JP6292535B2 - Outer sphere sealed LED lamp and manufacturing method thereof - Google Patents

Description

  The present invention relates to an outer sphere sealed LED lamp and a method for manufacturing the same.

  In general, incandescent lamps, fluorescent lamps, HID (High Intensity Discharge) lamps, and LED (Light Emitting Diode) lamps have been sequentially developed and put into practical use as illumination lamps. The LED lamp is a lamp using a light emitting diode element as a light source. LED lamps are capable of emitting white light due to the development of blue LED elements, and have low power consumption, so that their use as an illumination lamp is expanding.

  1A to 1C are diagrams illustrating an example of an LED lamp 100 that is currently widely sold. These LED lamps 100 are generally lamps having an output of 10 W or less (typically about 7 W). As shown in FIGS. 1A to 1C, there are various lamp shapes, but basically, the cap 102, the heat radiating portion 104, and the globe 106 are formed. The heat dissipating part 104 is formed from aluminum die-casting, and in many cases, heat dissipating fins are formed on the outer peripheral surface. The globe 106 is made of a translucent resin.

  Unlike incandescent bulbs, fluorescent lamps, HID lamps, and the like, LED elements are semiconductor elements, so there is basically no need to arrange them in a vacuum atmosphere or a predetermined gas atmosphere. Accordingly, the aluminum die cast part 104 and the globe 106 are fixed with an appropriate adhesive. That is, the internal space formed by the aluminum die cast part 104 and the globe 106 is not hermetically sealed between the lamp external space.

  The present inventors are aware that the following prior patent documents related to the present invention exist.

JP 2012-156036 "LED lamp" (release date: 2012/08/16) Applicant: Iwasaki Electric Co., Ltd. WO 2012/095931 “Lamp and Lighting Device” (International Publication Date: 2012/07/19) Applicant: Panasonic Corporation

  The LED element is a semiconductor element, and has a close relationship between the temperature of the semiconductor junction and the element lifetime. That is, when the temperature of the joint portion of the LED element at the time of use is relatively low, the element lifetime becomes long, but as the temperature increases, the element lifetime decreases rapidly. Therefore, in the LED lamp, the cooling means is an important matter.

  According to the above-mentioned patent document 1, the present applicant has proposed an LED lamp in which a cooling gas is sealed in a hermetically sealed outer sphere. Regarding this invention, it is confirmed that there is a certain cooling effect, and the effect is shown in a graph in FIG.

  In such an outer bulb-sealed LED lamp, since the LED module has a constant weight, for example, the mount weight is relatively heavy compared to a conventional HID lamp. Since the support is used as the power supply line, the structure in which the LED module is fixed to the support and the support is fixed to the stem lead may cause a problem in the stability of the mount structure.

  SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a novel outer sphere sealed LED lamp that stably holds a relatively heavy LED module and has a mount structure with good workability in manufacturing the lamp, and a method for manufacturing the same. And

  An LED lamp according to the present invention includes a plurality of LED modules each having a plurality of LED elements mounted thereon, a column holding the plurality of LED modules, and surrounding the plurality of LED modules and the column. A glass outer sphere that is hermetically sealed, the column is fixed to the stem body by a metal band, and a metal tube is welded to the tip of the lead wire extending from the LED module. The member is connected to a stem lead extending from the stem body and is supplied with power.

  Furthermore, in the outer bulb-sealed LED lamp, the metal tube welded to the tip of the lead wire and the metal member are welded and fixed in an intersecting state, and the metal tube and the stem lead are in an intersecting state. It may be fixed by welding.

  Furthermore, in the outer bulb sealed LED lamp, the metal tube may be made of Ni, and the metal member may be made of a Ni-plated iron wire.

