing impurities on both sides of a semiconductor substrate (plate-like member) to form a diffusion region, a step of dividing the semiconductor substrate into two in the thickness direction, and a semiconductor substrate divided into two. And a step of polishing the opposite surface of the diffusion region to make a mirror surface. Then, each of the two semiconductor substrates divided into two pieces is separated into individual pieces in a dicing process, and is mounted on an object to be mounted such as a lead frame.

Japanese Patent Laid-Open No. 1-114044

  However, in the conventional method of manufacturing a single piece, the holding surface is divided from the circuit surface side in order to divide the wafer into two pieces along the circuit surface after the wafer is divided into two in the thickness direction while holding the circuit surface side. There is a problem that the manufacturing process of the individual piece including the mounting step of mounting the individual piece on the mounted object becomes complicated because it must be held again on the surface side.

  An object of the present invention is to provide an individual piece manufacturing method capable of simplifying the manufacturing process of an individual piece.

To solve the above object, a method of piece body manufactured present invention includes a plate-like member preparing step of preparing a plate-like member, on both sides of the hand surface and the other surface of the plate-like member, a groove forming step of forming a groove that does not penetrate to the opposite face along the side face of the plate-like member on one surface or the other surface, and by forming a notch crossing said groove, those dividing at the same time thinning the plate-like member, each have a incision forming step of forming a plurality of individual body from both surfaces of the one surface and the other surface.

The individual piece manufacturing method of the present invention includes a plate-like member preparing step of preparing a plate- like member , a modified layer forming step of forming a modified layer on which the plate-like member becomes brittle, along the side surface of the plate-like member on one surface or the other surface, and wherein by forming a cut across the modified layer, when thinning the equivalent plate-like member divided at the same time, the one surface and the other each of both surfaces of the surface of and a incision forming step of forming a plurality of individual body.

  An expanding step of pulling the plate-like member may be included after the notch forming step.

According to the present invention, after dividing the plate-like member, there is no need to hold the divided surface side again, and the manufacturing process of the individual piece including the mounting step of mounting the individual piece on the mounted object is simplified. Can do.
Moreover, when it has an expanding process, the space | interval of each piece | piece piece connected mutually can be spaced apart after a notch formation process.

Explanatory drawing of the process of the individual piece manufacturing method which concerns on 1st Embodiment. Explanatory drawing of the process of the individual piece manufacturing method which concerns on the said embodiment. Explanatory drawing of the process of the individual piece manufacturing method which concerns on the said embodiment. Explanatory drawing of the process of the individual piece manufacturing method which concerns on the said embodiment. Explanatory drawing of the process of the individual piece manufacturing method which concerns on 2nd Embodiment. Explanatory drawing of the process of the individual piece manufacturing method of the modification 1. FIG. Explanatory drawing of the process of the individual piece manufacturing method of the modification 1. FIG. Explanatory drawing of the process of the individual piece manufacturing method of the modification 1. FIG. Explanatory drawing of the modification 2. FIG. Explanatory drawing of the modification 3. FIG. Explanatory drawing of the modification 4. FIG.

(First embodiment)
For example, when a direction such as up, down, left, right, or front and back is shown without giving a reference figure in each embodiment, all of FIG. The direction from the top to the bottom is the direction parallel to the page, the front is the front direction orthogonal to the page, and the back is the back direction orthogonal to the page. And

  1 to 4, the single-piece manufacturing method according to the first embodiment includes a plate-shaped member preparation step of preparing a wafer WF as a plate-shaped member, and both surfaces of one surface and the other surface of the wafer WF. A plurality of individual pieces are formed from the wafer WF by forming a groove forming step for forming a groove 11 that does not penetrate the opposite surface, and forming a notch 12 along one or the other surface from the side surface of the wafer WF. A semiconductor chip (hereinafter, may be abbreviated as “chip”) CP.

  In the plate-like member preparation step, as shown in FIGS. 1A to 1C, the circuit CA as a model is formed on both surfaces of the disk-shaped wafer by the circuit forming unit 10 as the model forming unit ( Modeling object formation process). As shown in FIG. 2A, streets ST are formed in a lattice pattern between the circuits CA on each surface of the wafer WF on which the circuits CA are formed.

