JP5254835B2 - Manufacturing method of electrode body for cold cathode lamp - Google Patents

Description

  The present invention relates to a method for manufacturing an electrode body for a cold cathode lamp used as, for example, a backlight of a liquid crystal screen.

  A liquid crystal display device such as a liquid crystal display used in a personal computer or a television basically has a liquid crystal panel provided with liquid crystal molecules whose arrangement and phase change when a voltage or electric field is applied, and light from the back surface of the liquid crystal panel. It consists of a backlight to irradiate.

  In general, a cold cathode lamp (CCFL: Cold Cathode Fluorescent Lamp), which is one of fluorescent tubes, is often used as such a backlight because it has a long lifetime and can be easily downsized.

  For example, Patent Document 1 discloses a cold cathode lamp electrode body including a cup-shaped electrode member disposed inside a glass tube and a sealing member sealed to the glass tube, and is used as the sealing member. It is described that after forming an oxide film on a wire in advance, a sealing member is formed by cutting the oxide film to a desired length, and the sealing member is joined to a cup-shaped electrode member by resistance welding. .

  Patent Document 2 discloses a cup electrode made of tungsten or molybdenum, a sealing member made of tungsten or molybdenum connected by welding to an outer end surface of the bottom of the cup electrode, and between the cup electrode and the sealing member. And an electrode body for a cold cathode lamp provided with a low-melting-point metal layer that melts during welding.

JP 2003-229060 A JP 2006-140129 A

  By the way, in the technique described in Patent Document 1, the joining between the cup electrode and the sealing member is performed by simple resistance welding. For this reason, there is no guarantee that sufficient bonding strength can be obtained between the cup electrode and the sealing member, and as a result, the reliability of the manufactured cold cathode lamp electrode body may be impaired.

  Further, the technique described in Patent Document 2 describes that resistance welding is performed using kovar (an alloy containing iron, nickel, and cobalt) on the low-melting-point metal layer provided between the cup electrode and the sealing member. ing. However, since the above-mentioned Kovar uses a very fine shape (foil shape made of a 0.6 mm square), it is difficult to handle, especially during the welding process between the cup electrode and the sealing member. It is not easy to place it precisely at a desired position between the electrode and the sealing member. In addition, when changing the size of the cup electrode or sealing member according to the specifications of the cold cathode lamp, it is necessary to change the shape of the Kovar accordingly, which is troublesome, reducing productivity and increasing costs. May cause.

  The present invention has been made in consideration of the above-described conventional problems, and can improve the bonding quality between the cup electrode and the sealing member, and can further improve the productivity. It aims at providing the manufacturing method of an electrode body.

  A manufacturing method of an electrode body for a cold cathode lamp according to the present invention includes a bottomed cylindrical cup electrode, a sealing member welded to a bottom outer end surface of the cup electrode, and a joint between the cup electrode and the sealing member. A cold-cathode lamp electrode body provided with a melting member that melts at the time of welding, wherein the wire-shaped melting member is formed on the outer end surface of the sealing member on the side joined to the cup electrode. Contacting one end side, joining the sealing member and the melting member by diffusion welding, and cutting the other end side of the melting member having one end side joined to the sealing member by a predetermined length; A step of bringing the other end side of the melting member into contact with the bottom outer end surface of the cup electrode, and joining the sealing member and the cup electrode by diffusion welding via the melting member. It is characterized by that.

  In addition, the manufacturing method of the cold cathode lamp electrode body according to the present invention includes a bottomed cylindrical cup electrode, a sealing member welded to the bottom outer end surface of the cup electrode, the cup electrode, and the sealing member. A cold-cathode lamp electrode body provided with a melting member that melts at the time of welding, wherein one end side of the wire-shaped melting member is applied to the outer end surface of the bottom of the cup electrode. Contacting the cup electrode and the melting member by diffusion welding, cutting the other end side of the melting member with one end side joined to the cup electrode by a predetermined length, and the sealing member A step of abutting the cut end of the melting member on the joining side outer end surface to the cup electrode, and joining the cup electrode and the sealing member by diffusion welding via the melting member. It is characterized by that.

  According to such a manufacturing method, by providing the step of cutting the other end side of the wire-shaped melting member whose one end side is joined to the cup electrode or the sealing member, it is provided between the cup electrode and the sealing member. The amount of the molten member to be produced can be adjusted easily and appropriately. Therefore, the quality and strength of diffusion welding between the cup electrode and the sealing member can be further improved. Furthermore, since the one end side can be easily positioned and joined to the cup electrode or the sealing member of the melting member, the productivity of the cold cathode lamp electrode body can be improved.

