JP2012248708A - Led package and manufacturing method of led package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of an LED package capable of effortlessly adjusting a direction of light emitted from the LED package into a desired direction in a manufacturing step after an LED element mounting even if a mounting position of the LED element is displaced.SOLUTION: A manufacturing method of an LED package includes: a mounting step of mounting an LED element on a body substrate; a sealing layer formation step of sealing the LED element mounted on the body substrate with a transparent sealing layer; a position detection step of detecting a position when the LED element is viewed from a plane direction; a groove formation position calculation step of calculating a formation position of a closed-end groove to be formed on a surface of the sealing layer on the basis of the LED element position detected by the position detection step; a closed-end groove formation step of forming an annular closed-end groove in the groove formation position calculated by the groove formation position calculation step; and a lens part formation step of forming a lens part by supplying a transparent resin being in a liquid state to a region enclosed by an inner peripheral edge of the closed-end groove on the surface of the sealing layer and raising the transparent resin by a surface tension which occurs in an inner periphery edge boundary.

Description

  The present invention relates to an LED package with a lens and a method for manufacturing the LED package.

  A conventional LED package with a lens is formed by, for example, filling a sealing resin in a cup on which an LED element is mounted and bonding the lens on the sealing resin after curing, as shown in Patent Document 1, for example. is there.

  By the way, a problem with this type of LED package is that a gap is created by air entering between the lens and the sealing resin. This reduces the light extraction efficiency due to the effect of the air layer, but in the manufacturing process, the sealing material is injected so that the volume in the cup is exactly the same, and it is not possible to eliminate the air layer when the lens plates are stacked. very difficult.

  Therefore, as shown in Patent Document 2, an annular concave groove is provided on the substrate, and after an LED element is mounted in a region surrounded by the concave groove, a silicone resin is dropped on the region so as to cover the LED element. In some cases, a silicone resin is formed in a hemispherical shape by utilizing the surface tension generated at the inner peripheral edge of the concave groove. This hemispherical silicone resin can provide a lens effect, and since the lens and the sealing resin are integrated, there is no problem that an air layer is formed.

JP-A-8-320656 JP 2008-071859 A

  However, with the configuration as in Patent Document 2, since the LED element is mounted by soldering or the like after cutting the concave groove, it is difficult to raise the mounting position accuracy beyond a certain level. As a result, the positional relationship between the lens formed by the concave groove and the LED element varies. For example, when line light is produced by arranging a plurality of LED packages in a straight line, the light emission direction from each LED package varies. This causes a problem that a line light source having a certain linear accuracy cannot be made. In particular, in a small LED package, a slight displacement of the LED element greatly affects the directionality of light, and this problem becomes significant.

  However, if it is attempted to correct the LED element misalignment during the manufacturing process, the LED element misalignment mainly occurs in the soldering process. Therefore, the misalignment correction must be performed during or after soldering. This is virtually impossible.

  Furthermore, in the configuration of Patent Document 2, unless the size (radius) of the concave groove is changed, the lens formed of the hemispherical silicone resin has a substantially constant shape and a constant size, and is positioned at a fixed position in the lens. Since the LED element is arranged, it is difficult to change the distance between the light emitting surface of the LED element and the lens surface. For example, it is almost necessary to adjust the light collection position by moving the LED light emitting surface closer to or away from the lens surface. I can't respond.

  In view of these problems, the present invention has been made, and the main purpose of the present invention is to manufacture the LED element from the LED package in the manufacturing process after mounting the LED element, even if the LED element is misaligned on the substrate. An object of the present invention is to provide a method of manufacturing an LED package and the like that can easily adjust the direction of emitted light in a desired direction and can easily adjust the light collection distance.

  That is, the manufacturing method of the LED package according to the present invention includes a mounting step of mounting the LED element on the main body substrate, and a sealing layer forming step of sealing the LED element mounted on the main body substrate with a transparent sealing layer. A position detecting step for detecting a position when the LED element is viewed from a plane direction, and a bottomed groove to be formed on the surface of the sealing layer based on the position of the LED element detected in the position detecting step A groove forming position calculating step for calculating the formation position of the groove, a bottomed groove forming step for forming an annular bottomed groove at the groove forming position calculated in the groove forming position calculating step, and the presence on the surface of the sealing layer. A lens part forming step of supplying a transparent resin in a liquid state to a region surrounded by the inner peripheral edge of the bottom groove and forming the lens part by raising the transparent resin by surface tension with the inner peripheral edge as a boundary. Characterized by Than is.

