KR20090064280A - Discharge lamp and manufacturing method thereof - Google Patents

Abstract

A discharge lamp and a manufacturing method thereof are provided to prevent a lighting error due to a crack thereof by forming a solder layer with a solder dipping process to suppress compressive strain to a circumferential direction of a discharge chamber. A discharge lamp includes a discharge vessel(1), a metal, and a solder layer(4). The inside of the discharge vessel is filled with a discharge medium. The discharge vessel including the discharge medium is sealed. The metal and the solder layer are formed at an end of the discharge vessel. The solder layer is covered with the metal. The compressive strain remains in a circumferential direction on the predetermined position of the discharge vessel on which the metal is formed. The compressive strain remains in a tubular axis direction on the predetermined position of the discharge vessel.

Description

DISCHARGE LAMP AND MANUFACTURING METHOD THEREOF {DISCHARGE LAMP AND MANUFACTURING METHOD THEREOF}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge lamp used as a light source of a backlight such as a liquid crystal television or a laptop and a manufacturing method thereof.

An example of a light source used for a backlight of a liquid crystal display is an outer electrode discharge lamp. The external electrode discharge lamp has external electrodes formed at both ends of a discharge vessel in which a discharge medium is encapsulated therein, and a phosphor layer is formed on the inner wall of the tube, and power can be supplied between the external electrodes to obtain visible light. It is a lamp. Conventionally, the solder electrode which was easy to manufacture at low cost as described in Unexamined-Japanese-Patent No. 2004-146351 was used for this external electrode.

However, the solder electrode has problems such as poor contact due to peeling of the solder and deterioration in heat dissipation. Therefore, in recent years, the sleeve-like or cap-shaped overlapping metals described in Japanese Unexamined Patent Publication No. 2007-134289, Japanese Unexamined Patent Publication No. 2004-179059, and Japanese Unexamined Patent Publication No. 2006-114271 have been used for the discharge vessel. An outer electrode discharge lamp provided at the end has been proposed.

However, in the discharge lamp using multiple metals, such as Unexamined-Japanese-Patent No. 2007-134289, Unexamined-Japanese-Patent No. 2004-179059, and 2006-114271, a lighting failure generate | occur | produces. When the lighting failure was investigated, it was found that the cracks formed in the discharge vessel portion where the stacked metal was formed were the cause.

An object of the present invention is to provide a discharge lamp in which the lighting failure due to the crack of the lamp is suppressed.

In order to achieve the above object, the discharge lamp of the present invention comprises a discharge container in which a discharge medium is enclosed therein, and a stacked metal and a solder layer provided at an end of the discharge container, wherein the solder layer covers the stacked metal. It is formed so that it may be characterized in that the compression deformation remains in the circumferential direction in the portion of the discharge vessel in which the stacked metal is formed.

Moreover, the manufacturing method of the discharge lamp of this invention is a process of forming the discharge container in which the discharge medium was enclosed inside, and attaching the composite metal which has a thermal expansion coefficient larger than the thermal expansion coefficient of the said discharge container to the edge part of the said discharge container. And a step of forming the solder layer by solder dipping so as to cover the stacked metal, and retaining compressive strain in at least the circumferential direction of the discharge vessel.

According to this invention, the lighting failure by the crack of a lamp can be suppressed.

(Best form for carrying out the invention)

(1st embodiment)

EMBODIMENT OF THE INVENTION Hereinafter, the discharge lamp of embodiment of this invention is demonstrated with reference to drawings. 1 is an overall view for explaining a discharge lamp of a first embodiment of the present invention.

The container of a discharge lamp is comprised by the discharge container 1 which consists of soft glass, for example. The discharge container 1 is an elongate cylindrical shape in which both ends are sealed by sealing, and a discharge space 11 is formed therein. The discharge space 11 is filled with a discharge medium made of mercury (Hg) and rare gas. Here, a mixed gas of neon (Ne) and argon (Ar) is suitable as the rare gas. Moreover, the phosphor layer 2 is formed in the inner surface of the discharge container 1 at least in the range which covers the light emitting area | region of a lamp | ramp. As the phosphor layer 2, a three-wavelength phosphor in which RGB is mixed in addition to the short-wavelength phosphor that emits light at R (red), G (green), and B (blue) can be used according to the intended use.