  In this case, when the melting member is used while being drawn out of the original fabric while being wound around the original fabric, it is necessary and sufficient for the end surface of the sealing member or the cup electrode. Can be arranged more easily and accurately, and the versatility of the melting member can be further improved.

  According to the present invention, the fusion provided between the cup electrode and the sealing member by cutting the other end of the wire-shaped melting member whose one end is joined to the cup electrode or the sealing member. The amount of the member can be adjusted easily and appropriately. Therefore, the quality and strength of diffusion welding between the cup electrode and the sealing member can be further improved. Furthermore, since the one end side can be easily positioned and joined to the cup electrode or the sealing member of the melting member, the productivity of the cold cathode lamp electrode body can be improved.

It is a partial cross section front view of the cold cathode lamp to which the electrode body for cold cathode lamps manufactured by the manufacturing method of the electrode body for cold cathode lamps concerning embodiment of this invention is applied. FIG. 2A is an explanatory view showing a melting member joining step for joining a wire-like melting member to the sealing member 18, and FIG. 2B is an explanatory view showing a state in which the melting member joining step has proceeded from the state shown in FIG. 2A. FIG. 2C is an explanatory view showing a melting member cutting step of cutting the melting member joined to the sealing member into a predetermined length, and FIG. 2D shows a state where the melting member cutting step shown in FIG. 2C is completed. It is explanatory drawing shown. FIG. 3A is an explanatory view showing a cup electrode joining step in which a sealing member to which a predetermined amount of molten members are joined and a cup electrode are joined to obtain an electrode body, and FIG. 3B is a cup electrode joining step shown in FIG. 3A. It is a front view of the electrode body formed by.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for manufacturing a cold cathode lamp electrode body according to the present invention will be described with reference to the accompanying drawings, referring to preferred embodiments in relation to the cold cathode lamp electrode body manufactured by this manufacturing method. To do.

  FIG. 1 is a partial cross-sectional front view of a cold cathode lamp 12 to which a cold cathode lamp electrode body 10 manufactured by a method for manufacturing a cold cathode lamp electrode body according to an embodiment of the present invention is applied.

  The cold cathode lamp 12 is, for example, a light source incorporated as a backlight of a liquid crystal display device, and includes a glass tube 16 having a phosphor layer 14 formed on an inner peripheral wall surface, and hemispherical ends of the glass tube 16. The cold cathode lamp electrode body 10 that functions as an introduction line and an electrode of the cold cathode lamp 12 is formed by sealing 16a, 16a penetrating in the axial direction. In the glass tube 16, for example, a gas (discharge sustaining medium) containing mercury or xenon is sealed at a predetermined pressure. Further, the glass tube 16 may be U-shaped or annular in addition to the straight tube.

  As shown in FIG. 1, the cold cathode lamp electrode body 10 (hereinafter also referred to as “electrode body 10”) is sealed to be welded to the glass tube 16 while penetrating through the end portions 16 a and 16 b of the glass tube 16. A sealing member (sealing metal) 18, a bottomed cylindrical cup electrode 20 joined to one end side of the sealing member 18 and enclosed in the glass tube 16, and the other end side of the sealing member 18 It is comprised from the lead wire 22 joined and connected to the external power supply which is not shown in figure by being arrange | positioned out of the glass tube 16. FIG.

  The sealing member 18 is a metal rod formed of molybdenum, tungsten, or the like, and is formed to have the same or slightly larger diameter as the lead wire 22. The sealing member 18 may be made of a material that is conductive and can secure sealing performance (sealing performance) at the welded portion with the glass tube 16.

  The cup electrode 20 is a metal cup formed of nickel, molybdenum, or the like, which has a bottomed cylindrical shape (cup shape) by press molding, and has a larger diameter than the sealing member 18.

  The lead wire 22 is composed of a thin wire, ie, a so-called dumet wire (jumet wire) in which a core material made of iron and nickel alloy is covered with a copper foil, and is connected to an external power source (not shown) as described above. Thus, electricity is supplied to the electrode body 10 (cup electrode 20).

  A method of manufacturing the cold cathode lamp electrode body 10 basically configured as described above will be described.

  First, the lead wire 22 is joined to one end surface in the axial direction of the sealing member 18 by diffusion welding, and these are formed as an integral part (see FIG. 2A). The joining of the lead wire 22 and the sealing member 18 may be performed in the final step of the method for manufacturing the electrode body 10 described below.

