JP2011165965A - Method of manufacturing light emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a light emitting element for fabricating, by a printing method, a light emitting device wherein the top faces of a phosphor layer and a light shielding material are flush with each other. <P>SOLUTION: A light shielding member 3 having a flat top face is mounted on a submount 1 so that a part of the light shielding member may cover part of an upper part of a light emitting element 2. Outside the light shielding member 3 and the light emitting element 2, a mask 5 with an opening having a predetermined shape is disposed. An uncured phosphor-containing resin 61 is applied on the top face of the light shielding member 3. A squeegee 62 is brought into contact with the top face of the light shielding member 3, and then is moved with a predetermined pressing force from the top face of the light shielding member 3 toward the upper part of the light emitting element 2 to form a phosphor-containing resin layer 64, the top face of which is flush with the top face of the light shielding member 3. After removing the mask 5, the phosphor-contained resin layer 4 is cured. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a light emitting device including a phosphor layer, and more particularly to a method for manufacturing a light emitting device having a configuration in which a light distribution pattern is controlled by blocking a part of light emission by a light shielding member.

  As a light emitting device that emits white light, a device including a blue LED chip mounted on a base material and a phosphor-containing resin that covers the LED chip is known. Part of the blue light of the LED excites the phosphor, and white light is obtained by mixing the blue light emitted from the LED chip and the yellow fluorescence emitted from the excited phosphor. As a method for forming the phosphor-containing resin, printing or a dispensing method is generally used. For example, Patent Document 1 discloses a method of forming a phosphor-containing resin layer around an LED chip by a stencil printing method.

  On the other hand, in some light-emitting devices such as vehicle headlamps, it is desirable to form a cut-off (boundary between the irradiated portion and the non-irradiated portion) where the light beam distribution pattern is clear. For this reason, for example, Patent Document 2 discloses a light-emitting device that blocks a part of a light beam emitted from a light-emitting element by a light-shielding member (beam shutter) standing beside the light-emitting element, thereby clarifying the cutoff. Yes.

  Patent Document 3 discloses a structure in which an LED chip is disposed on the bottom surface of a recess formed in a housing frame, and the recess is filled with a phosphor-containing resin. FIG. 4 of Patent Document 3 discloses a configuration in which a screen layer is mounted on a part of a housing frame, and a portion on which the screen layer is mounted is arranged so as to cover an upper part of the LED. Thus, a clear cut-off is formed by blocking the light emitted from the LED by the screen layer on a part of the LED.

Japanese Patent No. 4208449 JP 2006-222430 A US Publication No. 2009/0159912 (A1) (see FIG. 4)

  A light emitting device that is desired to form a clear cut-off of an irradiation pattern, such as a vehicle headlamp, has a structure in which a light beam irradiation pattern is enlarged and projected by a lens 101 as shown in FIG. . When such a light emitting device having a structure in which a beam shutter is set up beside the light emitting element as described in Patent Document 2, for example, a part of the light incident on the beam shutter is reflected to become stray light and a lens. 7 and is projected, the stray light blurs the vicinity of the cut-off line as shown in FIG. 7, causing a problem that the cut-off line becomes unclear.

  In the light emitting device disclosed in FIG. 4 of Patent Document 3, the screen layer 4 is positioned substantially horizontally on the upper surface of the phosphor-containing resin layer 6, but the screen layer 4 has a phosphor-containing resin layer corresponding to the thickness. Located above 6. For this reason, the light emitted from the phosphor is reflected by the end face (thickness portion) of the screen layer 4 and enters the lens as stray light. As in FIG. 7, the vicinity of the cutoff line is blurred and the cutoff line is unclear. become.

  In order to solve this problem, it is desirable to have a structure in which the upper surface of the light shielding material and the phosphor layer are arranged on the same plane so that light emitted from the phosphor layer does not enter the light shielding material. However, even if the stencil printing method described in Patent Document 1 is adopted in the structure in which the beam shutter is set up beside the light emitting element as in Patent Document 2, an attempt is made to form the phosphor layer up to a height matching the upper surface of the beam shutter. The difference in height between the beam shutter and the light emitting element is large and difficult. Further, when a stencil-printed mask is arranged, it interferes with the beam shutter.

  On the other hand, in Patent Document 3, since the concave portion is filled by potting (dropping) the phosphor-containing resin into the concave portion of the housing frame, the phosphor content can be increased only to a viscosity that can be filled by potting. Can not. This is because when the content of the phosphor is increased, the thixotropy of the resin is increased and the concave portions cannot be filled by potting. For this reason, it is necessary to use a resin having a low phosphor content, and there arises a problem that the phosphor settles on the bottom of the resin. When the phosphor settles on the bottom of the resin, the top surface of the phosphor-containing resin layer is substantially lower than the screen layer, and the top is filled with a transparent resin. The phenomenon that the reflected light is reflected by the end face of the screen layer and becomes stray light cannot be solved.

