LED light source and method of manufacturing the same

Abstract

The present application relates to an LED light source and a manufacturing method thereof. The relative positions of LEDs fixed to the surface of a substrate and a light-transmissive member are made highly accurate, and an optimal light distribution pattern is achieved. An LED light source (100) includes: a substrate (1) having a first surface (1a); a holding portion (5) provided on the first surface (1a); an LED (2) provided on the first surface (1a); a joining member (6) fixed to the LED (2) provided on the first surface (1a); a light-transmissive member (3) having a larger shape than the LED (2) when viewed from above and positioned above the upper surface of the LED, for refracting the light emitted from the LED and emitting the light; a support portion (4) provided on the surface of the light-transmissive member opposite to the first surface (1a) of the substrate (1) and positioned outside the LED when viewed from above; and an adhesive for bonding the support portion and the substrate. The support portion is held by the holding portion, and the light-transmissive member is arranged at a predetermined position on the first surface of the substrate.

Description

Technical Field

[0001] This invention relates to LED light sources and their manufacturing methods. Background Technology

[0002] LED light sources that refract the emitted light from LEDs through light-transmitting components such as optical lenses are under development. These LED light sources diffuse or focus the emitted light from LEDs using optical lenses for various applications. For example, LED light sources used in backlights for liquid crystal displays diffuse the emitted light from LEDs through optical lenses, suppressing uneven light emission caused by localized bright areas. Backlight LED light sources have multiple LEDs fixed on the surface of a substrate, and the emitted light from each LED is diffused and emitted outwards through optical lenses, thus homogenizing the light distribution across the entire emitting surface and suppressing uneven light emission. For LED light sources that refract the emitted light from LEDs through optical lenses, it is crucial that the optical lenses properly diffuse or focus the emitted light to form the correct light distribution pattern. To achieve this, it is important to ensure that the optical axes of the LEDs and optical lenses are correctly aligned. This is because the optical axis of the optical lens is designed to be aligned with the optical axis of the LEDs to form the desired light distribution pattern.

[0003] In order to fix chip components such as ICs and capacitors on the surface of a mounting substrate and to place the frame covering these chip components in a specified position, a structure has been developed in which a protrusion is provided on the surface of the mounting substrate and the frame is placed inside the protrusion to be fixed in a specified position (see Patent Document 1).

[0004] In addition, a mounting structure has been developed in which multiple protrusions are provided on a printed circuit board and a positioning recess is provided on the bottom surface of the mounting component on the printed circuit board, and the protrusions are fitted into the positioning recess to place the mounting component at a predetermined position on the printed circuit board (see Patent Document 2).

[0005] Patent Document 1: Japanese Patent Application Publication No. 9-130009

[0006] Patent document 2: Japanese Patent Application Publication No. 2002-198632. Summary of the Invention

[0007] One of the objectives of this disclosure is to provide an LED light source and a method for manufacturing the same, which allows for easy positioning of the relative positions of an LED and a light-transmitting component fixed to the surface of a substrate.

[0008] An embodiment of the present invention relates to an LED light source comprising: a substrate having a first surface; a holding portion disposed on the first surface; an LED disposed on the first surface; a bonding member for fixing the LED disposed on the first surface; a light-transmitting member located on or above the upper surface of the LED, having a larger shape than the LED in plan view, for refracting and emitting light emitted from the LED; a support portion located outside the LED in plan view and disposed on the surface of the light-transmitting member facing the first surface of the substrate; and an adhesive for bonding the support portion and the substrate, wherein the support portion is held by the holding portion, and the light-transmitting member is disposed at a predetermined position on the first surface of the substrate.

[0009] An embodiment of the present invention relates to a method for manufacturing an LED light source, comprising: preparing an LED; a substrate having a first surface; a substrate having a shape larger than the LED in plan view; a support portion having a support portion disposed on the outside of the LED in plan view on a surface facing the first surface; a light-transmitting member for refracting the emitted light of the LED; and a bonding member for fixing the LED to the substrate; fixing the LED to the first surface via the bonding member; forming a holding portion on the first surface using the bonding member; and bonding the support portion and the holding portion with an adhesive, and disposing the light-transmitting member at a predetermined position on the first surface.

[0010] This provides an LED light source and its manufacturing method that allow for easy positioning of the relative positions of the LED and the light-transmitting component, which are easily fixed to the surface of a substrate.

[0011] Furthermore, according to the LED light source manufacturing method, it is possible to simultaneously form a bonding component that fixes the LED and a holding component that holds the light-transmitting component in a specified position, thus achieving the advantage of simplifying the manufacturing process. Attached Figure Description

[0012] Figure 1 This is a schematic cross-sectional view of the LED light source according to Embodiment 1.

[0013] Figure 2 This is an exploded perspective view of the LED light source involved in Embodiment 1.

[0014] Figure 3A This is an enlarged cross-sectional view showing the LED positioned differently from the desired location on the substrate. Figure 3B It is an enlarged cross-sectional view showing the state in which the LED is self-aligned and soldered to the desired position on the substrate.

[0015] Figure 4It is a chart that shows the mounting accuracy of self-aligning and fixing the LED to a specified position on the substrate.

[0016] Figure 5 It is a chart that shows the installation accuracy of placing and fixing the light-transmitting component in a specified position on the substrate.

[0017] Figure 6 It means by Figure 4 LED and Figure 5 A distribution diagram showing the accuracy of the optical axis formed by the light-transmitting components.

[0018] Figure 7 This is an exploded perspective view of the LED light source involved in the modified example.

[0019] Figure 8 yes Figure 2 The top view of the substrate of the LED light source shown.

[0020] Figure 9 This is a top view and a cross-sectional view showing an example of the support portion of the light-transmitting component of an LED light source involved in the modified example 1 of the positioning by the retaining portion.

[0021] Figure 10 This is a top view and a cross-sectional view showing another example of the support portion of the light-transmitting component of the LED light source involved in the modified example 2 of the positioning by the retaining portion.

[0022] Figure 11 These are top and cross-sectional views showing another example of the support portion of the light-transmitting component of the LED light source according to Embodiment 2, which is positioned by retaining the part.

[0023] Figure 12 These are top and cross-sectional views showing another example of the support portion of the light-transmitting component of the LED light source involved in the modified embodiment 2, which is positioned by the retaining portion.

