JP6236484B2 - Light emitting device - Google Patents

Description

  The present invention relates to a light emitting device such as an LED device in which a lead frame corresponding to each electrode and a resin are integrally formed.

  As this type of conventional light emitting device, Patent Document 1 discloses an integrally molded lead frame and resin corresponding to each electrode.

  FIG. 6 is a cross-sectional view illustrating an exemplary configuration of a main part of a conventional light emitting device disclosed in Patent Document 1.

  In FIG. 6, in the conventional light emitting device 100, the cut side surface of the package 101 and the cut surface of the lead frame 102 are formed flush with each other. The side surface in the concave portion of the package 101 functions as a reflection wall, and the light emitting element 103 is disposed on the lead frame 102 on the bottom surface in the concave portion, and wire bonding is performed on the lead frame 102 constituting each electrode of the anode / cathode. Has been.

JP 2007-329219 A

The lead frame 102 corresponding to each electrode and the resin are integrally molded as in the conventional configuration described above, and the cut surface of the lead frame 102 and the cut side surface of the resin material package 101 coincide with each other. No description has been made on the generation of cracks in the package 101 by the lead frame 102 at the cut surface and the shape of the cut surface of the lead frame 102 for suppressing the crack at the cut surface in the light-emitting device dividing step, which is the subject of the present application.
On the other hand, in the light emitting device described above, a lead frame configuration having a holding portion (also referred to as a hanger lead or a suspension lead) for connecting and holding a plurality of lead frames serving as LED chip mounting surfaces of the light emitting device is adopted. There are some which are formed by being cut and separated into one piece together with a package made of a resin material at a place.

  FIG. 7 is a cut-away side view of the light-emitting device showing a case where the hanger lead has a square cut surface in the conventional light-emitting device having such a lead frame configuration. The hanger lead extends from the LED chip mounting surface portion of the lead frame to the package side surface made of a resin material, and is formed so that the package side surface and the cut surface of the hanger lead are flush with each other. When a thermosetting resin is used as the resin material of the package of such a light emitting device, since many of the mechanical strengths are weak, as shown in FIG. Of the four corners of the shape, cracks 203 are generated when dicing is performed starting from the cutting position of the lower corner.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems, and to provide a light emitting device capable of suppressing cracks generated in a package made of a resin material after dicing and a lead frame for constituting the light emitting device. To do.

The light emitting device of the present invention includes one or a plurality of light emitting elements that emit light, and a light emission using a resin cavity molding package that is integrally formed of a lead frame and a resin that constitute an electrode corresponding to the one or a plurality of light emitting elements. in the apparatus, the holding portion of the lead frame is a rectangular cross section is a square cross-section or a rectangular cross section, Ri cut surface and is flush der of the cut surface and the holding portion of the lead frame of the resin, the cutting On the mounting surface side of the surface, only one corner or two corners on the lower side are provided with rounds for preventing cracks, thereby achieving the above object.

  Preferably, in the light emitting device of the present invention, the roundness is formed at one or two corners that cause cracks during cutting out of the four corners of the cut surface of the lead frame holding portion. It is attached.

  Further preferably, in the light emitting device according to the present invention, one corner on the device mounting surface side or the device rear surface side of the four rectangular portions of the cut surface quadrangular shape in the holding portion of the lead frame exposed on the cut side surface of the package. The roundness is attached to the part or the corner.

  Further preferably, in the light emitting device according to the present invention, among the four corners of the cut surface of the lead frame holding portion exposed at the cut side surface of the package, the two corners facing the thinner side of the resin Are rounded at least at one corner.

  Further preferably, in the light-emitting device of the present invention, the corner is rounded at one corner or two corners on the side where a cutting load is applied to the resin by a cutting blade when cutting.

  Further, preferably, in the light emitting device of the present invention, the roundness is added to all or all of the four corners of the cut surface quadrangular shape in the holding portion of the lead frame exposed on the cut side surface of the package.

