JP4887529B1 - LED package manufacturing method - Google Patents

Abstract

A bottom surface of an LED package substrate is provided with a sufficient connection area with a radiator and a sufficient electrical connection area at an upper end portion, and the material cost is reduced and the cost is reduced.
An LED package substrate includes a flat bottom portion having a sufficient area for forming an LED chip mounting portion and an LED chip connection portion on an upper surface, and a pair of wall portion tips rising from both sides of the bottom end. A laminated structure is formed in which a metal layer is joined on an insulating layer made of a resin layer on a metal plate having a constant plate thickness that is drawn so as to be bent outward. The bending radius of the flat bottom portion of the metal plate and the corner portion where the wall portion rises from the bottom portion is R1, and the bending radius of the corner portion between the wall portion and the upper end portion extending outward is R2, and R1> Let R2 be the relationship. A pair of connection electrodes is formed on the upper surface on the distal end side where the distal ends of the wall portions are bent outward.
[Selection] Figure 1

Description

The present invention is an LED package substrate for LED chip relates to the production how the LED package constructed by processing a predetermined thickness of the metal plate.

  An LED (Light Emitting Diode) is widely used as an element that has both low power consumption, reduced carbon dioxide, high durability, and energy saving. A package on which such an LED chip is mounted is mounted on a wiring board, and is used for a large display, a backlight of an electronic device such as a mobile phone, a digital video camera, or a PDA, road illumination, general illumination, and the like. Since the LED itself is a light emitting element and emits heat, the LED package basically includes a heat dissipation device for cooling.

  In the method using a ceramic substrate or a silicon substrate as the LED package substrate, there is a problem that the heat conduction of ceramic or silicon is worse than that of a metal such as copper, so that heat cannot be radiated well, it is expensive, and processing is difficult. In order to solve such a heat dissipation problem, it is known that the LED package substrate is formed by processing a metal plate having good thermal conductivity.

  15A and 15B show an LED package disclosed in Patent Document 1, wherein FIG. 15A is a cross-sectional view at the center of the package, and FIG. 15B is a plan view thereof. The illustrated LED package includes an LED chip, a Cu substrate on which the LED chip is mounted, wires that electrically connect each electrode of the LED chip and a Cu wiring layer provided on the Cu substrate, and an element mounting portion of the Cu substrate. And a sealing resin for sealing.

The Cu substrate has a shape formed by pressing a concave depression on which the LED chip is mounted, and has a thin-film Cu wiring layer integrally on its surface with an insulating layer made of SiO ₂ as an adhesive. However, it can be said that forming a concave recess for mounting an LED chip on a Cu substrate material by press working has the following problems. In general, when forming depressions by pressing a thick metal plate, a larger force is required than when forming thin plates by bending. Therefore, the size of the depression is restricted, and SiO ₂ is pressed hard. It is easy to break sometimes and is unsuitable for pressing with a large force. For this reason, there is a need for a method that can be manufactured at low cost by using a thinner metal plate with a constant plate thickness to save material and reduce the size as much as possible.

  FIG. 16 is a view showing the LED lighting apparatus disclosed in Patent Document 2, wherein (A) shows a top view and (B) shows a partial cross-sectional view. As shown in the figure, the insulating metal substrate having a constant plate thickness has a recess for installing the LED chip provided by drawing. The insulating metal substrate includes a metal substrate layer, an electrical insulating layer made of an insulating material layer, an electrode pattern made of a conductive metal, and a lead pattern. Adjacent LED chips are electrically connected by a bonding wire via an electrode pattern.

  However, Patent Document 2 discloses a module in which a plurality of LED chips are mounted on a single insulating metal substrate. Patent Document 2 does not disclose an individual package that has been cut into individual pieces for each LED chip, and that this individual package is mounted on a wiring board and a radiator. Therefore, the connection of the individual package to the wiring board and the heat dissipation have not been studied.

  Patent Document 3 discloses a metal film forming method using an inkjet printing method, and Patent Document 4 discloses a metal film forming method using a screen printing method.

