JP2002093373A - Discharge lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a discharge lamp in which the possibilities of breakage of the quartz material are reduced by decreasing the thermal expansion of the terminal. SOLUTION: Plural holes 7d-2, 7d-4 are made respectively on the terminal disk parts 7a-2, 7a-4 and the volume of the terminal disk parts 7a-2, 7a-4 is made 80% or less of that of a conventional terminal disk parts. One circular groove 7d-3, 7d-5 is formed on the terminal disk parts 7a-3, 7a-5, respectively, and the volume of the terminal disk parts 7a-3, 7a-5 is made 80% or less of that of the conventional terminal disk part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-foil sealed discharge lamp for optically treating a work such as a semiconductor or a printed circuit board, and more particularly to a multi-foil sealed discharge lamp having reduced thermal expansion of a terminal.

[0002]

2. Description of the Related Art In general, a multi-foil sealed discharge lamp for optically processing a work such as a semiconductor or a printed circuit board has a structure of a sealing portion as shown in FIG. That is, in the discharge lamp 1, the sealing portions at both ends thereof (only one end is shown here) are such that the lead bar 3 of the electrode 2 is supported by the annular supporting glass 4, and the rear end of the lead bar 3 (the right end in the drawing) Is fitted into a fitting hole 5b at the front end of a glass core member (hereinafter, referred to as a bead bar) 5, and a metal foil 6 is provided on the outer peripheral side of the bead bar 5. The lead rod 3 is disposed so as to be in contact with the vicinity of the rear end. Further, the front end of the terminal 7 (the left end in the figure) is fitted to the fitting hole 5a at the rear end of the bead rod 5.
And the inner surface of the metal foil 6 is joined by electric spot welding to a side surface of a central disk portion (hereinafter, referred to as a terminal disk portion) 7a of the terminal. ing. In addition, a shaft portion (hereinafter, referred to as a terminal shaft portion) 7c which is a rear end of the terminal 7 and an external lead wire 8 are joined. A base portion 10 is fixed to the outer peripheral side of the sealing portion 1a and the terminal 7 via an insulating member 9.

The metal foil 6 is formed by bending the metal foil 6 along the end of the bead bar 5 so as to be in close contact with the shape of the bead bar 5 or by folding the metal foil in advance. The one that forms a song is used.

The dimensional range of the conventional terminal disk portion 7a is such that its thickness is t, its outer diameter is d, and the outer diameter of the bead rod 5 is D.
Then, it is preferable that t ≧ 3 (mm) and D ≧ d ≧ D / 2. The reason is described below.

If the thickness t of the terminal disk portion 7a is too small, the work becomes difficult due to the fact that the metal foil 6 and the terminal disk portion 7a are sandwiched between the electrodes of the spot welding machine and welded, so that the work becomes difficult and the welding is insufficient. The thickness of the terminal disk portion 7a is desirably 3 mm or more, because it causes a failure.

On the other hand, when the outer diameter d of the terminal disk portion 7a is larger than the outer diameter of the bead rod 5, the terminal 7 does not enter the base portion 10 or the sealing portion covering the base portion 10 and the terminal disk portion 7a. It is desirable that D ≧ d because the gap with 1a is reduced and it is difficult to ensure the positional accuracy between the discharge lamp arc point (between the cathode and the anode) with respect to the base portion 10.

On the other hand, if d is smaller than D / 2, the portion of the sealing portion 1a along the terminal disk 7a becomes thinner, which may cause problems such as breakage during subsequent work.
It is desirable that d ≧ D / 2.

[0008]

In a conventional multi-foil discharge lamp, all the quartz and metal materials constituting the discharge lamp expand due to heat during operation. At this time, the terminal 7 made of a metal material such as tungsten, tantalum, molybdenum, ruthenium, or rhenium or an alloy containing them also expands when the discharge lamp is turned on, similarly to the other parts of the metal. The volume of the terminal 7 is relatively larger than other metals, and the quartz material may be rarely damaged due to a difference in expansion coefficient from the quartz material covering the periphery of the terminal 7.

The present invention has been made in view of such circumstances, and has as its object to provide a discharge lamp with reduced thermal expansion of a terminal.

