JP2012227388A - Method of manufacturing linear light source - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a linear light source having a plurality of LEDs resin-sealed on a substrate, which achieves more efficient light extraction from the LEDs.SOLUTION: The method of manufacturing a linear light source comprises the step in which after a plurality of LEDs 40 are mounted on a substrate 31, the substrate 31 is sealed by supplying a liquid resin 50M from above the LEDs 40. The liquid resin 50M contains a fluorescent body 50F having a larger specific gravity than a basal resin 50R contained in the liquid resin 50M, and silica fine particles 50D for changing the viscosity of the liquid resin 50M. The step of sealing the LEDs 40 includes the step of controlling the temperature of the liquid resin 50M so that the temperature of the liquid resin 50M is higher than the temperature when the liquid resin 50M is already supplied to the LEDs 40, and is lower than the temperature when the liquid resin 50M is cured. The fluorescent body 50F precipitates toward the substrate 31 by the temperature control.

Description

  The present invention relates to a method for manufacturing a linear light source, and more particularly to a method for manufacturing a linear light source including a plurality of light emitting elements resin-sealed on a substrate.

  Japanese Patent Application Laid-Open No. 2008-103688 (Patent Document 1) discloses an invention relating to a method of forming an LED (Light Emitting Diode) lamp by dispersing phosphors in a desired state. In the LED lamp in Patent Document 1, the light color emitted from the LED element is converted or the light color emitted from the LED element is mixed by a phosphor incorporated therein.

  Japanese Patent Laid-Open No. 2006-165416 (Patent Document 2) discloses an invention relating to a method of manufacturing a white display that displays numbers or characters by white light. The manufacturing method in Patent Document 2 includes a step of placing the lamp house in a thermostatic chamber to precipitate the phosphor and curing the transparent resin layer. Patent Document 2 states that according to the invention disclosed in Patent Document 2, display contrast can be improved.

JP 2008-103688 A JP 2006-165416 A

  The present invention provides a method for manufacturing a linear light source including a plurality of light emitting elements sealed with resin on a substrate, and capable of extracting light from the light emitting elements more efficiently. For the purpose.

  A method of manufacturing a linear light source according to the present invention is a method of manufacturing a linear light source including a plurality of light emitting elements arranged on a substrate, the step of mounting the plurality of light emitting elements on the substrate, Sealing the plurality of light emitting elements with the substrate by supplying a liquid resin so as to cover the plurality of light emitting elements from above the light emitting elements, and the liquid resin comprises: A wavelength conversion material having a specific gravity greater than that of the base resin contained in the liquid resin and converting the wavelength of light emitted from the plurality of light emitting elements to another wavelength, and for changing the viscosity of the liquid resin The step of sealing the plurality of light emitting elements between the substrate and the substrate, wherein the temperature of the liquid resin supplied so as to cover the plurality of light emitting elements is a plurality of the light emitting elements. The above liquid tree for the element The temperature of the liquid resin is set to a predetermined value so as to be higher than the temperature of the liquid resin when the liquid resin is supplied and lower than the temperature of the liquid resin when the liquid resin is cured. And adjusting the temperature of the liquid resin supplied so as to cover the plurality of light emitting elements to be the predetermined temperature, thereby adjusting the predetermined time. In addition, the wavelength conversion material settles on the substrate side.

  Preferably, the viscosity adjusting material is composed of silica fine particles. Preferably, the specific gravity of the viscosity adjusting material and the specific gravity of the base resin contained in the liquid resin are equal, and the specific gravity of the wavelength conversion material with respect to the base resin is three times.

  According to the present invention, there is provided a method of manufacturing a linear light source including a plurality of light emitting elements sealed with a resin on a substrate, and a method of manufacturing a linear light source capable of extracting light from the light emitting elements more efficiently. Can be obtained.