  Furthermore, the manufacturing method of the outer sphere sealed LED lamp according to the present invention includes a column preparing step, an LED module preparing step, a column prepared in the column preparing step, and an LED prepared in the LED module preparing step. A mount assembly process using a module, an outer sphere sealing process in which the mount assembled in the mount assembly process is inserted into an outer sphere, and the stem is welded to the outer sphere; and the stem in the outer sphere sealing process An outer sphere exhaust process for exhausting the inside of the welded outer sphere, sealing a desired gas in an airtight manner, and a base mounting process for attaching the base to a lamp in which the desired gas is sealed in the outer sphere exhaust process, In the column preparing step, the column is fixed to the stem body with a metal band.

  Furthermore, in the manufacturing method of the outer bulb sealed LED lamp, in the mount assembling step, a metal tube welded to a leading end portion of a lead wire extending from the LED module is connected to a stem lead via a metal member. May be.

  Furthermore, in the manufacturing method of the outer bulb sealed LED lamp, the metal tube and the metal member are held and welded in an intersecting state, and the metal member and the stem lead are held and welded in an intersecting state. It may be.

  ADVANTAGE OF THE INVENTION According to this invention, the comparatively heavy LED module can be hold | maintained stably, and a new outer bulb | ball sealing type LED lamp with the mountability | operativity good at the time of lamp manufacture can be provided, and its manufacturing method.

FIG. 1A is a diagram showing an example of an LED lamp that is currently widely sold. FIG. 1B is a diagram illustrating an example of an LED lamp that is currently widely sold. FIG. 1C is a diagram illustrating an example of an LED lamp that is currently widely sold. FIG. 2 is an enlarged perspective view of the LED lamp according to the present embodiment. FIG. 3 is a flowchart for explaining a method of manufacturing the LED lamp according to this embodiment. FIG. 4 is a diagram for explaining the forming of the support column. FIG. 5A illustrates a situation in which the stem lead and the column according to the present embodiment are connected using a metal member. FIG. 5B illustrates a situation in which the stem lead and the column according to the present embodiment are connected using a metal member. FIG. 5C illustrates a situation in which the stem lead and the column according to the present embodiment are connected using a metal member. FIG. 5D illustrates a situation in which the stem lead and the column according to the present embodiment are connected using a metal member. FIG. 6 is a diagram for explaining the prior art corresponding to FIG. 5D. FIG. 7A is a diagram illustrating a situation where two LED modules are fixed to each other using a substrate fixing metal band in the LED module preparation step. FIG. 7B is a diagram for explaining a state in which the first LED module is bent around the leg portion of the column at the center portion of the substrate fixing metal band in the mount assembling step. FIG. 8A is a diagram illustrating an embodiment different from FIG. 5B. FIG. 8B is a diagram illustrating an embodiment different from FIG. 5C. FIG. 8C is a diagram illustrating an embodiment different from FIG. 5D.

  Hereinafter, embodiments of an outer bulb sealed LED lamp and a method for manufacturing the same according to the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. In addition, it should be understood that the embodiments described below are examples and do not limit the scope of the present invention.

[LED lamp]
(overall structure)
FIG. 2 is an enlarged perspective view of the LED lamp 10 according to the present embodiment. It should be noted in advance that the electrical connection between the base 2 and the LED module 14, the electrical connection between the LED modules 14, and the structure near the stem are omitted. These details will be described in detail with reference to the drawings individually when the manufacturing process of the lamp 10 is described later.

  This LED lamp 10 is different from the low-power LED lamp of about 7 W currently widely advertised and sold as described in FIGS. 1A to 1C, and is mainly a high-power 20-50 W class, typically 25 W LED lamp. Is targeted.

  The LED lamp 10 has a plurality of LED modules 14 arranged inside an outer sphere 6 whose one end is hermetically sealed. Each LED module 14 has a plurality of LED elements 18 mounted at appropriate intervals. This LED element mounting member typically comprises a metal core substrate 14a. The metal core substrate is a printed wiring board in which a base portion is made of a metal (for example, aluminum, copper, etc.), an insulating layer is formed on the metal surface, and a circuit pattern is formed on the upper surface of the insulating layer. The metal core substrate itself is known.

