JP2011128290A - Light source device, and backlight, exposure device and exposure method using the same - Google Patents

Abstract

A light source device in which an optical axis of a light emitting element and an optical axis of an optical component are accurately aligned on a substrate is realized at low cost.
The light source device of the present invention has the following configuration. The substrate 4 includes a first electrode pad 411 and a second electrode pad 412, and the light emitting element 2 includes a package having a light emitting surface 21 and a third electrode pad 26, and a light emitting element housed in the package. The optical component includes a lens portion 31, a pedestal portion 32, and a joint surface 33 formed on the pedestal portion 32, and the lens portion 31 covers the light output surface 21 of the light emitting element 2. The first electrode pad 411 formed on the first electrode pad 411 and the third electrode pad 26 formed on the light emitting element 2 are joined by the solder 10, and the second electrode pad 412 formed on the substrate 4 and the pedestal portion 32 of the optical component. The joint surface 33 formed in the above is joined by the solder 10.
[Selection] Figure 1

Description

  In particular, the present invention relates to a light source device using an LED as a light source, a backlight such as a liquid crystal display device using the same, an exposure device, and an exposure method.

  A light source module used in a light source device requires highly accurate alignment and fixing between an LED and a lens on a substrate. In the conventional technology, alignment is performed by aligning the optical axis of the LED and the optical axis of the lens using a method of aligning the outer shape of the LED fixed to the substrate and the alignment guide of the lens unit, and then using an adhesive or solder. The method of fixing the lens was taken. This method has a problem that a lot of tact and cost are required for alignment of the optical axis and fixing of the lens, resulting in a decrease in productivity and an increase in cost.

  As an example of a method for easily performing high-precision alignment, “Patent Document 1” discloses an optical assembly configuration and method as shown in FIG. 12 (sectional view) and FIG. 13 (top view). The optical subassembly 10 includes a group of solder balls 100 formed on a substrate 4 and arranged in a ring shape. The ring-shaped solder ball group 100 forms a female snap fit feature to accept a male snap fit feature. The solder ball group 100 is deposited on a circular solder pad 101 on the substrate 4.

  The lens cap 102 is attached to the substrate 4 from above the die 103. The lens cap 102 is made of an optical material such as a heat-resistant optical material, and the lens cap 102 has a hollow cylindrical shape having a base portion 104 and a cylindrical outer surface 105. The base 104 includes a lens 106 (for example, a collimator lens) on the front side and / or a lens 107 (for example, a converging lens) on the back side.

  The cylindrical outer surface 105 forms a male snap fit feature that will be received by the female snap fit feature formed by the ring-shaped solder ball group 100. With these snap fit features, the lens cap 102 is maintained on the substrate 4 and the lenses 106/107 are aligned to the die 103. The lens cap 102 fits with the solder ball group 100 and can have an outer surface 105.

  According to the optical subassembly 10 structure of Patent Document 1, since the solder pad 101 is a structure defined by photolithography, the solder balls 100 can be accurately arranged. Further, the geometric center of each solder ball 100 is arranged near the geometric center of the solder pad 101. Further, when a plurality of solder balls 100 are used as an alignment reference, the difference between the solder balls and the solder pads can be averaged, so that the lens cap can be maintained on the substrate while being able to align with high precision. Yes.

JP-A-2005-321772

  However, in this structure, since the lens cap is fitted in the solder ball group, there is a problem that the fixing strength to the substrate is not always sufficient. In this structure, as a method for improving the fixing strength, there is a method of increasing the fitting stress to the lens cap. However, since the lens cap is deformed at that time, the lens characteristics are deteriorated or the lens cap is damaged. There is a sexual problem. Alternatively, there arises a problem that accurate alignment cannot be performed due to deformation of the solder ball from the spherical shape or deformation of the lens cap due to an increase in fitting stress.

  The present invention solves the above-described conventional problems, and provides an LED light-emitting device capable of aligning the optical axes of a light-emitting element and a lens by a simple method and an LED light source device using the LED light-emitting device. Specific means are as follows.

  (1) A light source device in which a light emitting element and an optical component are arranged on a substrate, wherein the substrate has a first electrode pad and a second electrode pad, and the light emitting element has a light emitting surface and a third electrode pad. A package having an electrode pad; and a light emitting element chip housed in the package, wherein the optical component has a lens portion, a pedestal portion, and a joint surface formed on the pedestal portion, and the lens portion Covers the light-emitting surface of the light-emitting element, and the first electrode pad formed on the substrate and the third electrode pad formed on the light-emitting element are bonded to each other by solder and formed on the substrate The light source device, wherein the joining surface formed on the pedestal portion of the second electrode pad and the optical component is joined by solder.

