JP2000243797A - Semiconductor wafer, and cutting method thereof, and semiconductor wafer assembly and cutting method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically discriminate the quality of semiconductor chips based on whether or not a magnetic material layer is present on the side of the semiconductor chip, when the semiconductor chips are cut off by a method wherein a magnetic material layer is provided in the side of a semiconductor wafer with a primary surface, where electronic elements or patterns are physically and chemically formed. SOLUTION: A magnetic material layer 4, composed of magnetic powder and binder which binds magnetic powder together, is previously applied on the side of a semiconductor wafer laminate. Lastly, when a magnet is made to approach separated semiconductor chip laminates 8, the semiconductor chip laminate 8 with the magnetic material layer 4 formed on its side is attracted by the magnet. The semiconductor chip laminate 8 having no magnetic material layer 4 formed on its side is not attracted to the magnet. As a result, the semiconductor chip laminates 8 which are possessed of arc-shaped sides, defective in shape, and not suitable for use in the manufacture of products can be easily and surely sorted out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor wafer technology, and more particularly to a semiconductor wafer which can be easily separated from a defective product generated when cutting a semiconductor wafer or a semiconductor wafer assembly, a method for cutting the same, and a semiconductor wafer assembly And its cutting method.

[0002]

2. Description of the Related Art When manufacturing a semiconductor chip laminate, a plurality of identical electronic elements or patterns including various electronic elements or electronic circuits are formed physicochemically on a main surface of a semiconductor wafer formed in a thin plate shape. Then, the semiconductor wafer is cut and separated into individual electronic patterns. For example, when manufacturing a high-voltage diode, as shown in JP-A-10-217094, a thin plate-shaped semiconductor wafer having various electronic elements and patterns formed on a main surface thereof uses a well-known wire saw or dicing blade. Then, it is cut and separated into dice-shaped semiconductor chips.

[0003]

When a semiconductor wafer having a plane circular shape is cut and divided into chips having a plane square shape, the semiconductor chips on the peripheral side of the semiconductor wafer have a partially chipped shape instead of a plane square shape. Such a semiconductor chip becomes a chip having a defective shape and cannot be used for a product. Conventionally, since a semiconductor chip having a defective shape is visually determined and removed, a mass production process cannot be introduced, and there is a problem in productivity.

[0004] It is an object of the present invention to provide a semiconductor wafer capable of automatically selecting a semiconductor chip having a defective shape, and a method of cutting the same. Another object of the present invention is to provide a semiconductor wafer laminate capable of automatically selecting a semiconductor chip laminate having a defective shape, and a method for cutting the same.

[0005]

A semiconductor wafer according to the present invention has a magnetic material layer (4) provided on a side surface of a semiconductor wafer having at least one main surface on which electronic elements or patterns are formed physicochemically. Since the magnetic material layer (4) is provided on the side surface of the semiconductor wafer, when the semiconductor wafer is cut into individual semiconductor chips, the shape of the product depends on the presence or absence of the magnetic material layer (4) formed on the side surface of the defective semiconductor chip. Pass / fail can be automatically selected.

In the embodiment of the present invention, the magnetic material layer (4)
Is a binder for connecting the magnetic powder and the magnetic powder. The semiconductor wafer (2) forms a semiconductor wafer stack (1) in which a plurality of semiconductor wafers (2) are stacked, and a plurality of adjacent semiconductor wafers (2) are fixed to each other by a solder layer (3).

The method for cutting a semiconductor wafer according to the present invention comprises the steps of forming a magnetic material layer (4) on a side surface of a semiconductor wafer (2);
A step of forming individual semiconductor chips by cutting the semiconductor wafer (2) along a diametric surface or a plane parallel to the diametric surface, detecting the magnetic material layer (4), and detecting the magnetic material layer (4) Selecting a semiconductor chip having a defective shape having the following.