If this is the case, even if the mounting position of the LED element with respect to the main body substrate is deviated from the normal position, the formation position of the bottomed groove, that is, the position of the lens portion should be set in consideration of the deviation amount. Thus, the direction of light emitted from the LED package can be adjusted to be suitable for a desired purpose, for example, a line light source. Moreover, since the distance from the light emitting surface of an LED element to a lens part can be adjusted if only the thickness of a sealing layer is controlled, a condensing distance can also be adjusted easily. Since the accuracy can be increased in this way, it can be optimized for a reference light source or the like.
The main body substrate here means either a substrate on which the LED element is directly mounted (package substrate) or a substrate on which the LED element is indirectly mounted (substrate on which the package substrate is mounted).

  For example, in the case of a line light source, a plurality of LED elements are arranged in a straight line, and the lens portion is formed in each LED element. The formation position of each bottomed groove is calculated in the groove formation position calculation step so that the optical axis of the light that has passed through the corresponding lens portion passes through a predetermined line parallel to the arrangement direction of the LED elements. You can do it.

  In the case of spot light concentrated at one point, for example, a plurality of LED elements are laid out on the surface, and the lens portion is formed on each LED element, and a lens corresponding to the LED element is emitted from each LED element. The formation position of each bottomed groove may be calculated in the groove formation position calculation step so that the optical axis of the light that has passed through the portion passes through a predetermined point.

  In the case of a surface light source, for example, a plurality of LED elements are laid on the surface, and the lens portions are formed on the LED elements, respectively. The formation positions of the bottomed grooves may be calculated in the groove formation position calculating step so that the optical axes of the bottom grooves are parallel to each other.

  As a method of forming a bottomed groove that can be realized very easily found by the present inventors after intensive studies, the surface of the sealing layer is irradiated with a short pulse laser to form an annular altered portion, and the altered portion Examples of forming the bottomed groove by removing the are as follows.

As a specification of the short pulse laser in this case, the pulse width is preferably 3000 fs or less, and the lower limit is preferably about 100 fs. The average output is preferably in the range of 10 mW to 1000 mW. The wavelength is preferably 300 nm to 1500 nm. Moreover, it is more desirable if the pulse width is 150 fs to 1000 fs.
Further, the present invention includes a plurality of LED elements arranged side by side in accordance with a predetermined rule, and a lens portion arranged on each light emitting direction side of each LED element, and deviates from the predetermined rule. Corresponding to the LED element so that the direction or arrival point of the light emitted from the LED element arranged in this manner substantially matches the direction or arrival point of the light emitted from the LED element when arranged according to a predetermined rule It may relate to an LED package characterized in that the arrangement position of the lens portion is set.

  According to the present invention configured as described above, even if the mounting position of the LED element with respect to the main body substrate is deviated from the normal position, the position of forming the bottomed groove, that is, the position of the lens portion is taken into consideration by taking the deviation amount By setting, the direction of the light emitted from the LED package can be adjusted to facilitate the desired purpose, for example, suitable for a line light source. Moreover, since the distance from the light emitting surface of an LED element to a lens part can be adjusted if only the thickness of a sealing layer is controlled, a condensing distance can also be adjusted easily.

The top view and center sectional drawing of the LED package in 1st Embodiment of this invention. The manufacturing process figure which shows the basic manufacturing method of the LED package in the embodiment. The schematic diagram which shows the manufacturing apparatus of the LED package in the embodiment. Explanatory drawing which showed the process in which a modified part is made when a femtosecond laser is irradiated to a silicone resin. The expanded sectional view which shows the protrusion of a bottomed groove | channel, and a glassy layer. The center sectional view and top view which show the state in which the LED element is mounted in the position which shifted | deviated on the main body board | substrate in the same embodiment. The manufacturing process figure which shows the manufacturing process in case the LED element is mounted in the position which shifted | deviated on the main body board | substrate in the same embodiment. The perspective view which showed the state from which the light from each LED package was located in a line in the same embodiment. Sectional drawing which showed the optical axis direction of the light from each LED package in other embodiment of this invention. Sectional drawing which showed the optical axis direction of the light from each LED package in other embodiment of this invention. Sectional drawing which showed the optical axis direction of the light from each LED package in other embodiment of this invention.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