  (2) SA = SB (1 ± 0.2) where SA is the area of the first electrode pad in the soldered portion and SB is the area of the third electrode pad. (1) The light source device according to (1).

  (3) When the area of the second electrode pad in the part joined by the solder is SC and the area of the joint surface formed in front of the base is SD, SC = SD (1 ± 0.2 The light source device according to (1), wherein

  (4) The light source device according to any one of (1) to (3), wherein in the optical component, the lens and the pedestal portion are integrally formed.

  (5) The optical component according to any one of (1) to (3), wherein the optical part has a structure in which a notch is formed in the pedestal and the lens is fitted in the notch. Light source device.

  (6) An exposure apparatus having a light source unit having a plurality of light source devices, an optical system for controlling an optical path of light from the light source unit, and a table on which a work is placed and movable in at least one direction. Each of the plurality of light source devices includes the light source device described in (1).

  (7) The exposure apparatus according to (6), wherein the plurality of light source devices in the light source unit are cooled by a water cooling jacket.

  (8) An exposure method in which an exposure apparatus is used to expose a workpiece coated with a photosensitive agent through a mask, the exposure apparatus comprising: a light source unit having a plurality of light source devices; 2. An exposure apparatus having an optical system for controlling an optical path of light and a table on which a work is placed and movable in at least one direction, wherein each of the plurality of light source devices is a light source device according to claim 1. An exposure method comprising:

  (9) The time of the exposure process for exposing the workpiece is t1, and in the exposure process, the light emission time of the plurality of light source devices is t2, and t2 <t1. Exposure method.

  (10) A backlight in which a light emitting element, and the light emitting element and an optical component are arranged on a substrate, the substrate having a first electrode pad and a second electrode pad, and the light emitting element has a light emitting surface And a package having a third electrode pad, and a light emitting element chip accommodated in the package, and the optical component has a light guide plate, a pedestal portion, and a joint surface formed on the pedestal portion. The side surface of the light guide plate is opposed to the light output surface of the light emitting element, emits light from the main surface of the light guide plate, and is applied to the first electrode pad and the light emitting element formed on the substrate. The formed third electrode pad is bonded by solder, and the second electrode pad formed on the substrate and the bonding surface formed on the pedestal portion of the optical component are bonded by solder. Backlight characterized by

  According to the present invention, the optical axis of a light emitting element such as an LED can be easily aligned with the optical axis of an optical component such as a lens, and a high-performance light source device can be manufactured at low cost.

  In the manufacturing process, since a light emitting element such as an LED and an optical component can be mounted on the substrate using a conventional solder reflow process, it is not necessary to introduce new manufacturing equipment. For this reason, manufacturing cost can be suppressed.

  Furthermore, since the optical component and the light emitting element such as LED can be attached to the substrate at the same time in the reflow process, the manufacturing time is greatly reduced. Furthermore, when mounting many light emitting elements such as LEDs and optical components on a substrate, the time required for alignment is greatly reduced because the optical axis alignment can be performed by collectively performing the solder reflow process. Is possible.

It is sectional drawing which shows the structural example in Example 1 of the LED light source device of this invention. 1 is a perspective view of an LED 2 in Example 1. FIG. 2 is a cross-sectional view of an optical component 3 in Example 1. FIG. 2 is a top view of the optical component 3 in Embodiment 1. FIG. It is explanatory drawing of the junction part of Example 1 of this invention. It is sectional drawing which shows the structural example in Example 2 of the LED light source device of this invention. 6 is a top view illustrating a configuration example in Embodiment 2. FIG. It is sectional drawing which shows the structural example in Example 3 of the LED light source device of this invention. It is a general view of the exposure apparatus which shows Example 4 of this invention. It is exposure conditions of the exposure apparatus which shows Example 4 of this invention. It is sectional drawing which shows the structure of the conventional LED backlight module. It is a top view which shows the other structure in the conventional LED light source device.

  Hereinafter, a light source device of the present invention, a backlight device, an exposure device, and an exposure method using the light source device will be described in detail using embodiments.