  Further preferably, in the light emitting device of the present invention, the roundness is formed by rounding or chamfering.

  Still preferably, in a light emitting device according to the present invention, the thickness of the holding portion is half of the thickness of the lead frame.

  Further preferably, the resin in the light emitting device of the present invention uses a thermosetting resin.

  Further preferably, the resin cavity molded package in the light emitting device of the present invention is formed with a recess opened upward, and the one or more light emitting elements are mounted on the lead frame in the recess, and the recess is formed in the recess. Are formed in a tapered shape so that the side surfaces thereof open outward as reflecting walls.

  With the above configuration, the operation of the present invention will be described below.

  In the present invention, in a light emitting device using a resin cavity molding package in which a light emitting element that emits light is mounted and a lead frame constituting an electrode of the light emitting element and a resin are integrally molded, a cut surface of a holding portion of the lead frame is provided. Of the quadrangular portions of the square shape including the cross section, only one corner or two corners on the lower side on the mounting surface side are rounded, and the cut surface of the resin and the cut surface of the holding portion of the lead frame Is the same.

  As a result, only the lower one corner or two corners are rounded on the mounting surface side of the quadrangular portion having a quadrangular cross section including the cut surface of the lead frame. The concentrated stress from the holding part to the resin is alleviated, and it becomes possible to suppress the resin cracks after dicing division in the holding part of the lead frame.

  As described above, according to the present invention, of the quadrangular portion having a quadrangular cross section including the cut surface of the holding portion of the lead frame, only one corner or two corners on the lower side on the mounting surface side are rounded. Therefore, the concentrated stress on the package made of the resin material from the holding portion of the lead frame generated at the time of cutting can be alleviated, and the occurrence of cracks in the package made of the resin material after dicing division can be suppressed.

It is a perspective view which shows typically the example of an external appearance structure of the light-emitting device in Embodiment 1 of this invention. FIG. 2 is a perspective view of a lead frame showing a state before mounting a light emitting element such as an LED element in the light emitting device of FIG. 1. FIG. 2 is a perspective view of a lead frame and a light emitting element showing a state in which a light emitting element such as an LED element is mounted on the lead frame in the light emitting device of FIG. 1. FIG. 2 is a cut image view obtained by dividing into pieces to obtain the light emitting device of FIG. (A) is a cut side view showing a case where the hanger leads of the light emitting device of FIG. 1 are rounded at the lower two corners of the four corners of the hanger lead, (b) (A) An enlarged view of the cut surface shape of the hanger lead, (c) is a cut surface view of the hanger lead showing a case where chamfering is performed on the two corners instead of the rounded processing of (b), (d) is Hanger lead cut surface view showing a case where the hanger lead cut surface has a semicircular or semi-elliptical shape, (e) is the lower one of the four corners of the hanger lead cut surface. It is a sectional view showing the case where the corner is rounded only. It is sectional drawing which shows the principal part structural example of the conventional light-emitting device currently disclosed by patent document 1. FIG. It is a cut side view which shows the case where the cut surface shape of the hanger lead of the conventional light-emitting device of a product is a square shape. FIG. 8 is a cut-away side view illustrating a state in which a crack is generated from the hanger lead of the conventional light emitting device of FIG. 7 during cutting.

  Hereinafter, Embodiment 1 of the light-emitting device of the present invention will be described in detail with reference to the drawings. In addition, each thickness, length, etc. of the structural member in each figure are not limited to the structure to illustrate from a viewpoint on drawing preparation.

(Embodiment 1)
FIG. 1 is a perspective view schematically showing an external configuration example of a light-emitting device according to Embodiment 1 of the present invention. FIG. 2 is a perspective view of the lead frame showing a state before mounting a light emitting element such as an LED element in the light emitting device of FIG. 1. FIG. 3 is a perspective view of the lead frame and the light emitting element showing a state in which a light emitting element such as an LED element is mounted on the lead frame in the light emitting device of FIG. FIG. 4 is a cut image view of obtaining the light emitting device of FIG. 1 by dividing into pieces.

