JPH01233905A - Manufacture system for surface acoustic wave resonator - Google Patents

Abstract

PURPOSE:To improve the yield and to avoid the deterioration in the characteristic by applying half-cut from a rear face while a pattern face of a piezoelectric substrate with a thin film pattern formed thereon in advance is directed downward, adhering an assembling tape to the rear face of the substrate, cutting fully the remaining part so as co separate individual elements. CONSTITUTION:A tin film pattern 2 is formed on a crystal plate surface 1 to form a crystal substrate wafer 3. The crystal substrate wafer 3 is adhered onto an UV radiation cut tape 4 while its thin film pattern 2 is directed downward. The wafer 3 is subjected to half cut from the rear face 5 of the crystal substrate wafer 3, UV radiation is applied to the side of the thin film pattern 2 to reduce the adhering force of the UV radiation cut-tape 4 and the thin film pattern 2. Then the side of the thin film pattern 2 of the crystal substrate wafer 3 and the rear face 5 of the crystal substrate wafer 3 are adhered by an assembling tape 6 and then the UV radiation cut tape 4 is exfoliated. Then each chip is split completely by a metal blade 7 from the side of the thin film pattern 2 of the crystal substrate wafer 3. With the assembling tape 6 expanded while being heated to a temperature of 70 deg.C, a clean surface acoustic wave device element 8 separated completely is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in a manufacturing method for a surface acoustic wave resonator, and particularly to a process for cutting a piezoelectric substrate thereof.

(Prior Art) Conventionally, Ueno resin used in surface acoustic wave resonators, that is, surface acoustic wave devices, is made of quartz crystal or LiTa0. Substrates such as are used. Unlike the silicon wafers used in semiconductor devices, these wafers are hard and brittle, so they tend to peel off or crack when cut, and small pieces generated during cutting may stick to the chip surface. Or damage the pattern.

However, surface acoustic wave devices are made so that surface waves propagate on the chip surface, so the chip surface is not coated with a protective film. Therefore, the surface is easily damaged)
, the electrical properties deteriorate due to the adhesion of the cutting layer.

Surface acoustic wave devices use materials that tend to crack when cut, and if a cutting layer adheres, it will damage the device surface, so wafers for surface acoustic wave devices are cut using the following two methods.

The first method is a cutting method in which full cutting is performed at low speed using a thin grade from the viewpoint of suppressing the generation of cut layers as much as possible.

The second method is to completely eliminate the adhesion of the cut layer, by making 7 cuts with resist applied to Ueno®, and after removing the resist, the cutting method is divided into chips by hand. .

(Problem to be Solved by the Invention) The above-mentioned conventional surface acoustic wave resonator manufacturing method has the disadvantage that the electrical loss characteristics deteriorate due to adhesion of cutting chips in the first method, and the second method This method has the disadvantage that the reduction in chip size increases the number of man-hours and failure rate during chip division. In particular, recent surface acoustic wave devices have become high-frequency, broadband, and compact, and the above-mentioned drawbacks are noticeable.

The object of the present invention is to cut a piezoelectric substrate on which thin film nodules have been formed in advance from the back side with the pattern side facing down, and after applying assembly tape to the back side of the substrate,
It is an object of the present invention to provide a manufacturing method for a surface acoustic wave resonator configured to eliminate the above-mentioned drawbacks by completely cutting out the remaining portion and separating the individual elements, thereby improving the deterioration of characteristics and the yield.

(Means for Solving the Problems) A method for manufacturing a surface acoustic wave resonator according to the present invention is configured to include a half-cut means, an assembly tape, and a full-cut means.

The half-cut means is for half-cutting the upper back surface of the piezoelectric substrate on which a thin film pattern has been formed with the pattern surface facing downward.

The assembly tape is the ninth thing that prevents dispersion of the individual elements attached to the back side of the board.

The full cut means is for cutting the remaining half-cut portion to separate individual elements.

(Example) Next, the present invention will be explained with reference to the drawings.