FIG. 1 is a cross-sectional view showing a configuration example in Embodiment 1 of the LED light source device of the present invention. In FIG. 1, this LED light source device 1 includes an LED 2 as a light emitting element, a lens portion 31 having a lens function arranged so as to cover an upper part of a light emitting surface 21 of the LED 2, and a joint connected to the substrate by soldering. The optical component 3 is constituted by a pedestal portion 32 having a surface 33, and the substrate 4 is provided on the lower surface of the LED 2 and joined via the solder 10.

  FIG. 2 shows a perspective view of the LED 2. The LED 2 is a package in which an LED element chip 22 having a size of 0.3 mm to 2 mm square that emits ultraviolet light of 250 nm to 430 nm is accommodated in a package. The package 24 is made of ceramic or mold resin, has a size of 0.5 mm to 20 mm square, has a concave portion inside, and the LED element chip 22 is fixed to the bottom surface thereof by solder or adhesive. The LED element chip 22 is connected to a wiring pattern 25 installed in a package 24 through an Au connection wire 23. The light outgoing surface of the package 24 is covered with transparent glass and hermetically sealed.

  On the back surface of the package 24, for example, LED side electrode pads 26 electrically connected to the wiring pattern 25 by through holes or the like are provided. The size of one LED side electrode pad 26 formed on the back surface of the package is, for example, x1 = 1 mm and y1 = 6 mm in FIG.

  Some electrode pads 26 are not electrically connected to the wiring pattern 25. This is installed for the purpose of so-called heat spreader installed for the purpose of efficiently releasing the heat generated in the LED element chip 22.

  Although FIG. 2 shows an example of an ultraviolet light emitting LED, a visible light emitting and infrared light emitting LED can have the same structure as FIG. A transparent resin such as silicone, epoxy, or acrylic may be sealed in the recess of the package 24.

  In the present embodiment, an example in which the Au connection wire 23 is used for the electrical connection between the LED element chip 22 and the wiring pattern 25 is shown, but the electrode surface of the LED element chip 22 is directed to the package side, so-called In some cases, the flip chip type LED element chip 22 may be used.

  3 is a sectional view of the optical component 3, and FIG. 4 is a top view of the optical component 3. As shown in FIG. FIG. 3 is a cross-sectional view taken along the line AA in FIG. The optical component 3 is made of a transparent material made of a transparent resin such as glass, silicone, acrylic, or epoxy. The transparent material refers to a material having a transmittance of 50% or more with respect to the emission wavelength of the LED element. Therefore, since the transparent material differs depending on the emission wavelength of the LED element, the material shown in the above example can be used as an optical component.

  The optical component 3 includes a lens portion 31 having a lens function, four pedestal portions 32 that support the lens portion 31, and a joint portion 33 that joins the substrate 4. In the optical component 3, the lens portion 31 and the pedestal portion 32 are simultaneously manufactured by molding. The end of the pedestal 32 is made of a metal (Ni, Ti, Pt, Pd, Au, Ag, Sn, Cu) that can be soldered to a thickness of 0.1 μm or more by plating means, such as plating, vapor deposition, or sputtering. It has the joint surface 33 covered. In the present embodiment, the number of support columns of the pedestal portion 32 is exemplified as four, but the number of support columns is not limited to this. However, it is preferable that the support columns are arranged at highly symmetrical positions in the top view.

  The substrate 4 is composed of a plurality of layers of base materials such as glass epoxy, metal (Cu, Al, Fe), and polyimide, and the substrate surface has a substrate at a position where the LED electrode pad 26 is arranged in addition to the wiring. The electrode pad 411 is provided, and the substrate electrode pad 412 is provided at a position where the bonding surface 33 of the optical component 3 is mounted and fixed. The board solder pads 411 and 412 provided on the board 4 can be formed with a positional accuracy of about 10 μm because they are manufactured by a photolithography method.

  FIG. 5 is an explanatory view of a joint portion for explaining the optical element alignment method according to the first embodiment of the present invention. The substrate constituting the LED light source device, the optical axis of the LED, the optical axis of the lens portion, An example of a configuration for realizing the optical axis alignment with high accuracy is shown.

  The alignment method of the optical axis 27 of the LED and the optical axis 34 of the lens unit is as follows. When the electrode pad 26 on the LED side is bonded to each electrode pad 26 of the substrate via the solder ball 10 for bonding. The substrate-side electrode pad 411 and the LED-side electrode pad 26 are aligned using the surface tension of the melted solder ball 10, and at the same time, the substrate-side electrode pad 412 and the bonding surface 33 of the optical component 3 are aligned. It is characteristic that this is implemented by a self-alignment mounting method.

