JP3193838B2 - Optical semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical semiconductor device used for consumer appliances such as home electric appliances and game machines, information communication equipment such as computers, word processors and facsimile machines, and automobiles, and particularly to a high definition display. And a small and lightweight optical semiconductor device such as an LED array.

[0002]

2. Description of the Related Art Conventional LED (Light Emitting Diode)
As a method for mounting an LED on a substrate of an LED chip in a display device, there is a mounting method by wire bond assembly as a first method, and a mounting method by face-down bonding as a second method.

FIG. 12 is a plan view of an optical semiconductor device 111 on which an LED chip is mounted by wire bonding as a first mounting method, and FIG. 13 is a cross-sectional view taken along line XIII-XIII in FIG. And
FIG. 14 is a sectional view taken along section line XIV-XIV in FIG.

[0004] The optical semiconductor device 111 includes a hard substrate 100 formed of glass epoxy or the like and a cover 104. In the hard substrate 100, mounting holes 105 for fixing the semiconductor device 111 to other members are provided at four corners of the hard substrate 100, and a predetermined wiring pattern 109 is formed on one surface 100a. Hard substrate 1
The LED chip 101 is provided on one surface 100a of the hard substrate 100 at the center or any position of the one surface 100a of the hard substrate 100, and the conductive paste 1 is provided on the wiring pattern 109.
Implemented by 10. Further, the LED chip 101
IC (integrated circuit) chips 102 are mounted on a substrate pattern 109 by conductive paste 110 on both sides of the substrate pattern 109. A current for driving the LED chip 101 is supplied to each IC chip 102 from the outside via the conductor 112. LED chip 101 and each IC chip 102
The light emitting state of the LED chip 101 can be controlled by electrically connecting the LED chip 101 to the LED chip 101 via the conductor 103.

[0005] A cover 104 made of a light-transmissive material is provided so as to cover each component mounted on the hard substrate 100. Each component is protected from the outside by the cover 104. In addition, since each component is protected from the outside by the cover 104, each component does not corrode. The LED chip 101 emits light through the cover 104 in the emission direction indicated by the arrow 113 when the driving current is supplied.

FIG. 15 is a plan view of an optical semiconductor device 121 on which an LED chip is mounted by a face-down bonding method which is a second mounting method, and FIG. 16 is a cross-sectional view taken along a section line XVI-XVI in FIG. FIG.
FIG. 17 is a sectional view taken along section line XVII-XVII in FIG.

The optical semiconductor device 121 includes a glass substrate 106
, A mounting frame 107 for mounting the glass substrate 106, and a cover 125. A predetermined wiring pattern 126 is formed on one surface 106a of the glass substrate 106.

[0008] LED chip 122 and each IC chip 1
23 is functionally the same as the LED chip 101 and each IC chip 102, which are the components in the first mounting method described above, but the connection electrode has a diameter of 20 to
A convex bump 124 having a size of about 30 μm is formed.

The LED chip 122 is mounted on the glass substrate 106
Bump 124 is electrically connected via conductive paste 127 to wiring pattern 126 formed at the central portion or at an arbitrary position on one surface 106a. In addition, each IC chip 123 has a bump 124 facing the one surface 106 a of the glass substrate 106 via the conductive paste 110 on both sides of the LED chip 122, and the wiring pattern 12.
6 mounted.

In order to protect each component mounted on the glass substrate 106 as described above, a cover 125 is provided so as to cover each component. The mounting frame 107 is formed to have a size surrounding the glass substrate 106, and the glass substrate 106 fits into the center of the mounting frame 107. The mounting frame 107 has an LED mounted on the glass substrate 106 at the center thereof.
Along the chip 122, a through-hole 107b is formed so as to reach the glass substrate 106 from one surface 107a. Further, two mounting holes 108 are formed at each end of the mounting frame 107.

[0011]

In order to realize a high-quality display, it is necessary to increase the number of display dots and the display density. However, each chip is connected by a wire bonding method which is a first mounting method. Optical semiconductor device 11
In the case of 1, when the number of display dots increases, the number of conductors 103 connecting the IC chip 102 and the LED chip 101 increases, and when the display density increases, the connection of the conductors 103 becomes difficult. It becomes high and causes a decrease in yield.