JP 2006-245032 A JP-A-1-309201 Japanese Patent No. 3774638 Japanese Patent No. 3764349

  When mounting an individual package separated into individual pieces for each LED chip to the wiring board and the heat sink, it is separated from the back surface of the LED package board connected to the heat sink and is electrically connected to the wiring board at the upper end of the LED package board. By providing the unit, the electrical connection between the LED package board and the wiring board can be easily performed, and at the same time, the cost performance of each of the heat dissipation and electrical connection is optimized, so that it is cheap and highly efficient. Can be realized. For this reason, the individual LED package substrate is reduced in size as much as possible to reduce the material cost, while ensuring a large area on the flat bottom and transferring heat to the radiator through this large area. Instead, it is necessary to ensure a sufficient area for the electrical connection portion with the wiring board at the upper end portion of the substrate. In addition, when a thin metal plate having a certain thickness is drawn, distortion of the drawing appears at the periphery of the LED package substrate, so that it is particularly difficult to form individual downsized LED package substrates.

  The present invention solves such problems and devise an LED package substrate shape and a manufacturing method thereof when constructing an LED package substrate formed by drawing a metal plate having a constant thickness. It is an object of the present invention to provide a low-cost and highly reliable LED package by securing a sufficient electrical connection area at the upper end and a sufficient connection area, and reducing material costs.

Producing how the LED package of the present invention, the LED package substrate for LED chip is constituted by processing a predetermined thickness of the metal plate. A laminated body in which an insulating layer made of at least a resin layer is bonded onto a metal plate having a certain thickness is formed. In the periphery of the LED package substrate region, an opening that penetrates the stacked body is formed by punching. After forming the opening, the laminated body is drawn to have an area sufficient to form a pair of connection portions on the upper surface for connecting the LED chip mounting portion and the pair of connection electrodes of the LED chip. A flat bottom and a pair of wall tips rising from at least both sides of the bottom end are bent outward from each other. Using a molding punch having a corner angle smaller than that of the punch used for drawing, electrode portion angle molding is performed to increase the width of the connection electrode portion. That is, between the flat bottom portion of the metal plate having a constant plate thickness by the drawing, the bending radius R1 of the corner portion where the wall portion rises from the bottom portion, the wall portion by the angle forming punch and the distal end of the wall portion extending outwardly. The corner portion is molded so that the relationship with the bending radius R2 is R1> R2. A metal in which an LED chip is mounted on a wiring layer formed on an insulating layer on an LED package substrate or on an insulating layer, and a pair of electrodes of the LED chip are insulated and separated on both sides of a flat bottom surface Each of the metal layers connected to the layers and formed on the top surface on the front end side where the front ends of the wall portions are bent outward is configured as a pair of connection electrodes. Fill the recess sandwiched between the flat bottom and the wall with transparent resin.

  The laminate may be configured by further bonding a metal layer on an insulating layer bonded on a metal plate. In this case, before forming the opening that penetrates the stacked body, the metal layer on the insulating layer is processed to remove at least the metal layer corresponding to the opening. This metal layer is utilized as a wiring layer. A silver surface treatment that functions as a reflective material may be applied on the metal layer.

  Alternatively, the wiring layer is formed by performing electrode part angle molding, and then applying and baking using a conductive metal ink having reflectivity, and the connection electrode is a pair of connection electrodes that are thicker than the wiring layer. In order to form the film, the conductive metal film may be formed by applying a conductive metal film by a screen printing method using a conductive metal ink and baking it.

  The resin constituting the insulating layer is a polyimide resin, a polyamideimide resin, or an olefin resin. Further, the insulating layer may be constituted by two layers of a resin layer and an adhesive layer.

  The opening that penetrates the laminate is formed by punching and penetrating the resin layer against the metal plate from the insulating layer side.