  The alignment accuracy by the self-alignment effect is 10 μm if the ratio (S1 / S2) of the area (S1) of the substrate-side electrode pad 411 to the area (S2) of the LED-side electrode pad 26 is within 1 ± 0.2. The position can be adjusted with. Similarly, the alignment accuracy by the self-alignment effect in the optical component is the same for the ratio (S1 / S2) of the area (S1) of the substrate-side electrode pad 412 and the area (S2) of the bonding surface 33 of the optical component 3. .

  Therefore, the alignment accuracy d of the optical axis 27 of the LED 2 and the optical axis 34 of the lens portion 31 of the optical component 3 is the sum of squares of the alignment accuracy of the electrode pad on the substrate 10 μm and the accuracy 10 μm due to the self-alignment effect of the solder ball 10. 14 μm from the square root is possible.

  In the manufacturing process, since both the LED 2 and the optical component 3 can be mounted on the substrate 4 using a conventional solder reflow process, it is not necessary to introduce new manufacturing equipment. For this reason, manufacturing cost can be suppressed.

  Further, since the optical component 3 and the LED 2 can be attached to the substrate 4 in the reflow process at the same time, the manufacturing time is greatly reduced. Furthermore, when mounting a large number of LEDs 2 and optical components 3 on the substrate 4, it is possible to significantly reduce the time required for alignment because the optical axis can be aligned by performing a solder reflow process all at once. It is.

  In this specification, the solder ball includes not only ball-shaped solder but also bump-shaped solder and other bulk solders in various shapes, and all forms used for flip-chip bonding. The solder is included.

  In this example, the solder ball is fixed on the electrode pads 411 and 412 on the substrate 4 in advance. However, the solder ball 10 is fixed on the electrode pad 26 on the LED 2 side and the bonding surface 33 of the optical component 3. May be.

  In the above description, the case where there is one lens portion 31 in the optical component 3 is shown, but the case where a plurality of lens portions are formed as a lens array in the portion of the lens portion 31 shown in FIG. 1 is also included. .

  FIG. 6 is a cross-sectional view showing a configuration example in the first embodiment of the LED light source device of the present invention. When the optical member 3 shown in FIG. 3 is made of a material that is difficult to mold, such as quartz glass, it is difficult to process the pedestal 32 as shown in the first embodiment. In such a case, it is necessary to configure the pedestal as an individual member.

  In the present embodiment, an example is shown in which the lens portion 301 of the optical component 30 is made of high melting point glass such as quartz or synthetic quartz, and the pedestal 302 is made of ceramic or metal. In FIG. 6, the lens unit 301 indicates a one-side convex lens, but the lens shape is designed from the optical limitation of the LED light source device, and is not limited to the one-side convex lens.

  The pedestal 302 is made of a metal material made of iron, copper, brass, titanium, nickel, aluminum, or the like, a ceramic such as alumina, aluminum nitride, or silicon carbide (SiC), or a heat resistant resin. The pedestal 302 has a joint surface 33 that is joined via a notch 302 a for fixing the lens 301, the electrode pad 412 of the substrate 4, and the solder 10. The joint surface 33 is joined to a part of the solder 10 by forming an alloy layer. Thereby, the pedestal 302 can be fixed to the electrode pad 412 of the substrate 4.

Next, a method for fixing the lens 301 to the pedestal 302 will be described.
A predetermined amount of solder balls are placed on the electrode pads 411 and 412 installed on the substrate 4 by a solder printing process. The LED 2 and the pedestal 302 are temporarily arranged at predetermined positions by a mounter.

Further, the lens 301 is temporarily placed in alignment with the notch 302 a on the pedestal 302.
By melting and solidifying the solder ball by a normal reflow process, the LED 2 and the pedestal 302 can be positioned with high accuracy by a self-alignment effect.

  In the reflow process, since the temperature of the substrate 4 made of glass epoxy is higher than the melting temperature of the solder, the distance L between lands is larger than the distance between lands at room temperature due to thermal expansion.

