JPH06308002A - Three-point bending jig for small fragile material - Google Patents

Abstract

PURPOSE:To obtain a three-point bending jig for a small fragile material which can calculate a highly accurate loadflexibility line diagram in a three-point bending test for the small fragile material having a thin thickness. CONSTITUTION:A plurality of fulcrum guide grooves 6a are placed on an upper part of a supporting base 6 so that their distance is 20mm or less, a pair of fulcrum parts 7 having a double-bladed part on an upper part are fitted and fixed to the fulcrum guide groove 6a, a sample 3 being a small fragile material having a thickness of 200mum or less is mounted on the pair of the fulcrum parts 7, and a load 8 with its lower end conical is used to push the center of an upper face of the sample 3 at the center of the pair of the fulcrum parts 7 to apply load.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention conducts a three-point bending test on a minute brittle material having a thickness of 200 μm or less (for example, an ultrathin plate such as quartz or a silicon substrate) with a fulcrum distance (span) of 20 mm or less, The present invention relates to a three-point bending test jig for a minute brittle material used when obtaining a load-deflection diagram with accuracy.

[0002]

2. Description of the Related Art Conventionally, in a three-point bending test of a brittle material such as fine ceramics, as shown in FIGS. 4 (a) and 4 (b), a pair of round bar-shaped rollers are provided on a guide groove 1a of a support 1. The fulcrum part 2 of is the distance L between fulcrums
Samples of brittle material (usually 3 mm thick, 5 mm wide, 60 mm long) placed on a pair of fulcrums 2
A bending test jig having a structure in which the load P is applied by placing the load portion 5 on the sample 3 from the upper center of the fulcrum portion 2 through the center of the fulcrum portion 2 through the round rod-shaped roller 4 or the punch having the semicircular cross section was generally used. .

[0003]

By the way, single crystal device substrate materials represented by quartz and silicon substrates are brittle materials which have a smaller deformability than metal materials. However, when the plate thickness is reduced to about 150 μm or less, Deformability (flexure)
Is greatly increased. For example, FIG. 5 shows a sample of a quartz substrate (AT cut) (length 5.0 mm, plate width 1.7 mm, plate thickness t
μm) 3 above 3 point bending test (distance between fulcrums L
= 4 mm), the relationship between the plate thickness t (μm) and the maximum bending deflection amount δ (μm) is shown, and the deformability significantly increases when the plate thickness is about 150 μm or less.

In particular, in a bending test of a minute brittle material having a small plate thickness, the distance between fulcrums is inevitably small, and when the bending test jig shown in FIG. 4 is used, the bending deflection increases as the bending test jig increases. The sample 3 comes into contact with the inside of the roller of the fulcrum portion 2, and the distance between the fulcrums becomes narrower than the standard, and the degree of narrowing is remarkable as compared with the case where the distance between the fulcrums is sufficiently large.
Therefore, when a bending test of a thin and minute brittle material is performed using the bending sample jig shown in FIG. 4, even if the material is elastic, the load-deflection diagram becomes a downward convex curve, and linearity Was difficult to get. As an example, using the above jig,
The fulcrum part 2 is a round bar roller with a diameter of 1 mm, and the distance L between the fulcrums
FIG. 6 shows the relationship between the load P (g) and the bending deflection amount δ (μm) when a three-point bending test was performed on a quartz substrate (AT cut) with a value of 4 mm. The size of sample 3 is 5.0m long
m, plate width 1.7 mm, and plate thickness 77 μm. Pb = 6
0.7 g and δb = 118 μm are the load P and the bending deflection amount δ when the sample 3 breaks.

The present invention has been made in order to solve the above problems, and it is possible to obtain a highly accurate load-deflection diagram in a three-point bending test of a minute brittle material having a small plate thickness. The purpose is to obtain a three-point bending test jig for minute brittle materials.

[0006]

A three-point bending test jig for minute brittle materials according to the present invention has a support base in which a plurality of fulcrum guide grooves are arranged side by side so that the mutual distance is 20 mm or less. And a pair of fulcrum portions that are fitted and fixed in the fulcrum guide groove and have a double-edged upper portion, and a sample of a minute brittle material with a thickness of 200 μm or less that is placed on the pair of fulcrum portions.
The lower end has a conical shape, and a load portion is provided to press the center of the sample at the center position of the pair of fulcrum portions to apply a load to the sample.