FIGS. 1(a) and 1(b) are explanatory diagrams showing an embodiment of a method for manufacturing a surface acoustic wave resonator according to the present invention. In Fig. 1, 1 is a crystal substrate, 2 is a thin 1-character pattern, 3 is a crystal substrate wafer, 4 is a UV pre-irradiated cutting tape, 5 is the back side of the crystal substrate 1, 6 is an assembly tape, 7 is a 25 μm thick It is a metal blade.

As shown in FIG. 1(a), a thin film pattern 2 is formed on a crystal plate surface 1 having a thickness of 88011 m to form a crystal substrate wafer 3. The crystal substrate Ueno-3 is placed with the thin film pattern 2 facing down, heated to a temperature of 70° C., and attached to a UV heat-irradiated cutting tape 4 having a thickness of 80 μm.

The wafer 3 is half-cut leaving a thickness of 50 μm from the back surface 5 of the crystal substrate wafer 3. After no-7 cuts, UV irradiation of 24 mW/- was performed on the thin film pattern 2 side to
The adhesive force between the V-heat irradiation cut tape 4 and the thin film pattern 2 on the surface 1 of the crystal substrate is reduced to 1/10 or less of the initial strength.

Next, an assembly tape 6 is attached to the thin film pattern 2 side of the crystal substrate Ueno 3 and to the back surface 5 of the crystal substrate 3, and then the UV heat irradiation cutting tape 4 is peeled off from the surface 1 of the crystal substrate. Next, as shown in FIG. 1(b), the remaining 50 μm thickness is cut from the thin film pattern 2 side of the crystal substrate 3 using a 25 μm thick metal blade 7 to completely separate each chip.

By expanding the assembly tape 6 while heating it to a temperature of 70° C., completely separated and clean surface acoustic wave device elements 8 can be obtained.

Figures 2 (a) to (c) are explanatory diagrams showing details of Figures 1 (a) and (b).In Figure 2, the same elements as in Figure 1 are given the same numbers. 8 is a surface acoustic wave device element.

The UV heat-irradiated cutting tape 4 shown in FIG. 2(a) is
) is attached to the crystal substrate wafer 3. continue,
In order to remove the UV heat irradiation cutting tape 4, as shown in FIG. 2(e)
As shown in FIG. 3, an assembly tape 6 is attached so that the surface acoustic wave device element 8 can be separated.

(Effects of the Invention) As explained above, in the present invention, half-cutting is performed from the back side of a piezoelectric substrate on which a thin film pattern has not been formed with the pattern side facing down, and after applying an assembly tape to the back side of the substrate, The following first to eighth effects can be obtained by fully cutting the remaining portion and separating the individual elements.

In Figure 1, since the pattern surface is facing down and the cutting depth is 85π, the amount of cutting debris adhering to the pattern surface on the element is reduced, making it possible to obtain a good element with less contamination. The effect is that it can be done.

Second, since it is possible to perform full-cut cutting using tape after half-cutting, there is an effect that the number of man-hours can be significantly reduced.

Eighth, since cutting is performed from the back side opposite to the patterned side, cracks are less likely to occur in the substrate, so there is an effect that the cutting speed can be increased.

[Brief explanation of the drawing]

FIGS. 1(a) and 1(b) are explanatory diagrams showing an embodiment of a method for manufacturing a surface acoustic wave companion according to the present invention. FIGS. 2(a) to 2(i) are explanatory diagrams showing details of the manufacturing method shown in FIG. 1. 1. Proboscis/Crystal substrate surface 216. Thin film pattern 3...Crystal substrate ueno・4...-UV irradiation type cutting tape S-◆・Crystal substrate back side 6・@Medium assembly tape to fist metal blade 8 threat・・Surface acoustic wave device element

Claims (1)

[Claims] a half-cut means for half-cutting the upper back surface of a piezoelectric substrate on which a thin film pattern has been formed with the pattern surface facing downward; an assembly tape for preventing the individual elements attached to the back surface of the substrate from dispersing; 1. A method for manufacturing a surface acoustic wave resonator, comprising a full cut means for separating the individual elements by cutting the remaining portion after the half cut.