When the substrate temperature is lowered, the solder is solidified and the pedestal 302 is fixed to the substrate-side electrode land position. As the temperature of the substrate 4 decreases, the distance L between the lands on the substrate that has spread due to thermal expansion decreases, so the lens mounting distance L2 also decreases.
For example, in the case of a glass epoxy substrate, the linear expansion coefficient of glass epoxy is about 30 × 10 ⁻⁶ / K, and when L is 10 mm and the maximum reflow temperature is 260 ° C., it is about 75 μm at room temperature (20 ° C.). L contraction occurs. The lens mounting distance L2 is similarly reduced. On the other hand, quartz glass has a coefficient of thermal expansion of 0.4 × 10 ⁻⁶ / K. Therefore, the change in the diameter of the lens 302 having a lens diameter of 10 mm between the maximum reflow temperature and room temperature is about 1 μm. Therefore, a force for tightening the lens 301 by the pedestal 302 is generated by 75 μm−1 μm = 74 μm.

  Thus, at room temperature, the lens can be fixed by being sandwiched between the pedestals. Since the substrate never exceeds the reflow temperature, the lens 302 is not displaced or the lens cannot be removed due to thermal expansion.

  In the process described above, it is not necessary to provide a new process for attaching the lens 301 and the pedestal 302 of the optical component 30, and it is not necessary to introduce a new apparatus. Further, since the optical axis of the lens 301 and the optical axis of the LED 2 are determined by the self-alignment effect of the solder ball between the substrate-side electrode pad and the electrode pad of the LED 2 pedestal 302 as in the first embodiment, it is accurate. It is possible to match.

  In Example 3, the light output surface of the LED is perpendicular to the electrode pad surface (side view LED). Such an LED light source device can be used as a backlight of a liquid crystal display device, for example. FIG. 8: is sectional drawing which shows the structural example in Example 3 of the LED light source device of this invention. In FIG. 8, the LED light source device includes a substrate 4, a side view type LED 20 that emits visible light, and an optical member 310.

  The optical component 310 includes a light guide plate 311, a pedestal portion 312, and a joint portion 313. The light guide plate 311 is a surface illumination member having a function of propagating light emitted from the LEDs 20 from the incident surface to the inside and emitting light from the one surface side in a predetermined direction.

  The light incident surface of the light guide plate 311 needs to be aligned at a directional position where the amount of light taken in from the LED 20 is maximized. In FIG. 8, the light output surface of the LED 20 is arranged toward the light incident surface side of the light guide plate 311. The light from the LEDs 20 that is incident from one side of the light guide plate is evenly emitted from the upper surface (main surface) of the light guide plate 311. Note that a reflection layer is formed on the lower surface of the light guide plate 311, and directs light incident from the LED 20 toward the upper surface of the light guide plate 311.

  The bonding surface 313 provided on the LED 20 and the pedestal 312 is accurately positioned on the electrode pads 411 and 412 provided on the substrate 4 by the self-alignment effect by the solder 10. The pedestal 312 is provided with a recess for fixing the end of the light guide plate 311, and the light guide plate 311 is fixed to the recess. Thereby, accurate alignment of the light incident surface of the light guide plate 311 and the light emitting surface of the LED 20 is possible.

  FIG. 8 shows a case where the backlight thus formed is used as a backlight of a liquid crystal display device. In FIG. 8, an optical film 710 such as a diffusion film is disposed on a light guide plate 311 of a backlight, and a liquid crystal display panel 700 is disposed thereon.

  FIG. 9 is a view showing the schematic arrangement of an exposure apparatus showing Embodiment 4 of the present invention. The light source unit 500 that emits light is composed of a plurality of light source devices 1A, and each light source device 1A is attached to a water cooling jacket 501 in order to efficiently dissipate heat. The wiring provided on the connection board of each light source device 1A is connected to a lighting power source 502 that supplies power through a harness. The arrangement or inclination angle of the light source device 1A is designed so that light emitted from the light source device 1A can efficiently enter the integrator 503.

  The light emitted from the integrator 503 is irradiated to a workpiece 506 coated with a photosensitive agent such as a resist through a collimator mirror 504 and a mask 505, and a pattern formed on the mask 505 is exposed and formed on the photosensitive agent on the workpiece 506. . The table 600 mounts a work and can move in at least one direction.

  The exposure conditions for the light source device during exposure are shown in FIG. In FIG. 10, 507 is an exposure time, 508 is a non-exposure time, and 509 is an exposure process time. The exposure process in the exposure machine includes a time 508 when the workpiece is not exposed, such as loading the workpiece, fixing the workpiece to a predetermined position, aligning the mask and the workpiece, exposing the workpiece, releasing the workpiece, and unloading the workpiece. It is. The exposure process 509 requires 10 to 120 seconds, but the time 507 during which light is actually exposed to the workpiece is approximately 1 to 10 seconds.