  In addition, the structure described in Patent Document 3 adopts the stencil printing method described in Patent Document 1, and a phosphor-containing resin having a high phosphor content up to a height coincident with the upper surface of the screen layer in the concave portion of the housing frame. It is conceivable to fill by printing. However, there is a problem that the mask cannot be placed because it interferes with the housing frame when placing the mask for stencil printing. Normally, the opening shape of the mask needs to match the upper surface shape of the phosphor-containing resin layer to be filled. However, in the structure of Patent Document 3, the phosphor-containing resin layer is filled in the recess of the housing frame. It is.

  In addition, it is conceivable to make the opening of the mask for stencil printing in conformity with the outline of the housing frame. For this reason, the area of the phosphor-containing resin layer is increased, and the density of light emitted from the phosphor is decreased in accordance with the rate of increase in area, which is undesirable from the viewpoint of light distribution formation.

  For this reason, it is necessary to selectively deposit the phosphor-containing resin layer on the concave portion of the housing frame by the printing method while avoiding the formation of the phosphor-containing resin layer on the upper portion of the housing frame. Have difficulty.

  The objective of this invention is providing the manufacturing method of the light emitting element which forms the light-emitting device by which the upper surface of a fluorescent substance layer and a light shielding material exists in the same plane by a printing method.

  In order to achieve the above object, according to the first aspect of the present invention, the following method for manufacturing a light emitting device is provided. That is, on the submount on which the light emitting element is mounted, a step of mounting the light shielding member having a flat upper surface so that a part thereof covers a part of the upper part of the light emitting element, and the outside of the light shielding member and the light emitting element, A step of arranging a mask having an opening of a predetermined shape, a step of applying an uncured phosphor-containing resin to the upper surface of the light shielding member, a squeegee in contact with the upper surface of the light shielding member, and the squeegee being shielded by a predetermined pressure By moving from the upper surface of the light-emitting element toward the upper part of the light-emitting element, the uncured phosphor-containing resin is filled into the upper part of the light-emitting element, and a phosphor-containing resin layer whose upper surface is located in the same plane as the upper surface of the light shielding member is formed And a step of removing the mask and curing the phosphor-containing resin.

  For example, the above-described light shielding member has a shape having outer sides extending along both sides of the light emitting element, the height of the outer side is the same as the upper surface of the light shielding member, and the height of the mask is It is preferable to use a light-shielding member that is smaller than the height of the upper surface. When the squeegee moves to the upper part of the light emitting element, both ends of the squeegee are supported by the outer sides of the light shielding member, whereby a phosphor-containing resin layer having an upper surface that is the same height as the upper surface of the light shielding member can be formed.

  According to the present invention, a light-emitting device in which the phosphor-containing resin layer and the upper surface of the light shielding member are present on the same plane can be manufactured by a printing method, and therefore, the effect of preventing stray light from being generated by the end portion of the light shielding member, etc. Is obtained.

BRIEF DESCRIPTION OF THE DRAWINGS (a) Top view of the light-emitting device of embodiment of this invention, (b) AA arrow directional view. 2A is a top view, FIG. 2B is a rear view, and FIG. 3C is a side view of the light shielding member of the light emitting device of FIG. 1. FIG. 4 is a top view showing a state where the LED chip 2 and the light shielding member 3 are mounted on the LED submount in the manufacturing process of the embodiment. (A) The top view of the mask 5 used in the manufacturing process of embodiment, (b) The top view which shows the state which mounted the mask on LED submount. FIG. 6 is a top view showing a state in which a phosphor-containing resin 61 is applied and a squeegee 62 is arranged on the light shielding member 3 on which the mask 5 is arranged outside in the manufacturing process of the embodiment. (A)-(d) In the manufacturing process of the embodiment, the phosphor-containing resin 61 is applied on the light-shielding member 3 on which the mask 5 is arranged on the outside, and the squeegee 62 is moved to phosphor-containing resin layer 4. The BB arrow line view which shows the process of forming. Explanatory drawing which shows that a stray light produces the blur of a cut-off line in the conventional light-emitting device.

  Hereinafter, an embodiment of the present invention will be described.

  The present invention provides a method for manufacturing a light emitting device in which the upper surface of a phosphor resin layer and the upper surface of a light shielding material are located on the same plane.