  The LED module 14 is mounted on the inside of the outer sphere 6 by using the substrate fixing metal bands 28-1 and 28-2 on the upper and lower sides with respect to the column 20 extending from the stem 8 fixed to one end of the outer sphere 6. It is positioned and supported at an appropriate location. Therefore, a recess 14n (see FIG. 7A) for holding the substrate fixing metal band is formed in the metal core substrate 14a.

  Further, a heat shield plate 30 is provided inside the outer sphere 6 near the base 2. The heat shield plate 30 is formed of, for example, a ceramic, a metal plate, a mica plate, or the like. The function of the heat shield plate 30 will be described later in relation to the outer sphere sealing step S04 of the manufacturing method shown in FIG.

  A low molecular weight gas is sealed in the internal space 22 of the outer sphere 6. In the present application document, the “low molecular weight gas” is a gas having a large specific heat and good thermal conductivity, typically helium gas. The present inventors have empirically found that when helium gas is used, discoloration that occurs in a sealing body (typically a silicone layer) used for LED element mounting can be suppressed by mixing a small amount of oxygen. To know. Therefore, when helium gas is used, it is preferable to use a mixed gas of helium: oxygen = 93: 7 (unit:%) in volume ratio.

(Description of each component)
The base 2 may be a screw-in type (E type) or an insertion type used in incandescent bulbs or HID lamps.

  The outer sphere 6 is a BT tube made of translucent hard glass such as borosilicate glass, for example. However, it may be any shape. The outer sphere 6 may be either a transparent type or a diffusion type (frosted glass type).

  Similar to known incandescent bulbs and HID lamps, the LED lamp 10 is welded by heating the stem 8 and the outer bulb 6 with a burner in the manufacturing process, sealed with gas, and the inner space of the outer bulb is hermetically sealed. Stopped.

  In this LED lamp 10, for example, four LED modules 14 are provided, nine LED elements 18 are mounted on each LED module, and the LED lamp 10 of 25 W is realized by a total of 36 LED elements. These 36 LED elements are all electrically connected in series between the two stem leads 8-1 and 8-2 (see FIG. 5A) formed in the stem 8 and extending in the lamp axis direction. Yes. The four LED modules 14 are arranged so as to form a generally rectangular shape when viewed in a cross section perpendicular to the lamp axis. Furthermore, it is preferable that the adjacent LED modules 14 are not in contact with each other and are arranged with a gap (gap) 26 therebetween.

[Production method of LED lamp]
FIG. 3 is a flowchart illustrating a method for manufacturing the LED lamp 10 according to the present embodiment. The manufacturing process of the LED lamp 10 is roughly divided into a “post preparation process” in step S01, an “LED module preparation process” in step S02, a “mount assembly process” in step S03, an “outer ball sealing process” in step S04, It consists of an “outer ball exhausting process” in step S05 and a “cap attaching process” in step S06. The strut preparation step S01 and the LED module preparation step S02 are independent steps, and either may be the first step or may be simultaneous. The work in each process is as follows.

(Staff preparation step S01)
As shown in FIG. 4, the support column 20 is formed in a substantially rectangular shape (the direction of the stem 8 is released). Next, this support | pillar 20 is fixed to the main body of the stem 8 in two places in the lamp | ramp axial direction using the support | pillar fixed metal bands 29-1 and 29-2. Next, the heat shield plate 30 is fixed to the support column 20 near the upper end of the stem 8.

  Next, referring to FIG. 5A to FIG. 5D, a state in which a metal lead (also referred to as “buffer lead wire”) is used to connect between the stem lead extending from the stem 8 in the lamp axis direction and the support column. Will be explained. Specifically, as shown in FIG. 5A, two stem leads 8-1 and 8-2 extend from the stem 8. As shown in FIG. 5B, the stem lead 8-1 extending from the stem 8 and the leg portion 20-1 of the column are connected using a first metal member 34-1.