At both ends of the discharge vessel 1, a cylindrical metal 3 and a solder layer 4 are formed as stacked metals. In detail, the solder layer 4 is formed so that the cylindrical metal 3 may be covered, and the cylindrical metal 3 is covered with the solder layer 4 both inside and outside. However, the metal 3 does not necessarily need to be completely covered by the solder layer 4, and a part thereof may be exposed externally.

As shown in FIG. 2A, the tubular metal 3 is originally a plate-shaped foil having a thickness of 0.05 to 0.20 mm, which is composed of a plate-shaped portion 31 and a tongue piece portion 32. Iii) It is a metal plate. 2, the plate-shaped portion 31 is rounded in a cylindrical shape so that portions of both ends thereof overlap, and the tongue section portion 32 is bent almost perpendicularly to the surface of the plate-shaped portion 31. Formed. At this time, the R portion 311 is formed in each portion on the central side in the tube axis direction which overlaps when the plate-shaped portion 31 is rounded. When the cylindrical portion 3 is mounted on the discharge vessel 1, the R portion 311 makes it difficult to produce each portion that tends to be the starting point of the corona discharge due to the electric field concentration, thereby suppressing ozone generation.

In addition, the surface of the cylindrical metal 3 is previously subjected to metal plating selected from copper, tin, zinc, silver, gold and nickel. As a result, the solder layer 4 between the discharge vessel 1 and the cylindrical metal 3 enters well, and the filling rate of the solder can be improved.

In addition, the "exposed metal" means that it is a metal of the shape which covers at least most of the circumference of the discharge container 1, for example, 70% or more of the circumference. That is, when the thin metal plate is wound to form the tubular metal 3, parts thereof do not necessarily overlap as in the present embodiment, and the C-shaped tubular shape may be separated without overlapping ends. Examples of the material of the tubular metal 3 include metals or alloys selected from iron, nickel, copper, cobalt, and chromium.

In addition, as the material of the solder layer 4, a special solder having excellent adhesion with glass containing tin, an alloy of tin and indium, an alloy of tin and bismuth, and antimony, zinc, aluminum, etc., or general solder having excellent adhesion to metals Can be used. Here, "solder which is excellent in adhesiveness" means solder which adheres to the material to such an extent that these interfaces cannot be easily separated when solder is formed in the material.

Here, the discharge container 1, the cylindrical metal 3, and the solder layer 4 will be described in detail with reference to FIG. 3 is a view for explaining the end of the discharge lamp, Figure 3 (a) is a cross-sectional view taken along line XX 'shown in Figure 1, Figure 3 (b) is an enlarged view of the range (Y). In addition, the arrow in the figure shows the direction of deformation.

As can be seen from FIG. 3, tensile strain α in the radial direction of the discharge vessel 1 remains and compressive strain β in the circumferential direction. The crack of the lamp | ramp is suppressed by the compression deformation (beta) which remained in the circumferential direction of this discharge container 1. This prevents damaged openings when compression metals such as tubular metals 3 and the like are mounted on the surface of the discharge vessel 1 or against damage occurring during lighting, thereby preventing the openings from being damaged and preventing growth in a thick direction. I think it is. As a result, it is possible to suppress the lighting failure in order to suppress the leakage of the discharge medium sealed in the damage to the discharge space 11.

In addition, the compressive strain γ remains in the tube axis direction of the discharge vessel 1, and the crack of the lamp is also suppressed by the compressive strain γ. This is also for the same reason as above.

Here, the formation method of the cylindrical metal 3 and the solder layer 4 to the discharge container 1 is demonstrated.

First, the discharge container 1 which encloses a discharge medium inside, and apply | coated the fluorescent substance layer 2 on the inner wall surface is produced, and the cylindrical metal 3 as shown in FIG.2 (b) is produced. . Subsequently, the opening side of the cylindrical metal 3 is placed upward, and the end of the discharge vessel 1 is inserted into the opening. At this time, if the inner diameter of at least a part of the cylindrical metal 3 is formed to be somewhat smaller than the outer diameter of the discharge container 1, the discharge container 1 will be press-fitted into the cylindrical metal 3, so that the cylindrical metal The pressure vessel from (3) enables the discharge vessel 1 to be fixed and held.