[0024] Figure 13 This is a flowchart illustrating the manufacturing process of LEDs.

[0025] Figures 14A to 14F This is a process diagram illustrating the manufacturing process of an LED light source according to one embodiment.

[0026] Explanation of reference numerals in the attached figures

[0027] 100…LED light source; 1…substrate; 1a…first surface; 2…LED; 3…light-transmitting component; 3A…opposing surface of the substrate; 3B…non-opposing area; 4, 4B…support portion; 4A…front end surface; 4a…retaining recess; 5, 5B…retaining portion; 6…bonding component; 10…solder paste; 11…molten solder; 12…mating surface for LED fixing; 13…mating surface for lens fixing; 14…solder resist; 15…conductive film; 16…electrode conductive film; 17…retaining conductive film; 18…bonding solder; 19…retaining solder; 21…planar electrode; 30…adhesive Detailed Implementation

[0028] The embodiments of the present invention can also be determined by the following structure.

[0029] Preferably, there are multiple support portions, which are respectively disposed at different locations of the aforementioned light-transmitting component, and the aforementioned retaining portion retains each support portion by means of multiple support portions.

[0030] Preferably, the aforementioned plurality of retaining portions are each formed with a protrusion on the aforementioned first surface of the aforementioned substrate, and the plurality of aforementioned protrusions of each retaining support portion are respectively disposed at the vertices of the polygon, and the aforementioned support portion is disposed on the inner side surrounded by the vertices of the aforementioned polygon.

[0031] Preferably, the aforementioned polygon is either a triangle or a hexagon.

[0032] Preferably, the aforementioned protrusion provides an inclined surface for the region that guides the aforementioned support portion and forms the vertices of the polygon, and the aforementioned inclined surface is inclined toward the direction of insertion of the aforementioned support portion and toward the direction of approaching the aforementioned support portion.

[0033] Preferably, the vertical cross-sectional shape of the aforementioned protrusion relative to the vertical direction of the aforementioned substrate is circular or elliptical.

[0034] The aforementioned substrate is a printed circuit board, and the aforementioned holding portion is formed of the same material as the aforementioned bonding member. With the above structure, the holding portion that positions the light-transmitting member in a predetermined position can be formed simultaneously with the operation of setting the bonding member for fixing the LED on the substrate, which can provide the advantage of simplifying the manufacturing process.

[0035] The aforementioned bonding member and holding portion are solder. The aforementioned substrate has an electrode conductive film formed at the location where the bonding member is positioned on the first surface, and a holding conductive film formed at the location where the holding portion is positioned on the first surface. With this structure, when mounting an LED by melting the solder, a self-aligning effect of the LED along the pattern of the copper foil can be achieved, making LED positioning easy. Furthermore, the holding conductive film can easily form solder holding portions at predetermined positions, realizing the positioning of both the LED and the light-transmitting component.

[0036] The aforementioned support portion is formed in a columnar shape.

[0037] The aforementioned support portion is formed into a pointed shape.

[0038] The aforementioned support portion has a retaining recess formed on its front end face, and the aforementioned retaining portion has a retaining protrusion that guides the aforementioned retaining recess. The aforementioned retaining protrusion is guided by the aforementioned retaining recess, and the aforementioned support portion is retained by the aforementioned retaining portion.

[0039] The aforementioned LED light source is the light source used for the backlight of a liquid crystal display device.

[0040] The aforementioned light-transmitting component is an optical lens.

[0041] According to another embodiment of the LED light source manufacturing method, based on the above, in the process of forming the aforementioned bonding member and holding portion, the holding portion is formed of the same material as the aforementioned bonding member. Therefore, the holding portion that positions the light-transmitting member at a predetermined position can be formed simultaneously with the operation of setting the bonding member for fixing the LED on the substrate, thus providing the advantage of simplified manufacturing process.

[0042] According to another embodiment of the LED light source manufacturing method, based on any of the above, an electrode conductive film is formed on the first surface at the position where the aforementioned bonding member is disposed, and a holding conductive film is formed at the position where the aforementioned holding portion is disposed. Therefore, when mounting the LED by melting solder, a self-aligning effect of the LED along the pattern of the copper foil can be achieved, making LED positioning easy. Furthermore, the holding conductive film can be used to easily form solder holding portions at predetermined positions, achieving positioning of both the LED and the light-transmitting component.

[0043] According to another embodiment of the LED light source manufacturing method, based on any of the above, in the process of forming the aforementioned joining member and holding portion, the aforementioned holding portion is formed by a plurality of protrusions surrounding the aforementioned support portion, and is formed in a shape in which the upper surface of each protrusion is bent. Therefore, when the support portion of the optical component is held by the holding portion, being surrounded by a plurality of protrusions and having a bent upper surface, the support portion can be easily guided along the bent surface to the area surrounded by the protrusions, thereby positioning the light-transmitting component in a predetermined position.

[0044] The invention will now be described in further detail based on the accompanying drawings. Furthermore, in the following description, terms indicating specific directions or positions (e.g., "upper," "lower," and other terms including these terms) are used as needed to facilitate understanding of the invention with reference to the drawings, and are not intended to limit the technical scope of the invention by using the meaning of these terms. Additionally, the same reference numerals appearing in multiple drawings indicate the same or equivalent parts or components.

[0045] Furthermore, the embodiments shown below are specific examples illustrating the technical concept of the present invention and are not intended to limit the invention to these embodiments. Additionally, unless otherwise specified, the dimensions, materials, shapes, and relative arrangements of the structural components described below are illustrative and do not limit the scope of the invention to these specific examples. Furthermore, the descriptions in one embodiment or example can be applied to other embodiments or examples. Also, for clarity, the sizes and positional relationships of the components shown in the accompanying drawings are exaggerated.

[0046] [Implementation Method 1]

[0047] LED light sources, which refract the emitted light of an LED through a light-transmitting component, are used for various applications by controlling the light distribution pattern of the emitted light. For example, LED light sources used in backlights of liquid crystal display devices diffuse the emitted light of each LED through a light-transmitting component, thereby equalizing the light distribution and creating a light source with less uneven light emission. Additionally, LED light sources used in automotive headlights converge the emitted light of the LED through a light-transmitting component, creating a light distribution pattern that can brightly illuminate distant objects. Because LED light sources have light-transmitting components positioned on the LED's illumination surface to achieve the most suitable light distribution pattern for the application, and these components guide the emitted light along the optical axis to form a specific light distribution pattern, any misalignment between the position of the light-transmitting component and the LED becomes a drawback in achieving the desired light distribution pattern.