It is a front view which shows a liquid crystal display device provided with the linear light source manufactured by the manufacturing method of the linear light source in embodiment. It is a disassembled perspective view of a liquid crystal display device provided with the linear light source manufactured by the manufacturing method of the linear light source in embodiment. It is sectional drawing which shows a liquid crystal display device provided with the linear light source manufactured by the manufacturing method of the linear light source in embodiment. It is a perspective view which shows a part of light source module containing the linear light source manufactured by the manufacturing method of the linear light source in embodiment. It is a disassembled perspective view of the LED unit which has the linear light source manufactured by the manufacturing method of the linear light source in embodiment. It is sectional drawing which shows the leg part of the LED unit which has the linear light source manufactured by the manufacturing method of the linear light source in embodiment, and the surrounding member. It is a perspective view which shows the linear light source manufactured by the manufacturing method of the linear light source in embodiment. It is a top view which shows the linear light source manufactured by the manufacturing method of the linear light source in embodiment. It is arrow sectional drawing along the IX-IX line in FIG. It is arrow sectional drawing along the XX line in FIG. It is sectional drawing which shows the 1st process of the manufacturing method of the linear light source in embodiment. It is sectional drawing which shows the 2nd process of the manufacturing method of the linear light source in embodiment. It is sectional drawing which shows the 3rd process of the manufacturing method of the linear light source in embodiment. It is sectional drawing which shows the 4th process of the manufacturing method of the linear light source in embodiment. It is sectional drawing which shows the 5th process of the manufacturing method of the linear light source in embodiment. It is sectional drawing which shows the 6th process of the manufacturing method of the linear light source in embodiment. It is sectional drawing which shows the 7th process of the manufacturing method of the linear light source in embodiment. It is sectional drawing which shows the 8th process of the manufacturing method of the linear light source in embodiment. It is sectional drawing which shows the 9th process of the manufacturing method of the linear light source in embodiment. It is sectional drawing which shows the 10th process of the manufacturing method of the linear light source in embodiment, and has shown the linear light source obtained by the manufacturing method of the linear light source in embodiment. It is a figure which shows the relationship between content with respect to resin of a silica particle, and the sedimentation amount of a fluorescent substance. It is sectional drawing which shows typically the mode in the dispenser nozzle in case content of a silica fine particle is 0.5 wt%.

  Hereinafter, a method for manufacturing a linear light source according to an embodiment of the present invention and an electronic apparatus including the linear light source manufactured by the method for manufacturing a linear light source will be described. The embodiment will be described based on a liquid crystal display device to which the linear light source is applied. A liquid crystal display device is an example of an electronic device. The linear light source in the present invention can also be applied to other electronic devices such as a lighting device, a projector, or a signage.

  In the description of the embodiments, when referring to the number, amount, and the like, the scope of the present invention is not necessarily limited to the number, amount, or the like unless otherwise specified. In the description of the embodiments, the same parts and corresponding parts are denoted by the same reference numerals, and redundant description may not be repeated.

[Embodiment]
A liquid crystal display device 1 including a linear light source manufactured by the linear light source manufacturing method according to the present embodiment will be described with reference to FIGS. Details of the linear light source (see the linear light source 24a in FIG. 7) manufactured by the linear light source manufacturing method in the present embodiment will be described later with reference to FIGS.

(Liquid crystal display device 1)
FIG. 1 is a front view showing the liquid crystal display device 1. As shown in FIG. 1, the liquid crystal display device 1 is provided on a base 1A. The liquid crystal display device 1 has a screen on which an image is displayed. Although details will be described later, a light source module 20 is provided at the center of the back surface of the liquid crystal display device 1 in the height direction (see the dashed line in FIG. 1) (see also FIG. 3). The light source module 20 is provided so as to extend from one side of the liquid crystal display device 1 to the other side.

  FIG. 2 is an exploded perspective view of the liquid crystal display device 1. FIG. 3 is a cross-sectional view showing the liquid crystal display device 1. As shown in FIGS. 2 and 3, the liquid crystal display device 1 includes a backlight 10 having a light emitting surface that emits light, a diffusion sheet 2 disposed on the light emitting surface of the backlight 10, and a diffusion sheet 2. The prism sheet 3 disposed above, a liquid crystal panel 4 disposed on the prism sheet 3, and a frame 5 provided on the liquid crystal panel 4 are provided.

  The liquid crystal panel 4 is formed in a plate shape. On one main surface 4A of the liquid crystal panel 4, an image display area capable of displaying an image and a non-display area located on the outer periphery of the image display area are formed. The frame 5 covers a non-display area of the liquid crystal panel 4 and is formed in a frame shape so that an image displayed in the image display area can be observed from the outside.

  The backlight 10 is a surface light emitting unit and irradiates light toward the liquid crystal panel 4. The backlight 10 is disposed on the light source module 20, the chassis 11 provided with the opening 11a, the reflection sheet 12 disposed on the opposite side of the light source module 20 with respect to the chassis 11, and the reflection 10 A light guide plate 13 disposed on the opposite side of the chassis 11 with respect to the sheet 12 is included.

(Light source module 20)
The light emitted from the light source module 20 toward the light guide plate 13 enters the liquid crystal panel 4 through the diffusion sheet 2 and the prism sheet 3. As described above, the light source module 20 is provided at the center in the height direction of the back surface of the liquid crystal display device 1 (see the dashed line in FIG. 1). The light source module 20 is provided so as to extend from one side of the liquid crystal display device 1 to the other side. The image displayed on the liquid crystal panel 4 can be viewed by an observer by the light from the backlight 10.