  In an exposure apparatus using a conventional mercury lamp light source, the luminous intensity is not stabilized immediately after the mercury lamp is energized because the lamp temperature fluctuates. It takes about 30 minutes for the lamp temperature to stabilize. Therefore, in the conventional exposure process, it is necessary to always turn on the mercury lamp in order to stabilize the emitted light intensity. However, in the LED light source, since the emitted light intensity is stabilized within a few milliseconds immediately after energization, it is only necessary to energize the LED light source only during the exposure time in the exposure process, which greatly reduces the power consumption of the exposure machine. It becomes possible.

1 LED light source device 2 LED
3, 30 Optical component 4 Substrate 10 Solder ball 20 LED
DESCRIPTION OF SYMBOLS 21 Outgoing surface 22 LED element chip 23 Au connection wire 24 Package 25 Wiring pattern 26 Electrode pad 27 Optical axis 31 of LED 31 Lens part 32 Base part 33 Joint surface 34 Optical axis 301 of lens part Lens part 302 Base
302a Cut portion 310 Optical component 311 Light guide plate 312 Base portion 313 Joint portion 411, 412 Substrate side electrode pad 500 Light source module group 501 Cooling jacket 502 Lighting power source 503 Integrator 504 Collimator mirror 505 Mask 506 Work time 507 Exposure time 508 Time not exposed 509 Exposure process time d Positioning accuracy L Distance between lands.

Claims (10)

A light source device in which a light emitting element and an optical component are arranged on a substrate,
The substrate has a first electrode pad and a second electrode pad;
The light emitting device includes a package having a light emitting surface and a third electrode pad, and a light emitting device chip accommodated in the package,
The optical component has a lens portion, a pedestal portion, and a bonding surface formed on the pedestal portion,
The lens portion covers the light emitting surface of the light emitting element,
The first electrode pad formed on the substrate and the third electrode pad formed on the light emitting element are joined with solder,
The light source device, wherein the second electrode pad formed on the substrate and the joint surface formed on the pedestal portion of the optical component are joined by solder.   SA = SB (1 ± 0.2) where SA is the area of the first electrode pad in the soldered portion and SB is the area of the third electrode pad. The light source device according to claim 1.   SC = SD (1 ± 0.2), where SC is the area of the second electrode pad in the soldered portion and SD is the area of the bonding surface formed before the pedestal. The light source device according to claim 1.   The light source device according to claim 1, wherein in the optical component, the lens and the pedestal portion are integrally formed.   4. The light source device according to claim 1, wherein the optical component has a structure in which a notch is formed in the pedestal and the lens is fitted in the notch. 5. . An exposure apparatus having a light source unit having a plurality of light source devices, an optical system for controlling an optical path of light from the light source unit, and a table on which a work is placed and movable in at least one direction,
An exposure apparatus, wherein each of the plurality of light source devices comprises the light source device according to claim 1.   The exposure apparatus according to claim 6, wherein the plurality of light source devices in the light source unit are cooled by a water cooling jacket. An exposure method for exposing a workpiece coated with a photosensitive agent through a mask using an exposure apparatus,
The exposure apparatus is an exposure apparatus having a light source unit having a plurality of light source devices, an optical system for controlling an optical path of light from the light source unit, and a table on which a work is placed and movable in at least one direction. There,
An exposure method, wherein each of the plurality of light source devices includes the light source device according to claim 1.   9. The exposure method according to claim 8, wherein t2 <t1, where t1 is an exposure process time for exposing the workpiece and t2 is a light emission time of the plurality of light source devices in the exposure process. . A backlight in which a light emitting element and a light emitting element and an optical component are arranged on a substrate,
The substrate has a first electrode pad and a second electrode pad;
The light emitting device includes a package having a light emitting surface and a third electrode pad, and a light emitting device chip accommodated in the package,
The optical component has a light guide plate, a pedestal portion, and a joint surface formed on the pedestal portion,
The side surface of the light guide plate is opposed to the light exit surface of the light emitting element,
Light is emitted from the main surface of the light guide plate,
The first electrode pad formed on the substrate and the third electrode pad formed on the light emitting element are joined with solder,
The backlight, wherein the second electrode pad formed on the substrate and the joint surface formed on the pedestal portion of the optical component are joined by solder.

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