  According to the present invention, while using a metal plate with good processability and thermal conductivity for the LED package substrate and using an insulating layer that ensures insulation with the LED chip connection wiring mounted thereon, the LED The package substrate is devised to reduce the material cost by reducing the size as much as possible, while ensuring a large area on the flat bottom and transferring heat to the radiator through this large area As a result, not only the thermal conductivity from the LED chip to the radiator can be improved, but also a sufficient area can be secured in the electrical connection portion with the wiring board.

  In addition, according to the present invention, the electrical connection between the LED package substrate and the wiring board can be easily performed by separating the electrical connection portion between the LED package board and the wiring board from the heat radiating body on which the LED package board is mounted. At the same time, by optimizing the cost performance of heat dissipation and electrical connection, it is possible to achieve low-cost and high-efficiency exhaust heat overall.

  Further, according to the present invention, by devising the shape of the LED package substrate, it is possible to inject an expensive LED chip sealing resin limitedly to only the necessary portions.

It is side surface sectional drawing which shows the 1st example of the LED package which actualizes this invention. It is a figure which illustrates the laminated body of a metal plate, an insulating layer (polyimide), and a metal layer (for example, copper foil). It is a figure which illustrates the laminated body of another example different from FIG. It is a figure explaining a metal layer removal process, (A) is sectional drawing of the laminated body cut | disconnected by the X-X 'line shown in (B), (B) has shown the top view. It is a figure explaining the punching process of an opening part, (A) is sectional drawing of the laminated body cut | disconnected by the X-X 'line shown in (B), (B) has shown the top view. (A) is sectional drawing for further demonstrating the opening part punching process shown in FIG. 5, (B) is detailed sectional drawing in the circle | round | yen shown in (A), (C) is a reverse direction It is a figure explaining the inconvenience at the time of punching out from. (A) And (B) is a figure explaining the example of a drawing process, respectively. It is a figure explaining an electrode part angle shaping | molding process. (A) is sectional drawing which cut | disconnected the LED package board | substrate which carried out metal surface treatment by the X-X 'line in (B), (B) is the top view. It is sectional drawing which illustrates the LED module apparatus comprised using the 1st example of the LED package illustrated in FIG. It is a figure which illustrates the laminated body of another example different from FIG.2 and FIG.3. It is a figure explaining the formation process of a thin film wiring layer. It is a figure explaining the formation process of a thick film wiring layer, (A) shows sectional drawing of the LED package board | substrate cut | disconnected by line XX 'in (B), (B) shows the top view, respectively. Yes. It is sectional drawing which shows the 2nd example of the completed LED package. The LED package disclosed in Patent Document 1 is shown, (A) is a cross-sectional view at the center of the package, and (B) is a plan view thereof. It is a figure which shows the LED lighting fixture disclosed by patent document 2, (A) shows the top view, (B) has shown the fragmentary sectional view.

  Hereinafter, the present invention will be described based on examples. FIG. 1 is a side sectional view showing a first example of an LED package embodying the present invention. The illustrated LED package is configured on an LED package substrate. As will be described in detail later, the LED package substrate is formed by drawing a laminated body in which a metal layer (for example, copper foil) is bonded on a metal plate with an insulating layer sandwiched therebetween to a predetermined shape. A connecting portion for connecting the pair of electrodes is formed on the flat bottom surface. On the metal layer, silver plating that functions as a reflector is applied. The pair of connection electrodes (both ends of the metal layer) must be insulated from each other. For this purpose, in the first example of the LED package illustrated in FIG. 1, slits for insulating and separating the metal layer (and silver plating) functioning as connection wiring are opened on both the left and right sides.

  An LED chip is fixed on the silver-plated metal layer or insulating layer on the flat bottom surface of the LED package substrate using an adhesive. This LED chip has an LED light emitting surface on the upper surface. In addition, although the form which mounted only one LED chip in one recess was illustrated, a several chip | tip can also be mounted in one recess. Wire bond connection is performed between the LED chip and a metal layer functioning as connection wiring. After fixing the LED chip on the bottom metal layer of the LED package substrate, wire bonding is performed between the connection portions of the pair of connection electrodes on the metal layer and the pair of connection electrodes of the LED chip with bonding wires. As described above, since silver plating is formed as a reflective material on the metal layer, this silver plating can also function for improving wire bonding.

