JP6076429B2 - LED package device - Google Patents

Description

  The present invention relates to an LED package device that is mounted with an LED chip and can be used, for example, as a light source of a liquid crystal display device.

  Since LEDs have a long life, are small, and are excellent in luminous efficiency, they are widely applied to various uses such as displays, backlights, and lighting. Among these, an LED package device in which LED chips of three colors are mounted in one package can be used for a color display as a device capable of producing a full color by current distribution. As such an LED package device, for example, a device according to Patent Document 1 below is disclosed.

Japanese Patent No. 3476611 JP 2005-77853 A Special table 2007-536718 gazette

  In Patent Document 1, a green LED chip (101), a red LED chip (102), and a blue LED chip (103) are arranged side by side, and each LED chip (101, 102, 103) is molded with a mold (209). A multicolor light-emitting element designed to be protected is described (the reference numerals in parentheses are those described in the publication).

  In Patent Document 1, as the mold (209), a resin is used, a diffusing agent is added to reduce the directivity and the viewing angle is increased, and various shapes are used to provide a lens effect. Combining a plurality of them, coloring the resin mold itself to give a filter function, and the like are disclosed.

  However, the above-mentioned Patent Document 1 only describes a characteristic imparting generally performed as an LED chip mold.

  On the other hand, in recent years, as the application of LED chips to display devices such as color displays has expanded, due to differences in the light absorption characteristics of each light emitting element, etc., the difference in the light output as a whole even if the applied voltage is equalized. It has been regarded as a problem that color shift occurs due to the occurrence of. Specifically, for example, blue light emitted from a blue LED and green light emitted from a green LED are absorbed by an adjacent red LED, and as a result, the overall color may shift to red. Has occurred.

  When such a color shift occurs, the color reproducibility when used in a color display or the like is affected, which is extremely inconvenient.

  Therefore, it may be possible to improve the color shift by controlling the voltage applied to each light emitting element. However, since the brightness of each light emitting element is different, the light output from each package in a color display or the like has a predetermined brightness. In order to adjust to the color or the hue, the control becomes extremely complicated.

  On the other hand, Patent Document 2 and Patent Document 3 disclose techniques for ensuring optical characteristics with a film or an organic layer.

  As described above, in Patent Document 1, Patent Document 2, and Patent Document 3 as well, improvement of color shift by resin molding has not been studied so far. In this way, if the color shift can be improved by the resin mold provided as an almost essential component for protecting the LED chip, the above-mentioned problem in terms of control will not occur, and the film will be used when the display is made. This is very convenient.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an LED package device that realizes prevention of color shift by a resin mold.

To achieve the above object, an LED package device of the present invention is an LED package device having at least three LEDs having different wavelengths and a lead frame on which each LED is mounted,
The lead frame includes a cup portion on which the LEDs are mounted.
In the cup portion where each LED is mounted, a light-transmitting first resin mold is provided so as to cover each mounted LED,
A light transmissive second resin mold is formed so as to cover at least the opening of the cup part,
The gist is that the first resin mold and the second resin mold have different refractive indexes.

  In the LED package device of the present invention, a light-transmitting first resin mold is provided so as to cover each mounted LED in the cup portion where each LED is mounted, and at least covers the opening of the cup portion. In addition, a light transmissive second resin mold is formed. Thereby, the light emitted from each LED is transmitted through the first resin mold and the second resin mold and irradiated. Since the first resin mold and the second resin mold have different refractive indexes, color shift is effectively prevented, and good color reproducibility is exhibited when used in a color display or the like. Moreover, by preventing the color shift by the resin mold, it is not necessary to cover a film or the like when the display is made.

  In the present invention, when the surface of the first resin mold is provided so that the surface thereof is flush with the opening edge of the cup portion or slightly higher than that, the deterioration of the light distribution characteristics is prevented, and the first resin mold is good. It is preferable for obtaining light distribution characteristics.