Then, the solder layer 4 is formed so that the cylindrical metal 3 may be covered by the solder dipping which immerses the edge part of the discharge container 1 in which the cylindrical metal 3 was formed in the solder tank filled with molten solder from above. . At this time, it is more preferable to perform so-called ultrasonic solder dipping, which is immersed in the molten solder in the state of ultrasonic vibration by the ultrasonic vibrator described in JP-A-2004-146351. Since the solder layer 4 can be filled even in the minute gap between the discharge container 1 and the cylindrical metal 3 by performing ultrasonic solder dipping, the effective contact area of the discharge container 1 and the solder layer 4 is effective. This is because it is enlarged and connected to the reduction of the lamp voltage.

In addition, when the ultrasonic solder dipping is performed, the cylindrical metal 3 is easily shifted to the upper side, that is, the cylindrical metal 3 is shifted to the center side in the tubular direction of the discharge vessel 1, but in this embodiment, the cylindrical shape Since the tongue piece part 32 of the metal 3 contacts the edge part of the discharge container 1, relative shift | offset | difference is prevented and the mounting position precision of the cylindrical metal 3 with respect to the discharge container 1 can be improved.

In addition, by performing the air drying step after the solder dipping step, the surface of the solder layer 4 becomes smooth, and the shape of the unevenness in which the voltage concentrates is suppressed, so that ozone generation due to corona discharge can be suppressed.

Subsequently, an example of a method of forming the compressive strain β in the circumferential direction of the discharge vessel 1 and the compressive strain γ in the tube axis direction will be described with reference to the manufacturing method. When the thermal expansion coefficient of the cylindrical metal 3 is made larger than the thermal expansion coefficient of the discharge vessel 1, the solder layer 4 formed so as to cover the cylindrical metal 3 is formed into a cylindrical metal ( 3) heat shrinks in the inner direction of the discharge vessel 1, so that the tensile strain α remains in the radial direction of the discharge vessel 1, the compressive strain β remains in the circumferential direction, and compressive strain in the tube axis direction. (γ) remains.

At this time, the stronger the tensile strain in the radial direction, the stronger the compressive strain in the circumferential direction and the tubular direction, so that the strength of the strain can be adjusted by adjusting the thermal expansion coefficients of the discharge vessel 1 and the cylindrical metal 3.

In addition, the kind of residual strain and its stress value cut a portion of the discharge vessel 1 in which the tubular metal 3 and the solder layer 4 are formed perpendicularly to the tube axis direction, and the cross section is sharp. Judgment and measurement are possible by observing by a color plate method (a method of identifying the state of deformation occurring in glass by the optical path difference of light).

(Example)

An example of the discharge lamp of this embodiment is shown below. In addition, unless otherwise indicated, the test demonstrated below is performed based on this specification.

Discharge vessel 1; ER-N (soft glass made by Nippon Denki Glass Co., Ltd.), thermal expansion coefficient = 76 x 10 ^-7 / deg. C, total length = 960 mm, outer diameter = 3.4 mm, inner diameter = 2.4 mm, compression deformation in the circumferential direction ( β) (stress value = 40.2 kgf / cm 2), compressive deformation (γ) in the tube axis direction,

Discharge medium; Mercury (Hg), neon (Ne) and argon (Ar) mixed gas = 60torr,

Phosphor layer 2; Rgb, three wavelength phosphor,

Cylindrical metal (3); 50 alloy (nickel = 50%, iron = 50%), thermal expansion coefficient = 90 × 10 ⁻⁷ / ° C., thickness = 0.1 mm, silver plating on the surface,

Solder layer 4, cera solder (solder, tin-zinc-antimony, 94-96%, 3-5%, 1-3%, respectively) according to the registered trademark of Kuroda Techno Co., Ltd., total length = 25mm.

When the lighting test was done for 30 lamps of this example, no cracks occurred in all the lamps even after 3000 hours and no lighting failure was reached.