In the optical semiconductor device 121 on which each chip is mounted by the face-down bonding method, which is the second mounting method, since the substrate material on which each chip is mounted is glass, the optical semiconductor device 121 is mounted on another member. It is difficult to perform secondary processing, such as formation of mounting holes, which is necessary when mounting on a surface.
Therefore, in order to attach the optical semiconductor device 121 to another member, an attachment frame 107 having an attachment hole 108 formed separately from the glass substrate 106 is required, and the number of components increases and the number of work steps increases. In addition, since it is difficult to form a substrate pattern on both sides of the glass substrate 106, wiring can be performed only on one side of the substrate, and there are design restrictions, and the optical semiconductor device 121 can be downsized. Hateful. Also,
Since the glass substrate 106 is heavy, the optical semiconductor device 1
21 is difficult to reduce in weight.

An object of the present invention is to provide an optical semiconductor device which can easily perform high-density wiring and mounting, and can reduce the size and weight of the device.

[0014]

SUMMARY OF THE INVENTION The present invention provides an optical semiconductor chip having an optical semiconductor element and connection bumps on its surface,
A through hole having an opening shape corresponding to the optical semiconductor element and an electrode pad corresponding to the connection bump are provided on one surface side, and the through hole is integrally formed so that an opening area increases toward the other surface side. Wherein the optical semiconductor chip is mounted on the synthetic resin molded substrate made of the liquid crystal polymer by face-down bonding between connection bumps and electrode pads. Optical semiconductor device. Also, in the present invention, an LED array is formed as an optical semiconductor element on the optical semiconductor chip, and a plurality of LEs forming the LED array are formed on a synthetic resin molded substrate made of the liquid crystal polymer.
A plurality of slit-shaped through holes are formed individually corresponding to the D elements. Further, the present invention is characterized in that a light-transmitting synthetic resin is filled into a through hole of the synthetic resin molded substrate made of the liquid crystal polymer.

[0015]

According to the present invention, an optical semiconductor device is provided with a through hole integrally formed so as to increase an opening area from one surface side to the other surface side, and an electrode pad formed at a predetermined interval. An optical semiconductor chip having an optical semiconductor element and connection bumps on its surface is mounted on a synthetic resin molded substrate made of a liquid crystal polymer having face down bonding between the electrode pads and the connection bumps.
Therefore, light emitted from the optical semiconductor element of the optical semiconductor chip is emitted to the outside through a through hole provided in the synthetic resin molded substrate made of a liquid crystal polymer.

Preferably, an LED array is formed on the optical semiconductor chip as an optical semiconductor element, and a plurality of LEDs constituting the LED array are mounted on the synthetic resin molded substrate made of the liquid crystal polymer on which the optical semiconductor chip is mounted. A plurality of slit-shaped through holes are formed so as to individually correspond to the elements. Therefore, light emitted from each LED element constituting the LED array is emitted to the outside from the corresponding through hole.

More preferably, the through holes of the synthetic resin molded substrate made of the liquid crystal polymer are filled with a light transmitting synthetic resin. Therefore, it is possible to prevent dust and foreign matter from entering through the through hole, and to protect the optical semiconductor chip from the outside.

[0018]

FIG. 1 is a plan view of an optical semiconductor device 21 according to a first embodiment of the present invention, and FIG.
FIG. 3 is a sectional view taken along line I-II, and FIG. 3 is a sectional view taken along line III-III in FIG.

The optical semiconductor device 21 includes a substrate 1 and a cover 2.
, An LED chip 3 and IC chips 4 and 7. In the optical semiconductor device 21, each element was mounted by a face-down method in order to perform high-density mounting. The substrate 1 is molded as described later, and a tapered slit 6 formed in the center portion toward the short side direction of the substrate 1 is provided. In addition, insertion holes 5 are provided near the four corners of the substrate 1, respectively. When attaching the optical semiconductor device 21 to another member, the optical semiconductor device 21 is fixed by inserting a bolt or the like into the insertion hole 5. Wiring patterns 9, 14, 15, 16 which are predetermined patterns are formed on the substrate 1.

The LED chip 3 has conductive bumps 10 having a diameter of about 20 to 30 μm on the connecting electrodes.
a, 10b are formed. Similarly, bumps 12a and 12b; 13a and 13b are formed on the IC chips 4 and 7, respectively. The LED chip 3 has the bumps 10 a, 10 b facing the wiring patterns 15, 16 on both sides of the slit 6, respectively, and the wiring pattern 1 via the conductive paste 11.
5 and 16 are electrically connected. The IC chip 4 has the bumps 12 b facing the wiring pattern 15, the bumps 12 a facing the wiring pattern 14, and is electrically connected via the conductive paste 11. IC chip 7 has bump 1
3a is directed to the wiring pattern 16, the bump 13b is directed to the wiring pattern 9, and they are electrically connected via the conductive paste 11.