  In the present invention, the lead frame includes at least one of a leg portion and a terminal portion, and the second resin mold is formed so as to expose a part of the leg portion and / or the terminal portion. Legs and / or terminals are exposed and do not interfere with electrical connection or heat dissipation.

  In the present invention, when the refractive index of the second resin mold is larger than the refractive index of the first resin mold, it effectively prevents color shift and exhibits good color reproducibility when used in a color display or the like. To do.

  In the present invention, the first resin mold contains a light diffusing agent, but when the second resin mold does not contain a light diffusing agent, the color shift is effectively prevented and a color display or the like is obtained. Good color reproducibility when used.

It is a figure which shows the LED package apparatus of 1st Embodiment of this invention, (A) is a top view, (B) is sectional drawing. It is a light distribution characteristic measurement result of an Example. It is a light distribution characteristic measurement result of a comparative example.

  Next, the best mode for carrying out the present invention will be described.

  1A and 1B are diagrams showing an LED package device according to a first embodiment of the present invention. FIG. 1A is a plan view and FIG. 1B is a longitudinal sectional view thereof.

  In this example, the LED package device is an LED package device including at least three LEDs 2R, 2B, and 2G having different wavelengths and a lead frame 1 on which the LEDs 2R, 2B, and 2G are mounted.

  The LEDs 2R, 2B, 2G having different wavelengths are specifically a red LED 2R, a blue LED 2B, and a green LED 2G. The red LED 2R, the blue LED 2B, and the green LED 2G are all mounted on the mounting surface 3 in the lead frame 1 in the light irradiation direction of the LEDs 2R, 2B, and 2G.

  The lead frame 1 is formed by performing plastic working such as deep drawing or bending on a thin metal plate. In this example, the lead frame 1 includes a cup portion 5 that opens in a track shape in a plan view. The bottom surface of the cup portion 5 of the lead frame 1 functions as a mounting surface 3 on which the LEDs 2R, 2B, and 2G are respectively mounted facing the open side. The LEDs 2R, 2B, and 2G are mounted on the mounting surface 3 to irradiate light. At this time, the inner surface of the cup portion 5 that is spread upward functions as a reflective surface 4 that reflects the light emitted from the LEDs 2R, 2B, and 2G.

  Here, in the present embodiment, in the lead frame 1, the open portion side (the upper surface side in this example) of the cup portion 5 is the light irradiation side, the direction is the light irradiation direction, and at least the upper open portion of the cup is light irradiated. It becomes an area.

  In the lead frame 1, four leg portions 6 are extended at the upper end edge on one side with the longitudinal direction of the cup portion 5 as an axis. The lead frame 1 has one leg portion 6 extending from the end portion on the opposite upper end edge with the longitudinal direction of the cup portion 5 as an axis. The leg portion 6 extends laterally at the height of the upper edge of the cup portion 5 to suspend the cup portion 5, extends downward from the tip thereof to support the cup portion 5, etc. And a portion extending in the direction and in contact with the mounting surface.

  The lead frame 1 has three terminal members (the terminal portions of the present invention) 7 so as to be aligned with the one leg portion 6 at the upper end edge on the opposite side with the longitudinal direction of the cup portion 5 as an axis. Is provided. Each terminal member 7 is provided separately from the cup portion 5 and the leg portion 6. The terminal member 7 extends in the lateral direction at a height higher than the height of the upper end edge of the cup portion 5 and is electrically connected to the LEDs 2R, 2B, and 2G via the connection conductors 8, respectively. It is comprised from the part extended below from a front-end | tip, and the part extended again in the horizontal direction from the lower end, and contact | connects an attachment surface.

  That is, the lead frame 1 has a cup portion 5 and four leg portions 6 formed integrally, and three terminal members 7 are formed separately from the cup portion 5 and the leg portions 6. The first part includes four legs 6 and the second part functions as three terminal members 7.