  FIG. 4 is a perspective view showing a part of the light source module 20. As shown in FIGS. 3 and 4, the light source module 20 includes a light source holder 21 extending in the width direction of the liquid crystal display device 1 and a plurality of LED (Light Emitting Diode) units 25 provided in the light source holder 21. The plurality of LED units 25 are fixed on the light source holder 21 (mounting plate 26) in a state of being arranged in a straight line.

  The light source holder 21 includes a mounting plate 26, a peripheral wall portion 27 formed so as to rise from the side portion of the mounting plate 26, and a flange portion 28 that projects from the upper end portion of the peripheral wall portion 27. The mounting plate 26 is disposed at a distance from the chassis 11 (see FIG. 3). The collar portion 28 is fixed to the chassis 11.

(LED unit 25)
Each of the plurality of LED units 25 includes a plate-shaped heat sink 22 fixed on the mounting plate 26, linear light sources 24a and 24b arranged at intervals on the heat sink 22, and a linear light source. 24a and the arch-shaped optical coupling member 30 arranged to connect the linear light source 24b.

FIG. 5 is an exploded perspective view of the LED unit 25. As shown in FIG. 5, the linear light source 24 a includes a substrate 31 and a dam 32 formed on the main surface of the substrate 31. The substrate 31 and the dam 32 are formed long in the width direction of the liquid crystal display device 1. The dam 32 is formed in an annular shape. In the dam 32, a plurality (for example, 50) of LEDs (not shown) are arranged in the length direction of the dam 32 with an interval (for example, several mm). As described above, further details of the linear light source 24a will be described later with reference to FIGS.

  The linear light source 24b is configured in substantially the same manner as the linear light source 24a. The linear light source 24 b includes a substrate 33 and a dam 34 disposed on the main surface of the substrate 33. The substrate 33 and the dam 34 are also formed long in the width direction of the liquid crystal display device 1. The dam 34 is formed in an annular shape. A plurality of LEDs (not shown) are arranged in the dam 34 at intervals in the length direction of the dam 34.

  The optical coupling member 30 is formed long in the width direction of the liquid crystal display device 1. In the cross section perpendicular to the length direction of the optical coupling member 30, the optical coupling member 30 is formed in a bifurcated shape. The optical coupling member 30 includes a root portion 35, and a leg portion 36 and a leg portion 37 that are divided into two portions from the root portion 35.

  The apex portion 35a of the root portion 35 is formed in a flat shape. As shown in FIG. 3, the apex portion 35 a is in contact with the light guide plate 13 exposed from the opening portion 11 a formed in the chassis 11 and the slit 12 a formed in the reflection sheet 12. The light guide plate 13 and the optical coupling member 30 are separate members. Air is not interposed between the light guide plate 13 and the optical coupling member 30. The light guide plate 13 and the optical coupling member 30 are joined to each other by an adhesive or laser welding.

  Referring again to FIG. 5, the leg portion 36 and the leg portion 37 are formed such that the distance from each other increases as the distance from the root portion 35 increases. The bottom surface of the leg portion 36 is disposed on the dam 32 (see FIG. 6). The bottom surface of the leg portion 37 is disposed on the dam 34.

  FIG. 6 is a cross-sectional view showing the leg portion 36 of the LED unit 25 having the linear light source 24a and its surrounding members. As shown in FIG. 6, a protruding portion 38 is formed on the bottom surface of the leg portion 36. The protruding portion 38 is fixed to the substrate 31 with an adhesive 39.

  The linear light source 24 a includes a plurality of LEDs 40 (light emitting elements) disposed inside the annular dam 32. The dam 32 and the plurality of LEDs 40 are disposed outside the protruding portion 38. The outer peripheral surface of the leg part 36 is formed in a curved surface shape. A reflective surface 42 is formed by the outer peripheral surface of the leg 36.

  The light emitted from the LED 40 is reflected by the reflecting surface 42. The reflected light from the reflecting surface 42 reaches the apex portion 35a. The light reaching the apex portion 35a is incident on the light guide plate 13 shown in FIG. The light incident on the light guide plate 13 travels while being totally reflected inside the light guide plate 13. The light incident on the light guide plate 13 collides with an optical path changing unit (light scatterer) (not shown). Due to the collision with the optical path changing unit, the angle of light incident on the light guide plate 13 through the light guide plate 13 is changed, and the total reflection condition is broken. Thereafter, the light is emitted from the surface of the light guide plate 13 on the liquid crystal panel 4 (see FIG. 3) side. Light emitted from the light guide plate 13 travels to the liquid crystal panel 4 through the diffusion sheet 2 and the prism sheet 3.