  1 to 3, a light emitting device 1 such as an LED device according to the first embodiment includes an optical element 2 such as an LED element that emits light, and a metal lead frame that constitutes one electrode and the optical element 2 is disposed. 3, a metal lead frame 4 constituting the other electrode, and a pair 5 of these lead frames 3, 4 and a white resin cavity molded package 5 using a white resin molded integrally with resin.

  The white resin is a thermosetting resin, and other silicon-based (hard and brittle) resin materials such as epoxy and PPA (polyphthalamide) may be used as a resin material such as titanium oxide. A material to which a light diffusion material is added is used. The package 5 is formed with a recess having a side wall around it, and the side surface 5a of the reflection wall is tapered in the recess so as to open outward in four directions.

  The light-emitting device 1 has a pair of lead frames 3 and 4 constituting each electrode on which the light-emitting element 2 is mounted and the terminals of the light-emitting element 2 and the wires 2a are wire-bonded. A plurality of pairs are arranged in a matrix and provided with holding portions that connect between the adjacent lead frames 3 and 3 and between the adjacent lead frames 4 and 4. This holding portion is generally referred to as “hanging”. Here, the holding portion between the adjacent lead frames is referred to as a hanger lead (also referred to as a suspension lead).

  A method for manufacturing the light emitting device 1 of Embodiment 1 will be described.

  First, in the white resin cavity molding step of FIG. 2, a plurality of pairs of lead frames 3 and 4 are arranged in a matrix in the row direction and the column direction, and the lead frames adjacent in the row direction and the column direction are hangered with each other. They are connected by leads 3a or 4a. A package 5 made of a white resin is integrally formed with a plurality of pairs of lead frames 3 and 4 as described above. The package 5 made of an integrally formed white resin is formed with a recess opened upward, and the side surface 5a in the recess is tapered so as to open outward.

  Next, in the optical element mounting step of FIG. 3, the optical element 2 is mounted on the center portion of the bottom surface in the concave portion of the package 5 made of an integrally molded white resin. In short, the optical element 2 is fixed and mounted with an adhesive or the like at a predetermined position on the lead frame 3 exposed in the recess of the package 5, and wire-bonded from the optical element 2 to the lead frames 3 and 4, respectively.

  Subsequently, in the inner resin filling step of FIG. 1, the inside of the concave portion of the package 5 made of this white resin is embedded together with the optical element 2 with the sealing inner resin 6. The inner resin 6 for sealing (also referred to as sealing resin) is mixed with a light scattering material, a fluorescent material, or the like. For example, if the optical element 2 is a blue LED, a fluorescent material that emits red and green light by blue light can be mixed in the inner resin 6 to emit white light.

  Thereafter, in the singulation process of FIG. 4, each light emission is performed by the blade 7 (rotary cutting blade) in a state in which a plurality of light emitting devices 1 are attached to the back surface of the plate body 8 formed in a matrix. The plate body 8 is cut into a lattice shape between the devices 1 and separated into individual light emitting devices 1. In this case, the cut surfaces of the hanger leads 3a and 4a of the lead frames 3 and 4 coincide with the cut side surfaces of the white resin (Pkg resin) package 5. Moreover, each light-emitting device 1 cut | disconnected with the cutting tape which is not shown in figure does not fall apart. The cutting tape is removed in the final process.

  Here, each sectional shape which is a characteristic configuration of the present invention in cutting the hanger lead 3a of the lead frame 3 constituting the one electrode on which the optical element 2 is mounted and the hanger lead 4a of the lead frame 4 constituting the other electrode is shown. This will be described with reference to FIGS. 5 (a) to 5 (e).

  At the time of cutting, concentrated stress is applied to the white resin (Pkg resin) by the hanger leads 3a and 4a as the holding portions of the lead frames 3 and 4, and the corner portions that cause cracks are dropped and rounded. When the rotation direction of the blade 7 is right rotation, the force due to the downward rotation acts on the white resin, but when the rotation direction of the blade 7 is the left rotation, the force due to the upward rotation acts on the white resin. Usually, cutting is more stable when the blade 7 is rotated clockwise.