  In the present embodiment, a light transmissive resin mold 10 (functioning as a protective member) is provided so as to cover the LEDs 2R, 2B, and 2G.

  In the resin mold 10, a first resin mold 11 and a second resin mold 12 having different refractive indexes are laminated in the entire region irradiated with light from the LEDs 2R, 2B, and 2G.

  The first resin mold 11 is formed so as to cover the LEDs 2R, 2B, and 2G that are mounted by filling the cup portion 5 of the lead frame 1 with a light-transmitting resin. The second resin mold 12 is formed by molding a light transmissive resin so as to cover at least the opening of the cup portion 5. In this example, it is molded and arranged so as to cover the periphery of the lead frame 1 filled with the first resin mold 11. That is, the first resin mold 11 exists on the inner side and the second resin mold 12 exists on the outer side in the light irradiation direction of each LED 2R, 2B, 2G.

  Materials constituting the first resin mold 11 and the second resin mold 12 so that the refractive index of the second resin mold 12 arranged on the outer side is larger than the refractive index of the first resin mold 11 arranged on the inner side. Is selected.

  As a material constituting the first resin mold 11, a silicone resin or a silicone rubber having a refractive index of 1.35 to 1.45 can be used. The silicone resin or silicone rubber is suitable as a material constituting the first resin mold 11 from the viewpoints of excellent heat resistance and excellent reliability without long-term discoloration.

  Moreover, as a material which comprises the said 2nd resin mold 12, the epoxy resin which exists in the range of refractive index 1.45-1.65 can be used.

The reason why the color shift can be improved is as follows. First, since the R (red), G (green), and B (blue) three colors are mixed in a state close to complete diffusion over a wide viewing angle by the diffusing agent contained in the first resin mold 11, the directivity of light Can be improved. Further, it is conceivable that the lens effect due to the interface between the first resin mold 11 and the second resin mold 12 and the reflection from the inner surface of the cup portion 5 combine to increase the luminous intensity. Further, the second resin mold 12 is excellent in moisture resistance, has an effect of protecting the first resin mold 11, and has excellent characteristics even in harsh environments such as outdoors.
In addition, the refractive index here means an absolute refractive index when the vacuum is 1.0.

  The first resin mold 11 is formed by filling a resin material in the cup portion 5 of the lead frame 1 in a state where the LEDs 2R, 2B, and 2G are mounted and the connection conductors 8 are welded. At this time, if air remains in the first resin mold 11 as bubbles, the optical characteristics deteriorate, which is not preferable.

  In addition, it is preferable that the surface of the first resin mold 11 is filled with a resin material so that the surface of the first resin mold 11 is flush with or slightly raised from the upper end edge of the cup portion 5 in order to obtain good light distribution characteristics. That is, if the surface of the first resin mold 11 is recessed with respect to the upper end edge of the cup portion 5, the light distribution characteristic is deteriorated, and the amount of resin filled in the cup portion 5 is too large. This is because if the surface partially protrudes from the peripheral edge of the cup portion 5, irregular reflection occurs and the light distribution characteristics are extremely deteriorated.

  The second resin mold 12 is preferably formed so as to expose a part of the leg portion 6 and / or the terminal member 7 of the lead frame 1. In this example, the cup part 5 filled with the first resin mold 11 is completely covered, and the leg part 6 and the terminal member 7 are also covered with the second resin mold 12 except for the surface in contact with the mounting surface. By doing in this way, while preventing the deformation | transformation of the cup part 5, the drop | offset | removal, a deformation | transformation, etc. of the leg part 6 or the terminal member 7, it does not become a hindrance to electrical connection or heat dissipation.

  The first resin mold 11 arranged on the inner side contains a light diffusing agent, but the second resin mold 12 arranged on the outer side preferably contains no light diffusing agent. By doing so, the reflectance and the luminance are improved.