[0048] exist Figure 1 A rough cross-sectional view and Figure 2 The exploded perspective view shows the LED light source 100 according to Embodiment 1. The LED light source 100 shown in these figures includes: a substrate 1; an LED 2 fixed to a first surface 1a of the substrate 1; and a light-transmitting member 3 that refracts the emitted light from the LED 2. The substrate 1 has a first surface 1a. The first surface 1a... Figure 1 and Figure 2 The upper surface is the first surface 1a, where the LED2 is disposed. A bonding member 6 for fixing the LED2 is also provided on the first surface 1a. A holding portion 5 is also provided on the first surface 1a. On the other hand, a light-transmitting member 3 is located on or above the LED2, and is formed to be larger than the LED2 in plan view. A support portion 4 is provided on the surface of the light-transmitting member 3, which is outside the LED2 in plan view and faces the first surface 1a of the substrate 1. Furthermore, the support portion 4 and the substrate 1 are bonded together with an adhesive 30. For this LED light source 100, the support portion 4 is held by the holding portion 5, and the light-transmitting member 3 is disposed at a predetermined position on the first surface 1a of the substrate 1.

[0049] The support portion 4 is preferably formed in a columnar shape. Furthermore, the support portion 4 is preferably formed in a pointed shape. This allows for easy guidance of the support portion to the area enclosed by the protrusion when holding the support portion of the optical component by the holding portion. Additionally, multiple support portions 4 are provided at different locations on the surface 3A of the light-transmitting component 3 opposite to the first surface 1a of the substrate 1. The holding portion 5 holds each support portion 4 by means of multiple support portions 4.

[0050] Multiple retaining portions 5 are each formed with a protrusion on the first surface 1a of the substrate 1. Furthermore, the multiple protrusions of each retaining support portion 4 are respectively positioned at the vertices of a polygon. The support portion 4 is disposed on the inner side enclosed by the vertices of the polygon. The polygon is preferably a triangle or larger and a hexagon or smaller. By positioning the multiple protrusions at the vertices of the polygon, when the support portion of the optical component is held by the retaining portion, the effect of suppressing positional displacement of the optical component can be achieved. Figure 1 The image shows an example where the support portion 4 is arranged in a triangular shape.

[0051] Furthermore, the upper surface of each protrusion is preferably formed in a curved shape. Therefore, when the support portion of the optical component is held by the retaining portion, being surrounded by multiple protrusions and curved at the top, the support portion can be easily guided along the curved surface to the area surrounded by the protrusions, thereby positioning the light-transmitting component in a predetermined position. The area of ​​the protrusions that guides the support portion 4, forming the vertices of the polygon, is an inclined surface. This inclined surface is inclined towards the direction of insertion of the support portion 4. Furthermore, the vertical cross-sectional shape of the protrusion relative to the direction perpendicular to the substrate 1 is preferably circular or elliptical. Therefore, when the support portion of the optical component is held by the retaining portion, the effect of easily guiding the support portion to the area surrounded by the protrusions can be obtained. This will be described in detail below.

[0052] A conductive film 15 is partially formed on the first surface 1a of the substrate 1, and the electrodes of the LED 2 are soldered onto the conductive film 15. Furthermore, a light-transmitting component 3 is bonded to the substrate 1 to refract the emitted light from the LED 2 into a desired light distribution pattern. The LED 2 is fixed to the substrate 1 via a bonding component 6. A conductive component such as solder can be used in the bonding component 6. For the LED light source 100, the LED 2 is soldered and fixed to the substrate 1, and the light-transmitting component 3 is bonded to the substrate 1 via an adhesive 30.

[0053] The light-transmitting component 3 has multiple support portions 4 on the non-opposing area 3B outside the LED2 on the substrate opposing surface 3A. Each support portion 4 is configured and joined to a holding structure formed by multiple holding portions 5 provided on the first surface 1a of the substrate 1. The substrate 1 has: a bonding solder 18 for self-aligning and soldering the LED2 to a predetermined position; and a holding solder 19 that constitutes multiple holding portions 5 for positioning the support portions 4 in the predetermined position via the holding structure. Here, the bonding component 6 is referred to as the bonding solder 18 to distinguish it from the holding solder 19 constituting the holding portion 5. The support portions 4 are connected by the holding structure formed by the holding portions 5 of the holding solder 19, thereby positioning the light-transmitting component 3 at a predetermined position on the first surface 1a of the substrate 1. The LED2 is self-aligned and adjusted to the desired position and soldered by the surface tension of the molten solder 11, which is the molten state of the bonding component 6, i.e., the bonding solder 18.

[0054] The light-transmitting component 3 is provided with a plurality of support portions 4, which are connected to the retaining solder 19 provided on the substrate 1, i.e., a plurality of retaining portions 5, by a retaining structure, and are configured to be engaged in the correct position on the substrate 1. Figure 1 The LED light source 100 shown fixes both the LED2 and the light-transmitting component 3 in the correct position on the substrate 1, preventing the relative position of the LED2 and the light-transmitting component 3 from shifting. The light emitted by the LED2 is made to have the best light distribution pattern and radiate to the outside through the light-transmitting component 3.

[0055] (LED2)

[0056] Figure 3A This is an enlarged cross-sectional view showing the LED positioned differently from the desired location on the substrate. Figure 3B It is an enlarged cross-sectional view showing the state in which the LED is self-aligned and soldered to the desired position on the substrate. Figure 3A and Figure 3B This is a cross-sectional view showing the state in which LED2 is soldered to substrate 1. (Example) Figure 3A As shown, solder paste, forming the bonding component 6, is printed on the electrode conductive film 16 disposed on the first surface 1a of the substrate 1. An LED 2 is then placed on the printed solder paste. The LED 2 is square, with its upper surface as the light-emitting surface and its bottom surface as the electrode surface, and a pair of planar electrodes 21 are disposed in the electrode surface. Subsequently, as... Figure 3B As shown, in the soldering reflow process, the solder paste is melted by heating, and the pair of planar electrodes 21 of LED2 are self-aligned by the molten solder and soldered to the desired position.