  The first metal member 34-1 is preferably made of a material having good weldability, such as a Ni-plated iron wire. Here, the stem lead 8-1 and the first metal member 34-1 are held in an intersecting state, and both the members are spot-welded at the intersection 40. Similarly, the 1st metal member 34-1 and the leg part 20-1 of a support | pillar are hold | maintained in the state which cross | intersected, and both members are resistance-welded spot-like at the crossing location 42. FIG. The first metal member 34-1 is made of a metal wire having a certain thickness, that is, having a certain mechanical strength, and an insulating part 37 made of ceramics is connected to an intermediate portion. The first metal member 34-1 fulfills the function of securing the mechanical strength while maintaining the insulation between the leg 20-1 of the support column and the stem lead 8-1, while maintaining the insulation between the two members.

  As shown in FIG. 5C, the second metal member 34-2 is held in an intersecting state with respect to the stem lead 8-2, and both the members are spot-welded at the intersection 44. Similarly, the second metal member 34-2 is preferably made of a material having good weldability, such as a Ni-plated iron wire. However, the second metal member 34-2 has no insulating component. FIG. 5D will be described later.

  Here, in this embodiment, when connecting between the stem leads 8-1 and 8-2 and the metal members 34-1 and 34-2, the two members are held in a crossed state and welded. . Similarly, when connecting between the metal member 34-1 and the leg portion 20-1 of the support column, the two members are held in a crossed state and welded. This embodiment is characterized by this welding method. This feature will also be described later.

(LED module preparation step S02)
Four LED modules 14 are prepared. As shown in FIG. 7A, the two LED modules 14 are juxtaposed in the horizontal direction and fixed to each other using the substrate fixing metal bands 28-1 and 28-2 at two ends. This operation is repeated, and two sets of two LED modules 14 are prepared. At this stage, the two LED modules 14 are in a flat state juxtaposed in the lateral direction.

  The electrodes of the two LED modules 14 in the first set are electrically connected by soldering using inter-module lead wires 38-1. Similarly, the two LED modules 14 in the second set are soldered and electrically connected using inter-module leads 38-2 (not shown).

  One end of a lead wire 38-3 between the module and the metal member that connects the first set of LED modules 14 and the first metal member 34-1 is solder-connected to the electrode of the LED module 14. Next, one end of the inter-module lead wire 38-4 connecting the first set of LED modules 14 and the second set of LED modules 14 is solder-connected to the electrodes of the LED module 14. The second set of LED modules 14 is the same except that the positions of the module / metal member lead wire 38-3 and the module lead wire 38-4 are interchanged.

(Mount assembly process S03)
Two sets of LED modules 14 in a flat state fixed to each other by the substrate fixing metal bands 28-1 and 28-2 are fixed to the column 20. Specifically, the center portion of the board fixing metal band 28-1 and the center portion of the board fixing metal band 28-2 of the first set of LED modules 14 are respectively welded to the leg portions 20-1 of the column. Fix in place. Similarly, the second set of LED modules 14 is fixed by welding to the legs 20-2 of the support columns.

  In the next stage, as shown in FIG. 7B, the first LED module 14 is placed around the leg portions 20-1 of the fixed column around the center portions of the substrate fixing metal bands 28-1 and 28-2 (welding locations). ) And bend to 90 °. Similarly, although not shown, the second set of LED modules 14 is bent around the leg 20-2 of the column at an angle of 90 °. As a result, the two sets of four LED modules 14 are positioned so as to form a rectangular shape when viewed in a cross section perpendicular to the lamp axis.

  As a result of being bent at an angle of 90 °, the distance between the module and the metal member described in the LED module preparation step S02 becomes closer. At this stage, as shown in FIG. 5D, a metal tube (sleeve) 36-1 is welded to the other end of the module-metal member lead wire 38-3 extending from the first set of LED modules 14, and the metal The tube is welded to the first metal member 34-1. The metal pipe (sleeve) 36-1 is made of a material with good weldability, and is made of, for example, Ni. Similarly, a metal tube (sleeve) 36-2 is welded to the other end of the module-metal member lead wire 38-3 extending from the second set of LED modules 14, and this metal tube is connected to the second metal member 34. Weld to -2.