<First Embodiment>
An LED package 100 according to this embodiment is, for example, a surface-mount type. As shown in FIG. 1, an LED element 1, a main body substrate 2 on which the LED element 1 is directly mounted, and the LED element 1 are arranged. A sealing layer 3 to be sealed and a lens portion 4 provided on the surface of the sealing layer 3 are provided.

The LED element 1 is a known element in which a P layer and an N layer are joined.
The main body substrate 2 has, for example, a block shape (thick plate) having a circular element housing recess 21 in the center in plan view, and the LED element 1 is soldered to the center of the bottom surface of the element housing recess 21. It is joined by etc. In addition, although electric power is supplied to this LED element 1 by the wire etc. from the printed wiring of the main body board | substrate 2, illustration of these electrical wiring related members is abbreviate | omitted here.
The sealing layer 3 is formed, for example, by filling the element housing recess 21 with a transparent silicone resin.

The lens portion 4 is formed of the same transparent silicone resin as the sealing layer 3, and has a circular shape in which the center thereof coincides with the center of the LED element 1 in plan view.
Next, a basic manufacturing method of the LED package 100 will be described with reference to FIG.

  First, after mounting the LED element 1 on the bottom surface of the concave portion of the main body substrate 2 (for example, soldering), liquid transparent silicone resin is injected into the concave portion 21 of the main body substrate 2 to seal the LED element 1 so that there is no exposed portion. The sealing layer 3 to be formed is formed. In addition, as long as it has fluidity | liquidity even if it has a certain amount of viscosity here, it defines as liquid.

  Next, after the transparent silicone resin is cured to a predetermined hardness before being almost completely cured, or after being completely cured, as shown in FIG. The surface of the sealing layer 3 is irradiated with a femtosecond laser that is a short pulse laser, for example, along a circular orbit having a predetermined radius. This femtosecond laser R is emitted from the laser apparatus shown in FIG. The femtosecond laser R has a pulse width of 150 fs, an average output of 50 mW, and a wavelength of 800 nm. The scanning speed of the laser R, that is, the moving speed of the laser R is 200 μm / sec. The femtosecond laser R may be fixed and the main substrate 2 may be moved (rotated). Details of the irradiation position of the laser R will be described later.

  In the sealing layer 3 irradiated with the femtosecond laser R, an altered portion Q having a constant width and a constant thickness is formed. The altered portion Q has a change in physical properties and shape as compared with the surrounding silicone resin, and is solidified and peelable. More specifically, as shown in FIG. 4, when a void is formed by the irradiation of the femtosecond laser R, and heat and pressure waves propagate around it to change the physical properties and shape around the irradiation region, the present invention. Estimate.

  After the irradiation with the femtosecond laser R in this way to generate the altered portion Q having an annular shape in plan view, as shown in FIG. 2B, the altered portion Q is turned upside down or given vibration, for example. Or by pulling with a jig to form the bottomed groove 5. At this time, as shown in FIG. 5, an altered thin vitreous layer 51 is formed on the surface of the bottomed groove 5. Further, the periphery of the bottomed groove 5 may be slightly raised.

Next, a predetermined amount of the same liquid silicone resin as the sealing layer 3 (second resin in the claims) is dropped on the surface region of the sealing layer 3 surrounded by the inner peripheral edge 5a of the bottomed groove 5. As shown in FIG. 2C, the lens portion 4 having a substantially partial spherical shape is formed by preventing further spreading by surface tension acting on the inner peripheral edge 5a. The dripping amount of the silicone resin is a range in which the surface tension is not broken, that is, a range in which the silicone resin overflows from the inner peripheral edge 5 a of the bottomed groove 5 and does not enter the bottomed groove 5. It is determined according to the size of the area surrounded by, and the rising height of the lens unit 4.
Thereafter, the dripped silicone resin is cured as shown in FIG.

