JP2000323755A - Semiconductor light emitting device - Google Patents

Abstract

(57) [Problem] To provide an assembly structure for conductive mounting on a lead frame which can cope with miniaturization of a semiconductor light emitting element. SOLUTION: A pair of electrodes 5 and 6 are integrally formed on a mount cup 4 made of a synthetic resin, and the semiconductor light emitting element 1 is mounted by being electrically connected to the electrodes 5 and 6. The mounting cup 4 is mounted on the leads 3a and 3b of the lead frame 3 and the interval between the electrodes 5 and 6 provided on the mounting cup 4 is set short so that the semiconductor light emitting element 1 can be mounted in a small size.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor light emitting device having a flip-chip type semiconductor light emitting device, and more particularly to a semiconductor light emitting device which can be assembled with a lead frame which can cope with downsizing of the semiconductor light emitting device.

[0002]

2. Description of the Related Art GaN, GaAlN, InGaN and I
In a blue light emitting device using a GaN-based compound semiconductor such as nAlGaN, sapphire is currently most commonly used as a substrate for crystal growth. In this light emitting element using insulating sapphire as a substrate, both the p-side and n-side electrodes are formed on the surface opposite to the substrate and on the surface of the semiconductor laminated film. Thus p
A flip-chip type assembly in which bump electrodes are formed on each of these electrodes by utilizing the fact that the n-side and n-side electrodes are on the same surface and the substrate side faces the light-emitting direction has been known. Have been.

FIG. 5 is a schematic view of an LED lamp in which a semiconductor light emitting device using a GaN-based compound semiconductor is mounted on a lead frame as a flip-chip type. FIG. 5A is a longitudinal sectional view, and FIG. b) is a cross-sectional view.

In FIG. 5, a mounting portion 51 is provided at the upper end of each of a pair of leads 51a and 51b of a lead frame 51 which is conductively fixed to a printed wiring board (not shown).
c, 51d are formed, and these mount portions 51c, 5d are formed.
While mounting the semiconductor light emitting element 1 on 1d,
The whole is sealed with a resin head 52 using epoxy resin.

[0005] As shown in FIG.
Substrate 1 using sapphire that is insulative and light-transmissive
a, an n-type layer 1b and a p-type layer 1c of GaN are sequentially stacked on each other to form an active layer between these layers.
A p-side electrode pad 1e is formed on the surface of the side electrode pad 1d and the surface of the p-type layer 1c by a metal deposition method. The bump electrodes 2a and 2b are formed on the n-side and p-side electrode pads 1d and 1e, respectively.

The semiconductor light emitting device 1 includes bump electrodes 2a, 2
b is mounted on the mounting portions 51d and 51c, and is joined by applying ultrasonic pressure bonding and heating pressure bonding.
1a. Then, light from the active layer passes through the substrate 1a and is emitted upward in FIG.
The upper end surface of the substrate 1a is defined as a main light extraction surface.

[0007]

The general manufacture of the device, including the semiconductor light-emitting device 1 of the illustrated example, involves the use of G
An n-type layer or a p-type layer of aN is laminated in a wafer state, and n-side and p-side electrode pads are formed by vapor deposition, and dicing is performed with a dicer to obtain a chip-shaped light emitting element. In recent years, advances in dicing technology and improvements in patterning accuracy for forming electrodes have made it possible to further reduce the size of light-emitting elements.
Such miniaturization of the light emitting element is extremely effective in terms of adapting to electronic equipment in which miniaturization and thinning are the most important design issues.

On the other hand, in manufacturing the lead frame 51 for mounting the semiconductor light emitting element 1, it is necessary to process the mount portions 51c and 51d for conduction between the p side and the n side. That is, the leading end side of the lead frame 51, that is, the portion where the mount portions 51c and 51d are finally formed is integrally formed as a forked part with the leads 51a and 51b extended, and the center of the integrated portion is formed. Is cut and separated into mount portions 51c and 51d.

However, the cut-out mounting portion 51
The incision width of the gap 51e between c and 51d depends on the thickness of the lead frame 51, but is conventionally about 0.4 mm at the minimum. In most cases, the thickness becomes 0.4 mm or more when a processing error or the like is included.

As described above, the gap 51 between the lead frame 51 and the mount portions 51c and 51d is taken into consideration.
There is a lower limit to the width of e. On the other hand, the size of the semiconductor light emitting element 1 is further reduced, and the interval between the bump electrodes 2a and 2b tends to be shorter. Therefore, the bump electrode 2
If the interval between a and 2b is shorter than the width of the gap 51e, only one of the bump electrodes 2a and 2b can be joined to the mount portions 51c and 51d, and assembly cannot be performed.

As described above, while the size of the semiconductor light emitting element 1 is being reduced, the gap 51e between the mount portions 51c and 51d cannot be narrowed due to the manufacturing restrictions of the lead frame 51. is there. For this reason, in the case where the semiconductor light emitting device 1 and the lead frame 51 are mounted on the two separate mounting portions 51c and 51d to form an LED lamp, matching between the semiconductor light emitting device 1 and the lead frame 51 cannot be obtained, which is a major obstacle to miniaturization of the device. ing.

