JP2007189150A - Lead frame for low-height led device and method for manufacturing same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lead frame for a low-height LED device that prevents the occurrence of exfoliation between the lead frame and a resin, and cracks in the resin, and that has a height of ≤1 mm, and to provide a method for manufacturing the same. <P>SOLUTION: In the lead frame for a low-height LED device, a long deformed metal material is composed so that a thickness ratio is 2.5:1-3.5:1 between normal parts 2a, 2b and a thin-walled part 1; and the normal part 2b, the thin-walled part 1, and the normal part 2a are sequentially arranged in a longitudinal direction. The long deformed metal material is punched so as to form chip pads and inner leads 3a-8a at the thin-walled part, and to form outer leads 12c-12f at the normal parts. Next, a resin-made cup is injection-molded and cut so as to form an end of each outer lead after injection molding without bending the outer leads. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a lead frame for a low profile LED device for manufacturing a short LED (light emitting diode) device. The present invention also relates to a method for manufacturing a lead frame for a low-profile LED device.

FIG. 7 is a front sectional view of a conventional LED device.
A long plate-shaped metal material having a uniform thickness is subjected to multi-stage punching through a transfer press and then passed through an injection molding machine to form a resin cup portion by resin molding on the chip pad portion and the inner lead portions 12a and 12b. Subsequently, the outer lead portions 12c, 12d, 12e, and 12f are bent 90 ° at two locations to form a “U” shape, and the tips 12d and 12f of the outer lead portion are formed into the bottom surface 10d of the resin cup portion. The bases 12c and 12e of the outer lead part are parallel to the side face 10c of the resin cup part.

An upper surface 10a, an inner side surface 10b, and an inner upper surface 10f of the resin cup portion are formed, and the inner lead portions 12a and 12b are electrically insulated from each other and exposed adjacent to the inner upper surface 10f. The inner side surface 10b is not vertical but is inclined, and forms a space that expands upward.
The inner side surface 10b functions as a reflecting surface. A wire bonding process is performed in which an LED chip (not shown) is attached to the inner upper surface of the resin cup portion, and the inner lead portions 12a and 12b corresponding to the electrodes of the LED chip are connected with gold wires.
The height (height) of a conventional LED device is at least 1.4 mm, but in recent years, an LED device having a height (height) of less than 1 mm has been demanded.

In the conventional LED device, in order to reduce the height (height), the thickness of the resin portion below the lead frame is reduced, and the lengths of the roots 12c and 12e of the outer lead portion are correspondingly shortened. When this is attempted, the bending stress applied to the lead frame becomes too large, and a trouble such as separation between the lead frame and the resin or cracking of the resin is likely to occur. Therefore, the epoxy resin for sealing easily leaks to the outside through the peeled portion or the cracked portion, which causes a problem in the LED device.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a low-profile LED device in which peeling between a lead frame and a resin and cracking of the resin are difficult to occur, and the height (height) is low and is 1 mm or less. Moreover, the manufacturing method of such a low profile LED device is provided.

  The inventor has intensively studied to achieve the above object, and has led to the invention of a lead frame for an LED device according to the present invention, which has a completely different concept from that of a conventional LED device.

The object is to provide a lead frame for a low profile LED device according to claim 1, i.e.
A long irregular metal material in which a normal portion, a thin portion, and a normal portion having a thickness ratio of 2.5: 1 to 3.5: 1 are sequentially arranged in the longitudinal direction is punched into chips in the thin portion. Form the pad part and inner lead part, form the outer lead part in the normal part, then injection mold the resin cup part, then cut to form the end of the outer lead part, This is achieved by a lead frame for a low-profile LED device that does not bend the outer lead portion.

  In a preferred embodiment of the present invention, as described in claim 2, three LED chips of R, G, and B can be attached.

  In a further preferred embodiment of the present invention, as described in claim 3, the height is 1 mm or less.

  Another object of the present invention is to provide a method for manufacturing a lead frame for a low-profile LED device according to claim 4, that is, the ratio of the thickness of the normal part to the thin part is 2.5: 1 to 3.5: 1. The long irregular metal material in which the normal part, thin part and normal part are arranged in order in the longitudinal direction is passed through a transfer press and an injection molding machine, and punching, cutting, and resin molding are performed and bending is performed. This is also achieved by a method for manufacturing a lead frame for a low-profile LED device that obtains a lead frame for a low-profile LED device having a height of 1 mm or less without performing the process.

  Since the outer lead is not bent, bending stress does not act. Therefore, there is almost no peeling between the lead frame and the resin and there is almost no cracking of the resin. In addition, the manufacturing process can be shortened.

The outer lead part is thicker than the inner lead part and the chip pad part, so the heat dissipation effect is great. Therefore, an LED with a larger output can be mounted.
In particular, the height (height) of the LED device can be reduced to 1 mm or less, and can be reduced to about ½ compared with the LED device conventionally manufactured by the applicant. Therefore, the liquid crystal display can be further reduced in thickness.