  In the present embodiment, when the metal tube 36-1 and the first metal member 34-1 at the other end of the lead wire 38-3 extending from the first set of LED modules are connected, the two members are crossed. It is held and welded. Similarly, when connecting between the 1st metal member 34-1 and the leg part 20-1 of a support | pillar, both members are hold | maintained in the crossed state, and are welded. Similarly, when connecting the metal tube 36-2 and the second metal member 34-2 at the other end of the lead wire 38-3 extending from the second set of LED modules, the two members are held in an intersecting state. And welding.

  FIG. 6 is a diagram for explaining a conventional connection method, and corresponds to FIG. 5D of the present embodiment. Conventionally, when connecting the metal tube 36-1 of the lead wire 38-3 and the stem lead 8-1, and connecting the metal tube 36-2 of the lead wire 38-3 and the stem lead 8-2, Welded directly without using metal parts. In this case, since both the flexible members extend in the same direction (lamp axis direction), the contact location tends to be unclear, and the best welding location may not be specified. Welding is likely to occur and welding was performed at two locations to prevent this.

  On the other hand, in this embodiment, since the two members to be welded are held in an intersecting manner, the contact location between both members is clear, and the frequency of occurrence of welding deviation is significantly reduced. When welding two members, from the viewpoint of workability, it is most preferable to hold both members in an orthogonal state for welding.

(Outer sphere sealing step S04)
The mount assembled in the mount assembly step S05 is inserted into the outer sphere. Next, the stem 8 to which the mount is attached and the outer sphere 6 are heated by a burner and welded.

  In the outer sphere sealing step S04, the outer sphere mounting portion, stem, and the like are heated to near 1000 ° C. by the burner. In order to prevent this heat from being transmitted to the LED element 18 inside the outer sphere and damaging the element, a heat shield plate 30 is provided between the base mounting portion of the outer sphere and the LED element 18.

  At this stage, the inside of the outer sphere communicates with the outside through the exhaust pipe of the stem. That is, it is the outer sphere exhausting step S05 that completes the hermetic sealing of the outer sphere. However, for convenience of explanation, in this application document, the process up to the welding stage of the stem and the outer sphere is referred to as an outer sphere sealing step S04.

(Outer sphere exhaust process S05)
The inside of the outer sphere welded with the stem is evacuated to a vacuum state through an exhaust pipe (not shown). Thereafter, a low molecular weight gas, preferably a mixed gas of helium and oxygen, is sealed in the outer sphere through an exhaust pipe, and the exhaust pipe is melted with a burner and sealed (chip-off).

(Base attachment process S06)
The other end of one stem lead is soldered to the upper end of the side metal surface of the base 2. Similarly, the other end of the other stem lead is soldered to the center of the bottom metal surface of the base 2. Thereby, the LED lamp 10 is completed.

(Alternative example)
8A to 8C are diagrams illustrating another embodiment. Here, FIGS. 8A, 8B, and 8C correspond to FIGS. 5B, 5C, and 5D described above, respectively.
Since the first stage is the same as FIG. 5A, the illustration and description are omitted.
In FIG. 8A, the first metal member 34-1 is long and is welded to both the stem leads 8-1 and 8-2.
In FIG. 8B, the metal member 34-1 is cut between the stem leads 8-1 and 8-2.
As a result, as shown in FIG. 8C, the same structure as in FIG. 5D is obtained.

(Advantages and effects of this embodiment)
The LED lamp 10 according to the present embodiment has the following advantages and effects.

  (1) When a conventionally used support is used as a feeder line, it is necessary to connect the support directly to the stem lead. Fixing the column holding the relatively heavy LED module with the stem lead alone lacks the stability of the mount.

  On the other hand, in this embodiment, the leg portions 20-1 and 20-2 of the support column 20 are fixed to the main body of the stem 8 using the support column fixing metal bands 29-1 and 29-2. Therefore, the load related to the support column 20 is only the load related to the holding of the LED module 14. The power supply to the LED module 14 is separately performed by the module-metal member lead wire 38-3.