  Referring again to FIG. 5, the leg portion 37 is configured similarly to the leg portion 36. The outer peripheral surface of the leg part 37 is formed in a curved surface shape. A reflective surface 41 is formed by the outer peripheral surface of the leg portion 37. The light from the linear light source 24 b is reflected by the reflecting surface 41. The light reflected by the reflecting surface 41 enters the light guide plate 13 through the apex portion 35a. The light incident on the light guide plate 13 is emitted from the surface of the light guide plate 13 on the liquid crystal panel 4 (see FIG. 3) side. Light emitted from the light guide plate 13 travels to the liquid crystal panel 4 through the diffusion sheet 2 and the prism sheet 3.

  The light emitted from the linear light sources 24a and 24b is guided to the liquid crystal panel 4 as described above. The image displayed on the liquid crystal panel 4 can be viewed by an observer by the light guided to the liquid crystal panel 4.

(Linear light source 24a)
Hereinafter, the linear light source 24a manufactured by the linear light source manufacturing method according to the present embodiment will be described in detail with reference to FIGS. The above-described linear light source 24b (see FIG. 5) may be configured similarly to the linear light source 24a.

  FIG. 7 is a perspective view showing the linear light source 24a. FIG. 8 is a plan view showing the linear light source 24a. 7 and 8, the dam 32, the resin 50, and a part of the substrate 31 are shown as being broken, but these are actually continuous over a predetermined length. The length of the dam 32 in the longitudinal direction is, for example, 100 mm. 9 is a cross-sectional view taken along the line IX-IX in FIG. FIG. 10 is a cross-sectional view taken along line XX in FIG.

  As shown in FIGS. 7 and 8, the linear light source 24 a includes a substrate 31, a plurality of LEDs 40 (see FIG. 8) arranged in a line on the substrate 31, and a plurality of LEDs 40 on the substrate 31. A dam 32 is provided around the dam 32, and a resin 50 is provided on the inner surface 32J (see FIG. 8) side of the dam 32 formed in an annular shape and seals the plurality of LEDs 40.

  The plurality of LEDs 40 are not limited to being arranged in a line on the substrate 31, but may be arranged in a so-called staggered pattern on the substrate 31, and in a form along a straight line or a curve as a whole on the substrate 31. They may be arranged irregularly.

  Although details will be described later, the resin 50 includes a base resin 50R (see FIG. 20) that constitutes a main part of the resin 50, a phosphor 50F (see FIG. 20) as a wavelength conversion material, and a viscosity adjusting material (see FIG. 20). Silica fine particles 50D (see FIG. 20) as fillers.

  The dam 32 is made of, for example, a white resin having a high reflectance. The resin constituting the dam 32 is, for example, an epoxy type or a silicone type. The dam 32 can be formed by, for example, a transfer molding method using a mold corresponding to the shape of the dam 32. The light emitted from the LED 40 is reflected by the dam 32 and can be efficiently extracted to the optical coupling member 30 (see FIG. 6) side.

  The resin 50 is formed of a member having a reflectance smaller than that of the dam 32 with respect to the light emitted from the LED 40. The resin 50 is, for example, a transparent or milky white silicone resin applied by a potting method. As described above, the phosphor 50 (phosphor 50F in FIG. 20) and silica fine particles (silica fine particles 50D in FIG. 20) are mixed in the resin 50. The LED 40 and the wires 40W (see FIGS. 9 and 10) are physically or electrically protected by the resin 50.

  As shown in FIGS. 9 and 10, a substrate 31 is provided on an aluminum base 31A, an insulating resin 31P having high thermal conductivity, and wiring patterned in a predetermined shape on the insulating resin 31P. 31C, plating 31G provided so as to cover the surface of wiring 31C, and insulating resin 31R formed on plating 31G so that a part of plating 31G is exposed. The wiring 31C is formed from a metal material having high conductivity such as copper (Cu). The plating 31G is formed from a metal material having a high light reflectance such as silver (Ag).

  Each of the plurality of LEDs 40 is mounted on the plating 31G with a die bond paste 40S made of transparent silicone or the like interposed therebetween. Adjacent LEDs 40 are connected to each other by a wire 40W made of gold (Au) or the like. The linear light source 24a manufactured by the linear light source manufacturing method in the present embodiment is configured as described above.

(Method for manufacturing linear light source)
With reference to FIGS. 11-20, the manufacturing method of the linear light source 24a in this Embodiment is demonstrated.