In general, it is assumed that the cracking of the lamp is caused by the stress generated between the discharge vessel 1 and the tubular metal 3. For this reason, it is common to make the design which stress does not produce, such as making the thermal expansion coefficient of the discharge container 1 and the cylindrical metal 3 the same.

However, although the lamp of the example was a design in which stress remained, no cracking of the lamp occurred. This is considered to be because the compressive strains β and γ remaining in the circumferential direction and the tube axis direction of the discharge vessel 1 also act to suppress cracking. This is because, as described above, the compressive strains β and γ prevent openings of damage occurring on the surface of the discharge vessel 1 and prevent growth in the thick direction.

In addition, in order to acquire the effect of such a crack suppression, it is preferable that the stress value is higher to some extent, and it is preferable that the compressive deformation (beta) of the circumferential direction is 10 kgf / cm <2> or more specifically ,.

Then, the kind of deformation | transformation at the time of changing the material of the discharge container 1 and the cylindrical metal 3 was confirmed. The result is shown in FIG. Here, PS-94 is a soft glass made by Nippon Denki Glass Co., Ltd., and BKU is a soft glass made by Nippon Denki Glass Co., Ltd., and 42 aloe refers to an alloy of nickel = 42% and iron = 58%.

As can be seen from the results, in Examples 1 and 2, compressive strain remains in the radial direction of the discharge vessel 1 in the radial direction, and in the circumferential direction and the tube axis direction, and in Comparative Examples 3 and 4, the inverse strain , In Comparative Examples 5 and 6, almost no deformation remains. For this reason, it turns out that the deformation control greatly influences the coefficient of thermal expansion of the discharge vessel 1 and the cylindrical metal 3. Therefore, it is preferable to keep compressive strain in the circumferential direction and the tube-axis direction of the discharge vessel 1 by using a metal material whose thermal expansion coefficient of the cylindrical metal 3 is larger than that of the discharge vessel 1.

However, since the thickness of the cylindrical metal 3, the thermal expansion coefficient of the solder alloy constituting the solder layer 4, and the like are somewhat affected, it is more preferable to consider them and adjust them appropriately. In addition, when the lighting test was done about the lamp of an Example and a comparative example, it was Examples 1 and 2 that were effective about a crack.

On the other hand, if the compressive deformation β in the circumferential direction of the discharge vessel 1 is too strong, it may cause cracking. According to the inventor's test, when the stress value became higher than 80 kgf / cm <2>, it became easy to produce a crack. Therefore, it is preferable to design so that the stress value of the compressive deformation (beta) of the circumferential direction of the discharge container 1 may be 80 kgf / cm <2> or less, More preferably, 60 kgf / cm <2> or less. For this purpose, 42 alloys, 50 alloys, 52 alloys (nickel = 52%, iron = 48% alloy), 426 alloys (nickel = 42%, chromium 6%, iron = 52% alloy) are used in the glass constituting the discharge vessel. And other metals having a coefficient of thermal expansion such as 476 alloy (nickel = 47%, chromium 6%, iron = 47% alloy).

Moreover, the structure of this invention is especially effective when the solder layer 4 uses the special solder which is excellent in adhesiveness with glass like Example. When such a solder is used, the solder is in close contact with the discharge vessel 1 and the tubular metal 3, thereby enabling a firm connection, and it becomes difficult for the tubular metal 3 to be separated from the discharge vessel 1. On the other hand, it is because a gap is hardly formed between them, and strong stress tends to occur. That is, the present invention can realize a lamp in which the connection between the discharge vessel 1 and the tubular metal 3 is strong and hard to crack when such solder is used.

Therefore, in the first embodiment, compressive deformation (in the circumferential direction of the discharge container 1 in which the solder layer 4 is formed so as to cover the cylindrical metal 3 having a larger thermal expansion coefficient than the thermal expansion coefficient of the discharge vessel 1) By remaining the compressive strain γ in the tube axis direction, the compressive strains β and γ act so as to suppress cracking, so that lighting failure due to cracking of the lamp can be suppressed. At this time, the stress value of the compressive strain β is preferably 10 to 80 kgf / cm 2.