[0057] Figure 3AThe diagram shows the state in which the LED2 is positioned offset from the substrate 1. The LED2 is positioned such that the planar electrode 21 is placed on the solder paste 10, but due to the accuracy of the LED supply device, a positional offset sometimes occurs between the LED2 and the solder paste 10.

[0058] After placing LED2 in Figure 3A In its current position, the solder paste 10 is melted during the soldering reflow process. For example... Figure 3B As shown in the cross-sectional view, the molten solder diffuses along the surface of the planar electrode 21, and the contractile force of the surface tension pulls the planar electrode 21 of the LED2, causing it to move directly onto the conductive electrode film 16. Due to the surface tension generated by the intermolecular forces (i.e., the forces attracting each other) of the bonding solder 18, i.e., the molten solder 11, the contractile force reduces the exposed surface area, thus... Figure 3A The LED2, which is positioned differently from the desired position on the substrate, is moved to... Figure 3B The desired position of the substrate is shown. Move LED2 to... Figure 3B The molten solder 11 is cooled and solidified, thereby fixing the planar electrode 21 to the correct position on the electrode conductive film 16. Self-alignment effectively utilizes the surface tension of the molten solder 11 to move the LED 2 to the correct position on the substrate 1.

[0059] Figure 4 It is a chart that shows the mounting accuracy of self-aligning and fixing the LED to a specified position on the substrate. Figure 5 It is a chart that shows the installation accuracy of placing and fixing the light-transmitting component in a specified position on the substrate. Figure 6 It means by Figure 4 LED and Figure 5 A distribution diagram showing the accuracy of the optical axis formed by the light-transmitting components.

[0060] Figure 4 and Figure 5 It is a diagram illustrating the placement of numerous LEDs 2 and light-transmitting components 3 at predetermined positions on the first surface 1a of the substrate 1 by an automatic feeding machine, and the fixing of the LEDs 2 and light-transmitting components 3 to the first surface 1a of the substrate 1. Figure 6 It is a graph showing the deviation of the optical axis formed by these LEDs and light-transmitting components. Figure 4 The positions of many LEDs 2 that are self-aligned and fixed to the specified positions on the substrate 1 are marked. Figure 5The positions where the light-transmitting component 3 is placed and fixed on the substrate 1 are shown. As shown in these figures, the LED 2 and the light-transmitting component 3 are placed on the substrate 1 and supplied with the same precision via a supply device of the same mechanism. The LED 2 is self-aligned and fixed in many narrow areas shown in the figures, where the positional offset in the X-axis and Y-axis directions is within approximately 50 μm. However, the light-transmitting component 3 has a positional offset of 100 μm to 200 μm in the X-axis direction and approximately 100 μm in the Y-axis direction. As shown in these figures, the LED 2 is placed on the substrate 1 with the same precision as the light-transmitting component 3, and is fixed to the substrate 1 with a positional accuracy within 50 μm and more than twice that of the non-self-aligned light-transmitting component 3 through self-alignment of the molten solder 11.

[0061] Self-alignment automatically adjusts the position of the fixed LED2 by the contraction force of the exposed surface generated by the surface tension of the molten solder 11. The self-aligned LED2, positioned at a predetermined location, preferably has planar electrodes 21 disposed on its bottom surface. The LED2 is fixed to a predetermined position on the substrate surface by correctly controlling its posture and position through the self-alignment of each planar electrode 21 disposed on the bottom surface. Furthermore, the self-aligned LED2 can be effectively positioned by increasing the area of ​​the planar electrodes 21 and the conductive electrode film 16. This is because increasing the exposed surface area of ​​the molten solder 11 increases the contraction force generated by surface tension. Therefore, it is preferable that the total area of ​​the pair of planar electrodes 21 is at least half the total area of ​​the bottom surface of the LED2, so that it can be reliably self-aligned and soldered to the substrate 1. Moreover, each planar electrode 21 is preferably substantially the same in shape and area as the conductive electrode film 16 disposed on the substrate surface, enabling the LED2 to be soldered to the desired position through self-alignment.

[0062] LED2 can be constructed using a semiconductor stack with a light-emitting portion (hereinafter referred to as "semiconductor stack"), or by depositing one or more wavelength conversion layers on the surface of the semiconductor stack. The semiconductor stack has light-emitting properties and is constructed by stacking multiple semiconductor layers such as ZnS, SiC, GaN, GaP, InN, AlN, ZnSe, GaAsP, GaAlAs, InGaN, GaAlN, AlInGaP, and AlInGaN on a gas using liquid phase growth, HDVPE, or MOCVD methods, with any one of these semiconductor layers forming a light-emitting layer. By selecting the materials and crystallinity of the semiconductor layers, various light-emitting wavelengths from ultraviolet to infrared light can be selected. In particular, when used as a display device suitable for use even outdoors, a semiconductor stack capable of high-brightness light emission is required. Therefore, nitride semiconductors are preferably selected as the material for the light-emitting portion that emits high brightness in green and blue light. For example, In...X Al Y Ga 1-X-Y N (0≤X≤1, 0≤Y≤1, X+Y≤1), etc. Furthermore, an LED can be configured by combining such a semiconductor stack with a wavelength conversion layer consisting of various phosphors that, when excited by the light emission, emit light with wavelengths different from the emission wavelength of the semiconductor stack. When using multiple phosphors, the phosphors can be arranged in one layer or distributed across multiple layers. GaAlAs-based semiconductors and AlInGaP-based semiconductors are preferably selected as materials for the semiconductor stack that emits red light. Furthermore, for a color display device, it is preferable to combine semiconductor stacks with emission wavelengths of 610nm to 700nm for red, 495nm to 565nm for green, and 430nm to 490nm for blue.

[0063] In addition, an electrode is formed on one side of the semiconductor stack of LED2, so that the electrode forming surface in the semiconductor stack is located facing the substrate 1, and is mounted by molten solder, and is mounted with the back side of the electrode forming surface as the main light extraction surface facing down (so-called flip chip mounting).