  As the light diffusing agent, various types such as a polymer type and an inorganic type can be used. However, in the material constituting the first resin mold 11 (for example, silicone resin or silicone rubber), the light diffusing agent is not compatible with the matrix phase. Alternatively, it is difficult to be compatible with each other and it is necessary that the particles be dispersed as particles.

  Specific examples of the light diffusing agent include aluminum oxide, calcium carbonate, silica, silicone, zinc sulfide, zinc oxide, titanium oxide, titanium phosphate, magnesium titanate, mica, glass filler, barium sulfate, clay, talc, and silicone. Rubber-like elastic materials, inorganic diffusing agents such as polymethylsilsesoxane, acrylics, styrenes, polyesters, polyolefins, urethanes, nylons, methacrylate-styrenes, fluorines, norbornenes, etc. Examples include diffusing agents.

  Further, the particle size of the light diffusing agent is not particularly limited as long as the desired light diffusibility can be obtained by adding the diffusing agent, but those having an average particle size of about 1 to 50 μm are preferably used. it can. This is because if it is less than 1 μm, it may be difficult to obtain a light diffusion effect only by transmitting light. On the other hand, if it exceeds 50 μm, a sufficient light diffusion effect cannot be obtained and the visibility may be inferior.

  As a compounding quantity of a light-diffusion agent, 0.1 to 10 weight% is suitable with respect to base-material resin. If the blending amount is less than 0.1% by weight, it may be difficult to obtain a sufficient light diffusion effect. On the other hand, if it exceeds 10% by weight, the light transmittance is impaired, and on the contrary, sufficient light diffusion performance is obtained. This is because it may not be obtained. More preferably, it is in the range of 0.5 to 5% by weight.

  Further, two or more kinds of light diffusing agents having different average particle sizes, particle size distributions, and types may be used in combination, and the particle size distribution is not uniform, and those having two or more particle size distributions are used alone or It can also be used in combination.

  In particular, it is effective to use an inorganic light diffusing agent and an organic light diffusing agent in combination. As the inorganic light diffusing agent in this case, hydrophilic fumed silica, hydrophobic fumed silica, aluminum oxide or titanium oxide which is a hydrophilic fumed metal oxide can be suitably used. As the organic light diffusing agent, silicone / acrylic copolymer resin, crosslinked polymethyl methacrylate, crosslinked polybutyl methacrylate, crosslinked polystyrene, crosslinked polyacrylate, and the like can be suitably used.

  The material constituting the first resin mold 11 is easy to fill and easy to work, and from the necessity of obtaining high-precision weighing to obtain the stability of the mold surface shape, in a state where a light diffusing agent is dispersed and blended The viscosity is preferably 6 Pa · s or less, and is cured by chemical reaction or solvent volatilization after filling.

  Next, examples will be described.

  As shown in FIG. 1, each LED 2R, 2B, 2G is mounted on a lead frame 1, a first resin mold 11 made of silicone rubber having a refractive index of 1.41, and a second resin made of epoxy resin having a refractive index of 1.54. Examples were prepared using the mold 12. Note that 0.5 wt% of a diffusing agent was added to the first resin mold 11.

  As a comparative example, the first resin mold 11 was not provided, and only the second resin mold 12 made of epoxy resin was formed.

  FIG. 2 shows the measurement results of the light distribution characteristics of the above-described embodiment, and FIG. 3 shows the measurement results (horizontal placement) of the light distribution characteristics of the comparative example. As can be seen from these results, the comparative example has an irregular characteristic curve for each color of R (red), G (green), and B (blue), whereas the example shows that R (red), G ( It is clear that the characteristic curves of the respective colors (green) and B (blue) are almost circular. From this result, in the comparative example, there is a directivity characteristic in which any color appears strongly depending on the angle, whereas in the example, there is no tendency for any color to appear extremely strong, and the color shift It turns out that it is a level without a problem.