The method for cutting a semiconductor wafer laminate according to the present invention comprises the steps of: preparing a semiconductor wafer laminate (1) in which a magnetic material layer (4) is formed on the side surfaces of a plurality of laminated semiconductor wafers (2); Cutting the semiconductor wafer laminate (1) along a diametric surface or a surface parallel to the diametric surface to form a semiconductor chip laminate
The method includes a step of forming (8) and a step of detecting the magnetic material layer (4) and selecting a semiconductor chip laminate (8) having the magnetic material layer (4) and having a poor shape.

In the embodiment of the present invention, a magnet (10) is brought close to a semiconductor chip or a semiconductor chip laminate (8) to form a semiconductor chip or a semiconductor chip laminate having a magnetic material layer (4). 8) can be selected by adsorbing it to the magnet (10), or a semiconductor chip or semiconductor chip laminate (8) having a magnetic material layer (4) and having a poor shape can be selected by a magnetic sensing element. Further, in the semiconductor wafer assembly cutting method according to the present invention, the bonding resin (7) is applied to the cut portion (6) of the semiconductor wafer laminate (1) cut along a diametric surface or a surface parallel to the diametric surface. Filled, plate-shaped semiconductor wafer laminate (1)
A step of fixing the gap with an adhesive resin (7), a step of further cutting the semiconductor wafer laminate (1) along a plane perpendicular to the plane, and the step of cutting the semiconductor wafer laminate (1) in an etching solution. Immerse to dissolve the adhesive resin (7), and to laminate the semiconductor chip laminate (8)
And forming a.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a semiconductor wafer and a method of cutting the same, and a semiconductor wafer assembly and a method of cutting the same according to the present invention will be described below with reference to FIGS.

As shown in FIG. 1, a semiconductor wafer laminate (1) is prepared by laminating and laminating a plurality of disc-shaped semiconductor wafers (2) via a solder layer (3). Each semiconductor wafer laminate (1)
On one main surface (1a) and the other main surface (1b), an adhesive layer (1c) for fixing a lead member (not shown) is formed.
Each semiconductor wafer (2) is large enough to take a large number of semiconductor chips (1). Various electronic elements and wiring patterns are formed on the main surface of each thin semiconductor wafer (2).

Next, as shown in FIG. 2, a magnetic material layer (4) made of a magnetic powder and a binder for connecting the magnetic powder is applied to the side surface of the semiconductor wafer laminate (1). The magnetic powder is, for example, iron powder, and the binder is a thermoplastic adhesive such as an acrylic adhesive, a thermosetting adhesive such as an epoxy resin, or a hot melt adhesive such as an ethylene vinyl acetate copolymer, polyamide, or polyester. can do. Magnetic material layer covering the entire outer peripheral surface of each semiconductor wafer (2) and solder layer (3)
(4) is not applied to both main surfaces (1a) and (1b) of the semiconductor wafer laminate (1). The magnetic material layer (4) generates a magnetic flux density that generates a magnetic field to such an extent that the cut semiconductor wafer laminate (1) can be attracted to the adjacent magnet (10).

As shown in FIG. 2, the semiconductor wafer laminate (1) on which the magnetic material layer (4) is formed is fixed to a metal support plate (5) via an adhesive layer (1c). . Semiconductor wafer laminate
The step of fixing (1) on the support plate (5) is performed after forming the magnetic material layer (4) on the semiconductor wafer laminate (1).
It may be before forming (4).

Next, a known wire saw is prepared, and the main surfaces (1a) and (1b) of the semiconductor wafer stack (1), that is, the semiconductor wafer (2) disposed on the uppermost side of the semiconductor wafer stack (1) are prepared. ) Along a diametric plane or a plane parallel to the diametric plane (X
3), the semiconductor wafer laminate (1) composed of each semiconductor wafer (2) and the solder layer (3) is cut and separated into a plate shape as shown in FIG. The plate-shaped semiconductor wafer laminate (1) fixed to the support plate (5) via the adhesive layer (1c) and the solder layer (3) does not separate from each other. When performing a wire saw with the adhesive layer (1c) formed on the main surface of the semiconductor wafer (2) disposed on the uppermost side of the semiconductor wafer laminate (1), apply the wire to the adhesive layer (1c). Make contact and cut.