FIG. 4 shows an LED in the optical semiconductor device 21.
FIG. 3 is a plan view around a chip 3. The IC chip 4 and the LED chip 3 are composed of a plurality of wiring patterns 15a, 15b, 15
c, 15d,... and the IC chip 7 and the LE
The D chip 3 includes a plurality of wiring patterns 16a, 16b,
16c, 16d,... A plurality of light emitting portions 8 are formed on the LED chip 3 in the direction of the long side of the LED chip 3.
The light emitted from b, 8c,... passes through the slit 6 and is emitted in the emission direction indicated by the arrow 18.

A cover 2 for protecting each component is provided on the substrate 1 on which each component is provided as described above.
Since the light emitted from the LED chip 3 is emitted to the outside in the emission direction 18 from the slit 6 provided on the substrate 1, the cover 2 has no relation to the light transmission, and Materials need not be used.

In the optical semiconductor device 21, connection between the substrate 1 and each chip is performed by a face-down bonding method in order to realize high-density wiring and mounting. In order to mount each chip on the substrate 1 by the face-down bonding method, the substrate 1 needs to be able to transmit light and to easily form a circuit. In addition, a material other than glass is used as the material of the substrate 1 in order to secure secondary workability and further reduce the weight. When a transparent material such as a polycarbonate material or an acrylic material is used as the material of the substrate 1, molding is possible because both are thermoplastic resins. However, plating adhesion strength on the resin surface is low, and a wiring pattern can be formed. Can not. Therefore, a liquid crystal polymer material having a high adhesion strength on the resin surface is used as a material of the substrate 1, and a slit 6 for transmitting light to a portion corresponding to a light emitting portion is provided at the time of molding the substrate 1. When the substrate 1 is molded, the liquid crystal polymer is a resin having a high fluidity, and the molding pressure is set high to prevent insufficient filling.

The teeth of a mold used for molding the substrate 1 provided with the slits 6 have reduced strength because the width of the slits 6 is narrow. Further, since the stress is concentrated on the portion serving as the slit 6, the surface side on which each chip is mounted rises when the mold is removed. For this purpose, the shape of the slit 6 is formed so that the opening area increases from one surface 1a to the other surface 1b. For example, substrate 1
When the thickness is 1.0 mm, the slit width on the surface 1a side on the light emitting portion side is 150 to 200 μm, and the slit width on the other surface 1b side as the external opening is 300 to 400 μm.
When it is set to μm, the surface accuracy around the slit 6 on the surface 1a is not impaired. At the same time, the shape becomes wider toward the roots of the teeth of the mold, so that the durability of the mold is improved.

On the substrate 1 molded as described above, the MID
The wiring patterns 9, 14, 15, 16 are formed by a method called (Molded Interconnection Device).
The formation of a fine pattern required in the optical semiconductor device 21 is performed by a PSP (Photo Selective Plating) method using a photo process which is one of the MIDs. In the PSP method, first, an adhesion promoter and a photosensitive agent are applied to an injection-molded substrate, and a portion serving as a nucleus of plating is selectively formed. Next, a positive pattern is formed by exposure to ultraviolet light. Further, a portion other than the positive pattern is fixed, and a wiring pattern is formed by electroless plating.

As described above, since the substrate 1 is molded,
In the related art, it is possible to make attachment parts and the like provided after molding at the time of molding.

FIG. 5 is a plan view of an optical semiconductor device 22 as another configuration example in the first embodiment of the present invention, and FIG. 6 is a sectional view taken along the line VI-VI in FIG.
FIG. 7 is a cross-sectional view taken along section plane VII-VII in FIG.

In the optical semiconductor device 22, the same components as those of the optical semiconductor device 21 described above are denoted by the same reference numerals, and description thereof will be omitted. In the optical semiconductor device 22, an annular pedestal 23 having an insertion hole communicating with the insertion hole 5 is formed integrally with the substrate 1. By providing the pedestal 23, when attaching the optical semiconductor device 22 to another member, the difference in height between the cover 2 and the other member is reduced, so that no other member is sandwiched between the substrate 1 and the other member However, the mounting can be easily performed. As described above, since the shape of the substrate 1 can be arbitrarily processed as necessary, the number of mounting components can be reduced and simplified.