  The light emitting device manufactured according to this embodiment has four LED chips 2 on the LED submount 1 as shown in the top view in FIG. 1A and the AA arrow view in FIG. It is mounted side by side. A light blocking member 3 is fixed on the LED submount 1.

  As shown in FIGS. 2 (a), 2 (b), and 2 (c), the light shielding member 3 is composed of a side plate 3b and a back plate 3c on both sides, as shown in a top view, a rear view, and a side view. The LED submount 1 is supported on the upper surface. Thus, the light shielding plate 3a is supported in parallel with the upper surface of the LED submount 1. A part of the light shielding plate 3a covers a part of the upper part of the LED chip 2.

  At the front end of the light shielding plate 3a of the light shielding member 3, a part 3d is parallel to the row of the LED chips 2, a part 3e is cut obliquely, and the light from the LED chip 2 is partially obliquely inclined. The cut-off light distribution pattern is formed.

  In addition, the outer side portion 3f in contact with the side plate 3b of the light shielding plate 3a is provided longer than the width of the LED chip 2 (direction perpendicular to the column). This outer side portion also functions as a guide portion that supports a squeegee, which will be described later in the manufacturing process.

  The upper and front side surfaces of the four LED chips 2 are integrally covered with a phosphor-containing resin layer 4 as shown in FIGS. The upper surface of the phosphor-containing resin layer 4 is located on the same plane as the upper surface of the light shielding plate 3a as shown in FIG. 1B, and the end surface of the light shielding plate 3a is also covered with the phosphor-containing resin layer 4.

  Here, the LED chip 2 that emits blue light is used. The phosphor-containing resin layer 4 is a layer in which a phosphor that emits yellow fluorescence using blue light as excitation light (for example, a YAG phosphor) is dispersed in a resin that is transparent to visible light. Thus, a light emitting device that emits white light is manufactured.

  Hereinafter, the manufacturing process will be described.

(Installation process of LED chip 2 and shading member 3)
First, as shown in FIG. 3, the LED chip 2 is flip-chip mounted on the LED submount 1 on which electrodes are formed in advance. Next, an adhesive (for example, a thermosetting adhesive) is applied to the back surface of the side plate 3b of the light shielding member 3. The light shielding member 3 is manufactured in advance with a light shielding material, for example, a metal material such as stainless steel or copper. For example, a heat-resistant silicon-based adhesive can be used as the adhesive.

  Next, using the corner of the LED chip 2 as a reference point P1, grasping this position by image recognition, the light shielding member 3 is aligned and arranged as shown in FIG. Glue. Next, a predetermined adhesive curing step is performed, and the light shielding member 3 is fixed to the LED submount 1. The adhesive curing process is a process corresponding to the adhesive, for example, left in an environment of 160 ° C. for 1 hour.

(Mask alignment process)
Next, a mask 5 having a shape as shown in FIG. The mask 5 is made of a metal material and has a through hole 5a having a size that allows the outline of the LED chip 2 and the light shielding member 3 to be accommodated. One inner wall surface 5b of the through-hole 5a is smooth to mold a part of the outer surface on the front side of the phosphor-containing resin layer 4, and preferably has high releasability with respect to the applied phosphor-containing resin. . The inner wall surface 5b is disposed to face the side surface of the LED chip 2 and to be aligned with the front end portion of the light shielding member 3.

  The height of the upper surface of the mask 5 is designed to be slightly lower than that of the light shielding plate 3a on the upper surface of the light shielding member 3.

  The mask 5 is disposed so that the outline of the light shielding member 3 is accommodated in the through hole 5a as shown in FIG. 4B while grasping the position of the reference point P2 at the corner of the light shielding member 3 by image recognition.

(Print application process of phosphor-containing resin with squeegee)
Next, the printing application process of the phosphor-containing resin using a squeegee will be described with reference to FIGS. 5 and 6A to 6D.

  First, a predetermined amount of a phosphor is dispersed in an uncured resin to prepare a predetermined thixotropic phosphor-containing resin. The thixotropy is set to a value suitable for stencil printing using a mask. For example, a thixo coefficient of 1.0 to 15.0 is preferable, and more preferably 3.0 to 9.0.

  The prepared uncured phosphor-containing resin 61 is applied to the upper surface of the light shielding member 3 in a strip shape longer than the row of the four LED chips 2 as shown in FIGS. 5 and 6A.

  Next, the squeegee 62 is arranged at the position shown in FIG. The squeegee 62 is positioned by recognizing an image of the reference point P3 at the end of the light shielding member 3.