  FIG. 11 is a cross-sectional view showing a first step in the process of manufacturing the linear light source 24a. FIG. 12 is a cross-sectional view showing a second step in the process of manufacturing the linear light source 24a. FIG. 13 is a cross-sectional view showing a third step in the process of manufacturing the linear light source 24a. FIG. 14 is a cross-sectional view showing a fourth step in the process of manufacturing the linear light source 24a. FIG. 15 is a cross-sectional view showing a fifth step in the process of manufacturing the linear light source 24a. FIG. 16 is a cross-sectional view showing a sixth step in the process of manufacturing the linear light source 24a.

  FIG. 17 is a cross-sectional view showing a seventh step in the process of manufacturing the linear light source 24a. FIG. 18 is a cross-sectional view showing an eighth step in the process of manufacturing the linear light source 24a. FIG. 19 is a cross-sectional view showing a ninth step of manufacturing the linear light source 24a. FIG. 20 is a cross-sectional view showing a tenth step of the process of manufacturing the linear light source 24a. In addition, the viewpoint (cross-sectional direction) in FIGS. 11-17 respond | corresponds to FIG.

  Referring to FIG. 11, first, an aluminum base 31A is prepared. As shown in FIG. 11, an insulating resin 31P is formed on the aluminum base 31A. Referring to FIG. 12, a metal film is formed on insulating resin 31P by sputtering or the like. The metal film is patterned to form a wiring 31C.

  Referring to FIG. 13, after formation of wiring 31C, plating 31G is formed so as to cover the surface of wiring 31C by an electrolytic plating method or the like. Thereafter, an insulating resin is formed on the plating 31G. The insulating resin 31R is formed by patterning this insulating resin. As shown in FIG. 13, a part of the plating 31G is exposed by patterning for forming the insulating resin 31R. A substrate 31 is obtained.

  Referring to FIG. 14, a mold 70 having a cavity 71 is prepared. The lower surface of the cavity 71 is open. The mold 70 is placed on the substrate 31 such that the portion of the cavity 71 that is open faces the substrate 31. Resin for forming the dam 32 (see FIG. 15) is poured into the cavity 71 in a state where the lower surface of the mold 70 is disposed on the upper surface of the substrate 31.

  Referring to FIG. 15, the dam 32 is formed by curing the resin. As described above, the dam 32 is formed in an annular shape (see FIG. 7). Referring to FIG. 16, die bond paste 40 </ b> S is supplied onto plating 31 </ b> G located on the inner surface 32 </ b> J side of annularly formed dam 32. The LED 40 is placed on the die bond paste 40 </ b> S, and the wire 40 </ b> W is connected to the LED 40. The LED 40 is mounted on the substrate 31.

  Referring to FIG. 17, a dispenser nozzle 80 supplies (fills) a liquid resin 50M (hereinafter also referred to as a liquid resin 50M) to the inner surface 32J side of the dam 32 formed in an annular shape. The dispenser nozzle 80 is scanned from one end side in the longitudinal direction of the dam 32 formed in an annular shape toward the other end side (for example, from the left side to the right side in FIG. 8). The liquid resin 50M covers the LED 40 from above the LED 40. The LED 40 and the wire 40W are sealed with the liquid resin 50M.

  Referring to FIG. 18, as described above, liquid resin 50M supplied from dispenser nozzle 80 is a base resin 50R constituting the main part of resin 50 (in a cured state) (see FIG. 9), wavelength conversion. A phosphor 50F as a material and silica fine particles 50D as a viscosity adjusting material (filler) are included.

  The base resin 50R is, for example, a transparent or milky white silicone resin. As the base resin 50R, for example, “ASP1120” manufactured by Shin-Etsu Chemical Co., Ltd. can be used. The curing temperature in the case of “ASP1120” from Shin-Etsu Chemical Co., Ltd. is about 120 ° C.

  The phosphor 50F is, for example, YAG (yttrium-aluminum-garnet). The average particle diameter of the phosphor 50F is preferably 5 to 10 μm. As the phosphor 50F, a material having a specific gravity greater than that of the base resin 50R is used in order to precipitate the phosphor 50F inside the liquid resin 50M. The specific gravity of the phosphor 50F with respect to the base resin 50R is, for example, three times. The phosphor 50F converts the wavelength of light emitted from the plurality of LEDs 40 into another wavelength.

  Silica fine particles 50D as a viscosity adjusting material (filler) have an average particle diameter of 5 to 10 μm, for example. The silica fine particles 50D are mixed in the base resin 50R by a predetermined amount in order to adjust the viscosity of the liquid base resin 50R. As the viscosity adjusting material (filler) mixed in the base resin 50R, for example, glass fiber, graphite, or resin fine particles (fine particles made of polystyrene or polyimide) can be used in addition to the silica fine particles.