  Next, as shown in FIGS. 2A and 2B, a wire-shaped melting member 24 is joined to the other end surface of the sealing member 18 to which the lead wire 22 is joined (the outer end surface on the joining side with the cup electrode 20) by diffusion welding. A melting member joining step is performed. The melting member 24 is a so-called binder that is used to improve the bonding quality (bonding strength) when the sealing member 18 and the cup electrode 20 are bonded. As the melting member 24, for example, an alloy containing iron, nickel and cobalt (Fe—Ni—Co alloy), so-called Kovar (for example, trade name “KOV” manufactured by Toshiba Materials) is used.

  In the melting member joining step, first, as shown in FIG. 2A, the sealing member 18 is clamped by one electrode 26a constituting the diffusion welding apparatus 26, and the melting member wound around the original fabric 28 by the other electrode 26b. The vicinity of the tip of 24 is clamped. A wire-shaped melting member 24 is wound on the original fabric 28 by a predetermined length, and is held by a holder (not shown) in a state of being freely rotatable in the drawing direction of the melting member 24.

  Subsequently, as shown in FIG. 2B, the electrode 26b clamping the melting member 24 extending from the original fabric 28 is moved to the electrode 26a side clamping the sealing member 18, and the melting member 24 is moved to the original fabric 28. The power source 30 is energized after the tip of the melting member 24 is brought into contact with the end surface of the sealing member 18 while being pulled out from the power source. Thereby, the melting member 24 and the sealing member 18 are joined by diffusion welding at the joining point A1.

  Next, as shown in FIG. 2C and FIG. 2D, a melting member cutting step is performed in which the melting member 24 that is joined to the sealing member 18 at the joining point A1 and protrudes from the end surface of the sealing member 18 is cut to a predetermined length. Do.

  In the melting member cutting step, first, the sealing member 18 to which the melting member 24 is joined as described above is clamped by one chuck 32a constituting the cutting device 32, and the melting member 24 is joined by the other chuck 32b at the joining point A1. And clamped at a position separated by a predetermined length. Next, the fusion member 24 fixed and held by the chucks 32a and 32b is cut at a predetermined length L from the joining point A1 by the cutter (cutting means) 32c of the cutting device 32. As a result, as shown in FIG. 2D, a sealing member 18 is formed in which a melting member 24 having a predetermined length L is joined to one end face and a lead wire 22 is joined to the other end face.

  The cutting device 32 is not necessarily configured separately from the diffusion welding device 26. For example, the cutter 32c constituting the cutting device 32 is mounted on the diffusion welding device 26, and the electrode 26a of the diffusion welding device 26, While the sealing member 18 and the melting member 24 are clamped and joined at 26b, the melting member 24 may be cut by the cutter 32c.

  Next, as shown in FIGS. 3A and 3B, a cup electrode joining step is performed in which the sealing member 18 to which a predetermined amount of the melting member 24 is joined and the cup electrode 20 are joined to obtain the electrode body 10.

  In the cup electrode joining step, as shown in FIG. 3A, the sealing member 18 is clamped by one electrode 34a constituting the diffusion welding apparatus 34, and the cup electrode 20 is clamped by the other electrode 34b. The diffusion welding device 34 may use again the diffusion welding device 26 used in the above-described melting member joining step.

  Subsequently, the electrode 34b clamping the cup electrode 20 is moved to the side of the electrode 34b clamping the sealing member 18, and the melting member 24 is pressed and crushed by the bottom outer end surface of the cup electrode 20, while the cup electrode 20 At 20, the sealing member 18 is pressurized and the power source 36 is energized.

  As a result, as shown in FIG. 3B, the cup electrode 20 and the sealing member 18 are joined by diffusion welding at the joining point A2 via the melting member 24, and the cold cathode lamp electrode body 10 according to the present embodiment is obtained. It is formed. Thereafter, in order to manufacture the cold cathode lamp 12, a process of sealing the electrode body 10 manufactured as described above with the glass tube 16 may be performed.

  As described above, according to the manufacturing method of the cold cathode lamp electrode body according to the present embodiment, the one end side of the wire-shaped melting member 24 is applied to the outer end surface of the sealing member 18 on the joining side to the cup electrode 20. A fusion member joining step in which the sealing member 18 and the fusion member 24 are joined by diffusion welding, and the other end side of the fusion member 24 joined to the sealing member 18 at one end side at the joining point A1 And the other end side (cut portion) of the melting member 24 is brought into contact with the outer end surface of the bottom portion of the cup electrode 20, and the sealing member 18 and the cup are interposed via the melting member 24. The electrode body 10 is manufactured by performing the cup electrode joining process which joins the electrode 20 by diffusion welding.

