JP2013153126A - Led package and led light emitting element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an LED package and an LED light emitting element which prevent a sealing resin from leaking from the package and also prevent a sulfide from penetrating into a cavity.SOLUTION: An LED package includes: a lead frame 102 including one surface on which an LED chip 110 is placed and the other surface that is a rear surface of the one surface and a flat surface; a lead frame 101 facing the lead frame 102; and an insulation part 103 connecting connection end parts where the lead frames 101, 102 face each other. At least a part of the other surface of the lead frame 102 is exposed from the insulation part 103. Rough parts are formed by laser processing in an end part on the connection end part side on the other surface of the lead frame 102 and in at least a part of the connection end part.

Description

  The present invention relates to an LED (Light Emitting Diode) package and an LED light emitting element.

  In recent years, a light emitting device in which an LED chip having a size of several tens of μm to several mm is accommodated in a package, and its use is expanding as an electronic device, a vehicle, and various lighting devices.

  In the LED package, an LED chip is mounted on the bottom surface of the recess, molded with a sealing material such as silicone resin, and electrically and mechanically connected to the mounting substrate by electrodes exposed to the outside from the package.

  The most common LED package includes a heat sink, a lead frame, and a case. The heat sink is required for heat diffusion, the lead frame is required for electrical conduction, and the case is required for insulation and heat dissipation. The LED package is required to efficiently extract the light emitted from the LED chip. In addition to the light emitted directly from the LED, the LED package reflects the light by providing a reflector, and more light is emitted to the outside. Such high-brightness packages are being studied.

  The lead frame is manufactured by etching or stamping a metal material for a lead frame made of a plate-like alloy thin plate such as iron-nickel or a metal thin plate such as copper-nickel-tin. The lead frame manufactured in this way has a pad electrode (island electrode) for mounting the LED chip, an inner lead electrode electrically connected to the LED chip, and an externally connected pad electrode. An outer lead electrode electrically connected to the substrate;

  The sealing resin fills the recesses in the upper part of the package to protect the LED chip and the wiring, and converts the wavelength of the light from the LED chip from, for example, blue to white by containing a fluorescent material. Since the sealing resin is required to be filled in a narrow gap, a low-viscosity organic resin (for example, a silicone resin) is often used. For this reason, as a package, it is necessary to prevent the liquid resin that has flowed into the concave portion at the top from leaking out from the side surface or the bottom surface of the package.

  Since the package member is made of a resin material and a metal having different thermal expansion coefficients, the adhesion and adhesion are poor. As a result, if the sealing resin leaks from the gap at the interface between the resin part and the metal part, the LED chip and the wiring in the reflector intended for sealing cannot be protected, and various solder mounting defects, etc. Cause problems. Moreover, when the fluorescent material is contained in the sealing resin, the fluorescent material also leaks together with the sealing resin, resulting in deviation from the target chromaticity.

Patent Document 1 describes a semiconductor device in which a groove or a protrusion is formed in a part of a lead frame to prevent the sealing resin from leaking from the interface between the outer lead electrode and the package member toward the outer wall surface. ing. It is described that the forming direction of the groove and the protrusion is a direction perpendicular to the extending direction of the outer lead electrode. Further, it is described that the method of forming the groove and the protrusion is formed by punching (pressing) or etching. In addition, as a material of the lead frame, it is described that an alloy based on Cu and whose surface is treated with Ag is preferable from the viewpoint of conductivity, heat dissipation, mechanical strength, light reflection, and the like. ing.

JP 2006-222382 A

  However, since the semiconductor device described in Patent Document 1 is a technique that focuses on preventing leakage of the sealing resin from the interface between the outer lead electrode and the package resin portion toward the outer wall surface, it has the following problems.

  (1) Since a groove or protrusion is formed by punching (pressing) or etching on a lead frame made of Ag-plated Cu alloy surface, the formed groove or protrusion is made of Cu alloy. The Ag plating on the surface may be damaged. Moreover, even if the Ag treatment having a sufficient film thickness is performed on the surface, it is inevitable that the Ag treatment is not uniform in the groove or the protrusion.

  For this reason, it has been found that the Ag plating becomes thin or the Ag plating is peeled off at the groove or the protrusion, and a hydroxide, an oxide, or the like is generated due to moisture or the like to be corroded. When the Cu alloy is corroded, the corroded material is exposed on the surface, and the LED characteristics such as luminance are deteriorated.