As described above, according to the present embodiment, in the optical semiconductor devices 21 and 22, the LED chip 3 straddles the slit 6 with the light emitting part 8 directed to the tapered slit 6 provided on the substrate 1. Are connected to the wiring patterns 15 and 16 by face-down bonding, and are supplied with current from the respective IC chips 4 and 7 to emit light in the emission direction 18.
Since the light is emitted to each other, each component can be connected to each other without using a conductive wire, so that high-density wiring and mounting can be performed.

FIG. 8 is a sectional view of an optical semiconductor device 24 according to a second embodiment of the present invention. In the optical semiconductor device 24, the same components as those of the optical semiconductor device 21 in the first embodiment described above are denoted by the same reference numerals, and description thereof will be omitted. The feature of the optical semiconductor device 24 in the present embodiment is that the slit 6 provided in the substrate 1 and the gap between the LED chip 3 and the IC chips 4 and 7 are filled with the translucent resin 25. Light emitted from the LED chip 3 in the optical semiconductor device 24 is emitted in the emission direction 18 via the translucent resin 25 filled in the slit 6.

By configuring the optical semiconductor device 24 as described above, the LED chip 3 and the IC chips 4, 7
Since the gap between the substrate and the substrate 1 is filled with the translucent resin 25, it is possible to prevent the LED chip 3 and the IC chips 4 and 7 from coming off the wiring pattern due to an externally applied force. Also, the optical semiconductor device 2
It is possible to prevent dust and foreign matter from entering the inside of the housing 4.

FIG. 9 is a sectional view of an optical semiconductor device 28 according to a third embodiment of the present invention. In the optical semiconductor device 28, the same components as those of the optical semiconductor device 21 in the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted.

The feature of the optical semiconductor device 28 in the present embodiment is that each component provided on the substrate 1 is covered and protected by a light-transmitting resin 25 without using the cover 2. The slit 6 is filled with the translucent resin 25. As a material of the translucent resin 25, it is desirable to select a material that replaces the cover 2 and is excellent in strength and corrosion prevention. LED chip 3 in optical semiconductor device 28
Is emitted from the transparent resin 25 filled in the slit 6.
The light is emitted in the emission direction 18 through.

By configuring the optical semiconductor device 28 as described above, the cover 2 does not have to be attached, and the components of the optical semiconductor device 28 are fixed to each other by the translucent resin 25. In addition, it is possible to prevent the LED chip 3 and the IC chips 4 and 7 from coming off the wiring pattern due to externally applied force.

FIG. 10 is a sectional view of an optical semiconductor device 31 according to a fourth embodiment of the present invention. In the optical semiconductor device 31, the same components as those of the optical semiconductor device 21 in the first embodiment described above are denoted by the same reference numerals, and description thereof will be omitted.

The feature of the optical semiconductor device 31 of the present embodiment is that the transparent resin 25 filling the slit 6 is formed in a convex shape on the other surface 1b side of the substrate 1.

By configuring the optical semiconductor device 31 as described above, the light emitted from the LED chip 3 is collected into a certain size by the lens action of the translucent resin 25 and emitted in the emission direction 18. Further, since the gap between the LED chip 3 and the IC chips 4 and 7 is filled with the translucent resin 25, it is possible to prevent the LED chip 3 and the IC chips 4 and 7 from coming off the wiring pattern due to an externally applied force. Can be.

FIG. 11 is a sectional view of an optical semiconductor device 34 according to a fifth embodiment of the present invention. In the optical semiconductor device 34, the same components as those of the optical semiconductor device 21 in the first embodiment described above are denoted by the same reference numerals, and description thereof will be omitted.

The feature of the optical semiconductor device 34 in the present embodiment is that the gap between the slit 6 and each chip and the substrate 1 is filled with a translucent resin 25, and each component mounted on the substrate 1 is transparent. Resin 3 different from optical resin 25
5 is covered. As a material of the resin 35, it is preferable to select a material that replaces the cover 2 and has excellent strength and corrosion prevention.

By configuring the optical semiconductor device 34 as described above, the cover 2 does not have to be attached, and the respective components are fixed to each other by the resin 35. 3 and the IC chips 4 and 7 can be prevented from coming off the wiring pattern.

In each of the above embodiments, the slit 6
The transparent resin 25 filled in the LED chip 3 may be transparent or colored, and may be mixed with a scattering agent to scatter light emitted from the LED chip 3. In each of the above-described embodiments, a CCD (Charge Coupler) is used instead of the LED chip 3.
ed Device) may be used.