  (2) When power is supplied to the LED module 14 by the module-to-metal member lead wire 38-3, if the lead wire 38-3 is directly welded to the stem lead as described with reference to FIG. It is easy for welding to deviate between members extending in a uniform manner. In order to prevent the occurrence of welding slippage, welding was performed at two locations, and workability was poor.

  On the other hand, in this embodiment, a metal member is provided between the lead wire 38-3 and the stem lead, and the lead wire 38-3 and the metal member are held and welded in an intersecting state. Similarly, the metal member and the stem lead are held and welded in an intersecting state. When the two metal members were held in a crossed state and welded, there was no occurrence of welding failure, and as a result, workability was improved. At the same time, the lamp non-lighting phenomenon due to welding failure was significantly reduced.

  (3) In the present embodiment, a metal tube (sleeve) is welded to the tip of the lead wire 38-3, and this metal tube is welded to the metal member. By using a metal pipe (sleeve), the area of the welded portion is increased, enabling reliable spot welding.

  (4) In the present embodiment, the leg portion 20-1 of the support column is mechanically held by the stem lead 8-1 using the first metal member 34-1. Thereby, in addition to the holding | maintenance by the stem main body, the support | pillar 20 is also hold | maintained by the stem lead 8-1.

(Summary)
As mentioned above, although it demonstrated about embodiment of the LED lamp which concerns on this invention, these are illustrations and do not limit this invention. The technical scope of the present invention is defined by the description of the appended claims.

2: base, 6: outer sphere, 8: stem, 8-1, 8-2: stem lead, 10: lamp, 14: LED module, 14a: metal core substrate, 14n: recess, 18: LED element, 20: support 20-1 and 20-2: Legs of support column, 22: Internal space, 28: Metal band for fixing the substrate, 29: Metal band for fixing the column, 30: Heat shield plate, 34: Lead wire, 34: Metal member, Buffer Lead wire, 34-1: first metal member, 34-2: second metal member, 36: metal tube, sleeve, 37: insulation component, 38-1, 38-2: lead wire between modules, 38- 3: Lead wire between module and metal member, 38-4: Lead wire between module sets, 40, 42, 44: Crossing point, 100: Lamp, 102: Base, 104: Aluminum die cast part, 104: Heat radiation part 106: Globe,
S01: Strut preparation process, S02: LED module preparation process, S03: Mount assembly process, S04: Outer ball sealing process, S05: Mount assembly process, S05: Outer ball exhaust process, S06: Base mounting process

Claims (3)

A plurality of LED modules each mounting a plurality of LED elements;
A support for holding the plurality of LED modules;
A glass outer sphere surrounding and sealingly sealing the plurality of LED modules and the support column;
The column is fixed to the stem body by a metal band,
The metal tube welded to the tip of the lead wire extending from the LED module is welded and fixed to the metal member in a crossed state, and the metal member is welded and fixed to the stem lead extended from the stem body in a crossed state. An outer sphere sealed LED lamp. The outer sphere sealed LED lamp according to claim 1 ,
The metal tube is made of Ni;
The metal member is an outer sphere sealed LED lamp made of Ni-plated iron wire. The strut preparation process,
LED module preparation process;
A support assembly prepared in the support preparation process, a mount assembly process performed using the LED module prepared in the LED module preparation process,
An outer sphere sealing step of inserting the mount assembled in the mount assembly step into the outer sphere and welding the stem to the outer sphere;
The outer sphere exhausting step of exhausting the inside of the outer sphere welded with the stem in the outer sphere sealing step, sealing a desired gas and sealing hermetically,
A base attaching step of attaching a base to a lamp in which a desired gas is sealed in the outer sphere exhausting step,
In the strut preparation step, the strut is fixed to the stem body with a metal band,
In the mount assembling step, a metal tube welded to a tip portion of a lead wire extending from the LED module is welded and fixed to a metal member in a crossed state, and the metal member is crossed to a stem lead extended from the stem body. A method of manufacturing an outer bulb sealed LED lamp, which is fixed by welding to an outer bulb.

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