  As shown in FIG. 6B, the squeegee 62 is moved in the direction of the arrow while applying a predetermined pressure. Thereby, the phosphor-containing resin (uncured) 61 is filled in the space between the light shielding member 3 and the LED chip 2. At this time, since both ends of the squeegee 62 are supported by the outer side portion 3f of the upper surface of the light shielding member 3, the squeegee 62 moves horizontally at the same height as the upper surface of the light shielding member 3 even after the reference point P3. Therefore, the phosphor-containing resin (uncured) layer 64 on the upper surface coinciding with the upper surface of the light shielding member 3 is formed as shown in FIG.

  When the squeegee 62 is further moved, the squeegee 62 reaches the inner wall surface 5b on the front side of the through hole of the mask 5. Thus, the phosphor-containing resin fills the space surrounded by the light shielding member 3 and the inner wall of the mask 5, and forms a phosphor-containing resin (uncured) layer 64 around the LED chip 2.

  When the squeegee 62 is moved as it is as shown in FIG. 6C, the outer side 3f of the light shielding member 3 is formed to extend to the outside of the inner wall surface 5b of the opening of the mask 5, so Both ends move on the mask 5 while being supported by the outer side 3f. As a result, a thin phosphor-containing resin layer (uncured) 65 is also formed on the upper surface of the mask 5. Finally, the mask 5 and its Ueno fluorescence are removed by removing the mask 5 as shown in FIG. The body-containing resin layer (uncured) 65 is removed. Therefore, the phosphor-containing resin layer 64 having an upper surface whose height matches the upper surface of the light shielding member 3 is formed.

  Finally, a step of curing the phosphor-containing resin layer 4 under predetermined conditions is performed, and the phosphor-containing resin having an upper surface having a height matching the upper surface of the light shielding member 3 of the present embodiment as shown in FIG. A light emitting device comprising the layer 64 is obtained. The curing process is a process according to the resin, such as heating at 150 ° C. for 1 hour.

  As described above, according to the method for manufacturing the light emitting device of the present embodiment, the phosphor-containing resin layer 4 is made of the resin having a high thixotropy and the phosphor dispersed in a high concentration by the printing method. Can be formed to a height consistent with Therefore, the blue light from the LED chip 2 and the fluorescence from the phosphor are not reflected by the light shielding member 3 or its end face, and stray light does not occur. Therefore, by preventing blurring of the light distribution pattern from being cut off due to stray light generated by the light shielding member, it is possible to manufacture a light emitting device that realizes a clear cutoff of the light distribution pattern.

  Since the light-emitting device of this embodiment can irradiate the light distribution pattern of a partly oblique cut-off line, it can be suitably used as a light source for a vehicle headlamp.

  The shape of the end portion of the light shielding member 3 is not limited to the slanted shape as in this embodiment, and even when a light shielding member having a horizontal end portion is used, It can be manufactured similarly.

1 ... LED submount, 2 ... LED chip, 3 ... light shielding member, 3a ... light shielding plate, 3b ... side plate, 3b ... back plate, 3d ... part of the end, 3e ... one of the end cut diagonally Part, 3f ... outer side part, 4 ... phosphor-containing resin layer, 5 ... mask, 5a ... through hole, 5b ... inner wall surface on the front side, 61 ... uncured phosphor-containing resin, 62 ... squeegee, 64 ... fluorescence Body-containing resin (uncured) layer, 65 ... thin phosphor-containing resin (uncured) layer.

Claims (2)

Mounting a light-shielding member having a flat upper surface on a submount on which the light-emitting element is mounted so that a part thereof covers a part of the upper part of the light-emitting element;
Disposing a mask having an opening of a predetermined shape outside the light shielding member and the light emitting element;
Applying an uncured phosphor-containing resin to the upper surface of the light shielding member;
A squeegee is brought into contact with the upper surface of the light shielding member, and the squeegee is moved from the upper surface of the light shielding member toward the upper portion of the light emitting element by a predetermined pressure, whereby the uncured phosphor-containing resin is moved to the upper portion of the light emitting element. And forming a phosphor-containing resin layer whose upper surface is located in the same plane as the upper surface of the light shielding member,
And a step of removing the mask and curing the phosphor-containing resin layer. The light-emitting device manufacturing method according to claim 1, wherein the light-shielding member has outer side portions extending along both sides of the light-emitting element, and the height of the outer side portion is equal to that of the light-shielding member. The same as the top surface,
The height of the mask is smaller than the height of the upper surface of the light shielding member,
When the squeegee moves to the upper part of the light emitting element, both ends thereof are supported by the outer side portion of the light shielding member.

Images