An object of the present invention is to provide an assembly structure for conductive mounting on a lead frame which can cope with miniaturization of a semiconductor light emitting device.

[0013]

According to the present invention, a semiconductor thin-film layer is laminated on a light-transmitting substrate, and p-side and n-side electrodes are respectively formed on the surface side of the laminated film. A semiconductor light emitting element having a main light extraction surface as
A pattern of a pair of electrodes that respectively conduct to the side electrode and the n-side electrode is integrally formed, and a mount cup made of a synthetic resin on which the semiconductor light emitting element is mounted, and the mount cup is mounted on each end of a pair of leads. And a lead frame formed with stays that are electrically connected to the pair of electrode patterns, respectively, wherein an interval between the pair of electrodes formed on the mount cup is shorter than an interval between the stays of the lead frame. .

In this configuration, even if the distance between the stays must be a certain value or more from the viewpoint of manufacturing the lead frame, the interval between the electrodes provided on the synthetic resin mount cup can be reduced. As a result, even if the semiconductor light emitting device is miniaturized and the distance between the p-side and n-side electrodes is short, it is possible to conduct and mount it.

[0015]

According to the first aspect of the present invention, a semiconductor thin film layer is laminated on a light transmitting substrate, and p-side and n-side electrodes are formed on the surface side of the laminated film, respectively. A semiconductor light emitting element having the substrate side as a main light extraction surface,
A pattern of a pair of electrodes respectively conducting to the p-side and n-side electrodes is integrally formed, and a mount cup made of a synthetic resin on which the semiconductor light emitting element is mounted, and the mount cup is provided at each end of a pair of leads. A lead frame mounted thereon and having a stay formed to be electrically connected to the pair of electrode patterns, wherein an interval between the pair of electrodes formed on the mount cup is shorter than an interval between the stays of the lead frame. The semiconductor light emitting device has a function of conducting even a semiconductor light emitting device having a short distance between the p-side and n-side electrodes irrespective of the shape and size of the lead frame.

According to a second aspect of the present invention, in the semiconductor light emitting device according to the first aspect of the present invention, the mount cup has a light-reflective filler mixed in a synthetic resin of the material. Even a mount cup has an effect that light reflection by a filler can be used.

Hereinafter, specific examples of the embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing a main part of a semiconductor light emitting device according to an embodiment of the present invention, and FIGS. 2 and 3 are a plan view and a bottom view of FIG. The semiconductor light emitting device is shown in FIG.
And the same components are designated by the same reference numerals.

In FIG. 1, upper ends of a pair of leads 3a and 3b of a lead frame 3 whose base ends are conductively fixed to a printed wiring board (not shown) or the like are provided at right ends thereof with stays 3a-1 and 3b bent at right angles. -1 are formed, and a mount cup 4 to which the semiconductor light emitting element 1 is conductively fixed is fixed to the upper surfaces of these stays 3a-1 and 3b-1.

As in the prior art, the lead frame 3 is formed in a fork-like manner with the distal end side, that is, the stays 3a-1 and 3b-1 are integrally formed.
a-1 and 3b-1 are separated into gaps 3c. Then, the opening width W of the gap 3c
Is about 0.4 mm with current manufacturing technology.

The mount cup 4 is made of, for example, a white liquid crystal polymer (LCP), and is formed in a mortar shape surrounding the semiconductor light emitting device 1. Then, in order to reflect light exiting from below and from the side from the semiconductor light emitting element 1 in the light emitting direction, a compound such as TiO ₂ having light reflectivity is mixed as a filler.

A pair of electrodes 5 and 6 for conducting the semiconductor light emitting element 1 and the lead frame 3 are provided on the bottom 4a of the mount cup 4. These electrodes 5 and 6 are integrally sealed when the mold is manufactured together with the mount cup 4 mixed with the filler, and have a rectangular planar shape as shown in FIGS. 2 and 3. That is, the electrodes 5 and 6 form element-side conducting portions 5a and 6a projecting above the bottom 4a at the center of the bottom 4a, and form the bottom 4a.
Lead-side conductive portions 5b, 6b exposed in the same plane as the lower surface of
It has.

Here, since the electrodes 5 and 6 are integrally sealed when the mount cup 4 is molded with a resin, the positions of the electrodes 5 and 6 with respect to the mold for manufacturing are properly set so that the electrodes 5 and 6 can be mutually fixed. Can be reduced. That is, as shown in FIG.
It is possible to perform molding in which the distance between a and 6a is shorter than the opening width W of the gap 3c of the lead frame 3. Therefore, even if the distance between the n-side and p-side bump electrodes 2a and 2b of the semiconductor light emitting element 1 is shorter than, for example, the opening width W of the gap 3c, the semiconductor light emitting element 1 can be mounted on the element side conductive portions 5a and 6a.