[0007]

According to the present invention, a plurality of fulcrum guide grooves are arranged side by side on the upper part of the support base so that the mutual distance is 20 mm or less, and a pair of fulcrum parts with upper edges fitted and fixed to the fulcrum guide grooves. To be done. A sample having a thickness of 200 μm or less is placed on the pair of fulcrum portions, and a load is applied by pressing the center of the sample by a load portion having a conical lower end at the center position of the pair of fulcrum portions.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are a front view and a side view of a three-point bending test jig according to this embodiment, and 6 is a support base. On the upper part of the support base 6, fulcrum guide grooves 6a having a width of 1 mm are provided at intervals of 2 mm (interval between centers). However, a groove 6b slightly deeper than the fulcrum guide groove 6a is provided in the central portion. 7 is groove 6b
Is a fulcrum part fitted and fixed to the fulcrum guide grooves 6a on both sides of the fulcrum.
It is formed by polishing to (μm). The distance L between the fulcrums is 4 mm. By changing the position of the fulcrum guide groove 6a into which the fulcrum portion 7 is fitted, the distance L between the fulcrums is set to 8 mm, 12
It can be changed at intervals of 4 mm and 4 mm.

As the sample 3, the same sample as that shown in FIG. 6 was used. That is, it is a plate material having a thin plate thickness and a minute quartz substrate (AT cut), and its size is 5.0 mm in length, 1.7 mm in plate width, and 77 μm in plate thickness. The sample 3 is placed on the tips of the pair of fulcrums 7. Numeral 8 indicates that the load P is applied to the sample 3 by pressing the center of the upper surface of the sample 3 at the center position of the pair of fulcrums 7.
Which is a load portion to be added to, and has a conical tip made of hard steel (curvature radius of the tip is about 25 μm). Therefore, the load part 8 and the sample 3
The contact is changed from the conventional line contact to the point contact.

When a three-point bending test of the sample 3 is performed using the above bending test jig, the radius of curvature of the tip of the fulcrum portion 7 is extremely small, so that even if the deflection of the sample 3 increases, the distance between the fulcrums is always constant. Can be secured. As a result, when a three-point bending test is performed on an ultra-thin plate micro-brittle material that elastically deforms with a fulcrum distance of 4 mm, a load-deflection diagram can be obtained in a substantially straight line. The coefficient can be measured with high accuracy.
FIG. 3 is a load-deflection diagram as an example, and Pb
= 58.3 g, δb = 134 μm indicates the load P and the bending deflection amount δ when the sample 3 breaks.

Further, since the tip of the load portion 8 is formed into a conical shape, the contact with the sample 3 becomes a point contact, and the center of the sample 3 can be easily pressed. Further, by providing two or more fulcrum guide grooves 6a, the distance between fulcrums can be changed with high accuracy and easily.

In the above embodiment, the distance between fulcrums is 4 mm.
However, it may be 20 mm or less. Further, as the sample 3, a quartz substrate having a thickness of 77 μm was used.
The target material may be a brittle material such as a single crystal device substrate (quartz, silicon, or other oxide substrate), a thermosetting resin, or a polycrystalline sintered body (fine ceramic thin plate). is there.

[0013]

As described above, according to the present invention, since the radius of curvature of the tip of the fulcrum portion is extremely small, a constant fulcrum distance can always be secured even if the deflection of the sample increases, and the bending test can be performed. The load-deflection diagram of a thin and minute brittle material according to can be accurately obtained in a straight line. Further, since the tip of the loading part is conical, the center of the sample can be accurately pressed by the loading part. Furthermore, by providing two or more fulcrum guide grooves, the distance between fulcrums can be changed with high accuracy and easily.

[Brief description of drawings]

FIG. 1 is a front view of a three-point bending test jig according to the present invention.

FIG. 2 is a side view of a 3-point bending test jig according to the present invention.

FIG. 3 is a load-deflection diagram of a quartz substrate obtained as a result of a bending test using a test jig according to the present invention.

FIG. 4 is a front view and a side view of a conventional 3-point bending test jig.

FIG. 5 is a relationship diagram between a plate thickness and a maximum bending deflection amount in a three-point bending test of a quartz substrate.

FIG. 6 is a load-deflection diagram of a quartz substrate obtained as a result of a bending test using a conventional test jig.

[Explanation of symbols]

 3 ... sample 6 ... support base 6a ... support guide groove 7 ... fulcrum part 8 ... load part

Claims (1)

[Claims] 1. A support base in which a plurality of fulcrum guide grooves are arranged side by side so that a mutual distance is 20 mm or less, and a pair in which the fulcrum guide grooves are fitted and fixed to each other and the upper part has a double-edged shape. Fulcrum part, a sample made of a minute brittle material with a thickness of 200 μm or less placed on the pair of fulcrum parts, and the lower end has a conical shape, and the center of the sample is pressed at the center position of the pair of fulcrum parts. Then, a three-point bending test jig for minute brittle materials is provided with a load part for applying a load to the sample.