  (2) Although the sealing resin leakage due to the lowering of the adhesion between the mold resin and the lead frame has been described, the countermeasure against sulfuration of Ag plating that penetrates from the outside of the LED package into the cavity that is the mounting area of the LED chip. Not listed. When sulfides such as sulfur dioxide in the air permeate into the cavity from the interface between the outer lead electrode and the package member, the Ag plating becomes silver sulfide and blackens, and the optical characteristics deteriorate, for example, the reflectance decreases. There is no description about the countermeasure against sulfuration of this Ag plating, and no effective countermeasure has been taken.

  Moreover, the sealing resin does not necessarily prevent the penetration of gas and moisture. For this reason, the deterioration of the LED chip is often caused by the penetration of moisture and gas in the air, and the reliability is often lowered.

  (3) Further, there is no description about measures against leakage of the sealing resin at the interface between the lead frame and the reflector resin and measures against sulfurization into the cavity.

  An object of the present invention is to provide an LED package and an LED light emitting element that can prevent sealing resin from leaking out of the package and prevent sulfide penetration into the cavity.

  An LED package of the present invention includes a first lead frame including one surface on which an LED is placed, and the other surface that is the back surface of the one surface and is a plane, and is parallel to the one surface. A second lead frame that faces the first lead frame in a direction, and a resin that connects between the connection ends of the first lead frame and the second lead frame that face each other, and at least A part of the other surface of the first lead frame is exposed from the resin, an end of the other surface of the first lead frame on the connection end side, and at least a part of the connection end Is characterized in that a rough portion is formed by laser processing.

  ADVANTAGE OF THE INVENTION According to this invention, the LED package and LED light emitting element which can prevent the sealing resin leaking out from a package and can prevent the penetration | infiltration of impurities, such as a sulfide which contaminates or corrodes the inside of a cavity, are implement | achieved. be able to.

The perspective view which shows typically the LED package which concerns on one embodiment of this invention Cross-sectional perspective view of LED package according to the present embodiment Sectional drawing of the LED package which concerns on this Embodiment Sectional drawing of the LED package which concerns on this Embodiment The figure explaining the amplitude average parameter of the height direction of the LED package which concerns on this Embodiment The figure explaining the laser processing conditions from the relationship between the laser scanning speed and the laser output of the LED package according to the present embodiment The figure which shows the photograph before and behind the laser processing of Ag plating which was image | photographed with the laser micrograph of the LED package which concerns on this Embodiment Manufacturing process diagram until sealing of sealing resin of LED package according to the present embodiment The figure which shows the photograph which expanded the lead frame of the LED package which concerns on this Embodiment.

  The invention according to claim 1 is a first lead frame comprising one surface on which an LED is placed, and the other surface which is the back surface of the one surface and is a plane, and the one surface. A second lead frame that faces the first lead frame in a parallel direction; and a resin that connects between the connection ends of the first lead frame and the second lead frame facing each other. , At least a part of the other surface of the first lead frame is exposed from the resin, and an end of the other surface of the first lead frame on the side of the connection end, and at least of the connection end Part of the LED package is characterized in that a rough portion is formed by laser processing. According to a second aspect of the present invention, there is provided the LED package according to the first aspect, the LED mounted on the first lead frame, and the one of the LED and the first and second lead frames. And a transparent resin that seals at least part of the surface of the LED. As a result, even if it is very difficult to process the connecting end portion of the first lead frame facing the second lead frame in the direction parallel to the one surface, the rough portion can be formed by laser processing. As a result, even if a part of the other surface of the first lead frame is exposed from the resin, the sealing resin can be prevented from leaking out of the package, and impurities such as sulfides can contaminate or corrode the cavity. Can be prevented.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment)
FIG. 1 is a perspective view schematically showing an LED package according to an embodiment of the present invention.

As shown in FIG. 1, the LED package 100 includes a pair of rectangular lead frames 101 and 102, a rectangular insulating portion 103 that electrically insulates the lead frame 101 and the lead frame 102, a lead frame 101, 102 and the reflector part 104 surrounding the outer peripheral part of the insulating part 103.