[0064] (Light-transmitting component 3)

[0065] A light-transmitting component 3 is positioned directly above the LED 2 to align its optical axis with the LED 2, diffusing or converging the incident light from the LED 2 and radiating it. The light-transmitting component 3 refracts the light incident from the LED 2, radiating it outwards as a specific light distribution pattern in the application of the LED light source 100. Such a light-transmitting component 3 can be appropriately utilized with optical components such as optical lenses. When the light-transmitting component 3 is used as an optical lens, concave lenses or convex lenses can be used. The light-transmitting component 3 is fixed to the substrate 1 with its optical axis aligned with the LED 2, thus realizing the designed light distribution pattern. The light-transmitting component 3, which realizes the specific light distribution pattern, has concave and convex portions on its surface to refract the incident light from the LED 2 and radiate it outwards. The light-transmitting component 3 is fixed to the substrate 1, and is fixed via the substrate 1 so that its position does not shift relative to the LED 2. In the process of soldering the LED2 to the substrate 1, the LED2 is self-aligned by the molten solder 11 and soldered to the correct position on the substrate 1. The light-transmitting component 3 is bonded to the substrate 1 by the adhesive 30. Therefore, without automatic position adjustment based on self-alignment, it is extremely difficult to bond to a specific position with high precision. Figure 5 The diagram illustrates the positions where numerous light-transmitting components 3 are bonded to the substrate 1 with a shifted center position. As shown in the figure, the non-self-aligned light-transmitting component 3 has a larger positional shift on the substrate 1 than the LED 2, making it difficult to align the optical axis with the LED 2. The positional shift of the LED 2 is amplified by the optical axis shift of the light-transmitting component 3, resulting in a situation where... Figure 6 The diagram showing the distribution of optical axis offset illustrates the cause of the abnormal light distribution pattern in the design.

[0066] Figure 2 The perspective view shows that the light-transmitting component 3 is provided with multiple support portions 4 for high-precision bonding to specific positions on the substrate 1. The support portions 4 are integrally formed with the light-transmitting component 3 using a light-transmitting resin such as acrylic resin or silicone resin. However, the present invention is not limited to a structure where the support portions are integrally formed with the light-transmitting component; the support portions may also be composed of components different from the light-transmitting component. The support portions 4 are formed on the substrate-opposing surface 3A of the LED 2 (on...). Figure 1 The non-opposing region 3B (located below) and not opposite the surface of LED2 protrudes towards the substrate 1. The support portions 4 of each of the non-opposing regions 3B have their front ends joined to the first surface 1a of the substrate 1 on the outer side of LED2, aligning and fixing the optical axis when LED2 is parallel to the substrate 1. The substrate 1 has a lens-fixing mating surface 13 in the area where the support portions 4 are joined. The lens-fixing mating surface 13 is the area of ​​the substrate 1 surface that is not coated with solder resist 14, and a plurality of retaining portions 5 (described later) are provided therein. The support portion 4 is joined to the central portion of the plurality of retaining portions 5 by a retaining structure. The substrate 1 has almost its entire surface coated with solder resist 14, but the LED-fixing mating surface 12 and the lens-fixing mating surface 13 for fixing LED2 are not covered by solder resist 14. The solder resist 14 is white and can reflect the light emitted by LED2, thereby increasing the brightness of the LED light source 100.

[0067] The gap between the light-transmitting component 3 and the substrate surface can be adjusted by the length of the support portion 4. The support portion 4 is set to a length such that its lower surface contacts or approaches the upper surface of the LED 2, depending on the material of the light-transmitting component 3. The support portion 4 is set to a length that minimizes the gap between the light-transmitting component 3 and the surface of the LED 2, allowing the emitted light from the LED 2 to enter the light-transmitting component 3. A light-transmitting component 3 with three or more support portions 4 can have its front end face 4A of each support portion 4 joined to the substrate surface and fixed to the substrate 1 in a parallel orientation. A light-transmitting component 3 with multiple support portions 4 arranged in a ring or polygonal shape centered on the LED 2, by joining each support portion 4 to the substrate 1, can be fixed to a predetermined position on the substrate 1 with high precision and orientation. Figure 2 In the example shown, the light-transmitting component 3 is provided with three support portions 4, but the support portions 4 can also be provided with more than four.

[0068] Figure 7 This is an exploded perspective view of the LED light source involved in the modified example. For example... Figure 7As shown, two support portions 4B are symmetrically positioned around LED2, and the lower end area of ​​each support portion 4B is enlarged, thereby allowing LED2 to be fixed to a predetermined position on substrate 1 in a parallel posture by multiple retaining portions 5B. The light-transmitting component 3 can be used to bond and fix the front end face 4A of the support portion 4 to the lens fixing mating surface 13 via adhesive 30, or to bond the front end face 4A of the support portion 4 and its vicinity to the surface of substrate 1 via adhesive 30.

[0069] like Figure 1 As shown in the enlarged view, the support portion 4 preferably has an outer peripheral surface that tapers towards the front end face 4A. The outer peripheral surface of this support portion 4 is an inclined surface, which slides into the retaining portions 5 and is connected via a retaining structure. Therefore, multiple retaining portions 5 can be smoothly connected to the retaining structure, and by sliding into the inclined surface, the position of the support portion 4 can be self-aligned and smoothly connected to the correct position. Furthermore, as... Figure 1 As shown in the enlarged view, the support portion 4 can be curved at the corner of its outer peripheral surface and the front end surface 4A. The front end of the support portion 4 can be smoothly guided and connected to the retaining structure without hooking with the retaining portion 5.

[0070] (Substrate 1)

[0071] The substrate 1 has an insulating plane, on which a wiring layer (not shown) is provided. The wiring layer has an electrode conductive film 16 electrically connected to the electrodes of each LED 2 by welding. The substrate 1 can preferably be an insulating substrate with excellent heat dissipation. For example, a ceramic substrate can be used; in this example, an alumina ceramic substrate is used. Alternatively, a glass epoxy substrate, an aluminum nitride substrate, etc., can also be used appropriately.

[0072] like Figure 1 As shown, a conductive film 15 electrically connected to the LED 2 is provided on the surface of the substrate 1. Furthermore, a light-reflective solder resist 14 is provided on the substrate 1 in areas other than the LED fixing mating surface 12 for fixing the LED 2 and in areas other than the lens fixing mating surface 13 for joining the support portion 4 of the light-transmitting component 3, thereby improving luminous efficiency. The light-reflective solder resist 14 utilizes an insulating material. The substrate 1, on which multiple LEDs 2 are disposed, has multiple LED fixing mating surfaces 12, and multiple lens fixing mating surfaces 13 are disposed around each LED fixing mating surface 12.