  As described above, according to the LED package device of the present embodiment, the cup portion 5 in which the LEDs 2R, 2B, and 2G are mounted covers the LEDs 2R, 2B, and 2G that are mounted. The first resin mold 11 is provided, and a light transmissive second resin mold 12 is formed so as to cover at least the opening of the cup portion 5. Thereby, the light emitted from each LED 2R, 2B, 2G is transmitted through the first resin mold 11 and the second resin mold 12 and irradiated. Since the first resin mold 11 and the second resin mold 12 have different refractive indexes, color shift is effectively prevented, and good color reproducibility is exhibited when used for a color display or the like. . Moreover, by preventing the color shift by the resin mold 10, it is not necessary to cover a film or the like when the display is made.

In addition, when the first resin mold 11 is provided so that the surface thereof is flush with the opening edge of the cup portion 5 or slightly higher than that, the light distribution characteristics are prevented from deteriorating and good. It is preferable for obtaining light distribution characteristics.
Here, the reason for obtaining good light distribution characteristics is presumed as follows. First, the light distribution characteristics of the red LED 2R could not be corrected with one type of resin mold, whereas a lens effect is produced by providing a light boundary with two types of resin mold. This lens effect improves the light distribution characteristic of the red LED 2R, and as a result, the light distribution characteristic as a whole is improved. Moreover, the convex lens effect is born when silicone rises slightly from the cup portion 5, and the light distribution can be controlled by changing its shape.

  The lead frame 1 includes at least one of a leg portion 6 and a terminal member 7, and the second resin mold 12 is formed so as to expose a part of the leg portion 6 and / or the terminal member 7. In this case, the leg portion 6 and / or the terminal member 7 are exposed and do not hinder electrical connection or heat dissipation.

  Further, when the refractive index of the second resin mold 12 is larger than the refractive index of the first resin mold 11, it effectively prevents color shift and exhibits good color reproducibility when used in a color display or the like. To do.

  In addition, when the first resin mold 11 contains a light diffusing agent, but the second resin mold 12 does not contain a light diffusing agent, color shift is effectively prevented, and a color display or the like is achieved. Good color reproducibility when used.

1 Lead frame 2R Red LED
2B Blue LED
2G green LED
DESCRIPTION OF SYMBOLS 3 Mounting surface 4 Reflecting surface 5 Cup part 6 Leg part 7 Terminal member 8 Connection conducting wire 10 Resin mold 11 1st resin mold 12 2nd resin mold

Claims (2)

An LED package device having at least three LEDs having different wavelengths and a lead frame on which each LED is mounted,
The lead frame forms a cup portion having a bottom surface on which the LEDs are mounted.
In the cup portion where each LED is mounted, a light-transmitting first resin mold is provided so as to cover each mounted LED,
A light transmissive second resin mold is provided so as to cover the first resin mold,
The first resin mold and the second resin mold have different refractive indexes, and the refractive index of the second resin mold is larger than the refractive index of the first resin mold,
The second resin mold has a surface in contact with the surface of the first resin mold , a flat upper surface facing the opposite side of the contact surface, and a flat lower surface ,
In the first resin mold, at least a part of a surface that contacts the surface of the second resin mold is higher than a position of a virtual plane that passes through the upper edge of the cup portion and is parallel to the bottom surface of the cup portion. , Is formed to be a convex curved surface that bulges toward the outside of the cup part ,
The lead frame includes a leg portion and a terminal portion,
The second resin mold is formed so as to expose a part of the leg part and to expose a part of the terminal part,
The leg exposed from the second resin mold includes a first contact surface in contact with the mounting surface,
The terminal portion exposed from the second resin mold includes a second contact surface in contact with the mounting surface,
The first contact surface and the second contact surface are disposed on the periphery of the lower surface of the second resin mold, and are flush with the lower surface.
An LED package device. The LED package device according to claim 1, wherein the first resin mold contains a light diffusing agent, but the second resin mold does not contain a light diffusing agent.

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