JPS62108007A - Method of dividing semiconductor board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The present invention relates to a method for dividing a semiconductor board to obtain a large number of semiconductor chips by dicing the semiconductor board. [Prior art and its problems]

When manufacturing small semiconductor devices, there is a step of dicing a circular silicon plate to divide it into square semiconductor chips. In this process, a disc-shaped diamond blade made by mixing and sintering diamond powder and metal powder is rotated at high speed, A groove 21 parallel to one direction is formed in the silicon plate 1, and then Fig. 2 +C1 and its B-BvA sectional view fd
2 (el, (fl
It consists of a step of dividing into individual semiconductor chips 2 by applying a bending force 25 as shown in FIG. The silicon plate has (111), (110), (100
) having three types of crystal planes are used. As shown in FIG. 3, when the surface 31 of the silicon plate is the (100) plane, the (011) plane 32. which is the cleavage plane. (0
11) Since the plane 33 is 90″ from the (100) plane, the second
When breaking by applying force as shown in Figure [el], it is easily cleaved and shown in Figure 3 (1.(C) in Figure 3, which is a cross-sectional view of The side surface perpendicular to the surface 32.
A square chip 2 having a diameter of 33 can be obtained. However, if the surface 31 of the silicon plate 1 shown in FIG.
11) plane, the (110) cleavage plane 34 is perpendicular to the surface 31, but since the (011) cleavage plane is at an angle of 30° to the surface 31, the (110) cleavage plane 34 is perpendicular to the plane 34. TT2) is connected to the (OTI) surface 36 without being connected to the surface 35. Further, when the surface 31 of the silicon plate 1 shown in FIG. 5 is a (110) plane, the (110) cleavage plane 36 is at an angle of 90° to the surface 31, but
011) The cleavage plane is at an angle of 45° to the surface 31. Therefore, when dividing, as shown in Figure 5 (bl)
It is not separated from the (001) plane 37 but separated by the (Ojl) plane 38. Therefore, if the groove 21 shown in Fig. 2 is placed in the (110) plane and the groove 22 is placed in the (001) plane, they will be separated as shown in Fig. 6 18+, and the obtained thousand knobs will be shown in the 6th entry). The (001) plane 37 is formed by the (110) plane 31 and the groove 21, and the (110) plane is formed by the (Oll) planes 38 and 422 that form a 45° angle with the surface below it.
It is surrounded by a surface 36. As shown in Figure 4 (111
) The same applies to wafers. As a result of this IZ splitting, defective chip shapes and poor pancasing occur, and furthermore, due to defects such as micro clutches that occur during splitting,
Particularly, when a pattern is formed also on the lower surface side, reliability decreases. As a countermeasure to this problem, it is conceivable to perform a full cut by cutting through the entire thickness of the silicon plate with a diamond blade. However, if the silicon plate is fixed on the base with a vacuum chuck and then fully cut, chips that are not present on the suction port will scatter.To avoid this, the silicon plate is placed on the base with adhesive or adhesive tape. A method of fixing the chip to the chip surface could also be considered, but some adhesive would remain on the chip surface, which would interfere with the subsequent assembly process.

[Purpose of the invention]

The present invention solves the above-mentioned problems and provides a method for dividing a semiconductor board, which is capable of guising a semiconductor board fixed on a base by a vacuum chuck without causing any cleavage effects on both sides of the semiconductor board. With the goal.

[Key points of the invention]

The present invention forms parallel grooves in at least two directions at opposing positions on both sides of a semiconductor board, leaving a central part of the board thickness, and then applying bending stress to prevent the effect of cleavage from occurring near both sides. Since it is not separated into chips during grooving, it is possible to use a vacuum chuck, and the above purpose is achieved.

[Embodiments of the invention]

FIG. 1 shows one embodiment of the present invention.
Parallel grooves 23 are formed on the back surface 12 of the silicon plate 1 using a diamond blade as shown in FIG. Figure 1 (
Ml shows a sectional view taken along the line ■-■. Next, as shown in FIG. 1 (01, +d), a groove 21 is formed on the side opposite to the groove 23 on the surface 11 of the silicon plate 1, and a groove 22 is formed on the opposite side to the groove 24. Figure 1 (fl is J in Figure 1 (a)
- Shows the JvA cross section. This silicon plate is shown in Figure 2 (81,
When bending force is applied as shown in <1), regardless of the crystal plane of the surface of the silicon plate l and the surface where the grooves are formed, a complicated A cleavage plane 3 is generated, and the cleavage does not extend into the divided chip 2. The silicon plate 1 is connected by the thin part between the grooves until bending force is applied, so the groove cut is fixed by a vacuum chuck. It can be performed on a silicon plate. Furthermore, since the cleavage occurs at the center of the plate thickness, it does not affect the formation of the diffusion pattern of the semiconductor element from both sides, improving the reliability of the element. Of course, the same effect can be obtained even if the grooves 21 to 24 on both sides are formed first, starting with the grooves 21 and 22 on the front side. Further, the grooves are not limited to be formed using a diamond blade, but may be formed using a diamond tool or a diamond scriber.

Effects of the Invention According to the present invention, grooves facing each other from both sides of the semiconductor board are inserted to the extent that the semiconductor board is not cut, and guising is performed, regardless of the crystal plane of the semiconductor board surface and the dividing plane. For example, it is possible to obtain a rectangular semiconductor chip surrounded by mutually perpendicular surfaces, which reduces the influence of cleavage on the semiconductor chip, especially near both sides, reduces chip shape defects, pancaging defects, or characteristic defects, and improves the semiconductor element. It is effective in improving the manufacturing yield of semiconductor devices and the reliability of finished semiconductor devices.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of the present invention, tel, (bl,
(C). (dl is a plan view sequentially showing the groove forming process, (el is fat
(f) is a J-Jg sectional view of (al), Figure 2 shows the conventional guissing process in sequence, (bl is a line A-A of tal, (d) is a B-- B! Cross section, tel.
(f) is a cross-sectional view at the time of division, and FIG. 3 shows an example of division of a (100) wafer by conventional dicing, (al is a plan view, (bl is C-C&I of (al). (dl is (al of D-D 4% cross-sectional view, FIG. 4 shows an example of dividing a (Ill) wafer by conventional dicing,
(a) is a plan view, (bl is E-El of tal, (cl is +1 ml cross-sectional view on line F-F), FIG. 5 shows an example of dividing a (110) wafer by conventional dicing, and (4) is Plan view, mountain) is line GG of (al), (C) is line H-H of (shi)
Line sectional view, Figure 6 is an enlarged view of the division example in Figure 5, t8)
A cross-sectional view showing the formation of cleavages; Figure 3) is a perspective view of the resulting chip. 1: Silicon plate, 11.127 plate surface, 2: Chip, 21
, 22.23.24F groove, 3: Cleavage plane. (c) (d) Figure 1 [Yes]) (C) Cb) (d) (f) Figure 2 Figure 3 (υ (c) Figure 4 (Q)

Claims (1)

[Claims] 1) A method for dividing a semiconductor board, which comprises forming parallel grooves in at least two directions in opposing positions from both sides of the semiconductor board, leaving a central portion of the board thickness, and then applying bending stress to the board.