[0010]

According to the present invention, there is provided a discharge lamp comprising: an electrode; a lead rod formed at a base end side of the electrode; a bead tube for supporting the lead rod; A metal foil to be in contact with, a bead rod supporting the metal foil from the inside, a disk portion provided at a rear end of the bead rod, and abutting on an inner surface side of a rear end of the metal foil; and In a discharge lamp including a terminal having a shaft portion protruding toward an external lead wire side, by removing a part of the disc portion without changing the outer diameter of the disc portion, the disc portion is removed. Is characterized by a reduced volume. With this configuration, the thermal expansion of the terminal of the discharge lamp can be reduced.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a sectional view showing a structure of a sealing portion in a discharge lamp according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of the sealing portion, and FIG. 3 is a diagram showing a configuration example of a terminal disk portion. In these figures, FIG.
The same reference numerals as those used in FIG. 5 denote the same or corresponding components as those of the discharge lamp of FIG.

As shown in FIG. 1, a multi-foil sealed discharge lamp 1
Are an electrode lead bar 3 formed on the base end side of the electrode (anode or cathode) 2, a bead tube 4 made of quartz glass as a support cylinder for supporting the electrode lead bar 3, and a back of the bead tube 4. A plurality of metal foils 6 made of molybdenum which is a metal for sealing a discharge tube, a bead rod 5 supporting the metal foil 6 from the inside thereof, and a rear end of the metal foil 6, It comprises a terminal 7-2 fitted and supported by the bead rod 5, and an external lead wire 8 connected to the rear end of the terminal 7-2.

Further, as shown in FIG. 1, a terminal 7 fitted and supported by a bead rod 5 is a sealing portion of the discharge lamp 1.
It is covered with the glass member constituting 1a. A predetermined position on the outer peripheral surface of the sealing portion 1a is configured to be supported by a base (discharge tube cap) 10 via an insulating member 9. Further, although the configuration on the anode side is shown in the drawings, the configuration on the cathode side is the same.

Further, as shown in FIG. 1, the bead rod 5 has a fitting hole 5b for fitting and supporting the electrode lead rod 3 on its front end face, and has the terminal hole on its rear end face.
It has a fitting hole 5a for supporting 7-2.

As shown in FIGS. 1 and 2, the metal foil 6 is supported at regular intervals along the outer periphery of the bead bar 5, and both ends 6a of the metal foil 6 are It is provided so as to protrude from both ends of the bead rod 5.

Further, the terminal 7 is provided with a terminal disk portion 7a-2 formed at the center thereof and protruding from one end of the terminal disk portion 7a-2.
And the terminal disk portion, the fitting convex portion 7b-2 supported on the side
A terminal shaft portion 7c-2 is provided to protrude from the other end of 7a-2 and is connected to the external lead wire 8.

The terminal 7 is formed of a metal material such as tungsten, tantalum, molybdenum, ruthenium or rhenium, which is a high melting point metal, or an alloy containing them.

The terminal disk 7a-2 is shown in FIG.
As shown in (a), a plurality (eight in this case) of through-holes are made so that the volume of the terminal disk 7a-2 is smaller than the volume of the conventional terminal disk 7a. This volume is preferably less than 80% of the conventional one. In addition,
In FIG. 3 (a) and FIGS. 3 (b) to 3 (d) to be described later, the figure on the left side connected by a dashed line is the terminal disk portion 7a.
-2 is a cross-sectional view taken at the position passing through the center of the terminal in the vertical direction of the terminal, and the figure on the right is the terminal shaft 7c.
It is the figure seen from -2 side.

FIGS. 3B to 3D show another example of the structure of the terminal disk. Terminal 7-3 shown in Fig. 3 (b)
Is the terminal shaft in the terminal disk 7a-3
One circular groove 7d-3 is formed on the side of 7c-3.
Terminal 7-4 shown in Fig. 3 (c) is the terminal disk
This is one in which eight non-through holes 7d-4 are formed on the side of the terminal shaft 7c-4 in 7a-4. The terminal 7-5 shown in FIG. 3D has one circular groove 7d-5 formed on the side of the terminal shaft 7c-5 in the terminal disk portion 7a-5. These terminal disks 7a-3 ~ 7a
-5 is the volume of the terminal disk 7a-2 shown in FIG.
Similarly to the above, it is preferable to make it 80% or less of the conventional one.