  The lead frames 101 and 102, the insulating portion 103, and the reflector portion 104 are configured integrally.

  The lead frames 101 and 102 are used by processing a metal plate made of Cu or a Cu alloy from the viewpoint of conductivity, heat dissipation, mechanical strength, light reflection, and the like. The lead frames 101 and 102 are used after their surfaces are Ag-plated in order to improve the optical characteristics of light.

  A pair of the lead frame 101 and the lead frame 102 is disposed so as to sandwich the insulating portion 103 from the horizontal direction. That is, the connection surface between the lead frame 101 and the lead frame 102 and the insulating portion 103 is a surface where the lead frame 101 and the lead frame 102 face each other. The lead frame 101 is, for example, an anode side lead portion, and the lead frame 102 is a cathode side lead portion.

  The insulating portion 103 is made of a thermosetting resin such as epoxy or a thermoplastic resin such as polyphthalamide, and holds the lead frame 101 and the lead frame 102. The upper surface (front surface) of the insulating portion 103 as one surface forms the concave bottom portion of the LED package 100 together with the upper surfaces (surface) of the lead frames 101 and 102.

  The reflector unit 104 is made of a thermosetting resin such as epoxy or a thermoplastic resin such as polyphthalamide, and efficiently reflects light from the LED element in the upper direction of the LED package 100. The reflector unit 104 is preferably a white resin containing, for example, titanium oxide.

  An LED chip 110 that is a light emitting element is mounted on the upper surface (front surface) of the lead frame 102 of the LED package 100. The upper surface of the LED package 100 has a concave LED mounting space (cavity) 105 by the upper surface of the lead frame 102, the lead frame 101, and the insulating portion 103 on which the LED chip 110 is mounted surrounded by the reflector portion 104. Forming. The reflector unit 104 is not always necessary.

  The LED chip 110 is connected (wire bonded) to the lead frames 101 and 102 by bonding wires 111 and 112 which are conductive members. The diameters of the bonding wires 111 and 112 are preferably 25 μm to 35 μm. As the material, Al, Cu, Pt, Au or the like is preferably used.

  As the LED chip 110, for example, a GaN blue light emitting diode chip is used.

  The cavity 105 is filled with a sealing resin (not shown), and the LED chip 110 and the bonding wires 111 and 112 disposed in the cavity 105 are sealed by the sealing resin. Since this sealing resin has a high light transmittance at the emission wavelength of the LED element and is required to be filled in a narrow gap, a low viscosity organic resin (for example, a silicone resin) is used.

  FIG. 2 is a cross-sectional perspective view of the LED package 100, and FIG. 3 is a cross-sectional view of the LED package 100. 2 and 3, the description of the LED chip 110 and the bonding wires 111 and 112 in FIG. 1 is omitted.

As shown in FIGS. 2 and 3, the connection portion between the lead frames 101 and 102 and the insulating portion 103 has a step structure in which concave and convex portions are combined. More specifically, the lead frames 101 and 102 have a step structure in which the upper surface (front surface) which is one surface is wide and the lower surface (back surface) which is the other surface is narrow, and is sandwiched between the lead frames 101 and 102. The insulating portion 103 has a step structure opposite to the upper surface (front surface) and a lower surface (back surface) wide. Further, the connecting portion between the lead frames 101 and 102 and the reflector portion 104 has a structure in which an uneven portion is fitted as shown in FIG. This step structure is not actually formed at a right angle as shown in FIGS. That is, it is difficult to form the step structure at a right angle by, for example, etching, and a gentle curve may be drawn. The size of the curve depends on the processing accuracy.

  With these structures, the adhesion between the lead frames 101 and 102, the insulating part 103, and the reflector part 104 is improved, leakage of a low-viscosity sealing resin (for example, silicone resin) is prevented, and the inside of the cavity 105 of the outside air To prevent penetration. The step structure of the lead frames 101 and 102 and the insulating portion 103 is a structure that places more importance on improving the sealing performance between the inside and outside of the cavity.

  Even if the above structure is adopted, the portions surrounded by the broken lines in FIGS. 2 and 3, that is, the connection surfaces of the lead frames 101 and 102 and the insulating portion 103 and the connection surfaces of the lead frames 101 and 102 and the reflector portion 104 are still This is the part where adhesion is required.