(2nd embodiment)

It is a figure for demonstrating the discharge lamp of 2nd Embodiment of this invention. About each part of subsequent embodiment, the same part as each part of the discharge lamp of 1st embodiment is shown with the same code | symbol, and the description is abbreviate | omitted.

In this embodiment, the electrode mount 5 which consists of the cup electrode 51, the inner lead 52, the outer lead 53, and the bead glass 54 is sealed by the both ends of the discharge container 1, The outer lead 53 protruding outward from (1) and the tubular metal 3 formed on the outer surface of both ends are electrically connected through the solder layer 4. That is, although the first embodiment is configured as an external electrode discharge lamp, in the present embodiment, the internal electrode discharge in which the cup electrode 51 acts as the electrode, the tubular metal 3, and the solder layer 4 as the power supply portion. It is a lamp.

In the lamp of this embodiment, compressive strains β and γ can be retained in the circumferential direction and the tube axis direction by using, for example, 50 alloys as the BKU and the cylindrical metal 3 as the discharge vessel 1.

Therefore, also in 2nd embodiment, the lighting failure by the crack of a lamp can be suppressed similarly to 1st embodiment.

As mentioned above, although this invention was demonstrated in detail based on embodiment of this invention, taking a specific example as an example, this invention is not limited to the said content, All the deformation | transformation and a change are possible as long as it does not deviate from the range of this invention.

The cross-sectional shape of the discharge vessel 1 is not limited to a perfect circle, but may be an ellipse, a flat portion having a straight portion in part. For example, you may use the cap metal 3 of an opening state with a bottom like FIG.

Further, as shown in FIG. 7, the slope 312 is formed on the edge of the tubular metal 3 formed as the stacked metal by polishing, so that the end portion of the solder layer 4 in the tube axis direction center side is sloped on the discharge container 1. (slope) can be formed. In this case, ozone generation by corona discharge can be suppressed more effectively.

In addition, in the formation process of the cylindrical metal 3 and the solder layer 4 to the discharge container 1, as shown in FIG. 8, the cylindrical metal 3 partially contacts with the discharge container 1, and others. After attaching without contact, the gap 6 is formed between the discharge vessel 1 and the solder layer 4 can be formed. This makes it easier for solder to enter between the discharge vessel 1 and the tubular metal 3 through the gap 6, so that the filling rate of the solder can be increased.

1 is an overall view for explaining a discharge lamp of a first embodiment of the present invention;

2 is a diagram for explaining a tubular metal;

3 is a view for explaining the end of the discharge lamp,

4 is a diagram for explaining deformation when changing materials of a discharge vessel and a cylindrical metal;

5 is a view for explaining a discharge lamp in a second embodiment of the present invention;

6 is a view for explaining Modification Example 1 of the present invention;

7 is a view for explaining a second modification of the present invention, and

8 is a diagram for explaining a third modification of the present invention.

* Explanation of symbols for the main parts of the drawings

1: discharge vessel 2: phosphor layer

3: cylindrical metal 4: solder layer

Claims (5)

A discharge vessel in which a discharge medium is sealed therein, and Provided with an overlapping metal and a solder layer provided at an end of the discharge vessel; And said solder layer is formed so as to cover said overlapping metal, and compressive deformation remains in the circumferential direction in the portion of said discharge container in which said overlapping metal is formed. The method of claim 1, A discharge lamp, characterized in that compressive strain remains in the direction of the tube axis in the discharge vessel portion where the stacked metal is formed. The method according to claim 1 or 2, The thermal expansion coefficient of the said laminated metal is larger than the thermal expansion coefficient of the said discharge container, The discharge lamp characterized by the above-mentioned. A process of forming a discharge vessel in which a discharge medium is enclosed therein, Attaching a composite metal having a thermal expansion coefficient greater than that of the discharge vessel to an end of the discharge vessel, and And forming the solder layer by solder dipping so as to cover the stacked metal, and retaining compressive strain at least in the circumferential direction of the discharge vessel. The method of claim 4, wherein And said solder layer is formed by ultrasonic solder dipping.

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