  Hereinafter, a lead frame for a low-profile LED device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 3 is a cross-sectional view of a long irregular metal material used for manufacturing a lead frame for a low-profile LED device according to an embodiment of the present invention, and is a cross-sectional view of a cross section orthogonal to the longitudinal direction.
Both sides of the thin portion 1 having a thickness of about 0.15 to 0.25 mm are sandwiched in parallel by the normal portions 2a and 2b having a thickness of about 0.4 to 0.5 mm, and the lower surface is flat. However, the thin-walled portion 1 is recessed on the upper surface, and there is a step. As a material, copper alloy, stainless steel, or the like can be used from the viewpoint of electrical conductivity and cost.

FIG. 4 is a cross-sectional view showing a state in which the long irregular metal material shown in FIG. 3 is passed through a transfer press (multistage progressive press machine group) and punched to form a V-shaped groove. A punching portion 1a is provided by punching, an inner lead portion and a chip pad portion are formed in the thin portion 1, and an outer lead portion is formed in the normal portions 2a and 2b.
Further, the normal portions 2a and 2b are cut in a subsequent process, and V-shaped grooves 5c and 8c are formed from the upper surface and the lower surface at positions to be the tips of the outer lead portions.

  FIG. 5 is a cross-sectional view showing a state in which a resin-made cup portion is formed by inserting and molding the half-processed long irregular metal material shown in FIG. 4 through an injection molding machine. A part of the inner lead part and the chip pad part are exposed on the lower surface of the long irregular metal material, and a resin cup part main body is formed so as to protrude downward around them. The resin cup part body is surrounded by an upper surface 10a, a side surface 10c, and a reflection surface 10b which is an inner surface. On the other hand, the upper surface of the long irregular metal material is resin-molded so as to fill the dents associated with the thin-walled portion 1, the punched portion 1a of the inner lead portion, and the punched portion of the outer lead portion (not shown). . Reference numeral 10d denotes a bottom surface, and 10e denotes a dent part of the resin injection part. From the side of the resin cup part, the outer lead part slightly protrudes vertically, and the V-shaped grooves 5c and 8c are located. Further, on the front and back (longitudinal direction) side surfaces of the resin cup portion, the edge of the hanger lead portion formed slightly apart from the inner lead portion in the thin portion is slightly bitten.

  After the insert molding process, the outer lead portion is cut at the positions of the V-shaped grooves 5c and 8c to form the end portion of the outer lead portion. After chip bonding, sealing with epoxy resin or silicon, and completing the LED device, push the LED device itself, remove the hanger leads from the front and back sides of the resin cup, and remove the LED device separately. To do.

  FIG. 1 is a plan view of a lead frame for a low-profile LED device according to an embodiment of the present invention, and FIG. 2 is a bottom view thereof. 5 is a cross-sectional view taken along the line CC in FIG. 1, and FIG. 6 is a cross-sectional view taken along the line DD in FIG.

  For example, an R (red) LED chip is placed and bonded across the inner lead portions 3a and 6a. Similarly, for example, a G (green) -LED chip is placed and bonded across the inner lead portions 4a and 7a. Similarly, for example, a B (blue) -LED chip is placed and bonded across the inner lead portions 5a and 8a. By mounting three color LED chips, full color can be emitted.

  The upper part of the resin cup is covered with a lens and sealed with an epoxy resin or the like to complete a low-profile LED device. Use the outer lead part protruding slightly from the side of the resin cup part at a right angle without bending.

Plan view of lead frame for low profile LED devices Bottom view of lead frame for low profile LED devices Cross-sectional view of a long irregular metal material used to manufacture a lead frame for low-profile LED devices FIG. 3 is a cross-sectional view showing a state in which a long irregular metal material shown in FIG. 3 is punched through a transfer press (multistage progressive press machine group) to form a V-shaped groove. CC sectional view in FIG. DD sectional view in FIG. Front sectional view of a conventional LED device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Thin part 2a Normal part 2b Normal part 3a Inner lead part 4a Inner lead part 5a Inner lead part
6a Inner lead part 7a Inner lead part 8a Inner lead part 1a Punched part
5c V-shaped groove 8c V-shaped groove 10a Upper surface 10b Reflecting surface (inner surface)
10c Side surface 10d Bottom surface 10e Resin injection part dent part 10f Inner upper surface 12a Inner lead part 12b Inner lead part 12c Outer lead part 12d Outer lead part 12e Outer lead part 12f Outer lead part

Claims (4)

  A long irregular metal material in which a normal portion, a thin portion, and a normal portion having a thickness ratio of 2.5: 1 to 3.5: 1 are arranged in order in the longitudinal direction is punched into chips in the thin portion. Form the pad part and inner lead part, form the outer lead part in the normal part, then injection mold the resin cup part, then cut to form the end of the outer lead part, A lead frame for low-profile LED devices that does not bend the outer lead.   The lead frame for a low-profile LED device according to claim 1, wherein three LED chips of R, G, and B can be attached.   The lead frame for a low-profile LED device according to claim 1 or 2, wherein the height is 1 mm or less. A ratio of the thickness of the normal part to the thin part is 2.5: 1 to 3.5: 1, and a long irregular metal material in which the normal part, the thin part, and the normal part are sequentially arranged in the longitudinal direction is transfer-pressed. The lead frame for a low-profile LED device is obtained by performing punching, cutting, and resin molding through an injection molding machine to obtain a lead frame for a low-profile LED device having a height of 1 mm or less without performing a bending process. Production method.

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