  The present invention drastically improves the adhesion between the lead frame 101, 102 and the insulating portion 103, and the connection between the lead frame 101, 102 and the reflector portion 104 enclosed by the broken lines in FIGS. It is.

  FIG. 4 is a cross-sectional view of the LED package 100. 4A is a reprint of FIG. 3, FIG. 4B is an enlarged view of the main part of the connection part (A part) between the lead frames 101 and 102 and the insulating part 103, and FIG. It is a figure which expands and shows the interface of a connection part (B part). In this embodiment, the connecting portion (B portion) is described for the sake of clarity, but the connecting portion is not limited to the B portion in FIG. 4 (b) as shown in FIG. 4 (b).

  As described above, in the present embodiment, the lead frames 101 and 102 are made of a Cu alloy, and the surface thereof is Ag-plated. The insulating part 103 and the reflector part 104 are made of epoxy resin.

  The present invention is characterized in that the Ag plating surfaces of the lead frames 101 and 102 are roughened in a predetermined state by laser processing. That is, as shown in FIG. 4C, a rough surface having a surface roughness (Ra) of 0.1 to 10 μm is formed on the Ag plating surfaces of the lead frames 101 and 102 by laser processing. The Ag plating surfaces of the lead frames 101 and 102 are roughened by laser processing so as to form a rough surface of 0.1 to 10 μm, and then the lead frames 101 and 102 are bonded to the insulating portion 103 or the epoxy resin of the reflector portion 104. Resin molding.

  Next, the place which performs laser processing is demonstrated.

As shown in FIG. 4B, the step structure in the laser irradiation portion such as the A portion (connection portion) is not actually formed at a right angle as shown in FIGS. That is, it is difficult to form the step structure at a right angle, and a gentle curve is often drawn. If the lead frames 101 and 102 are curved, irregularities cannot be formed on the surfaces of the lead frames 101 and 102 unless the laser is irradiated with high output. This is because the laser irradiation power density decreases as the irradiation area of the lead frames 101 and 102, which are objects, increases. On the other hand, for example, the lead frames 101 and 102 are planar and approach the direction perpendicular to the laser irradiation direction, so that irregularities are easily formed on the surfaces of the lead frames 101 and 102 even when the laser output is low. That is, the surface area of the lead frames 101 and 102 that receive the laser light is substantially the same as the area (size) of the laser light, such as the laser being irradiated onto the surfaces of the lead frames 101 and 102 more vertically. Is easy to form irregularities on the surfaces of the lead frames 101 and 102 even if the output is low. Because the lead frames 101 and 102 are curved, the surface area of the lead frames 101 and 102 that receive the laser beam is too large relative to the area of the laser beam, and the lead frame 101 must be irradiated with a high output of the laser. , 102 cannot form irregularities on the surface. When processing is performed with the laser set to a high output, when the laser is irradiated onto a portion where the laser hits vertically, such as a flat portion, the power is too large and the periphery of the processing portion is discolored by heat. As a result, in the upper surface (front surface) of the lead frames 101 and 102, where the LED light is reflected, the lead frames 101 and 102 are discolored, the optical characteristics are deteriorated, and the brightness of the LED is lowered. Further, if the lower surface (rear surface) of the lead frames 101 and 102 is used, the possibility of a decrease in solderability is increased due to the influence of the high-power laser. Furthermore, when a large amount of scattered material corresponding to the portion scraped by the laser is scattered, the scattered material also scatters on the upper surface (surface) of the lead frames 101 and 102 and reflects the LED light, and is reflected on the upper surface. The optical characteristics such as the rate decrease. Further, if the lower surface (rear surface) of the lead frames 101 and 102 is scattered, the scattered matter becomes an obstacle and the possibility of a decrease in solderability increases. Therefore, in the laser processing, sufficient unevenness must be formed with a lower output in consideration of the influence on the surroundings that leads to quality degradation.

  On the other hand, if the reflectivity of the surfaces of the lead frames 101 and 102 (Ag plating surface) is high, the laser beam is reflected without being absorbed by the surfaces of the lead frames 101 and 102 (Ag plating surface). Thus, it is impossible to form irregularities on the surfaces of the lead frames 101 and 102 without irradiation. This is because the LED package of the present invention needs to reflect the LED efficiently, and thus Ag plating is applied to improve the optical characteristics. Therefore, the surfaces of the lead frames 101 and 102 (Ag plating surface) basically have high optical characteristics, and laser processing must be performed at a high output accordingly.