  After the LED chip is mounted and electrically connected and wired, a transparent resin is filled to form an LED package. Resin sealing (transfer molding or potting) is performed using a transparent resin (for example, epoxy or silicone). Resin sealing can also be performed by a dispenser or screen printing. The height of the sealing resin is injected up to the same plane as the upper surface of the reflective material functioning as a connection electrode. Hereinafter, the manufacturing method will be described in detail with reference to FIGS.

  FIG. 2 is a diagram illustrating a laminate of a metal plate, an insulating layer (for example, polyimide), and a metal layer (for example, copper foil). This laminated body is drawn by press working using a later mold. As the insulating layer, a polyamide-imide resin can be used in addition to the polyimide resin. Polyamideimide has a property of being soluble in a solvent as compared to polyimide, and is an easy-to-use material in some cases. Alternatively, an olefin resin may be used. Both resins are flexible and will not be damaged by subsequent pressing.

  For example, when bonding a polyimide resin as an insulating layer on a metal plate, a solution obtained by dissolving a polyimide resin containing a thermoplastic polyimide in a solvent is first applied to the metal layer (or metal plate) and dried to form a metal plate. (Or a metal layer). Usually, in order to ensure a certain withstand voltage in consideration of the flatness of the metal plate and the metal layer, a polyimide resin having a film thickness of at least 5 μm must be applied. The thickness of the polyimide resin is preferably thin from the viewpoint of heat dissipation characteristics, but a certain thickness is required from the viewpoint of withstand voltage and tear strength. When a polyimide resin layer is used as an insulating layer, the withstand voltage of the insulating film required for LED mounting is generally 2.5 to 5 kV, and the withstand voltage of the polyimide resin varies depending on the structure, but is several hundred to Since it is 500 V / μm, a minimum thickness of 5 μm is required. On the other hand, in order to increase the heat dissipation effect, the polyimide resin layer cannot be thickened, and the thickness is 40 μm or less, preferably 20 μm or less.

  FIG. 3 is a diagram illustrating another example of the laminated body different from FIG. 2. In the illustrated laminate, an insulating layer sandwiched between a metal plate and a metal layer is composed of two layers of a resin layer (polyimide resin, polyamideimide resin, or olefin resin described above) and an adhesive layer. Since the resin layer is in charge of electrical insulation and the adhesive is in charge of adhesiveness, optimization is possible for each, resulting in improved heat conduction characteristics. In order to manufacture this laminated body, the polyimide film side of the laminated film (for example, copper foil which stuck the polyimide film) which consists of a metal layer with a resin is affixed on a metal plate using an adhesive material. By making the thickness of the resin layer thinner than that of the adhesive layer, it is advantageous in terms of both cost and heat dissipation. This adhesive is preferably filled with a heat conductive filler. As a result, a two-layer insulating layer composed of a resin layer and an adhesive layer is laminated between the metal plate and the metal layer. The resin layer and the adhesive layer can not only provide insulation between the pair of connection electrodes of the LED chip, but also can utilize a copper foil as the connection wiring of the LED chip. Moreover, not only copper foil but the metal layer (metal foil) of high heat conductivity like aluminum can be used. In addition, the presence of the resin layer facilitates etching of the upper surface copper foil. There is no concern that the adhesive layer is eroded by the etchant during etching.