[0073] The mating surface 12 for fixing the LED exposes the electrode conductive film 16 for welding to the electrodes of the LED 2. A pair of electrode conductive films 16 are provided on the mating surface 12 for fixing the LED. The pair of electrode conductive films 16 are positioned opposite to a pair of planar electrodes 21 provided on the bottom surface of the LED 2. In the surface mount process, solder paste 10 is printed onto the pair of electrode conductive films 16. The LED 2 is placed on the solder paste 10, and each electrode conductive film 16 is bonded to the pair of planar electrodes 21, temporarily fixing the LED 2 in a predetermined position. In this state, the solder paste 10 is heated by a method such as reflow soldering. The heated solder paste 10 melts and welds the planar electrodes 21 of the LED 2 to the electrode conductive films 16. The molten solder self-aligns through surface tension, thereby correctly moving the planar electrodes 21 of the LED 2 to the electrode conductive films 16. In this state, it cools and solidifies, thereby welding the pair of planar electrodes 21 to the electrode conductive films 16.

[0074] The substrate 1 self-aligns the LED 2 and places a pair of planar electrodes 21 on the electrode conductive film 16 and solders them. The LED light source 100 fixes the LED 2 and the light-transmitting component 3 to the substrate 1 with their optical axes aligned, thereby achieving an optimal light distribution pattern. The LED 2 is self-aligned and correctly fixed to the desired position on the substrate 1, but the light-transmitting component 3 is not self-aligned when fixed to the substrate 1. Therefore, the lens fixing mating surface 13 is provided with a plurality of retaining parts 5, which, through a retaining structure, place the support part 4 of the light-transmitting component 3 in a predetermined position. The support part 4 is connected to the retaining parts 5 through the retaining structure, thereby placing the light-transmitting component 3 at the desired position on the substrate 1. The position of the retaining parts 5 determines the position of the light-transmitting component 3, thus improving the accuracy of placing the retaining parts 5 on the substrate 1.

[0075] To significantly improve the accuracy of fixing the light-transmitting component 3 to the substrate 1, a plurality of retaining portions 5, each composed of retaining solder 19, are provided on the lens fixing mating surface 13. Furthermore, to prevent the retaining portions 5 from shifting relative to the LED 2, the retaining portions 5 are formed at predetermined positions on the lens fixing mating surface 13 during the surface mount process. In the surface mount process, solder paste 10 is printed on the electrode conductive film 16 of the LED fixing mating surface 12 and the retaining conductive film 17 of the lens fixing mating surface 13. This solder paste 10 is heated and melted, and the LED 2 is self-aligned and soldered to the correct position using the molten solder 11. The solder paste 10 on the retaining conductive film 17 is melted and solidified to form the retaining portions 5.

[0076] Figure 8 yes Figure 2 The top view of the substrate of the LED light source shown. Figure 9This is a top view and a cross-sectional view showing an example of the support portion of the light-transmitting component of an LED light source involved in the modified example 1 of the positioning by the retaining portion. Figure 10 This is a top view and a cross-sectional view showing another example of the support portion of the light-transmitting component of the LED light source involved in the modified example 2 of the positioning by the retaining portion.

[0077] Figure 2 and Figure 8 The substrate 1 of the LED light source 100 shown in Embodiment 1 has three holding portions 5 on each lens fixing mating surface 13. However, the present invention does not limit the number of holding portions to three; four or more holding portions may also be provided. For example, as shown in Embodiment 1... Figure 9 As shown in the top view, the lens fixing mating surface 13 of the LED light source according to Modification Example 1 can also be provided with six retaining portions 5 arranged in a ring. The structure that arranges a plurality of retaining portions 5 in a ring and guides the support portion 4 to the inside of the ring-shaped retaining portions 5, thereby connecting the support portion 4 and the retaining portions 5 by a retaining structure, allows the support portion 4 to be more accurately positioned at the predetermined position on the lens fixing mating surface 13. Figure 9 In the example shown in the top view, each retaining part 5 has a circular planar shape, but the present invention does not limit the shape of the retaining part to a circle. For example, as Figure 10 As shown in the top view, as the LED light source involved in Modification Example 2, the holding part 5 can also be shaped along the outer periphery of the support part 4.

[0078] Alternatively, it can be configured such that the supporting portion surrounds the retaining portion. Figure 11 These are top and cross-sectional views showing another example of the support portion of the light-transmitting component of the LED light source according to Embodiment 2, which is positioned by retaining the part. Figure 11 In the LED light source according to Embodiment 2 shown, a circular retaining portion 5 is surrounded by a support portion 4 with a central recess.

[0079] The retaining portion 5 is formed by melting the solder paste 10 attached to the retaining conductive film 17. For example... Figures 9 to 11As shown in the cross-sectional view, the molten solder 11 solidifies into an approximately semi-circular cross-sectional shape due to the contraction force of surface tension. The retaining portion 5 of this shape becomes a wide downward swing towards the substrate 1. The outer peripheral surface of the retaining portion 5 is an inclined surface, thus causing the support portion 4, which is disposed on the inner side of the ring-shaped retaining portions 5, to move towards the center, i.e., to perform self-alignment and be positioned in the correct position. As each support portion 4 is integrally constructed with the light-transmitting member 3, it is self-aligned and positioned at the center of the ring-shaped retaining portions 5 by the multiple retaining portions 5. Therefore, the light-transmitting member 3 connects the support portion 4 and the multiple retaining portions 5 in the retaining structure and is positioned in the correct position on the substrate 1. In particular, the structure in which each support portion 4 is positioned in a predetermined position on the substrate 1 by self-alignment through the multiple retaining portions 5 allows the light-transmitting member 3 to be fixed to the substrate 1 with extremely high precision.