  In addition, when the optical characteristics are low, such as the reflectance of the surface of the lead frames 101 and 102 (Ag plating surface) is low, the surface of the lead frames 101 and 102 (Ag plating surface) absorbs the laser beam without reflection, so the laser is Even if the output is low, irregularities are easily formed on the surfaces of the lead frames 101 and 102. Further, for example, when irregularities are formed on the surfaces of the lead frames 101 and 102 (Ag plating surfaces) by the first laser irradiation, the scattered matter corresponding to the scraped portions of the lead frames 101 and 102 is formed around the irregularities. Splashes around. Thereby, the optical characteristics of the surfaces of the lead frames 101 and 102 (Ag plating surface) are deteriorated.

  From this relationship, in this embodiment, the laser processing of the Ag plating surfaces of the lead frames 101 and 102 is performed on the lower surface (back surface) of the lead frames 101 and 102 and the boundary portion with the step structure (FIG. 4). (C) of (b). In other words, it is applied to the lower surface (rear surface) which is the other surface of the lead frames 101 and 102 and to the boundary portion (C portion in FIG. 4B) with the connection surface (A portion). In addition, it may be formed on the surface of the lead frames 101 and 102 (B portion in FIG. 4B) of the connection portion (A portion) between the lead frames 101 and 102 and the insulating portion 103 later.

As described above, irregularities can be easily formed in the C portion having a planar shape even with a low-power laser. Then, scattered objects corresponding to the lead frames 101 and 102 scraped off by forming the unevenness of the C portion are scattered, so that small unevenness due to the scattered objects is formed around the C portion (including the B portion). As a result, a rough surface is formed on the Ag-plated surface of the lead frames 101 and 102, so that the epoxy resin flows into the rough surface, and the adhesion area between the epoxy resin and the Ag-plated surface of the lead frames 101 and 102 is increased. Increase. As a result, the adhesion at the interface between the lead frames 101 and 102 and the insulating portion 103 and the reflector portion 104 is improved. However, in this case, the amount of scattered matter is not so large as to adhere to the upper surface (surface).

  Furthermore, the optical characteristics of the periphery of C part (including B part) deteriorate due to the above scattered matter, for example, the reflectivity decreases. As a result, even the curved B portion can easily absorb the laser beam, and the unevenness can be sufficiently formed even with the low-power laser beam. That is, it is good to form a recessed part by laser processing in the boundary part with the connection surface (B part) of a lower surface, and to form a recessed part by laser processing in a connection surface (B part) after that. As a result, a rough surface having large irregularities is easily formed on the Ag plating surfaces of the lead frames 101 and 102 by the low-power laser beam, so that the epoxy resin flows into the rough surface, and the epoxy resin and the lead frames 101 and 102. This further increases the adhesion area between the Ag plating surface and the surface. As a result, the adhesion at the interface between the lead frames 101 and 102 and the insulating portion 103 and the reflector portion 104 is greatly improved.

  Further, depending on the positional relationship between the laser and the lead frames 101 and 102, the laser irradiation portion is not always in the direction perpendicular to the lead frames 101 and 102 (directly above). Therefore, for example, when the laser beam is irradiated from an oblique direction (X direction in FIG. 4B) with respect to the lead frames 101 and 102, the laser is irradiated to the B portion in FIG. When trying to do so, the laser does not strike the B part of the lead frame 101 well. That is, since the surface areas of the lead frames 101 and 102 that receive the laser light are extremely different with respect to the same laser irradiation area, there is a large variation in the degree of laser absorption between the lead frame 101 and the lead frame 102. On the other hand, when the laser is applied to the portion C, the surface areas of the lead frames 101 and 102 that receive the laser light are the same for the same laser irradiation area. Both are processed with approximately the same level of laser processing. Therefore, even if laser irradiation is performed from an oblique direction, the degree of laser processing is less likely to vary.

  Hereinafter, a method for manufacturing the LED package 100 configured as described above will be described.