Thereafter, the cutting portion (6) between the plate-like semiconductor wafer laminates (1) is filled with an adhesive resin (7), and the space between the plate-like semiconductor wafer laminates (1) is filled with the adhesive resin (7). Secure with 7). Thereby, as shown in FIG. 4, the plurality of plate-shaped semiconductor wafer laminates (1) are integrated via the bonding resin (7), and are returned to the original planar circular semiconductor wafer laminate (1). Will be restored.

Subsequently, the main surface (1) of the semiconductor wafer laminate (1)
a) That is, the wire is reciprocated in the second direction (Y direction) orthogonal to the first direction (X direction) with respect to the semiconductor wafer (2) disposed on the uppermost part of the semiconductor wafer stack (1). Let me
As shown in FIG. 5, an adhesive resin (7) for fixing the semiconductor wafer (2) and the solder layer (3) of the semiconductor wafer laminate (1) and the plate-like semiconductor wafer laminate (1) to each other. In the second direction. As a result, the semiconductor wafer stack (1) is separated into the rod-shaped semiconductor wafer stack (1). At this time, some rod-shaped semiconductor wafer laminates (1) may come off from the support plate (5).

Further, an adhesive layer (1c) for dipping the semiconductor wafer laminate (1) in an etching solution to fix the semiconductor wafer laminate (1) (chip laminate) to the support plate (5); The adhesive resin (7) for fixing the semiconductor wafer laminates (1) to each other is dissolved and removed with an etchant. The magnetic material layer (4) formed on the side surface of the semiconductor wafer stack (1) (chip stack) is not removed by the etching solution. As a result, as shown in FIG. 6, each semiconductor wafer stack (1) is separated from the support plate (5) and separated from each other, and individual rod-shaped semiconductor chip stacks (8) are obtained. . FIG.
As shown in the figure, in the semiconductor chip laminate (8) having a regular shape disposed inside the semiconductor chip laminate (8) and having a rectangular cross section, the magnetic material layer (4) is not fixed to the flat side surface. However, among the semiconductor chip laminates (8), the semiconductor chip laminate (8) arranged on the outer peripheral side has a magnetic material layer (4) fixed to an arc-shaped side surface as shown in FIG. .

Finally, as shown in FIG. 7, when the magnet (10) is brought close to the semiconductor chip laminate (8) separated from each other,
Semiconductor chip laminate (8) with magnetic material layer (4) on the side
Is attracted to the magnet (10). Meanwhile, a magnetic material layer on the side
The semiconductor chip laminate (8) of FIG. 6 where (4) is not formed is a magnet
Not adsorbed to (10). As a result, the semiconductor wafer laminate
The semiconductor chip laminate (8) having an arc-shaped side surface which is arranged on the outer peripheral side of (1) and has an arc-shaped side face that cannot be used for manufacturing a product can be easily and reliably identified and removed. Thus, in the present embodiment, the semiconductor wafer (2)
Since the magnetic material layer (4) is provided on the side surface of the semiconductor wafer (2), the individual semiconductor chips or the semiconductor chip laminate (8)
When cut into semiconductor chips or semiconductor chip laminates
Based on the presence or absence of the magnetic material layer (4) formed on the side surface of (8), the quality of the product shape can be automatically identified.

Various modifications can be made to the above embodiment of the present invention. For example, in the above-described embodiment, the case where a plurality of semiconductor wafers (2) are cut through a semiconductor wafer laminate (1) fixed via a solder layer (3) has been described. It can be applied to the case. The adhesive resin (7) for fixing the plate-like semiconductor wafer laminates (1) to each other may not be provided.
In the case of (1), it is desirable to provide an adhesive resin (7) so that it can be easily cut in the Y direction with a wire saw. Instead of cutting using a wire saw, cutting and separating may be performed using a well-known dicing blade (a high-speed rotating circular blade). In the embodiment of the present invention, instead of determining the shape of the product by bringing the magnet (10) close to the semiconductor chip laminate (8), the shape of the product is selected by a magnetically sensitive element such as a Hall element. You may.