  FIG. 5A is a cut-away side view showing a case where the lower two corners of the hanger leads 3a, 4a of the light emitting device 1 of FIG. 5 (b) is an enlarged view of the cut surface shape of the hanger leads 3a and 4a in FIG. 5 (a), and FIG. 5 (c) is a chamfering C process instead of the rounded R process in FIG. 5 (b). FIG. 5 (d) is a cross-sectional view of the hanger lead showing the case where the hanger lead has a semicircular or semi-elliptical shape, FIG. FIG. 5E is a cross-sectional view showing a case where the cut surface shape of the hanger lead in FIG. 5A is rounded only at the lower corner of the four corners.

  As shown in FIGS. 5 (a) and 5 (b), the rear surface side of the light emitting device 1 or the mounting surface of the light emitting device 1 out of the quadrangular portions of the square shape or rectangular shape of the hanger leads 3a, 4a. The two corners on the side (lower side) are provided with roundness (referred to as a rounded portion (R processed portion)) for preventing cracks during cutting. In short, the rounded curved surface portion of the hanger leads 3a, 4a is located on the side surface (cut surface) of the package 5 from the cut surface position of the hanger leads 3a, 4a to the mounting surface (lower side) position of the light emitting device 1. The thickness of the white resin (Pkg resin) is less than the thickness of the white resin around the hanger leads 3a, 4a, or the white resin package 5 is cut when cut. On the other hand, it is formed so that the cutting load by the blade is rounded (referred to as a rounded portion (R processed portion)) at the two corners (lower side) applied to the white resin. Since cracks at the time of cutting need only be suppressed, all or all of the squares of the squares of the cross-sectional squares or rectangulars of the hanger leads 3a and 4a may be curved surfaces (for example, circular or elliptical cross-sections). For example, as shown in FIG.5 (d), the cut surface shape of the hanger leads 3a and 4a may be a semicircle or a semi-elliptical shape.

  In addition, the lead frame main body (excluding the curved surface portion of the suspended lead) of the lead frames 3 and 4 is formed by etching with an acid or alkali solution (etching to reduce the thickness of the lead frame base material to approximately half, and then half etching). May be formed by press molding.

  An example of formation will be described below.

  The back surface of the metal plate base that is the base of the frame body of the lead frames 3 and 4 (the back surface that is the mounting surface of the light emitting device, the back surface opposite the mounting surface (light emitting surface side) of the light emitting element 2 (for example, LED chip) ), A mask is formed at a portion to be the mounting surface of the light emitting device 1, and the periphery thereof is half-etched. Next, on the surface of the metal plate base (the surface on the LED chip mounting surface side), a mask is formed at a location corresponding to the hanger leads 3a and 4a and the LED chip mounting surface portion and the wire bond portion, Half-etch. At this time, a full-face mask is formed so that the back side of the metal plate base material is not etched.

  In this step, the portion between the lead frames 3 and 4 of the metal plate base material is etched in full thickness, and electrical insulation between the lead frames 3 and 4 is ensured. The lead frames 3 and 4 are held by the hanger leads 3a and 4a between the pair of other lead frames 3 and 4.

  In addition, in forming the mask on the surface of the metal plate base material, it is possible not to form a mask corresponding to the concave portion serving as the anchor portion in order to improve the adhesion with the white resin and / or the inner resin. Good. The same applies to the half-etching process on the back side of the metal plate base material.

  Moreover, the order of the half etching may be performed in the order of the front surface side and the back surface side, and the front and back surfaces may be performed simultaneously.

  As the mask material, a commonly used mask material such as a resist is used.

