JP2006253344A - Led lead frame, injection molding mold used for insert moulding process - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an LED lead frame, and an injection molding mold used for insert molding process of the LED lead frame in which no housing position failure occurs when the outer lead of the LED lead frame is housed in the housing slot of the injection molding mold, no metal powder occurs from falling of flash of the LED lead frame, and no leakage of molten resin occurs at the outer lead of the LED lead frame. <P>SOLUTION: In order to cause flash on the upper surface at the central part such as a die pad 1 and an inner lead 2, and in order to cause it on the lower surface around the outer leads 3 and 4, the metal material is punched in the direction opposite to the forward direction. A mold for insert molding process with the lead frame is provided with an R part corresponding to sagging at the periphery of the lead frame. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an LED lead frame and an injection mold used for insert molding.

  Conventionally, LED lead frames have been manufactured by punching a strip or plate of a metal material a plurality of times from only one direction from top to bottom. Therefore, burrs were generated only on the back surface of the LED lead frame.

  Therefore, the state in which the LED lead frame is housed in an injection mold used for insert molding is as shown in FIG. The boundary between the storage groove bottom surface 81a and the storage groove side surface 81b provided in the cup side mold 8 is a right angle. Further, when the LED lead frame 10 is stored in the storage groove, the sag surface 10a of the LED lead frame 10 is located on the joint surface between the cup side mold 8 and the bottom side mold 9, and part of the joint surface The gap due to the sag portion is continuously generated.

  However, when the LED lead frame is to be stored in the storage groove of the injection mold, the burr of the LED lead frame is caught on the edge of the storage groove of the injection mold and cannot be stored in the correct position. A part of the metal chip is chipped and the metal powder is placed on the injection mold or the LED lead frame, which causes a problem of shape failure or LED short circuit.

  In addition, since a gap due to the sag of the LED lead frame is formed on the joint surface between the upper mold and the lower mold of the injection mold, there is a problem that the molten resin is likely to leak. In particular, in the case of LED devices used for small LED devices and liquid crystal backlights where the thickness of the upper part of the cup is extremely thin, short-circuiting (unsatisfaction) of the molten resin is likely to occur, so the pressure of the molten resin must be increased. The problem is that molten resin is likely to leak near the outer lead of the LED lead frame.

  Accordingly, the object of the present invention is to prevent the storage position from being defective when the outer lead of the LED lead frame is stored in the storage groove of the injection mold, and to prevent the metal powder from being lost in the burr of the LED lead frame. Another object is to provide an LED lead frame that does not occur and does not leak molten resin with respect to the outer leads of the LED lead frame, and to provide an injection mold used for insert molding of the LED lead frame.

  The object of the present invention is to provide an LED lead frame according to claim 1, that is, a metal material such that burrs are formed on the upper surface of the central portion such as the die pad portion and inner lead portion, and burrs are formed on the lower surface of other peripheral portions. Is achieved by an LED lead frame obtained by punching in the forward direction and punching in the reverse direction.

  The above object can also be achieved by an injection mold used for insert molding of an LED lead frame according to claim 2.

  According to the LED lead frame according to the present invention, the central portion such as the die pad portion and the inner lead portion is burred on the upper surface, so that the flat portion is wide on the upper surface, and chip bonding of the LED chip and Au wire It is easy to wire bond and there is almost no adhesion failure.

  Further, according to the LED lead frame according to the present invention, burrs are formed on the upper surface of the peripheral portion such as the outer lead. Therefore, when the peripheral portion of the LED lead frame is stored in the storage groove of the injection mold. In addition, it is difficult to be caught, and it is difficult to cause a position defect. Moreover, since there is almost no burrs, there is no generation of metal powder and leakage of molten resin is difficult to occur.

  As a result, it is only necessary to pay attention to defective resin filling at the upper end of the cup portion, and the management of injection molding is greatly facilitated.

  Hereinafter, embodiments of an LED lead frame according to the present invention will be described with reference to the accompanying drawings.

  FIG. 2 is an explanatory view showing a punching process of the LED lead frame of the present invention.

  In the first step, as shown in FIG. 2A, the portions 5a, 5b, and 5c are punched so that burrs are generated on the lower surface and sagging is generated on the upper surface. Usually, punching is performed by bringing a die into contact with the lower surface, pressing a punch from the upper surface side, moving the die downward, and inserting the die into the die.

  In the second step, as shown in FIG. 2B, the portion 6 adjacent to the portion 5b is punched so that burrs are generated on the upper surface and sagging is generated on the lower surface.

  Subsequently, in the third step, as shown in FIG. 2C, the portion 7a adjacent to the portions 5a, 6 and 5c is punched so that burrs are generated on the upper surface and sagging is generated on the lower surface. The portion 7b adjacent to 5b and 6 is also punched so that burrs are generated on the upper surface and sagging is generated on the lower surface.