  After a predetermined amount of liquid resin 50M is filled on the inner surface 32J side of the annular dam 32, supply of the liquid resin 50M from the dispenser nozzle 80 is stopped.

  FIG. 18 shows a state in which the liquid resin 50M covers the LED 40 and is not cured after the supply of the liquid resin 50M by the dispenser nozzle 80 is stopped. As shown in FIG. 18, in a state immediately after the liquid resin 50M is supplied from the dispenser nozzle 80 (for example, within 1 hour), the silica fine particles 50D and the phosphor 50F are dispersed substantially uniformly inside the liquid resin 50M. doing. In other words, in the present embodiment, in a state immediately after the liquid resin 50M is supplied from the dispenser nozzle 80 (for example, within 1 to 2 hours), the silica fine particles 50D and the phosphor 50F are substantially within the liquid resin 50M. The viscosity of the liquid resin 50M is optimized by the silica fine particles 50D so as to be uniformly dispersed.

  In this state, the temperature of the liquid resin 50M is adjusted to a predetermined temperature for a predetermined time. Specifically, the temperature of the liquid resin 50M is higher than the temperature of the liquid resin 50M when the liquid resin 50M is supplied to the plurality of LEDs 40, and the liquid resin when the liquid resin 50M is cured. It is set to a value lower than the temperature of 50M.

  Referring to FIG. 19, the temperature of liquid resin 50M is adjusted (eg, heated) as described above, so that phosphor 50F moves in the direction of gravity after a predetermined time has elapsed (eg, after 2 hours of heating). Along the substrate 31 side. In other words, in the present embodiment, the temperature of the liquid resin 50M is adjusted as described above (for example, heated), so that after a predetermined time has elapsed (for example, after 2 hours of heating), the phosphor 50F is The viscosity of the liquid resin 50M is optimized by the silica fine particles 50D so as to settle toward the substrate 31 along the direction of gravity.

  After sedimentation of the phosphor 50F, the temperature of the liquid resin 50M is raised to a temperature at which the liquid resin 50M is cured and becomes a solid (up to a temperature at which the resin 50 in FIG. 20 is formed). By curing the liquid resin 50M, a linear light source 24a shown in FIG. 20 is obtained. The method for manufacturing a linear light source in the present embodiment is configured as described above.

(Action / Effect)
As shown in FIG. 20, the precipitated phosphor 50 </ b> F gathers around the LED 40 mounted on the substrate 31. The light emitted from the LED 40 collides with the phosphor 50F while spreading in the radiation direction. The wavelength of the light from the LED 40 is converted by collision with the phosphor 50F. The light from the LED 40 changes to a desired color according to the characteristics of the phosphor 50F. The light from the LED 40 is reflected by the dam 32 (and, in some cases, the phosphor 50F) and extracted to the optical coupling member 30 (see FIG. 6) side.

  Here, in the linear light source 24a, the phosphors 50F settled on the substrate 31 side are gathered around (near) the LEDs 40. The light emitted from the LED 40 reaches the phosphor 50F in a state where the light energy intensity is high. The light emitted from the LED 40 can be converted in wavelength by the phosphor 50F in a state where the light energy intensity is high. Since there is little loss of light energy intensity at the time of wavelength conversion, the light emitted from the LED 40 can be efficiently extracted to the optical coupling member 30 (see FIG. 6) side.

  On the contrary, it is assumed that the phosphor 50F does not settle and the phosphor 50F is not gathered around (near) the LED 40 (the phosphor 50F is widely dispersed throughout). In this case, the light from the LED 40 needs to guide the inside of the resin 50 for a relatively long time before it reaches the phosphor 50F and its wavelength is converted by the phosphor 50F. The light energy intensity of the LED 40 loses the light energy intensity by guiding a relatively long distance before the light wavelength is converted. The wavelength of the light from the LED 40 is converted by the phosphor 50F in a state where the light energy intensity is relatively low. The loss of light energy intensity at the time of wavelength conversion is larger than in the case of this embodiment.

  According to the linear light source 24a obtained by the method of manufacturing the linear light source in the present embodiment, the wavelength of the light emitted from the LED 40 is converted by the phosphor 50F with high light energy intensity. Since the loss of light energy intensity at the time of wavelength conversion is small, light from the LED 40 can be efficiently extracted to the optical coupling member 30 (see FIG. 6) side.