Step S1: Lead frame board preparation process The lead frame board used as the material of lead frames 101 and 102 (refer to Drawing 2) uses Cu or Cu alloy with good heat conduction.

Step S2: Lead Frame Processing Step In this embodiment, the lead frame is processed from the lead frame plate by etching. Further, instead of etching, the lead frame may be processed by die punching from the lead frame plate.

Step S3: Ag plating step In this embodiment, the processed lead frame is subjected to Ni plating + Cu plating, and then Ag plating is performed. The Ni and Cu plating is very thin plating (flash plating). Further, the Ag plating after Ni plating + Cu plating is a sufficiently thick plating with a film thickness of about 1-10 μm.

  The Ag plating uses glossy Ag plating, but semi-glossy or matte Ag plating may be used.

Step S4: Ag plating surface processing step Processing is performed to roughen the surface of the lead frame by irradiating the Ag-plated lead frame with a laser. In the present embodiment, laser processing is performed using, for example, a FAYb laser, a YAG laser (Y
, Al, Garnet LASER). Further, it has been found that the surface roughness (Ra) of the Ag plating surface of the lead frame is determined by the energy of the YAG laser.

  In the Ag plating surface processing step, the Ag plating surface of the lead frame is obtained by laser processing under the conditions of YAG laser (oscillation wavelength is about 950 to 1100 nm, preferably 1000 to 1070 nm, peak power is 8 kW or more, preferably 10 kW or more). Surface roughness (Ra): A rough surface of 0.1 to 10 μm is formed. If the peak power is less than 8 kW, it is difficult to process the lead frame well. Thus, by processing the Ag plating surface with a laser, the Ag plating surface or the lead frame plate becomes a rough surface. At this time, the scattered matter of the scraped portion scatters around the scraped portion. Thereby, not only the shaved portion but also the Ag plating surface or the lead frame plate becomes a rough surface with scattered matter. As a result, the surface areas of the lead frames 101 and 102 are increased by the amount of scattered matter, and at the same time, the optical characteristics around the processing are lowered and the laser absorption rate is improved.

  A desired surface roughness (Ra): a rough surface of 0.1 to 10 μm is formed on the Ag plating surface of the lead frame processed by Ag plating. However, the surface of the Ag plating may turn brown due to laser processing, which may affect the brightness of the product. In that case, it is desirable to remove the brown discoloration by washing the frame before the next resin molding step.

  Hereinafter, the same process as the conventional process is performed using the lead frame on which the rough surface is formed.

Step S6: Resin molding step In this embodiment, the resin molding uses transfer molding or injection molding. Note that although an epoxy resin is used in this embodiment, the resin material can be changed to another material. For example, silicone, polyphthalamide (PPA), polycarbonate, polyphenylene sulfide (PPS), liquid crystal polymer (LCP), ABS, phenol, acrylic, PBT resin, etc. Resin or composite resin of resin and inorganic material.

Step S7: Thermosetting process When the molding resin is a thermoplastic resin, this thermosetting process is unnecessary.

  The resin is thermally cured to complete the LED package 100.

  Next, the definition and optimum range of the surface roughness (Ra) will be described.

  FIG. 5 is a diagram illustrating the amplitude average parameter in the height direction.

  As shown in FIG. 5, when a reference length lr and an arithmetic average roughness Ra are taken on a certain rough surface to obtain an arithmetic average height Pa and an arithmetic average waviness Wa of the cross-sectional curve, Z (x) at the reference length The average of the absolute values of is shown by the following (Equation 1).

  The surface roughness (Ra) is defined by (Equation 1).

  FIG. 6 is a diagram for explaining the laser processing conditions from the relationship between the laser scanning speed and the laser output.

  As shown in FIG. 6, when the scanning speed of the laser is high, there is no continuity of the laser spot, which is not suitable. When the laser scanning speed is low, the laser spot continuity is maintained, but the processing time becomes long. On the other hand, if the laser output is small, the desired surface roughness (Ra) cannot be formed due to poor roughening of the Ag surface. In addition, when the laser output is large, a large amount of scattered matter corresponding to the lead frames 101 and 102 scraped off when the rough surface is formed adheres to the periphery, and the optical characteristics (for example, reflectivity) of the lead frames 101 and 102. Is greatly reduced.