  4A and 4B are diagrams for explaining the metal layer removing step, in which FIG. 4A is a cross-sectional view of the laminate cut along the line XX ′ shown in FIG. 4B, and FIG. 4B is a plan view. . In the illustrated example, a plurality (illustrated as four) LED package substrates are illustrated as being simultaneously formed on a single metal plate. In a later step, after mounting the LED chip on the LED package substrate and sealing with resin, the individual package is cut into individual pieces. As shown in the figure, the metal layer on the insulating layer is processed to remove the metal layer at a position corresponding to the slit (see FIG. 1) and the opening (see FIG. 5) (shown as a metal layer removing portion). For example, photolithography technology is used for this processing. A resist is applied on the metal layer (copper foil), the pattern is exposed and developed, and etching is further performed to remove the resist, thereby completing the slit and the metal layer removing portion. The presence of the resin layer facilitates etching of the upper metal layer. Since the slit portion does not function as a reflector for light emission from the LED chip, it is desirable that the slit portion is narrow.

  5A and 5B are diagrams for explaining the punching process of the opening, in which FIG. 5A is a cross-sectional view of the laminate cut along the line XX ′ shown in FIG. 5B, and FIG. 5B is a plan view. Yes. As shown in the drawing, an opening that penetrates the stacked body is formed by punching along each side in the periphery of the package substrate region on the left and right and left and right of each LED package substrate. However, all of the metal layers on one metal plate are electrically connected together through a joint provided around the package substrate area so that the metal layer can be used as an electrode for subsequent plating. It is connected. By providing this punching opening, it is possible to prevent distortion at the time of drawing of the laminated body from affecting the peripheral portion. This makes it possible to produce an LED package substrate that secures a large area on the flat bottom while reducing the material cost by drawing the thin metal plate as much as possible and reducing the material cost.

  6A is a cross-sectional view for further explaining the opening punching step shown in FIG. 5, FIG. 6B is a detailed cross-sectional view in a circle shown in FIG. It is a figure explaining the inconvenience at the time of punching from the reverse direction. As shown in the drawing, the laminated body is placed on a punching die, and a punching blade having a width narrower than that of the metal layer removing portion is aligned with the opening, and punching is performed. At this time, as shown in (B) showing the details in the circle in (A), the punching blade is punched and penetrated by pressing the resin layer against the metal plate from the resin layer (insulating layer) side. . On the contrary, as shown in (C), when a punching blade is inserted from the metal plate side, a force is applied to peel off the resin layer.

  FIGS. 7A and 7B are diagrams illustrating an example of a drawing process. As shown in FIG. 7A, the laminated body after the opening is formed in the opening punching step shown in FIG. 5 is placed between a drawing die having a desired shape and the punch and drawn by press working. Processing. Alternatively, as shown in FIG. 7B, the knockout (stripper) is configured separately from the drawing punch, and by this knockout, the LED package substrate end portion (connection electrode portion) is pressed and drawn by the drawing punch. Process. This drawing process is performed so as to form a recess for mounting the LED chip and a connection electrode part where the upper part is bent outward (see FIG. 9). However, the width t of the electrode part is still insufficient in the LED package substrate after the drawing process.

  FIG. 8 is a diagram illustrating an electrode part angle forming process. The LED package substrate after the drawing process is placed on an angle forming die, and an electrode part angle forming is performed using a forming punch. The molding punch used here has a smaller corner angle than the drawing punch described above. As a result, the width T is wider than the width t of the electrode portion after the drawing.

  FIG. 9A is a cross-sectional view of an LED package substrate that has been subjected to a metal surface treatment, taken along line X-X ′ in FIG. 9B, and FIG. 9B is a plan view thereof. As shown in FIG. 7, let R1 be a bending radius of a flat bottom portion of a metal plate formed by drawing and a corner portion where left and right and front and rear wall portions rise from the bottom portion, so-called R. Also, as shown in FIG. 8, after the electrode portion angle molding is performed, the upper end portions of the left and right wall portions extend parallel to the flat bottom portion and outward, but the upper end portions extend outward from the left and right wall portions. Let R2 be the corner radius between. Further, as shown in the drawing, W: package width, A: recess (cavity) width, T: connection electrode width, the exemplary LED package substrate ensures a sufficient recess width A with respect to the package width W. However, in order to ensure the width of the connection electrode T as wide as possible, the relationship between the corners R1 and R2 is R1> R2. In order to prevent solder from electrically short-circuiting the connection electrode and the metal plate when the connection electrode is soldered to the wiring substrate, the electrode end portion shown in FIG. Thus, the connection electrode tip side is partially removed. That is, the connection electrode end portion is disposed inside the metal plate end.