(Relationship between content of silica fine particles in liquid resin and sedimentation amount of phosphor)
Here, the relationship between the content of the silica fine particles 50D with respect to the liquid resin 50M and the sedimentation amount of the phosphor 50F will be described with reference to FIG.

  With respect to the liquid resin 50M supplied from the dispenser nozzle 80, the content of the silica fine particles 50D was set to 1 wt%, 0.7 wt%, and 0.5 wt%, respectively, and the following experiment was performed.

(Content: 1 wt%)
When the content of the silica fine particles 50D is 1 wt%, the liquid resin 50M is filled (applied) into the dam 32 from the dispenser nozzle 80, and the liquid resin 50M is cured immediately after the application. When the liquid resin 50M was cured and measured with a microscope, the phosphor 50F was hardly precipitated. It was confirmed that the phosphor 50F was dispersed throughout the resin 50. This is considered to be because the viscosity of the liquid resin 50M is large and the phosphor 50F did not flow (sediment) well.

  Next, when the content of the silica fine particles 50D is 1 wt%, the liquid resin 50M is filled (applied) from the dispenser nozzle 80 into the dam 32, and is placed in an oven at 50 ° C. for 2 hours. Was cured. When the liquid resin 50M was cured and measured with a microscope, the precipitation of the phosphor 50F was hardly observed. It was confirmed that the phosphor 50F was dispersed throughout the resin 50. Also in this case, it is considered that the viscosity of the liquid resin 50M is large and the phosphor 50F did not flow (sediment) well.

(Content: 0.7wt%)
When the content of the silica fine particles 50D was 0.7 wt%, the liquid resin 50M was filled (applied) into the dam 32 from the dispenser nozzle 80, and the liquid resin 50M was cured immediately after the application. When the liquid resin 50M is cured and measured with a microscope, most of the phosphor 50F is dispersed throughout the resin 50, but the phosphor 50F is slightly settled at the top of the resin 50. This was confirmed (see region R1 in FIG. 21).

  Next, in the case where the content of the silica fine particles 50D is 0.7 wt%, the liquid resin 50M is filled (applied) from the dispenser nozzle 80 into the dam 32 and placed in a 50 ° C. oven for 2 hours. Resin 50M was cured. When the liquid resin 50M was cured and measured with a microscope, it was confirmed that the phosphor 50F was well settled (see region R2 in FIG. 21).

  In addition, when a plurality of linear light sources based on this configuration are continuously manufactured and luminance measurement and chromaticity measurement are performed on each linear light source, chromaticity unevenness is found between the plurality of linear light sources. It hardly occurred. In addition, it is confirmed that the chromaticity is almost uniform along the arrangement direction of the LEDs 40 in each linear light source, and high brightness is obtained as compared with the case where the content of the silica fine particles 50D is 1 wt%. It was done. The reason why the high luminance is obtained is considered to be because the phosphor 50F is well settled as described above.

(Content: 0.5wt%)
When the content of the silica fine particles 50D was 0.5 wt%, the liquid resin 50M was filled (applied) into the dam 32 from the dispenser nozzle 80, and the liquid resin 50M was cured immediately after the application. When the liquid resin 50M was cured and measured with a microscope, most of the phosphor 50F was settled (see region R3 in FIG. 21). This is considered to be because the phosphor 50F immediately flowed (sedimented) immediately after application to the time of curing due to the low viscosity of the liquid resin 50M.

  However, when a plurality of linear light sources based on this configuration are continuously manufactured and chromaticity is measured for each linear light source, chromaticity unevenness occurs between the individual linear light sources. It was. Similarly, when the liquid resin 50M was cured after being placed in an oven at 50 ° C. for 2 hours, it was confirmed that most of the phosphor 50F was settled (see region R4 in FIG. 21). There was chromaticity unevenness between the linear light sources.

  Referring to FIG. 22, when the content of silica fine particles 50D with respect to liquid resin 50M is 0.5 wt%, the viscosity of liquid resin 50M is small (viscosity resistance as a fluid is low). For this reason, it is considered that most of the phosphor 50 </ b> F sinks in the dispenser nozzle 80.

  Therefore, the amount of the phosphor 50F supplied to the linear light source manufactured at an early stage is larger than the amount of the phosphor 50F supplied to the linear light source manufactured at a late stage. As a result, chromaticity unevenness occurs between a linear light source manufactured at an early stage and a linear light source manufactured at a late stage.