  After the above lead frame forming process, in order to obtain the cross-sectional shape of the hanger leads 3a and 4a and the desired curved surface shape (for example, the round process shown in FIG. 5B), the mask is removed and then soft etching (short time) Treatment with acid or alkali solution). Separately from this, as shown in FIG. 5 (c), chamfering (also referred to as C processing) is performed on the lower two corners of the four corners so as to drop the corners instead of the rounding in FIG. 5 (b). You may make it apply to.

  Furthermore, as shown in FIG. 5 (e), one of the left and right corners on the back side (lower side) of the light emitting device 1 out of the squares of the squares or rectangulars of the hanger leads 3a and 4a. You may make it attach roundness (Ru process or chamfering process) for crack prevention at the time of cutting. In short, when cutting each light-emitting device 1 with a blade, a round (roughing or chamfering) for preventing cracks at the time of cutting is attached to either one of the left and right corners on the side where the hanger leads 3a, 4a are cut first. To disperse the concentrated stress.

  When the cross-sectional dimensions of the hanger leads 3a, 4a of the lead frames 3, 4 are, for example, a long side (width) 150 μm × short side (thickness) 120 μm of a rectangular cross section, the roundness of the cut surfaces of the hanger leads 3a, 4a (R The radius (r) of the curved surface portion to which processing or chamfering processing (chamfering portion C) is applied is set to r = 30 to 90 μm (or 40 to 60 μm). When the radius (r) is smaller than 30 μm, the effect of dispersing concentrated stress is lacking. From the viewpoint of consistency in the manufacturing process, the radius (r) is preferably set to a value of 60 μm, which is half of the short side (thickness) of 120 μm. Note that the radius (r) is equal to R indicating the radius of machining in FIGS. 5 (b), 5 (d), and 5 (e). 5A is a position 5b of the surface of the lead frames 3 and 4 and the mounting surface of the light emitting element 2, which indicates the position of the bottom surface of the recess.

  In short, as described above, the cross section of the holding portion (hanger leads 3a, 4a) that causes concentrated stress to be applied to the white resin by the holding portions (hanger leads 3a, 4a) of the lead frames 3, 4 at the time of cutting. Some or all of the corners are rounded.

  Specifically, for example, one corner or two corners that cause cracks at the time of cutting out of the four corners of the cut surface of the holding portions (hanger leads 3a and 4a) of the lead frames 3 and 4 May be provided with a roundness for preventing cracks. In addition, one of the four corners of the cut surface quadrangular shape of the holding portions (hanger leads 3a and 4a) of the lead frames 3 and 4 exposed on the cut side surface of the package 5 is one corner on the device mounting surface side or the device back surface side. Alternatively, the corners may be rounded. Further, of the square portions of the cut surface quadrangular shape of the holding portions (hanger leads 3a, 4a) of the lead frames 3 and 4 exposed on the cut side surfaces of the package 5, the two corner portions facing the thinner one of the white resin At least one of the corners may be rounded. Furthermore, one corner or two corners on the side where the cutting load by the cutting blade is applied to the white resin of the package 5 at the time of cutting may be rounded. Furthermore, all or all of the four corners of the cut surface quadrangular shape in the holding portions (hanger leads 3a, 4a) of the lead frames 3, 4 exposed on the cut side surfaces of the package 5 may be rounded. Furthermore, these roundings can be formed by rounding or chamfering.

  In the first embodiment, one light emitting element 2 that emits light is mounted, and light emission using the lead frame 3 and 4 that constitutes an electrode corresponding to the one light emitting element 2 and the package 5 that is made of white resin. The apparatus 1 is applied with rounding of the cross section of the holding portion (hanger leads 3a, 4a), which is a characteristic configuration of the present invention, but is not limited to this, and a plurality of light emitting elements (for example, 2 or 3) that emit light are mounted. In addition, a light emitting device using a lead frame constituting electrodes corresponding to the plurality of light emitting elements and a package made of white resin is used to round the cross section of the holding portion (hanger leads 3a, 4a) which is a characteristic configuration of the present invention. May be applied.