  FIGS. 7A and 7B are photographs taken before and after laser processing of Ag plating, taken by a laser micrograph. FIG. 7A is an Ag plating surface photograph before laser processing, and FIG. 7B is an Ag plating surface photograph after laser processing.

  As shown by comparing FIG. 7A and FIG. 7B, it can be seen that an appropriate surface roughness (Ra) is formed on the Ag plating surface after laser processing. This is formed by roughness due to laser processing itself and roughness due to scattered matter corresponding to a portion cut by laser processing.

  The manufacturing process of the LED package having the lead frame with the rough surface formed on the Ag plating surface by laser processing has been described above.

  Next, the manufacturing process up to the sealing of the LED package sealing resin will be described.

  FIG. 8 is a manufacturing process diagram up to the sealing of the sealing resin of the LED package.

LED package 100 preparation process (see FIG. 8A)
As shown in FIG. 8A, an LED package 100 having lead frames 101 and 102 having a rough surface formed on an Ag-plated surface produced by a method for producing an LED package is prepared.

As shown in FIG. 8A, (1) the Ag plating surface of the lead frames 101, 102 at the connection portion between the lead frames 101, 102 and the insulating portion 103, and (2) the lead frames 101, 102 and the reflector portion 104. The surface of the Ag plating with the outer peripheral connection portion and the surface of the Ag plating with the connection portion between the lead frames 101 and 102 and the trapezoidal bottom portion of the reflector portion 104 are surface roughness (Ra): 0.1 by laser processing. The resin is molded after a rough surface of −10 μm is formed.

LED chip 110 mounting process (see FIG. 8B)
As shown in FIG. 8B, the LED chip 110 is mounted on the upper surface (front surface) of the lead frame 102 of the LED package 100, and fixed via, for example, a die bonding paste. As the die bonding paste, a die bonding paste made of a heat-resistant / light-resistant resin such as epoxy or silicone, or a metal having higher thermal conductivity can be used.

  As a result, the LED chip 110 is mounted on a substantially central portion of the bottom surface of the LED mounting space (cavity) 105 of the LED package 100. Further, the outer peripheral direction of the LED chip 110 is surrounded by the reflector portion 104.

Wire bonding process (see FIG. 8C)
As shown in FIG. 8C, the anode electrode pad (not shown) of the LED chip 110 placed on the upper surface of the lead frame 102 and the lead frame 101 are wire-bonded by a bonding wire 111, and the cathode of the LED chip 110. An electrode pad (not shown) and the lead frame 102 are electrically connected by bonding with a bonding wire 112.

Resin sealing process (see FIG. 8D)
As shown in FIG. 8D, the cavity 105 is filled with a sealing resin 120 containing a fluorescent material so as to cover the LED chip 110 and the bonding wires 111 and 112 disposed in the cavity 105. The LED chip 110 and the bonding wires 111 and 112 disposed in the cavity 105 are sealed with the sealing resin 120. Since the sealing resin 120 has a high light transmittance at the emission wavelength of the LED element and needs to be filled in a narrow gap, a low-viscosity organic resin (for example, a silicone resin) is used. Further, the sealing resin 120 contains a fluorescent material that converts the wavelength of light from the LED element. The fluorescent material is variously selected according to the wavelength of light from the light emitting element. For example, when an LED element emitting blue light is used, nitrogen-containing CaO—Al 2 O 3 activated with YAG: Ce, Eu and / or Cr is used. An inorganic fluorescent material such as —SiO 2 is preferably used.

  A fluorescent substance that converts light from the LED element into a longer wavelength is good in luminous efficiency. The mixed color light that has been wavelength-converted by the LED element and the fluorescent material is preferably white.

  For example, when a GaN-based blue light-emitting diode chip is used for the LED chip 110, a fluorescent substance (wavelength conversion member) that converts the wavelength of light emitted from the LED chip 110 is (Si · Al) 6 ( O.N) 8: Eu, and a silicone resin containing CaAlSiN3: Eu is used as a red phosphor. Thereby, part of the blue light emitted from the LED chip 110 is converted into red or green light having a longer wavelength than the blue light.

  In addition, the silicone resin which does not contain the said fluorescent substance may be used, and sealing resins other than a silicone resin may be used.