The mount cup 4 integrally provided with the electrodes 5 and 6 is mounted on the stays 3a-1 and 3b-1 of the leads 3a and 3b so as to have the positional relationship shown in FIGS. Then, the lead-side conductive portion 5 is closer than the stays 3a-1 and 3b-1.
By increasing the plane shapes of b and 6b, these stays 3a-1 and 3b-1 and lead-side conductive portions 5b and 6b can be soldered 7 as shown in FIG. At the same time, the conduction between the electrodes 5, 6 and the leads 3a, 3b is obtained.

By integrating the mount cup 4 with the lead frame 3 in this manner, the electrodes 5 and 6 provided in advance on the mount cup 4 conduct to the leads 3a and 3b. Therefore, the bump electrodes 2a, 2a,
If the semiconductor light emitting device 1 is mounted by ultrasonic pressure bonding and heat pressure bonding with the 2b placed thereon, the semiconductor light emitting device 1 is mounted. In this mounting, as described above, since the distance between the element-side conductive portions 5a and 6a is shorter than the gap 3c of the lead frame 3, the semiconductor light emitting element 1 is small and the bump electrodes 2a and
It is possible to cope with a case where the interval of 2b is narrow.

Also, since a highly light-reflective filler such as TiO ₂ is mixed into the mount cup 4, the light that escapes from the semiconductor light emitting element 1 to the bottom 4 a and the inner peripheral surface 4 b side is removed from the substrate 1 a in FIG. The light can be collected by being reflected in the direction of light emission from the main light extraction surface on the upper surface. Therefore, even if the mount cup 4 is made of a synthetic resin, it is possible to improve the light emission luminance by the reflected light.

FIG. 4 shows electrodes 5 provided on the mount cup 4.
It is a top view of an important section showing another example of the formation pattern of No. 6.

In the illustrated example, the n-side and p-side electrode pads 1d, 1e are diagonally separated from each other in the plane outline of the semiconductor light emitting device 1, so that the device-side conductive portions of the electrodes 5, 6 are connected. 5a and 6a have shapes developed so as to include the bump electrodes 2a and 2b bonded to the electrode pads 1d and 1e. As described above, even if the arrangement and positional relationship of the p-side and n-side electrodes of the semiconductor light emitting element 1 are changed, only the patterns of the electrodes 5 and 6 in the mount cup 4 need to be changed. It can also support mounting of light emitting elements.

[0029]

According to the first aspect of the present invention, when the electrodes are formed on the mount cup made of synthetic resin, the pattern can be freely formed, so that the distance between the electrodes can be shortened, and the distance between the p-side and n-side electrodes can be reduced. Even a small semiconductor light emitting element having a short distance can be assembled without any trouble, and the miniaturization of the device is further promoted.

According to the second aspect of the present invention, a light reflecting function can be provided by mixing a light-reflective filler into the mount cup. Therefore, even if the mount cup is made of a synthetic resin, the emission luminance is reduced. Nothing.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a semiconductor light emitting device according to an embodiment of the present invention.

FIG. 2 is a schematic plan view showing a positional relationship between an electrode pattern provided on a mount cup and a semiconductor light emitting element.

FIG. 3 is a schematic bottom view showing a positional relationship between a lead-side conductive portion of an electrode provided on a mount cup and a lead.

FIG. 4 is a schematic plan view showing another example of an electrode pattern provided on a mount cup.

5A and 5B show an example of an LED lamp including a conventional flip-chip type semiconductor light emitting device, wherein FIG. 5A is a longitudinal sectional view and FIG.

FIG. 6 is a longitudinal sectional view of a main part showing a conductive mounting structure of a semiconductor light emitting element on a lead frame in a conventional example.

[Explanation of symbols]

 Reference Signs List 1 semiconductor light emitting element 1a substrate 1b n-type layer 1c p-type layer 1d n-side electrode pad 1e p-side electrode pad 2a, 2b bump electrode 3 lead frame 3a, 3b lead 3a-1, 3b-1 stay 3c gap 4 mount cup 4a Bottom part 4b Inner peripheral surface 5, 6 Electrode 5a, 6a Element side conductive part 5b, 6b Lead side conductive part

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Yuji Kobayashi 1-1, Sachimachi, Takatsuki-shi, Osaka Matsushita Electronics Corporation F-term (reference) 5F041 AA47 DA09 DA16 DA20 DA43 EE23

Claims (2)

[Claims] 1. A semiconductor thin film layer is laminated on a light-transmitting substrate, p-side and n-side electrodes are respectively formed on the surface side of the laminated film, and the substrate side is defined as a main light extraction surface. A semiconductor light emitting element, a pattern of a pair of electrodes that respectively conduct to the p-side and n-side electrodes are integrally formed, and a synthetic resin mount cup mounting the semiconductor light emitting element; and a pair of leads, respectively. A lead frame on which the mount cup is mounted at the tip of the lead frame and a stay is formed to be electrically connected to the pair of electrode patterns, and the distance between the pair of electrodes formed on the mount cup is determined by the distance between the stays of the lead frame. A semiconductor light emitting device characterized by being shorter than the interval. 2. The semiconductor light emitting device according to claim 1, wherein the mount cup has a light-reflective filler mixed in a synthetic resin of the material.