  In the groove forming step, as shown in FIG. 2B, the wafer WF on which the circuit CA is formed is placed on the holding table 20 with one surface facing upward, and a decompression pump, a vacuum ejector, etc. It is held by decompression means (not shown). Next, a groove 11 that does not penetrate to the other surface side along the street ST on one surface side is formed by groove forming means BL such as a cutting blade, a laser irradiation device, and etching. Thereafter, the wafer WF having the groove 11 formed on one surface side is turned upside down and placed on the holding table 20 with the other surface facing upward, as shown in FIG. Do not hold by decompression means. Next, the groove forming means BL forms the groove 11 that does not penetrate the groove 11 formed from one surface side and the one surface side along the street ST on the other surface side. Thereby, as shown in FIG. 3B, a wafer WF in which the grooves 11 are formed along the periphery of the circuit CA on both sides is formed.

  As shown in FIG. 4, in the notch formation process, the wafer WF having the grooves 11 formed on both sides thereof is held from both sides by a holding member 30 such as an adhesive sheet or a suction table. Next, a cutting means 40 such as a wire saw, a laser irradiation device, a blade, or the like forms a notch 12 from the side surface of the wafer WF along one or the other surface of the wafer WF and across the groove 11, and the thickness of the wafer WF is increased. Divided into two. As a result, the wafer WF is divided into a plurality of chips CP along the grooves 11. Thereafter, each chip CP is mounted on a mounting member (not shown) such as a lead frame or a substrate by bonding or bonding in a chip mounting process. Note that the thickness of the chip CP after cutting can be adjusted by changing the wire diameter, laser width, and blade width of the cutting means 40. For example, if a cutting means 40 having a wire diameter of 675 μm, a laser width, and a blade width is used for a wafer WF having a thickness of 775 μm, a plurality of chips CP having a thickness of 50 μm can be formed on both surfaces. In this case, the back surface grinding process is not necessary, and the manufacturing process of the individual pieces can be shortened. However, the chip CP may be ground thinner in the back surface grinding process.

  According to the first embodiment as described above, after dividing the wafer WF (after dividing within the thickness), it is not necessary to hold the divided surface side again, and the mounting step of mounting the chip CP on the mounted object is included. In addition, the manufacturing process of the chip CP can be simplified.

(Second Embodiment)
In FIG. 5, the individual body manufacturing method according to the second embodiment includes a plate-shaped member preparation process for preparing a wafer WF as a plate-shaped member, and a modified layer formation for forming a modified layer 21 that makes the wafer WF fragile. A step of forming a semiconductor chip CP as a plurality of individual pieces from the wafer WF by forming the cut 12 along one or the other surface from the side surface of the wafer WF, and the wafer WF And an expanding step of pulling.

  In the plate-like member preparation step, as in the first embodiment, a wafer WF having a circuit CA and a street ST as modeling objects on both sides is prepared.

  In the modified layer forming step, as shown in FIG. 5A, the wafer WF on which the circuit CA is formed is placed on the holding table 20 with one surface facing upward, and is reduced by a decompression unit (not shown). Hold. Next, the modified layer forming means 60 such as a laser irradiation apparatus irradiates the laser beam 60A to form the modified layer 21 that makes the wafer fragile along the street ST on one surface side.

  In the notch formation step, the wafer WF on which the modified layer 21 is formed is held by the holding member 30 from both sides as shown in FIG. Next, the cutting means 40 forms a cut 12 from the side surface of the wafer WF along one or the other surface of the wafer WF and across the modified layer 21, and the wafer WF is divided into two within the thickness.

  In the expanding step, as shown in FIG. 5C, the holding member 30 is pulled by an expanding means (not shown), so that the wafer WF is divided into a plurality of chips CP along the modified layer 21. Thereafter, each chip CP is peeled off from the holding member 30 by a pickup device or the like and mounted on a mounted member (not shown). In the case where the modified layer 21 is destroyed and a plurality of chips CP are formed along the modified layer 21 in the notch forming step, or when the expansion is performed in another step, the expanded layer is used in the present invention. No process is required.