  FIG. 1 is a plan view showing an embodiment of an LED lead frame of the present invention. Through the punching process as described above, the portions 1a, 1b, 1c, 2a, 2b, and 2c in which burrs are generated on the upper surface and the portions 3a, 3b, 4a, and 4b in which burrs are generated on the lower surface are mixed. . That is, portions 1a, 1b, and 1c with burrs on the upper surface are formed around the die pad 1, and portions 2a, 2b, and 2c with burrs on the upper surface are also formed around the inner leads 2. . On the other hand, around the outer leads 3 and 4, there are formed portions 3a, 3b, 4a and 4b where burrs are generated on the lower surface.

  FIG. 3 is a schematic view showing a state in which the LED lead frame of this embodiment is set in the injection mold of this embodiment. An R portion 81c is formed at the corner of the boundary between the storage groove bottom surface 81a and the storage groove side surface 81b provided in the cup side mold 8, and is rounded. In addition, when the LED lead frame 10 is stored in the storage groove, in this embodiment, the sag surface of the LED lead frame 10 is in contact with the storage groove bottom surface 81a, and the R portion 81c substantially matches the shape of the sag portion. Therefore, there is almost no gap, and the burr surface of the LED lead frame 10 is located on the joint surface between the cup-side mold 8 and the bottom-side mold 9, so there is almost no gap in this portion.

  With the cup-side mold 8 and the bottom-side mold 9 closed and in contact, the molten resin is injected under pressure to fill the space inside the mold. The injection port is near the center of the LED lead frame, and many manufacturing parameters such as the resin temperature, injection pressure, and injection speed are controlled to prevent the occurrence of burrs and shortage around the resin.

  4A and 4B are explanatory views showing a product obtained by resin insert molding the LED lead frame of this embodiment, wherein FIG. 4A is a plan view and FIG. 4B is a cross-sectional view taken along line AA in FIG. Burrs are generated on the upper surface of the LED lead frame 1 and the inner lead portion 2, that is, the side surface of the cup. On the other hand, sagging is generated on the upper surface of the outer lead portions 3, 4 that is the peripheral portion of the LED lead frame. It is manufactured by stamping.

  Such an LED lead frame is resin-molded by insert molding. A resin upper portion 11a is formed on the upper surface of the LED lead frame, that is, the side surface of the cup, a mortar-shaped cup portion is formed at the center, and portions of the die pad portion 1 and the inner lead portion 2 are exposed at the bottom portion. The cup surface 11b is inclined. On the other hand, a resin lower portion 11c is formed on the lower surface of the LED lead frame, and a protrusion 11d appears near the resin injection port.

  As for the peripheral portion of the LED lead frame, since the burr surface is located at the joint surface between the upper mold and the lower mold when set in the insert mold, the resin hardly leaks and the burr hardly occurs. Therefore, there is no problem even if the injection pressure at the time of injecting the molten resin is slightly increased, the setting range of the injection pressure is widened, and the degree of freedom of control is increased. For this reason, even if the wall thickness of the cup is 0.07 mm, if the injection pressure is increased somewhat, there will be no shortage around the resin and the occurrence of defective products will be reduced.

  On the other hand, since the upper surface of the central portion of the LED lead frame is a burr surface, since the ratio of the flat surface of the upper surface is large, poor adhesion of semiconductor chips and poor bonding of wire bonding are unlikely to occur.

It is a top view which shows the embodiment of the lead frame for LED of this invention. It is explanatory drawing which shows the punching process process of the lead frame for LED of this invention. It is the schematic which shows the state which has set the lead frame for LED of this embodiment to the injection mold of this embodiment. It is explanatory drawing which shows the product which carried out resin insert molding to the lead frame for LED of this embodiment, (a) is a top view, (b) is AA sectional drawing in (a). It is explanatory drawing which shows the state accommodated in the injection die used for insert mold processing for LED lead frame.

Explanation of symbols

1 Die Pad 1a Part 1b Part 1c Part 2 Inner Lead Part 2a Part 2b Part 2c Part 3 Outer Lead Part 3a Part 3b Part 4 Outer Lead Part 4a Part 4b Part 5a Part 5b Part 5c Part 6 Part 7a Part 7b Part 8 Cup Side Mold 9 Bottom mold 10 LED lead frame 10a Sag surface 11a Resin upper portion 11b Cup surface 11c Resin lower portion 11d Projection 81a Storage groove bottom surface 81b Storage groove side surface 81c R portion

Claims (2)

For LEDs obtained by stamping metal materials in the forward direction and in the opposite direction so that burrs are generated on the upper surface of the central part such as the die pad and inner lead, and burrs are generated on the lower surface of other peripheral parts. Lead frame. Insert mold processing of the LED lead frame, in which R corresponding to the sagging shape of the peripheral portion of the LED lead frame is formed at the boundary portion between the bottom surface and the side surface of the groove portion that houses the peripheral portion of the LED lead frame Injection mold used for

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