Next, the effects of the discharge lamp of the present invention will be described with reference to FIG. 4 and Tables 1 to 3. FIG. 4 is a graph showing experimental data on the difference in thermal expansion between the conventional terminal and the terminal according to the embodiment of the present invention. The terminals used in this experiment are shown in Table 1 below. Here, the shape of the terminal is as shown in FIG.

[0021]

[Table 1]

In the graph of FIG. 4, the vertical axis shows the difference in outer diameter from the temperature rise of the terminal disk at normal temperature, and the horizontal axis shows the terminal temperature. According to the graph of the experimental data, the terminal temperature during the lighting of the discharge lamp is about 150 ° C.
Since it is 00 ° C, the expansion of the conventional product at this temperature is 1
If it is set to 00%, the expansion of a terminal having a volume of 90% is about 80%, and the expansion of a terminal having a volume of 80% is about 60%.
It turns out that it is about.

Table 3 below shows comparative data of a conventional multi-foil sealed discharge lamp having a terminal and a multi-foil sealed discharge lamp having a terminal according to an embodiment of the present invention. Specifically, for example, an electric lamp is lit for 1 hour in a state where an input that is about 1.2 times the normal value is given to a discharge lamp used under the condition 1 of the following Table 2 as in the condition 2 of the table 2, This graph shows the number of blinks when the quartz covering the outside of the terminal is broken when the discharge lamp is turned on again in the lighting state of the condition 2 of Table 2 30 minutes after the discharge lamp is turned off. Here, the base temperature and the terminal temperature in Table 2 show the temperature under each condition. At this time, two samples were prepared as the number of samples.

[0024]

[Table 2]

[0025]

[Table 3]

According to the experimental data shown in Table 3, the terminal disk can be flickered more times when the volume of the terminal disk is smaller than that of the conventional product. Also, at this time, the terminal disk portion whose volume is 80% can blink more times than the terminal disk portion whose volume is 90%, and the possibility of crack breakage due to heat during lighting is lower than that of the conventional terminal.

[0027]

As described above in detail, according to the present invention, the terminal disk can be removed by removing a part of the terminal disk without changing the outer diameter of the terminal disk in the discharge lamp. Since the volume has been reduced,
Thermal expansion of the terminal can be reduced. Thus, it is possible to provide an excellent discharge lamp in which the quartz material covering the periphery of the terminal is less likely to be damaged.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a structure of a sealing portion in a discharge lamp according to an embodiment of the present invention;

FIG. 2 is an exploded perspective view of a sealing portion in the discharge lamp according to the embodiment of the present invention;

FIG. 3 is a diagram showing a structure of a terminal in the discharge lamp according to the embodiment of the present invention;

FIG. 4 is a graph showing experimental data on the difference in thermal expansion between the conventional terminal and the terminal according to the embodiment of the present invention;

FIG. 5 is a sectional view showing a structure of a sealing portion in a conventional discharge lamp.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Discharge lamp 2 Electrode 3 Electrode lead rod 4 Bead tube 5 Bead rod 6 Metal foil 7 Terminal 7a Disk part 7d-2, 7d-4 Hole 7d-3, 7d-5 Groove

Claims (6)

[Claims] 1. An electrode, a lead rod formed on the base end side of the electrode, a bead tube supporting the lead rod, a metal foil in contact with a rear end of the bead tube, and a metal foil. A bead rod supported from the inside, a disc portion provided at the rear end of the bead bar, abutting against the inner surface of the rear end of the metal foil, and protruding from the disc portion to the external lead wire side. In a discharge lamp including a terminal having a shaft portion, without changing the outer diameter of the disk portion,
A discharge lamp characterized in that the volume of the disk portion is reduced by removing a part of the disk portion. 2. The discharge lamp according to claim 1, wherein one or more holes are formed in said disk portion. 3. The discharge lamp according to claim 1, wherein one or more grooves are formed in said disk portion. 4. The discharge lamp according to claim 2, wherein said hole is a through hole. 5. The discharge lamp according to claim 2, wherein the hole is formed on a surface of the disk on the side of the bead rod or on a surface opposite thereto. 6. The discharge lamp according to claim 3, wherein the groove is formed on a surface of the disk on the side of the bead rod or on a surface opposite thereto.