[0080] Figure 9 The lens fixing mating surface 13 has six holding portions 5 arranged in a ring or polygonal shape, and a support portion 4 is arranged on the inner side to hold the light-transmitting member 3 in a predetermined position on the substrate 1. On the other hand, Figure 10 The lens fixing mating surface 13 is provided in a ring shape. The inner edge of the ring-shaped or polygonal holding part 5 facing the center is set as the shape along the outer periphery of the support part 4. The support part 4 is arranged inside each holding part 5, thereby connecting the light-transmitting member 3 to a predetermined position on the substrate 1. Figure 12 These are top and cross-sectional views showing another example of the support portion of the light-transmitting component of the LED light source according to a variation of Embodiment 2, which is positioned by retaining the portion. As a variation of Embodiment 2, in... Figure 12 The lens fixing mating surface 13 shown also includes a plurality of retaining portions 5 arranged in a ring. The support portion 4 is disposed inside the ring, and a retaining recess 4a is provided on the front end face 4A of the support portion 4. A retaining portion 5 guiding to the retaining recess 4a is provided at the center of the ring-arranged retaining portions 5. The lens fixing mating surface 13 has a plurality of retaining portions 5 arranged in a ring, with a retaining portion 5 also provided at the center of the ring. This configuration, based on positioning the support portion 4 in a predetermined position using the ring-arranged retaining portions 5, guides the retaining portion 5 located at the center of the ring to the retaining recess 4a on the front end face 4A of the support portion 4, thereby enabling a more accurate connection of the support portion 4 to the predetermined position on the substrate 1. Figure 12 As shown, the support portion 4 with a retaining recess 4a provided on the front end face 4A can be positioned in a predetermined position by a retaining portion 5 without providing multiple retaining portions 5 in a ring.

[0081] The electrode conductive film 16 and the holding conductive film 17 on the surface of the substrate 1 can be simultaneously disposed by etching away a portion of the conductive film 15 stacked on the surface of the substrate 1. Therefore, the relative positional offset between the two is minimal, and the electrode conductive film 16 and the holding conductive film 17 can be simultaneously disposed on the substrate surface without relative positional offset.

[0082] Furthermore, the solder paste 10 adhering to the surfaces of the electrode conductive film 16 and the retaining conductive film 17 can be simultaneously applied by printing, thus they are also arranged in a manner without relative positional misalignment. In this state, during the soldering reflow process of soldering the LED2 to the substrate 1, the solder paste 10 is heated and melted, thereby self-aligning and soldering the LED2 to the correct position on the substrate 1. For this process, the solder paste 10 adhering to the retaining conductive film 17 is simultaneously melted and solidified, thereby setting the retaining portion 5 in the correct position. The retaining portion 5, formed by solder simultaneously with the soldering of the LED2, can be formed to prevent relative positional misalignment with the LED2, thus it is possible to fix both the light-transmitting component 3 and the LED2 to the substrate 1 with extremely high precision and prevent relative positional misalignment between the two. Furthermore, although the retaining portion 5 can be set with extremely high precision relative to the LED2, it is not necessary to set up a specific process for setting the retaining portion 5.

[0083] The conductive film 17 is etched onto the conductive film 15 on the substrate surface, preventing positional misalignment with the electrode conductive film 16, thus allowing them to be disposed together. Solder paste 10 can be printed onto both the electrode conductive film 16 and the conductive film 17 without causing positional misalignment. Furthermore, the solder paste 10 disposed on both the electrode conductive film 16 and the conductive film 17 allows for simultaneous heating of both during the LED 2 soldering process, thereby soldering the LED2. The solder-set holding part 5 is thus used. Therefore, the above-described LED light source 100 and its manufacturing method particularly enable the LED2 and the light-transmitting component 3 to be fixed to the substrate 1 with high positional accuracy while preventing relative positional misalignment.

[0084] Therefore, the optical axes of the LED2 fixed to the substrate 1 and the light-transmitting member 3 can be correctly aligned. This characteristic offers ideal advantages in applications where the emitted light from the LED2 is refracted through the light-transmitting member 3 to form a specific light distribution pattern. For example, regarding LED light sources for backlights in liquid crystal display devices, by using the light-transmitting member as a secondary lens, the emitted light from the LED is radiated outward with a uniform light distribution through the secondary lens, thereby reducing uneven light emission in the liquid crystal display device. Furthermore, regarding LED light sources for vehicle headlights that converge and radiate the emitted light from the LED through the light-transmitting member, the emitted light from the LED is converged into a specific beam, achieving the advantage of brightly illuminating distant objects.

[0085] (Manufacturing method of LED light source)

[0086] The following is based on Figure 13 as well as Figures 14A to 14F The manufacturing method of LED light source is explained. Figure 13 This is a flowchart illustrating the manufacturing process of LEDs. Figures 14A to 14F This is a process diagram illustrating the manufacturing process of an LED light source according to one embodiment.

[0087] (1) First, as step S1, substrate 1 is prepared. The conductive film 15 on the surface of substrate 1 can be fabricated using conventional printed circuit board manufacturing processes. For example, as Figure 14A As shown, by etching away a portion of the conductive film 15, the electrode conductive film 16 and the holding conductive film 17 can be formed. The electrode conductive film 16 is positioned opposite to the planar electrode 21 of the LED 2, and the holding conductive film 17 is positioned where the holding portion 5 is formed. On a substrate 1 on which multiple LEDs 2 are fixed at predetermined intervals, the electrode conductive film 16 is formed opposite to the planar electrode 21 of each LED 2, and the electrode conductive films 16 are connected by a wiring pattern. The holding conductive film 17 is not a conductive film 15 for conducting electricity and does not necessarily need to be connected to the electrode conductive film 16, but it can be formed by connecting it to the electrode conductive film 16. The holding conductive film 17 is positioned where the support portion 4 of the light-transmitting member 3 is positioned at a predetermined location by a holding structure.

[0088] For example, in the etching of substrate 1, ultraviolet light can be irradiated onto the surface of photosensitive resist film via wiring pattern film on substrate surface to expose and cure the area irradiated by ultraviolet light, set the unirradiated area as non-cured, etch and remove the non-cured area, remove the film and set electrode conductive film 16 and holding conductive film 17 on the surface of substrate 1.