  A metal that functions as a reflective material for light emission from the LED chip on the upper surface of the metal layer of the LED package substrate after the drawing process and the electrode part angle molding as described above (for example, Silver) plating (metal surface treatment). By using the metal layer as a plating electrode for the plating process, it is possible to plate only on the upper surface of the metal layer except for the slit and the copper foil removing portion. Alternatively, instead of metal plating, a glossy surface (reflecting material) can be formed by applying silver ink to a portion requiring metal surface treatment using an ink jet and firing it.

  In addition, although it demonstrated as what performs a metal reflection process after the press processing of a laminated body (drawing process process of the metal plate shown in FIG. 7, and the electrode part angle shaping | molding process shown in FIG. 8), before press processing, Metal reflection treatment can also be performed. In this case, the laminate is pressed in a state where at least the metal reflection treatment surface is covered with the protective tape, and then the protective tape is peeled off.

  Thus, the illustrated LED package substrate has a flat bottom portion and left and right wall portions that extend from the bottom end to the same side as the light emitting direction of the LED chip in the direction of bending up from the bottom end. And front and rear wall portions connected to and orthogonal to the left and right wall portions. These left and right front and rear wall portions function to confine a transparent resin for sealing the LED chip mounted on the flat bottom from the left and right front and rear. The metal layers on the upper surfaces of the left and right wall portions (and the silver plating thereon) function as a pair of connection electrodes. As described above, a sufficient width T for the connection electrode portion is ensured by performing the electrode portion angle molding. Further, the flat bottom portion has an area sufficient for mounting the LED chip on the upper surface thereof and forming a connection portion for connecting the pair of connection electrodes. Since the heat radiating body is mounted in contact with the lower surface of the flat bottom portion, the heat radiation from the LED chip is efficiently transferred to the heat radiating body.

  In addition, by providing the wall portions not only on the left and right but also on the front and rear, the subsequent resin sealing becomes easy, but the front and rear wall portions are not necessarily required. Resin sealing when walls are provided only on the left and right sides of the recess is resin that flows in the horizontal direction in the figure when the resin is sealed in the mold after the LED chip is mounted on the LED package substrate. The resin flowing in the front-rear direction can be regulated by edge processing of the package substrate, for example, by providing a wall only at the edge.

  Thereafter, as described above with reference to FIG. 1, the LED chip is mounted on one of the bottom metal layers divided into two by the slits to make one wire bond connection, while the other of the two divided bottom metal layers is attached to the other. Makes the other wire bond connection. Thereafter, resin sealing is performed.

  FIG. 10 is a cross-sectional view illustrating an LED module device configured using the first example of the LED package illustrated in FIG. 1. The illustrated LED module device includes an LED package having the above-described configuration, a wiring board having an opening for mounting the LED package, and a heat sink fixed to the back surface of the LED package. The LED package is attached to the opening of the wiring board by connecting the pair of connection electrodes of the LED package to the wiring on the lower surface of the wiring board by soldering or the like. The LED chip light emitting surface is directed to the upper surface side in the figure, and emits light toward the upper surface without being blocked by the wiring board. The back surface of the LED package on which the wiring board is mounted is fixed on the heat sink by solder connection. Alternatively, instead of this solder connection, it is possible to bond using a highly heat conductive adhesive.

  As described above, the LED package substrate of the present invention has a flat bottom portion having an area sufficient for mounting the LED chip and forming a connection portion for connecting the pair of connection electrodes. Since the heat radiating body is mounted on the lower surface of the flat plate-shaped bottom portion, the heat radiation from the LED chip is efficiently transferred to the heat radiating body. Furthermore, a connection electrode width T that is sufficient to connect to the wiring board is secured on the upper end surface.