  On the other hand, when the content of the silica fine particles 50D is 0.7 wt%, the phosphor 50F hardly settles in the dispenser nozzle 80 even before application. The phosphor 50F can be supplied into the dam 32 in a state of being uniformly dispersed inside the liquid resin 50M. Therefore, the amount of the phosphor 50F supplied to the linear light source manufactured at an early stage and the amount of the phosphor 50F supplied to the linear light source manufactured at a later stage are substantially the same amount. It becomes. Thereby, chromaticity unevenness does not occur between a linear light source manufactured at an early stage and a linear light source manufactured at a late stage.

  Further, after the liquid resin 50M containing 0.7 wt% of silica fine particles 50D is supplied into the dam 32, the liquid resin 50M is set to a predetermined temperature (heated up), whereby the phosphor 50F becomes a substrate. It can settle uniformly toward the 31 side. Therefore, when the content of the silica fine particles 50D is 0.7 wt%, the phosphor 50F can be uniformly and satisfactorily settled. Therefore, the light from the LED 40 is in a state where the light energy intensity is high. The wavelength can be converted by. Since the loss of light energy intensity at the time of wavelength conversion is small, the light from the LED 40 can be efficiently extracted to the optical coupling member 30 (see FIG. 6) side, and the luminance is increased.

  Regarding the content of the silica fine particles 50D, the size of the dam 32 (the size of the portion where the LED 40 is mounted and filled with the liquid resin 50M), the material of the liquid resin 50M (silica fine particles 50D and the base resin 50R), the linear shape Depending on the overall size of the light source 24a, the temperature at which the liquid resin 50M is supplied from the dispenser nozzle 80, and the like, an optimum value is set so that the viscosity of the liquid resin 50M can be obtained in which the phosphor 50F is satisfactorily settled. It is good to set to. By using the silica fine particles 50D as the viscosity adjusting material, the viscosity of the liquid resin 50M can be easily adjusted, which is highly convenient. If the silica fine particles 50D are not used as the viscosity adjusting material, it is inconvenient because it is necessary to change the material of the liquid resin 50M to the viscosity of the liquid resin 50M.

  As mentioned above, although embodiment based on this invention was described, embodiment disclosed this time is an illustration and restrictive at no points. The technical scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Liquid crystal display device, 1A base, 2 Diffusion sheet, 3 Prism sheet, 4 Liquid crystal panel, 4A Main surface, 5 Frame, 10 Backlight, 11 Chassis, 11a Opening part, 12 Reflective sheet, 12a Slit, 13 Light guide plate, 20 Light source module, 21 Light source holder, 22 Heat sink, 24a, 24b Linear light source, 25 LED unit, 26 Mounting plate, 27 Perimeter wall portion, 28 collar portion, 30 Optical coupling member, 31, 33 Substrate, 31A Aluminum base, 31C Wiring, 31G plating, 31P, 31R insulating resin, 32, 34 dam, 32J inner surface, 35 root, 35a apex, 36, 37 leg, 38 protrusion, 39 adhesive, 40S die bond paste, 40W wire, 41, 42 Reflective surface, 50 resin, 50D silica fine particles (viscosity adjustment Fee), 50F phosphor (wavelength converting material), 50M liquid resin (liquid resin), 50R base resin, 70 mold 71 cavity, 80 dispenser nozzle, R1, R2, R3, R4 area.

Claims (3)

A method of manufacturing a linear light source comprising a plurality of light emitting elements arranged on a substrate,
Mounting a plurality of the light emitting elements on the substrate;
Sealing the plurality of light emitting elements with the substrate by supplying a liquid resin so as to cover the plurality of light emitting elements from above the plurality of light emitting elements,
The liquid resin is
A wavelength conversion material having a specific gravity greater than that of the base resin contained in the liquid resin and converting the wavelength of light emitted from the plurality of light emitting elements to another wavelength;
A viscosity adjusting material for changing the viscosity of the liquid resin,
The step of sealing a plurality of the light emitting elements between the substrate,
The temperature of the liquid resin supplied so as to cover the plurality of light emitting elements is higher than the temperature of the liquid resin when the liquid resin is supplied to the plurality of light emitting elements, and Adjusting the temperature of the liquid resin to a predetermined temperature for a predetermined time so as to be a value lower than the temperature of the liquid resin when the liquid resin is cured,
By adjusting the temperature of the liquid resin supplied so as to cover the plurality of light emitting elements to be the predetermined temperature, the wavelength conversion material settles on the substrate side during the predetermined time. To
A method of manufacturing a linear light source. The viscosity adjusting material is composed of silica fine particles,
The manufacturing method of the linear light source of Claim 1. The specific gravity of the viscosity adjusting material and the specific gravity of the base resin contained in the liquid resin are equal,
The specific gravity of the wavelength conversion material with respect to the base resin is three times.
The manufacturing method of the linear light source of Claim 1 or 2.