  In such a case, since the liquid silicone resin is dropped on the surface of the sealing layer 3 to form the lens part 4, there is no room for an air layer to enter between the lens part 4 and the sealing part 3. The optical interface formed by the same silicone resin as the layer 3 is completely absent, and the light extraction efficiency can be maximized.

  In addition, it is extremely difficult to form the bottomed groove 5 on the surface of the elastic silicone resin by conventional methods, whether it is mechanical processing or thermal processing such as continuous laser irradiation. For example, it can be realized very simply by irradiating the femtosecond laser R. This was discovered by the inventor of the present application as a result of intensive studies, and was not considered in the past.

  Further, since the peripheral edge of the bottomed groove 2 is slightly raised and the edge portion is a vitreous layer 51 as shown in FIG. 8, it overflows even if a large amount of the silicone resin forming the lens portion 4 is dripped. Absent. Therefore, there is an advantage that the degree of freedom of the shape of the lens unit 4 can be increased, such as increasing the curvature of the lens unit 4 to increase the curvature.

  Therefore, in this embodiment, in order to determine the irradiation position of the laser R, as shown in FIG. 3, the position detection sensor 6 such as a CCD camera for detecting the position of the LED element and the laser device are driven. Control means 8 for controlling is provided.

  The position detection sensor 6 uses, for example, a two-dimensional area sensor, images the LED element 1 and the main body substrate 2 from the plane direction, in other words, from the light emission direction of the LED element 1, and controls the image data. To send to. Note that the position detection timing may be appropriately determined after the LED element 1 is mounted on the main body substrate 2 and before the lens portion 4 is formed.

  In terms of hardware, the control means 8 is composed of, for example, an analog or digital electric circuit, and includes a CPU and a memory (not shown). On the other hand, functionally speaking, the CPU and other hardware cooperate in accordance with a program stored in the memory, whereby the image data receiving unit 81 that receives the image data, and a predetermined process on the received image data. The LED element position specifying unit 82 for specifying the mounting position of the LED element 1 on the main body substrate 2, and the formation position of the bottomed groove 5, that is, the irradiation position of the laser R, is calculated based on the mounting position of the LED element 1. The groove forming position calculation unit 83 functions as a laser drive control unit 84 that drives and controls the laser device 7 so that the laser R is irradiated to the calculated groove formation position.

Next, an example of the manufacturing process of the LED package 100 in the case where the mounting position of the LED element 1 is deviated from the normal position (for example, the center position) of the main body substrate 2 also serves as an explanation of the operation of each part of the control means 8. This will be described with reference to FIGS.
First, the position detection sensor 6 images the main body substrate 2 on which the LED element 1 is mounted from the plane direction, and transmits the image data to the control means 8.

  In the control means 8, the image data receiving unit 81 receives this image data, and the LED element position specifying unit 82 performs image processing on the image data, specifies the mounting position of the LED element 1, and The amount of deviation in the XY direction from the mounting position is calculated. Here, for example, as shown in FIG. 6, it is assumed that the position of the LED element 1 mounted on the substrate is shifted from the normal position by e in the X direction.

Next, based on this deviation amount (deviation vector) e, the groove formation position calculation unit 83 calculates the formation position of the bottomed groove, that is, the irradiation position of the laser R. Here, for example, as shown in FIG. 7, the light emitted from the LED element 1 is refracted by the lens portion 4 formed along the bottomed groove 5, and its optical axis G is the original optical axis C. The formation position of the bottomed groove 5 is calculated so as to pass through a point P having a predetermined height on the main substrate 2 or the mechanical central axis C of the element housing recess 21 here.
Then, the laser drive controller 84 controls the position of the laser device 7 or its optical system or the position of the main body substrate 2 so that the calculated bottomed groove forming position is irradiated with the laser R.
Then, as described above in the basic manufacturing method, the lens portion 4 is formed using the formed bottomed groove 5 to complete the LED package.