[0020]

As described above, according to the present invention, the quality of a semiconductor chip can be automatically and reliably selected, so that the productivity of the semiconductor chip can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a semiconductor wafer laminate used for manufacturing a semiconductor wafer laminate according to the present invention.

FIG. 2 is a perspective view of a semiconductor wafer laminated body having a magnetic material layer formed on a side surface and fixed on a support plate.

FIG. 3 is a perspective view of the semiconductor wafer laminate cut in a first direction.

FIG. 4 is a perspective view of a semiconductor wafer laminate in which a cut portion is filled with an adhesive resin.

FIG. 5 is a perspective view of the semiconductor wafer laminate cut in a second direction.

FIG. 6 is a perspective view of a semiconductor chip laminate having a regular shape;

FIG. 7 is a perspective view of a failed semiconductor chip laminate.

[Explanation of symbols]

(1) ・ ・ Laminated semiconductor wafer, (1a) ・ ・ Main surface, (1b)
・ ・ Main surface, (1c) ・ ・ Adhesive layer, (2) ・ ・ Semiconductor wafer, (3) ・ ・ Solder layer, (4) ・ ・ Magnetic material layer, (5) ・ ・
Support plate, (6) ... cut section, (7) ... adhesive resin,
(8) ・ ・ Semiconductor chip laminate,

Claims (11)

[Claims] 1. A semiconductor wafer having at least one main surface on which electronic elements or patterns are formed physicochemically, wherein a magnetic material layer is provided on a side surface of the semiconductor wafer. 2. The semiconductor wafer according to claim 1, wherein the magnetic material layer is a magnetic powder and a binder for connecting the magnetic powder. 3. The semiconductor according to claim 1, wherein said semiconductor wafer forms a semiconductor wafer laminate in which a plurality of semiconductor wafers are stacked, and said plurality of adjacent semiconductor wafers are fixed to each other by a solder layer. A semiconductor wafer assembly comprising a wafer. 4. The semiconductor wafer assembly according to claim 3, wherein the magnetic material layer is a magnetic powder and a binder for connecting the magnetic powder. 5. A step of forming a magnetic material layer on a side surface of a semiconductor wafer; a step of cutting the semiconductor wafer along a diametric surface or a surface parallel to the diametric surface to form individual semiconductor chips; Detecting the magnetic material layer and selecting a semiconductor chip having a defective shape having the magnetic material layer. 6. A magnet is brought close to the semiconductor chip,
6. The method of cutting a semiconductor wafer according to claim 5, wherein the semiconductor chip having the magnetic material layer and having a poor shape is attracted to the magnet and selected. 7. The method for cutting a semiconductor wafer according to claim 6, wherein a semiconductor chip having a defective shape having said magnetic material layer is selected by a magnetically sensitive element. 8. A step of preparing a semiconductor wafer laminate in which a magnetic material layer is formed on side surfaces of a plurality of laminated semiconductor wafers, and forming the semiconductor wafer laminate along a diametric surface or a plane parallel to the diametric surface. A semiconductor wafer comprising: a step of cutting to form a semiconductor chip laminate; and a step of detecting the magnetic material layer and selecting the defective semiconductor chip laminate having the magnetic material layer. Assembly cutting method. 9. The cutting of the semiconductor wafer assembly according to claim 8, wherein a magnet is brought close to the semiconductor chip laminate, and the semiconductor chip laminate having the magnetic material layer having a poor shape is attracted to the magnet and selected. Law. 10. The method for cutting a semiconductor wafer assembly according to claim 8, wherein a semiconductor chip laminate having a shape defect having the magnetic material layer is selected by a magnetically sensitive element. 11. A cutting portion of the semiconductor wafer laminated body cut along a diametrical surface or a plane parallel to the diametrical surface is filled with an adhesive resin to bond the plate-shaped semiconductor wafer laminated bodies to each other. Fixing with a resin for application, further cutting the semiconductor wafer laminate along a plane perpendicular to the plane, and immersing the semiconductor wafer laminate in an etchant to dissolve the adhesive resin. 9. A method for cutting a semiconductor wafer assembly according to claim 8, further comprising: forming a semiconductor chip laminate.