JPH0482714A - Preparation of radiation shielding grid plate - Google Patents

Abstract

PURPOSE:To easily obtain shielding effect with high accuracy and to enhance assembling work efficiency by forming a material having high radiation absorptivity into a fine powdery form to mix the same with a resin and a curing agent and casting the resulting mixture in a mold to cure the same. CONSTITUTION:A material having high radiation absorptivity is formed into a fine powdery form and this fine powder is mixed with a resin and a curing agent to prepare a mixture 1 which is, in turn, cast in a mold to be cured. For example, an upper substrate 4 having an opening part 3 formed to the central part thereof is placed on a lower substrate 2 to form such a mold that the protruding parts 6 of the substrate 2 are arranged within the opening part 3. The mixture 1 is cast in this mold to uniformly fill the mold. The fine powder of the mixture 1 is obtained from a material excellent in radiation shielding effect such as a lead compound, tungsten or a tungsten compound. This fine powder is mixed with a thermosetting or photo-setting vinyl or epoxy type resin and a curing agent to prepare a creamy composition. The mixture 1 is cured by heat or light to be demolded from the mold. A grid plate having thickness necessary for shielding radiation and slits each having a constant shape and opening width is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a radiation shielding grid plate used in a semiconductor radiation measuring device.

Conventional Semiconductor Radiation Measurement Device A semiconductor radiation measuring device is formed by arranging a grid plate having a large number of minute slits formed at a constant pitch on one side of a strip-shaped semiconductor element that is sensitive to radiation.

The semiconductor device is used by being substantially divided into a plurality of measurement sections corresponding to the individual slits formed in the horizontal grid.In other words, the radiation passing through the slits and entering the semiconductor device is Each time is measured independently.

Therefore, this slit substantially affects the resolution and positional measurement accuracy in radiation measurement.
Requires high precision machining.

Laser processing, etching, etc. have been commonly used to process radiation shielding grid plates having such slits.

Laser machining methods (such as laser machining) are difficult to process when processing materials with high radiation absorption rates, such as tungsten and lead, which can cause warping, distortion, etc. due to thermal effects, which can have an adverse effect on machining accuracy.

In the etching process, as shown in FIGS. 4(a) and 4(b), a slit 14 is formed by reducing the thickness of the substrate 13 made of tungsten to a thickness of 25 μm, which is less affected by side etching due to the etching process. By forming and simultaneously machining a plurality of arbitrarily determined reference holes 15 for positioning, the reference holes 15 for positioning and the base 1
The thickness of the radiation shielding plate is determined by stacking a plurality of substrates 13 to a predetermined thickness using positioning pins 17 provided at 6 and fixing them with adhesive.

Problems to be Solved by the Invention In this conventional grid plate manufacturing method, the thickness of the tungsten substrate must be 25 μm or less in order to prevent side etching that occurs during etching. Therefore, in order to obtain a radiation shielding effect. As shown in Figure 5, the width of the opening of the slit 14 in the substrate 13 is determined by the etching accuracy and mounting accuracy, so that the thickness of the grid plate is equal to the number of grid plates relative to the radiation energy. This reduces the radiation shielding effect and requires time for assembly.

Furthermore, tungsten is a hard and brittle material and has drawbacks such as chipping and cracking during installation and removal due to the influence of the accuracy of the dowel positioning holes and positioning pins.

The present invention (Table 1) An object of the present invention is to provide a method for manufacturing a radiation shielding grid plate that solves the above problems.

Means for Solving the Problems The present invention (1) In a method for manufacturing a grid plate having slits for shielding radiation, a mixture is prepared by mixing a fine powder obtained by pulverizing a material with a high radiation absorption rate into a fine powder, a resin, and a hardening agent. Then, the curing agent is cured and a radiation shielding grid plate is created by molding.

Functions of the present invention (mainly) Since a grid plate is obtained by molding using a fine powder material with high radiation absorption rate, side etching in the conventional etching method or thermal distortion in the laser processing method can be avoided. At the same time, a highly accurate grid plate with constant thickness, slit shape, and opening width required for radiation shielding can be obtained.

It is also possible to prevent chipping and cracking.

Furthermore, by varying the size of the fine powder, the filling rate of the mixture during molding can be increased, and the radiation shielding ability can be improved.

Example Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 (main) is a perspective view showing an embodiment of the method for manufacturing a radiation shielding grid plate of the present invention.

As shown in FIG. 1(a), an upper substrate 4 having an opening 3 at the center of the substrate is placed on a lower substrate 2 having convex portions 6 arranged at a constant pitch of 500 μm or less, so that the convex portions 6 A mold placed in the opening 3 is formed. A predetermined amount of mixture 1 is poured into this mold, and a squeegee 5 is used to uniformly fill the mixture with mixture 1.

Here, the mixture 1 (air) is a lead compound that has excellent radiation shielding effects due to its high mass. Tungsten, a tungsten compound, etc., is formed into a fine powder by a reduction method or an electrolytic method. It contributes to thermosetting and photocuring with the above fine powder. Vinyl double: Mixed with epoxy resin and curing agent, it is made into a cream.The mixture 1 is then cured with heat or light and released from the mold, as shown in Figure 2. Necessary for radiation shielding. A highly accurate grid plate 9 with a constant thickness, the shape of the slits 7, and the opening width 8 can be obtained. Also, chipping and cracking can be prevented due to the influence of positioning accuracy. 10 is a positioning hole, 11 is a positioning hole. The bottle 12 is attached with screws.

As shown in Figure 3, by making the fine powders of different particle sizes, the gap between the fine powders can be reduced and the filling rate when filling the mold with the mixture can be increased. , the radiation shielding effect of the resulting grid plate can be improved.

In addition, the effects of external noise can be prevented by mixing fine copper powder, which has an excellent electromagnetic shielding effect, with tungsten, a tungsten compound, etc., which has a high radiation absorption rate.

Effects of the Invention According to the present invention, it is possible to easily and accurately obtain the radiation shielding effect, which is reduced due to the influence of etching processing accuracy and mounting accuracy, etc., with respect to the thickness of the radiation shielding grid plate and the opening width of the slit. This also improves assembly work efficiency.

[Brief explanation of the drawing]

1...Mixing plate 2...Lower board 3...Opening plate
4... Upper substrate, 5... Squeegee, 6... Convex a
7... Slit, 8... Opening i9... Grid plate, 10... Positioning hole 11... Positioning pin,
12... Installation is with screws. Name of agent: Patent attorney Shigetaka Awano Figure 3 is an enlarged view of the mixture in the same example @ Figure 4 is a doctor explaining the method for manufacturing a radiation shielding grid plate in the conventional example Figure 5 is a sectional view of a conventional radiation shielding grid plate. Cause 8 Opening M2 Figure 7 Zrit 8 Opening width Figure 3

Claims (4)

[Claims] (1) In a method for manufacturing a grid plate with slits that shield radiation, a mixture of a fine powder obtained by pulverizing a material with high radiation absorption rate, a resin agent, and a hardening agent is poured into a mold, and then , a method for producing a radiation shielding grid plate by curing and forming a curing agent of the mixture. (2) Claim (1) characterized in that the fine powder contains any one of a lead compound, tungsten, and a tungsten compound.
Method for manufacturing the radiation shielding grid plate described (3) The method for manufacturing a radiation shielding grid plate according to claim (1), wherein the fine powder has different particle sizes. (4) The method for manufacturing a radiation shielding grid plate according to claim (1), wherein the fine powder contains fine copper powder.