[0089] (2) Next, as step S2, solder is printed. Here, for example... Figure 14B As shown, solder resist 14 is coated on the surface of substrate 1. The solder resist 14 is not coated on the entire surface of substrate 1; it is coated only on the LED-fixing mating surface 12 in the area where the LED 2 is fixed, and on the lens-fixing mating surface 13 in the area where multiple retaining parts 5 are arranged. Furthermore, as... Figure 14C As shown, solder paste 10 is applied to the surfaces of the electrode conductive film 16 and the holding conductive film 17 by printing. The height of the holding part 5 can be adjusted by the amount of solder paste 10 applied. For example, by setting the thickness of the solder paste 10 to 0.2 mm, the LED2 can be reliably soldered to the electrode conductive film 16, and the holding part 5 can be provided in a predetermined position by the holding structure (printing process).

[0090] (3) Next, as step S3, the LEDs are installed. Here, for example... Figure 14DAs shown, the planar electrode 21 of LED2 is bonded to the solder paste 10 of the electrode conductive film 16, and LED2 is temporarily fixed.

[0091] (4) Next, as in step S4, reflow welding is performed. Here, as... Figure 14E As shown, the solder paste 10 with LED2 attached is heated and melted, and the LED2 is soldered to a predetermined position on the substrate 1. The solder holding the conductive film 17 is melted and solidified, and a holding part 5 is provided on the surface of the conductive film 17.

[0092] (5) Further, as step S5, adhesive 30 is applied. Here in Figure 14E In the prepared state, adhesive 30 is applied to the location where the light-transmitting component 3, i.e., the support portion 4 of the lens, is disposed. Adhesive 30 is applied, for example, to the mating surface 13 for lens fixing, to bond the light-transmitting component 3 to the substrate 1. The adhesive 30 uses an epoxy resin that is liquid or paste in its uncured state. Suitable materials used in the adhesive 30 include thermosetting resins that cure by heating and UV-curing resins that cure by ultraviolet radiation.

[0093] (6) Further, as step S6, the lens is installed. Here, as... Figure 14F As shown, a light-transmitting member 3 is placed in a holding structure of a plurality of holding portions 5 provided on the lens fixing mating surface 13, and the light-transmitting member 3 is positioned at a predetermined position on the substrate 1.

[0094] (7) Finally, as in step S7, the adhesive 30 for fixing the lens is cured. Here in Figure 14F In the state of holding the light-transmitting component 3 in the predetermined position of the substrate 1 by the holding structure, the light-transmitting component 3 is fixed to the substrate 1 by curing the adhesive 30.

[0095] Industrial availability

[0096] The LED light source and its manufacturing method of the present invention, as an LED light source that diffuses or focuses the emitted light of the LED by refracting through a light-transmitting component and thus radiates it to the outside with a predetermined light distribution pattern, can be appropriately used, for example, as a backlight source for liquid crystal displays, televisions, lighting, indicators, headlights of vehicles, etc.

Claims

1. An LED light source, characterized in that, have: The substrate has a first surface; A retaining part is provided on the first surface; LEDs are disposed on the first surface; A connecting component is used to secure the LED disposed on the first surface; A light-transmitting component, located on or above the upper surface of the LED, is larger than the LED when viewed from above, and is used to refract the light emitted by the LED. The support portion, viewed from above, is located outside the LED and is disposed on the surface of the light-transmitting component facing the first surface of the substrate; as well as Adhesive is used to bond the support portion and the substrate together. The support portion is held by the retaining portion, and the light-transmitting component is disposed at a predetermined position on the first surface of the substrate. Multiple support portions are provided at different locations on the light-transmitting component. The support portion is held in place by a plurality of the retaining portions. The plurality of retaining portions are respectively formed with protrusions on the first surface of the substrate. The plurality of protrusions of each support are respectively positioned at the vertices of the polygon, and the support is disposed on the inner side enclosed by the vertices of the polygon. The substrate is a printed circuit board. The retaining part is formed of the same material as the engaging part.

2. The LED light source according to claim 1, characterized in that, The polygon is either a triangle or a hexagon.

3. The LED light source according to claim 1, characterized in that, The protrusion will guide the region of the support portion that forms the vertices of the polygon as an inclined surface. The inclined surface is inclined toward the direction of insertion of the support and toward the support.

4. The LED light source according to claim 1, characterized in that, The vertical cross-sectional shape of the protrusion relative to the vertical direction of the substrate is circular or elliptical.

5. The LED light source according to claim 4, characterized in that, The bonding component and the holding portion are solders. The substrate has an electrode conductive film formed at the position where the bonding component is disposed on the first surface, and a holding conductive film formed at the position where the holding portion is disposed on the first surface.

6. The LED light source according to any one of claims 1 to 5, characterized in that, The support portion is formed in a columnar shape.

7. The LED light source according to any one of claims 1 to 5, characterized in that, The support portion is formed into a pointed shape.

8. The LED light source according to claim 1 or 2, characterized in that, The support portion has a retaining recess formed on its front end face. The retaining portion has a retaining protrusion that guides the retaining recess. The retaining protrusion is guided by the retaining recess, thereby the support portion is held by the retaining portion.

9. The LED light source according to any one of claims 1 to 5, characterized in that, The LED light source is the light source used for the backlight of the liquid crystal display device.

10. The LED light source according to any one of claims 1 to 5, characterized in that, The light-transmitting component is an optical lens.

11. A method for manufacturing an LED light source according to any one of claims 1 to 10, characterized in that, include: The process of preparing an LED, a substrate having a first side, a shape larger than the LED in top view, a support portion having a support portion on the side opposite to the first side that is mounted on the outside of the LED in top view, a light-transmitting member for refracting the emitted light of the LED, and a bonding member for fixing the LED to the substrate. The process of fixing the LED to the first surface via the joining member; the process of forming a retaining portion on the first surface using the same material as the joining member; as well as The process of bonding the support portion and the retaining portion with an adhesive, and then positioning the light-transmitting component at a predetermined position on the first surface.

12. The method for manufacturing an LED light source according to claim 11, characterized in that, In the process of forming the joining component and the retaining part The retaining part is formed of the same material as the engaging part.

13. The method for manufacturing an LED light source according to claim 12, characterized in that, An electrode conductive film is formed at the position where the bonding member is disposed on the first surface, and a retaining conductive film is formed at the position where the retaining part is disposed.

14. The method for manufacturing an LED light source according to any one of claims 11 to 13, characterized in that, In the process of forming the joining component and the retaining part The retaining portion is formed by a plurality of protrusions surrounding the support portion, and is shaped such that the upper surface of each protrusion is bent.

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