  Next, a second example of an LED package embodying the present invention will be described with reference to FIGS. FIG. 11 is a diagram illustrating another example of a laminated body different from those in FIGS. 2 and 3. The illustrated laminate is different from the example shown in FIGS. 2 and 3 having a metal layer (copper foil) in that it is composed of only a metal plate and an insulating layer. As shown in the figure, an insulating layer (polyimide resin, polyamideimide resin, or olefin-based resin described above) is bonded onto a plate-like member (metal plate). In the right side of the figure, detailed sectional views are shown, respectively, (a) shows an example in which an insulating layer is bonded on a metal plate without using an adhesive, and (b) shows an adhesive on the metal plate. The example which stuck the insulating layer using the material is shown.

  As shown in (a), by using an insulating layer made of resin, heat generated in the LED chip is sufficiently dissipated through a metal plate while insulating the heat sink mounted on the lower surface thereof. be able to. Alternatively, as shown in (b), the insulating layer is composed of two insulating layers composed of a resin film and an adhesive layer. In this case, since the resin film has insulation resistance, the adhesive layer can easily increase the heat conduction.

  Due to the opening formed in the same manner as the punching process (see FIG. 5) in the manufacture of the first example of the LED package, the laminate composed of the metal plate and the insulating layer is distorted during the drawing process in the next process. Can be removed. Thereafter, the metal plate drawing step shown in FIG. 7 and the electrode angle forming step shown in FIG. 8 are sequentially performed.

  FIG. 12 is a diagram for explaining a thin film wiring layer forming step. As described above, as shown in FIG. 12, with respect to the LED package substrate after the drawing process and the electrode portion angle molding, as shown in FIG. A silver thin film wiring layer is formed by applying and baking the conductive metal paste dispersed in the dispersion solution by an inkjet method or the like (see, for example, Patent Document 3 for the inkjet method). With this silver thin film wiring layer, wiring that also serves as a glossy surface (reflecting material) is formed on the insulating layer except at least slits (see FIG. 13B for a top view). The slit opening is for insulating and separating the pair of wiring layers of the LED chip.

  Alternatively, it can be applied by flexographic printing or gravure printing using a conductive metal ink having the same reflectivity as the ink jet method described above. However, when applying by flexographic printing or gravure printing, it is performed before the drawing process of the metal plate shown in FIG. If flexographic printing or gravure printing is a flat surface, fine patterns can be processed with high throughput. After coating by ink jet method or flexographic printing or gravure printing, it is fired to be metallized. However, since the wiring thickness is also thin in this case, it is necessary to apply a metal thick film by the screen printing method in the next process.

  FIGS. 13A and 13B are diagrams for explaining a process for forming a thick wiring layer. FIG. 13A is a cross-sectional view of the LED package substrate taken along line XX ′ in FIG. Respectively. As shown in the drawing, a conductive metal thick film is applied by a screen printing method using a conductive metal ink such as copper, and then fired (for the screen printing method, see, for example, Patent Document 4). The conductive metal thick film is applied on the insulating layer at the upper end on both sides when the metal plate is bent outward, and is connected to the wiring board by being electrically connected to the thin film wiring layer. It functions as an electrode. As shown in the figure, it is sufficient that the thin film wiring layer and the thick film wiring layer are adjacent to each other so as to be electrically connected. It may be integrated by stacking a thick film wiring layer thereon. Since only the thin film wiring layer formed by the ink jet method may cause a problem in connection reliability with the wiring substrate (see FIG. 10), the connection electrode portion is wired by the screen printing method in order to thicken the wiring as a countermeasure. . Thereby, the LED package substrate is completed.