  According to the second embodiment as described above, the same effect as that of the first embodiment can be obtained.

  The means and steps in the present invention are not limited in any way as long as the operations, functions, or steps described for these means and steps can be performed. The process is not limited at all. For example, the groove forming step is within the scope in view of the technical common sense at the beginning of the application, as long as the groove can be formed on at least one surface of the plate-like member without penetrating the opposite surface. There is no limitation as long as it is present (the description of other means and steps is omitted).

[Modification 1]
As shown in FIG. 6A, a wafer WF having a circuit CA and a street ST formed on one surface is prepared in the plate-shaped member preparation step, and in the groove forming step as shown in FIG. 6B. The groove forming means BL forms the groove 11 that does not penetrate the other surface side along the street ST on the one surface side. Thereafter, as shown in FIG. 7, the wafer WF is held by the holding member 30 from both sides, and the cutting means 40 cuts the notch 12 along one or the other side of the wafer WF from the side and across the groove 11. And the wafer WF is divided into two within the thickness. Thereby, the wafer WF is divided into a plurality of chips CP along the groove 11 and a lower half wafer WF1 in which the circuit CA is not formed. As shown in FIG. 8A, in the lower half wafer WF1, the circuit CA and the street ST are formed by the circuit forming means 10 in the plate-shaped member preparation step. As shown in FIG. 8B, the lower half wafer WF1 on which the circuit CA is formed is held on the holding table 20 in the groove forming step, and is divided into a plurality of chips CP by the groove forming means BL. Mounted on the member. According to the first modification, since it is not necessary to determine the circuits CA on both surfaces of the wafer WF during the plate-shaped member preparation process, it is possible to increase the degree of freedom in combining each circuit formation.
Note that the modified layer forming step of the second embodiment may be applied instead of the groove forming step of the first modification.
Further, the “one surface” and the “other surface” in the first modification may be exchanged.

[Modification 2]
As shown in FIG. 9, in the plate member preparation process, a wafer WF having circuits CA1 and CA2 having different sizes and patterns formed on one surface and the other surface is prepared, and a groove forming process and a modified layer are prepared. In the forming process, the grooves 11 and the modified layers 21 may be formed to form a plurality of chips CP.

[Modification 3]
As shown in FIG. 10, in the plate-shaped member preparation step, a wafer WF having a circuit CA shifted in the vertical direction is prepared on both surfaces of the wafer WF. In the groove forming step, the depth does not penetrate the opposite surface along the street ST, and the sum of the depth from one surface of the wafer WF and the depth from the other surface is the total of the wafer WF. A groove 11a larger than the thickness may be formed, and a plurality of chips may be formed in the same manner as described above. In this case, a modified layer forming step may be used instead of the groove forming step.

[Modification 4]
As shown in FIG. 11, in the plate-shaped member preparation step, for example, a wafer WF having a thickness of 725 μm is prepared, and in the incision forming step, a cutting means having a wire diameter of 317.5 μm, a laser width, and a blade width If 50 is used, a plurality of chips CP having a thickness of 30 μm can be formed on both surfaces, and a wafer WF 2 having a thickness of 30 μm can be formed in the center. Such a wafer WF2 can also be divided into a plurality of chips CP on which the circuit CA is formed by appropriately performing a plate-like member preparation process, a groove forming process, a modified layer forming process, an expanding process, and the like. When the wafer WF is divided into three in this way, two cutting means 50 may be used side by side in the notch forming process, or the notch forming process is performed twice by one cutting means 50. May be. According to Modification 4 as described above, the thickness of the divided wafer WF can be adjusted.