  In the case of such a configuration, for example, when a plurality of LED packages are arranged in a straight line and used as a line light source, the light from each LED package 100 is emitted from the main body substrate of each LED element 1 as shown in FIG. Regardless of the variation in position with respect to 2, the lines are aligned on the straight line L at the predetermined height P without deviation. Therefore, line light with very high linear accuracy can be obtained by using the predetermined height P as a light irradiation surface or a diffusion surface for an object. In FIG. 8, the LED element 1 is not misaligned only in the left front package 100.

  The present invention is not limited to the above embodiment. For example, the bottomed groove may be formed by a mechanical cutting means such as a router, a trimmer, or a high-pressure liquid jet, or may be formed by a thermal means such as a hot wire, and the method is not particularly limited. Absent.

As shown in FIG. 9, the bottom groove formation position may be set so that the optical axis G of the light emitted from the LED element 1 and refracted by the lens unit 4 is parallel to the original optical axis. . Such a setting method is effective when a surface light source is configured by laying a large number of LED packages 100 on a surface. In FIG. 9, a plurality of element receiving recesses 21 are provided in the common main body substrate 2. In other words, a plurality of LED packages share one main body substrate.
Further, as shown in FIG. 10, the optical axis G of the light emitted from the LED element 1 and refracted by the lens unit 4 may be set to be gathered at one point. Such a setting method is effective when a spot light source is configured by laying a large number of LED packages on a surface.
Further, as shown in FIG. 11, a plurality of LED elements 1 are arranged on a straight line, and the distances between the optical axes G are separated from each other by a predetermined distance Y from the upper surface of the LED elements 1 or the main body substrate 2. You may make it equal. In this case, for example, if the diffuser plate is arranged at a site separated by Y, the light from each LED element 1 that irradiates the diffuser plate is evenly distributed, and light without unevenness can be emitted from the diffuser plate. The LED elements may be laid out in a grid pattern. In that case, the optical axes G may be arranged at equal lattice points in the portions separated by the predetermined distance Y.
In addition, the present invention can be variously modified without departing from the spirit of the present invention.

100 ... LED package 1 ... LED element 1
DESCRIPTION OF SYMBOLS 3 ... Sealing layer R ... Short pulse laser Q ... Altered part 5 ... Bottomed groove 5a ... Inner peripheral edge of bottomed groove 4 ... Lens part

Claims (5)

A mounting process for mounting the LED element on the main body substrate;
A sealing layer forming step of sealing the LED element mounted on the main body substrate with a transparent sealing layer;
A position detection step of detecting a position when the LED element is viewed from a plane direction;
A groove formation position calculating step of calculating a formation position of a bottomed groove to be formed on the surface of the sealing layer based on the position of the LED element detected in the position detection step;
A bottomed groove forming step of forming an annular bottomed groove at the groove forming position calculated in the groove forming position calculating step;
A transparent resin is supplied in a liquid state to a region surrounded by the inner peripheral edge of the bottomed groove on the surface of the sealing layer, and the transparent resin is raised by surface tension with the inner peripheral edge as a boundary to form a lens portion. A method of manufacturing an LED package. A plurality of LED elements are arranged side by side, and are applied to an LED package in which each LED element is formed with the lens portion,
In the groove forming position calculating step, the optical axis of the light emitted from each LED element and passed through the corresponding lens unit passes through a predetermined point or a predetermined line, or is substantially parallel to each other. 2. The method of manufacturing an LED package according to claim 1, wherein the formation position of the bottom groove is calculated.   The bottomed groove forming step includes forming a bottomed groove by irradiating a surface of the sealing layer with a short pulse laser to form an annular deteriorated portion and removing the deteriorated portion. The manufacturing method of the LED package in any one of 1 or 2. A plurality of LED elements arranged side by side in accordance with a predetermined rule, and a lens portion respectively arranged on the light emission direction side of each LED element,
The direction or the arrival point of the light emitted from the LED element arranged so as to deviate from the predetermined rule substantially matches the direction or the arrival point of the light emitted from the LED element when arranged according to the predetermined rule. An LED package, wherein an arrangement position of a lens portion corresponding to the LED element is set.   The arrangement position of the lens unit is set so that the optical axis of the light emitted from each LED element and passed through the corresponding lens unit substantially passes a predetermined point or a predetermined line, or is substantially parallel to each other. The LED package according to claim 4.