  That is, in this embodiment, the wire-shaped (linear) melting member 24 is brought into contact with and joined to the end surface of the sealing member 18 while being pulled out from the original fabric 28. Therefore, it is possible to easily and stably position the melting member 24 at a predetermined position (joining point A1) on the end face of the sealing member 18 in a state where the melting member 24 is clamped by the electrode 26b. 18 can be joined very easily and accurately by diffusion welding. Therefore, unlike the prior art described in Patent Document 2, it is not necessary to dispose the minute foil-shaped melting member 24 on the end face of the sealing member 18, and the melting member joining step and the subsequent cup electrode joining step. It is possible to simplify and improve the efficiency and improve the welding quality and welding strength. Further, since the melting member 24 can be easily positioned on the end face of the sealing member 18, it is possible to easily cope with the downsizing of the sealing member 18 and the cup electrode 20, that is, the further downsizing of the electrode body 10. be able to.

  In this case, the melting member 24 is directly pulled out from the raw fabric 28 and cut at a predetermined length L in the melting member cutting step, so that the necessary and sufficient amount on the end face of the sealing member 18 can be more easily obtained. And since it can arrange | position correctly, the quantity (volume) of the fusion | melting member 24 required at a subsequent cup electrode joining process can be adjusted easily. That is, the amount of addition of the melting member 24 can be easily changed simply by adjusting the cutting position with the cutter 32c, and the size of the joining point A2 between the sealing member 18 and the cup electrode 20, that is, various types The large-sized electrode body 10 can be manufactured using the common melting member 24, and productivity and manufacturing cost can be reduced. Further, for example, the wire-shaped melting member 24 formed of Kovar is cut by the cutter 32c, so that the quality of the cut surface that comes into contact with the end surfaces of the cup electrode 20 and the sealing member 18 is improved. As a result, the bonding strength between the cup electrode 20 and the sealing member 18 can be improved.

  In the above embodiment, the melting member 24 is first bonded to the sealing member 18 and cut, and then the cup electrode 20 is bonded. For example, the melting member 24 is first bonded to the cup electrode 20. After cutting at a predetermined length L, the sealing member 18 may be joined.

  The present invention is not limited to the above-described embodiment, and it goes without saying that various configurations can be adopted without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Electrode body for cold cathode lamps (electrode body) 12 ... Cold cathode lamp 16 ... Glass tube 18 ... Sealing member 20 ... Cup electrode 22 ... Lead wire 24 ... Melting member 26, 34 ... Diffusion welding apparatus 26a, 26b, 34a 34b ... Electrode 28 ... Raw fabric 30, 36 ... Power source 32 ... Cutting devices 32a, 32b ... Chuck 32c ... Cutter

Claims (3)

A bottomed cylindrical cup electrode;
A sealing member welded to the bottom outer end surface of the cup electrode;
A fusion member provided at a joint between the cup electrode and the sealing member, and melted during welding;
A method for producing a cold cathode lamp electrode body comprising:
A step of bringing one end side of the wire-shaped melting member into contact with an outer end surface of the sealing member on the side of joining to the cup electrode, and joining the sealing member and the melting member by diffusion welding; and
A step of cutting the other end side of the melting member having one end side joined to the sealing member by a predetermined length;
A step of bringing the other end side of the melting member into contact with the bottom outer end surface of the cup electrode, and joining the sealing member and the cup electrode by diffusion welding via the melting member;
A method for producing an electrode body for a cold cathode lamp, comprising: A bottomed cylindrical cup electrode;
A sealing member welded to the bottom outer end surface of the cup electrode;
A fusion member provided at a joint between the cup electrode and the sealing member, and melted during welding;
A method for producing a cold cathode lamp electrode body comprising:
A step of bringing one end of the wire-shaped melting member into contact with the bottom outer end surface of the cup electrode, and joining the cup electrode and the melting member by diffusion welding;
Cutting the other end side of the melting member having one end side joined to the cup electrode by a predetermined length;
The other end side of the melting member that is cut is brought into contact with the outer end surface of the sealing member joined to the cup electrode, and the cup electrode and the sealing member are connected by diffusion welding via the melting member. Joining, and
A method for producing an electrode body for a cold cathode lamp, comprising: In the manufacturing method of the electrode body for cold cathode lamps of Claim 1 or 2,
The method for producing an electrode body for a cold cathode lamp, wherein the melting member is used while being wound around a raw material while the one end side is drawn directly from the raw material.

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