JPH0422283Y2 - - Google Patents

Description

[Detailed description of the invention] In the present invention, a film or thin plate coated with a measurement sample (hereinafter referred to as the sample base) is mounted on a sample stage, and the sample is exposed to radiation such as X-rays.
In a radiation-applied measurement device that measures the thickness of the sample, the concentration of required components, etc. from the spectrum of fluorescent The present invention provides an improved structure of a sample holding block used to suppress

The above-mentioned measuring device for analyzing the concentration and thickness of substances coated on the surface of photographic film, printed circuit boards, etc. is publicly known.To explain photographic film as an example, it is possible to analyze the state in which the photographic film is set on a sample stage. irradiate with X-rays, detect the fluorescent X-rays emitted, and measure the concentration of silver chloride coated from the fluorescent X-ray spectrum. Furthermore, during this measurement, in order to prevent the photographic film set on the sample stage from waving and to smooth the X-ray irradiated surface, a sample holding block made of an iron plate or the like is usually superimposed on the back of the photographic film as a weight. During X-ray irradiation, scattered X-rays or fluorescent X-rays enter from the sample holding block, so by measuring the interference components in advance, these can be removed and accuracy can be improved. I have to.

However, the film thickness of the photographic film used as a sample actually varies depending on the photographic manufacturer, and even within the same manufacturer, there are variations due to manufacturing errors, so the film thickness is not constant. The amount of X-rays that arrive changes, resulting in an increase or decrease in interference components, and the conventional method described above has the disadvantage that it is not possible to accurately measure the silver chloride concentration. In addition, as the film thickness changes, the intensity of scattered X-rays from the film itself changes, which also causes analysis errors.

The present invention was devised to solve these difficulties.The sample holding block is made of the same material as the sample base such as photographic film, and the block thickness is sufficiently large relative to the sample base thickness. By configuring this structure, the amount of change in the sample base thickness, which is a factor of analysis error, is made extremely small in proportion to the overall thickness between the sample base and the block, and the X-rays passing through the sample coating film are The purpose of this method is to eliminate analysis errors by giving substantially the same effect as using a sample base of infinite thickness for isoradiation.

Hereinafter, the details of the present invention will be explained based on the drawings.A sample stage 1 has an opening 2 for fitting a sample base 4 and a sample holding block inserted therein, and a lower edge of the opening 2 extends inwardly. A sample base 4 (for example, a photographic film) whose surface is coated with a sample 4a is hooked and set on this flange 3, and the sample is placed on top of the sample base 4 (for example, a photographic film). They are overlapped by a presser block 5, and the load prevents the sample base 4 from waving. This sample holding block 5 is made of the same material as that constituting the sample base 4 (for example, polyethylene resin), and its thickness D is sufficiently larger than the sample base thickness d (D >> d). . For example, when the sample base thickness d is 200 to 300 μm, the block thickness D is preferably 5 m/m to several tens of m/m. 4a shows a sample coated on the sample base 4. Furthermore, corresponding to sample stage 1,
A radiation generator 6, a fluorescent X-ray detector 7 for detecting fluorescent X-rays from the sample 4a, and a calculator that counts the concentration or thickness of a target substance (for example, silver chloride) from the output of the detector. It is equipped with 8.

In such a configuration, the X-ray generator 6
The sample 4a is excited by the X-rays 9 irradiated by the substance, and fluorescent X-rays 10 with energy specific to the substance and scattered X-rays from the sample 4a and the sample base 4 (not shown) are generated.
is generated and enters the fluorescent X-ray detector 7, and
A calculator 8 counts the output pulses of the fluorescent X-ray detector, and measures the concentration, thickness, etc. of the sample 4a. At this time, the interference components of the scattered X-rays or fluorescent X-rays from the sample holding block 5 as the background have been measured in advance, and by excluding these interference components in the fluorescent Analysis of the sample 4a, which is the objective described above, becomes possible. However, when the thickness d of the sample base 4 changes, the amount of X-rays absorbed by the sample holding block 5 changes, and the secondary excitation effect inside the sample base increases or decreases. Since the sample base thickness is significantly larger than the thickness d, and the variation Δd in the sample base thickness is extremely small with respect to the block thickness D, the relationship D>>d+Δd still holds, and the variation Δd is equal to D. Compared to this, the ratio is negligible. At the same time, since the sample holding block 5 is made of the same material as the sample base 4, in practice, for the X-rays that have passed through the sample 4a,
Regardless of the increase or decrease in the sample base thickness d, the same effect as using an infinitely thick sample base can always be obtained, and therefore the increase or decrease in interference components and the increase or decrease in secondary excitation effects can be avoided before they grow into analytical errors. However, accurate analysis results can be obtained.

It goes without saying that the present invention can be used to analyze samples other than photographic films and printed circuit boards, such as aluminum vapor deposited substances in capacitors, and can be applied to plating thickness gauges, and its uses are not particularly limited.

The present invention has been described above, and is capable of high-precision measurement of a target substance without being hindered by variations in sample thickness, and without requiring any operations or electronic circuits to eliminate analysis error factors. in,
It is extremely effective in practice.

[Brief explanation of drawings]

The drawing is a schematic diagram of an X-ray applied measurement device for explaining an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Sample stage, 2... Opening, 3... Flange part, 4... Sample base, 4a... Sample, 5... Sample holding block, 7... X-ray detector, 8... Computing unit, 9...Irradiation X-ray, 10...Fluorescent X-ray.

Claims (1)

[Scope of utility model registration request] In a radiation applied measurement device, a film or a thin plate coated with a measurement sample is mounted on a sample stage, the sample is irradiated with radiation, and necessary components of the sample are measured using fluorescent X-rays emitted by the sample. Alternatively, a sample holding block superimposed above the thin plate is made of the same material as the film or thin plate, and the block thickness is sufficiently large relative to the thickness of the film or thin plate,
A radiation applied measuring device characterized in that the sample holding block is also used as a member for eliminating analysis errors caused by changes in the thickness of the film or thin plate.