  As described above, in the light emitting device in which the hanger lead cutting surface and the light emitting device dividing (cutting) surface are flush with each other, the above-described hanger lead configuration has excellent weather resistance and light resistance, but is hard and brittle thermosetting resin Can be stably used for Pkg resin.

  In other words, according to the present invention configuration (hanger lead configuration), the load on the Pkg resin by the lead frame can be reduced, and furthermore, a thermosetting resin having excellent weather resistance and light resistance can be used as the Pkg resin. Reliability can be improved. Further, since the light emitting device configuration in which the hanger lead cutting surface and the light emitting device dividing (cutting) surface are flush with each other can be adopted, the outer lead configuration protruding outside the Pkg resin is not provided, and the light emitting device can be downsized Since the number of kgs that can be arranged on the lead frame can be increased, there is a cost reduction effect.

  As mentioned above, although this invention has been illustrated using preferable Embodiment 1 of this invention, this invention should not be limited and limited to this Embodiment 1. It is understood that the scope of the present invention should be construed only by the claims. It is understood that those skilled in the art can implement an equivalent range from the description of the specific preferred embodiment 1 of the present invention based on the description of the present invention and the common general technical knowledge. Patents, patent applications, and documents cited herein should be incorporated by reference in their entirety, as if the contents themselves were specifically described herein. Understood.

  In the field of light emitting devices such as LED devices in which a lead frame corresponding to each electrode and a resin are integrally formed, the present invention is rounded in part or all of the cross-sectional corner portion of the holding portion of the lead frame. The stress concentrated on the white resin from the holding portion of the lead frame that is sometimes generated is relieved, and the white resin crack after the dicing division can be suppressed.

DESCRIPTION OF SYMBOLS 1 Light-emitting device 2 Optical element 2a Wire 3, 4 Lead frame 3a, 4a Hanger lead 5 White resin cavity molding package 5a Side surface which comprises the reflecting wall in a recessed part 5b The position of the surface of a lead frame, and the mounting surface of a light emitting element 6 Inner Resin (sealing resin)
7 Blade (Rotating cutting blade)
8 Plate body R Round diameter C Chamfer

Claims (9)

In a light-emitting device using a resin cavity molding package in which one or a plurality of light-emitting elements that emit light are mounted and a lead frame constituting an electrode corresponding to the one or a plurality of light-emitting elements and a resin are integrally molded, the lead frame holding portion is a rectangular cross section is a square cross-section or a rectangular cross section, Ri cut surface and is flush der of the cut surface and the holding portion of the lead frame of the resin, down in the mounting surface side of the cutting plane A light emitting device in which only one corner or two corners on the side have a roundness for preventing cracks . Wherein among the four corner portions of the cutting surface square shape of the holding portion of the lead frame, the light emitting device according to claim 1 marked with the rounded first corner portion or corner portion as the result of cracking of the switching section .   Of the four corners of the cut surface of the lead frame holding portion exposed at the cut side surface of the package, the corner is rounded at one or two corners on the device mounting surface side or the device back surface side. The light emitting device according to claim 1.   At least one corner portion of the square portion of the lead frame holding portion exposed at the cut side surface of the package that faces the thin side of the resin is rounded at the corner portion. The light-emitting device according to claim 1.   The light-emitting device according to claim 1, wherein the roundness is attached to one corner or two corners on a side where a cutting load is applied to the resin by a cutting blade when the resin is cut.   2. The light emitting device according to claim 1, wherein the rounding is provided on all or all of the four corners of the cut surface quadrangular shape in the holding portion of the lead frame exposed on the cut side surface of the package.   The light emitting device according to claim 1, wherein a thickness of the holding portion is half of a thickness of the lead frame.   The light emitting device according to claim 1, wherein the resin is a thermosetting resin.   The resin cavity molding package is formed with a recess opened upward, and the one or more light emitting elements are mounted on a lead frame in the recess, and a side surface in the recess opens outward as a reflection wall. The light emitting device according to claim 1, wherein the light emitting device is tapered.

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