  FIG. 14 is a cross-sectional view showing a second example of a completed LED package. As shown in the figure, the LED package substrate has a flat bottom where the LED chip is to be mounted, and a light emitting direction of the LED chip in a direction where the bottom is located on the left and right of the bottom and bends from the bottom end. Are provided on at least the left and right sides. The pair of left and right wall tip surfaces are bent outward from each other, and the thick film wiring layer formed on the top surface tip side functions as a pair of connection electrodes. In addition, a slit for electrically separating the pair of connection electrodes is formed in the thin film wiring layer. An LED chip is mounted on one of the thin film wiring layers divided by the slit to make one wire bond connection, while the other of the two divided bottom thin film wiring layers is made to the other wire bond connection.

  In the second example of the LED package illustrated in FIG. 14 as well, as in the LED package substrate described above with reference to FIG. 9, the connection electrode T is secured while ensuring a sufficient recess width A with respect to the package width W. In order to secure as wide a width as possible, the relationship between the corners R1 and R2 is R1> R2. Thus, as in the first example of the LED package described above, the LED package substrate has a flat bottom portion having an area sufficient to mount the LED chip and form a connection portion for connecting the pair of connection electrodes. Since the heat sink is mounted on the lower surface of the flat bottom having a large area, the heat radiation from the LED chip is not only efficiently transferred to the heat sink, but also on the wiring board on the upper end surface. A connection electrode width T sufficient to connect to is secured.

  Although several embodiments have been described in detail in the present disclosure by way of example only, many modifications may be made to the embodiments without substantially departing from the novel teachings and advantages of the present invention. Examples are possible.

Claims (7)

In an LED package manufacturing method in which an LED package substrate for an LED chip is formed by processing a metal plate having a constant thickness,
A laminated body in which an insulating layer composed of at least a resin layer is joined on a metal plate having a constant thickness,
In the periphery of the LED package substrate region, forming an opening that penetrates the laminate by punching,
A flat plate having an area sufficient to form a pair of connection portions for connecting the LED chip mounting portion and the pair of connection electrodes of the LED chip by forming the opening and then drawing the laminate. A pair of wall ends rising from at least both sides of the bottom end and the bottom end are configured to bend outward from each other,
By using the forming punch having a corner angle smaller than that of the punch used for the drawing process and performing electrode portion angle forming to increase the width of the external connection electrode portion, the flat plate shape of the metal plate having the constant plate thickness A bending radius R1 of the corner portion between the bottom portion and the wall portion rising from the bottom portion, and a bending radius R2 of the corner portion between the wall portion by the punch for angle molding and the tip of the wall portion extending outward. The relationship is R1> R2, and
The LED chip is mounted on the LED package substrate, the pair of electrodes of the LED chip are respectively connected to the metal layers that are insulated and separated on both sides of the upper surface of the flat bottom, and the front ends of the wall portions are directed outward. The metal layer formed on the bent top side upper surface is configured as a pair of external connection electrodes,
A method for manufacturing an LED package, comprising filling a recess sandwiched between the flat bottom and the wall with a transparent resin. The laminate is configured by further joining a metal layer on the insulating layer joined on the metal plate, and before forming the opening penetrating the laminate, the laminate on the insulating layer. The manufacturing method of the LED package of Claim 1 which processes a metal layer and removes the metal layer of the position corresponding to the said opening part at least. The wiring layer is formed by applying and baking a reflective conductive metal ink after the electrode portion angle molding, and the pair of external parts having a thicker film than the wiring layer. The method for producing an LED package according to claim 1, wherein a conductive metal film is applied by a screen printing method using conductive metal ink and baked to form the connection electrode. The manufacturing method of the LED package of Claim 1 which gave the silver surface treatment which functions as a reflecting material on the said metal layer. The LED package manufacturing method according to claim 1, wherein the resin constituting the insulating layer is a polyimide resin, a polyamideimide resin, or an olefin resin. The method for manufacturing an LED package according to claim 1, wherein the insulating layer includes two layers of a resin layer and an adhesive layer. 2. The method of manufacturing an LED package according to claim 1, wherein the opening that penetrates the stacked body is punched and penetrated so as to press the resin layer against the metal plate from the insulating layer side.

Images