Any circuit CA may be formed in the plate-shaped member preparation step. For example, the circuit CA may have a through electrode (or only a through electrode). In this case, a through electrode embedding step for embedding the through electrode is provided, and the wafer WF in which the through electrode is embedded in the incision forming step is divided into two within the thickness to form a plurality of chips and wafers with the through electrode. it can.
In the plate-like member preparation process, a wafer WF having the circuits CA and streets ST formed in advance on at least one surface may be prepared. In this case, the formation object forming process by the circuit forming means 10 is not necessary.
The wafer WF may have any thickness such as 725 μm and 625 μm, and may have any diameter such as 300 mm and 450 mm.
Examples of the wafer WF include a silicon semiconductor wafer, a SiC (silicon carbide) wafer, a sapphire wafer, and a compound semiconductor wafer. Examples of the compound semiconductor wafer include a GaP (gallium phosphide) wafer, a GaA (gallium arsenide) wafer, an InP (indium gallium phosphide) wafer, and a GaN (gallium nitride) wafer.
The shape of the wafer WF may be any shape such as a circle, a D shape, an ellipse, a rectangle, and other polygons.
The circuit formed on the wafer WF may have a different size and pattern on one surface and the other surface.
The wafer WF may have a portion showing a crystal orientation such as a V notch and an orientation flat.
In addition to the wafer WF, the plate-like member may be any form of member or article, such as a circuit board, a base board, a lead frame, a glass plate, a steel plate, ceramics, a wooden plate, or a resin plate, and is not limited at all. is not. Therefore, the individual piece may be cut from any member or article in any form, and is not limited at all.
The modeled object is not limited to a circuit pattern CA, a predetermined pattern, a picture, a pattern, a character, a number, a three-dimensional diagram, a concavo-convex pattern, or a combination thereof. There is no limitation as long as it can be formed.

In the groove forming step, the depth of the groove 11 can be arbitrarily determined.
In the groove forming step, the groove 11 having a depth that does not interfere with the notch 12, that is, the groove 11 having a depth that does not cross the notch 12 is formed, and after the notch forming step, It may be divided into a plurality of chips CP in a grinding process or the like.
You may perform both a groove | channel formation process and a modified layer formation process with respect to one wafer WF.

The modified layer formed in the modified layer forming step is formed from both sides of one surface and the other surface, and these modified layers may or may not be connected to each other.
In the modified layer forming step, the modified layer 21 having a depth that does not interfere with the notch 12, that is, the modified layer 21 having a depth that does not cross the notch 12, is formed, and after the notch forming step, the same as described above. It may be divided into a plurality of chips CP in the expanding process, the back grinding process or the like.
In the modified layer forming step, a weakening member such as a chemical or a chemical substance that can weaken the wafer WF may be administered to form a modified layer that makes the wafer WF brittle along the street ST.

Each chip CP may be ground to a predetermined thickness by providing a grinding step after the notch forming step.
In the notch formation step, the wafer WF may be divided into four or more within the thickness by the cutting means 40 and 50, or three or more cutting means 40 and 50 may be used side by side.
The thickness of the wafer or chip after the notch formation process or the back grinding process may be any thickness such as 20 μm, 30 μm, 60 μm, 100 μm, or the like.

11, 11a Groove 12 Notch 21 Modified layer CP Semiconductor chip (single piece)
WF Semiconductor wafer (plate member)

Claims (2)

A plate-shaped member preparation step of preparing a plate-shaped member;
On both sides of the hand surface and the other surface of the plate-like member, a groove forming step of forming a groove that does not penetrate to the opposite face
Along the side surface of the plate-like member on one surface or the other surface, and by forming a notch crossing said grooves, those plate-like member at the same time dividing the thinning the one surface and the other of said piece body manufacturing method characterized by and an incision forming step of forming a plurality of pieces body from both sides of the plane. A plate-shaped member preparation step of preparing a plate-shaped member;
A modified layer forming step of forming a modified layer in which the plate-shaped member becomes brittle on the plate-shaped member ;
Along the one surface or the other surface from the side surface of the plate-like member, and by forming a notch crossing said modified layer is divided at the same time thinning the person said plate member, said one surface and And a notch forming step of forming a plurality of individual pieces from both surfaces of the other surface , respectively .

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