FIG. 9 is a view showing an enlarged photograph of the lead frame of the LED package according to the present embodiment. It can be seen that laser processing is performed on the C portion of FIG. As described above, one surface (upper surface) of the first lead frame 102 including one surface (upper surface) on which the LED chip 110 is placed and the second lead frame 101 facing the first lead frame 102 are disposed. A rough portion is formed on the other surface (bottom surface) opposite to the boundary surface (C portion) between the connection surface (B portion) where the first lead frame 102 and the second lead frame 101 face each other. Process,
In the step of forming the rough portion, the resin (insulating portion 103) for fixing the first lead frame 102 and the second lead frame 101 is formed so as to cover the connection surface (B portion) to which the scattered matter of the lead frame 102 adheres. And a step of performing. As a result, the optical characteristics are maintained by tightly connecting the pair of lead frames and the package resin to prevent the intrusion of impurities such as moisture and sulfur dioxide from the outside of the package through the gap between the lead frame and the package resin. can do.

  Also, by forming a recess by laser processing at the boundary with the connection surface, and then forming a recess by laser processing on the connection surface, the pair of lead frames and the insulating portion are connected very firmly. Since it is difficult for moisture to enter from the gap between the insulating portion and the insulating portion, the life can be extended while maintaining the optical characteristics. Further, low power laser processing can be performed on the connection surface.

  Further, in the present embodiment, the surface of the lead frames 101 and 102 at the connecting portion between the lead frames 101 and 102 and the trapezoidal bottom of the reflector unit 104 is roughened by laser processing. It is possible to connect the lead frames 101 and 102 and the reflector unit 104 more firmly. Further, by laser processing, unlike the etching processing or the like, the rough surface forming processing can be performed only on necessary portions.

  Here, the laser processing of the Ag-plated surfaces of the lead frames 101 and 102 is performed on the surface of the lead frames 101 and 102 at the connection portion between the lead frames 101 and 102 and the insulating portion 103, and the outer periphery of the lead frames 101 and 102 and the reflector portion 104. It may be carried out on the surface of the lead frame 101, 102 of the connecting part or the surface of the lead frame 101, 102 of the connecting part between the lead frame 101, 102 and the trapezoidal bottom of the reflector part 104. , 102 is preferably not carried out from the viewpoint of ensuring optical properties and durability of light. In laser processing, the setting of the processing region can be easily specified.

  The above description is an illustration of a preferred embodiment of the present invention, and the scope of the present invention is not limited to this.

  For example, the planar shapes of the lead frames 101 and 102 and the insulating portion 103 are substantially rectangular, but the shape is not limited to this, and may be a shape such as a circle, an ellipse, or a polygon.

  In the present embodiment, one LED chip 110 is disposed in the cavity 105, but the number of LED chips may be one or more, and is not limited thereto.

  In the above embodiment, the name “LED package” is used. However, this is for convenience of explanation, and may be a package for a semiconductor element, a package for an optical semiconductor element, or the like. Moreover, the manufacturing method of an LED package may be called the manufacturing method of an optical semiconductor element.

  Furthermore, each component part which comprises the said LED package, for example, the kind of board | substrate, the resin sealing method, etc. are not restricted to embodiment mentioned above.

  The LED package and the LED package manufacturing method of the present invention are suitable for use in a package on which an LED chip is mounted. In particular, it is excellent in reliability and useful for use as a long-life light-emitting device having liquid leakage resistance of a sealing resin.

100 LED package 101, 102 Lead frame 103 Insulating part 104 Reflector part 105 Cavity (LED mounting space)
110 LED chip 111, 112 Bonding wire 120 Sealing resin

Claims (2)

A first lead frame comprising one surface on which the LED is placed and the other surface that is the back surface of the one surface and is a plane;
A second lead frame facing the first lead frame in a direction parallel to the one surface;
The first lead frame and the second lead frame include a resin that connects between connection ends facing each other, and
At least a part of the other surface of the first lead frame is exposed from the resin,
The LED package, wherein a rough portion is formed by laser processing at an end of the other surface of the first lead frame on the connection end portion side and at least a part of the connection end portion. An LED package according to claim 1;
An LED mounted on the first lead frame;
An LED light emitting element comprising: the LED and a transparent resin that seals at least a part of the one surface of the first and second lead frames.

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