[0042]

As described above, according to the present invention, a through hole is formed in a synthetic resin molded substrate in an optical semiconductor device so that the opening area increases from one surface side to the other surface side. The element is arranged on the substrate by face-down bonding toward the through-hole, and light emitted from the optical semiconductor element is emitted to the outside through the through-hole, so that high-density wiring and mounting can be performed. . Further, since a synthetic resin made of a liquid crystal polymer is used as the material of the substrate, the adhesion of the wiring pattern is good, and the size and weight of the device can be reduced.

According to the present invention, an LED array is formed as an optical semiconductor element on the optical semiconductor chip, and a plurality of LED elements constituting the LED array are individually formed on the synthetic resin molded substrate made of the liquid crystal polymer. A plurality of corresponding slit-shaped through holes are easily formed at the time of molding, and light emitted from each LED element is emitted from each through hole, so that visibility of display by the LED elements can be improved.

Further, according to the present invention, the through holes of the synthetic resin molded substrate made of the liquid crystal polymer are filled with a light-transmitting synthetic resin, so that it is possible to prevent dust and foreign matter from entering the through holes. Can be.

[Brief description of the drawings]

FIG. 1 is a plan view of an optical semiconductor device 21 according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the line II-II in FIG.

FIG. 3 is a cross-sectional view taken along line III-III in FIG.

FIG. 4 is a plan view of the periphery of the LED chip 3 in the optical semiconductor device 21.

FIG. 5 is a plan view of an optical semiconductor device 22 as another configuration example according to the first embodiment of the present invention.

FIG. 6 is a sectional view taken along line VI-VI in FIG. 5;

FIG. 7 is a sectional view taken along section line VII-VII in FIG. 5;

FIG. 8 is a sectional view of an optical semiconductor device 24 according to a second embodiment of the present invention.

FIG. 9 is a sectional view of an optical semiconductor device 28 according to a third embodiment of the present invention.

FIG. 10 shows an optical semiconductor device 31 according to a fourth embodiment of the present invention.
FIG.

FIG. 11 shows an optical semiconductor device according to a fifth embodiment of the present invention.
FIG.

FIG. 12: LED by wire bond assembly
FIG. 3 is a plan view of the optical semiconductor device 111 to which the chip 101 is connected.

FIG. 13 is a section line XIII-XIII in FIG.
It is sectional drawing seen from.

FIG. 14 is a cross-sectional view taken along the section line XIV-XIV in FIG. 12;

FIG. 15 shows an example in which L is determined by a face-down bonding method.
FIG. 3 is a plan view of the optical semiconductor device 121 to which the ED chip 122 is connected.

FIG. 16 is a cross-sectional view as viewed from a section line XVI-XVI in FIG. 15;

17 is a section line XVII-XVII in FIG.
It is sectional drawing seen from.

[Description of Reference Numerals] 1 substrate 2 cover 3 LED chip 4, 7 IC chip 6 slit 9 wiring pattern 10, 12, 13 bump 11 conductive paste 18 emission direction 21, 22, 24, 28, 31, 34 optical semiconductor device 25 Translucent resin

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-7-228003 (JP, A) JP-A-7-131071 (JP, A) JP-A 8-129344 (JP, A) JP-A-6-129344 151977 (JP, A) JP-A-5-347434 (JP, A) JP-A-8-104030 (JP, A) JP-A-3-32447 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 33/00 H01L 21/60

Claims (3)

(57) [Claims] 1. An optical semiconductor chip having an optical semiconductor element and a connection bump on the surface, an opening having an opening corresponding to the optical semiconductor element, and an electrode pad corresponding to the connection bump are provided on one surface side, The through hole includes a synthetic resin molded substrate made of a liquid crystal polymer integrally formed so that an opening area increases toward the other surface side; and the optical semiconductor chip is formed on a synthetic resin molded substrate made of the liquid crystal polymer. An optical semiconductor device mounted by face-down bonding between a connection bump and an electrode pad. 2. An LED array is formed on the optical semiconductor chip as an optical semiconductor element, and an LED array is formed on a synthetic resin molded substrate made of the liquid crystal polymer.
2. The optical semiconductor device according to claim 1, wherein a plurality of slit-shaped through holes are formed individually corresponding to the plurality of LED elements forming the array. 3. The optical semiconductor device according to claim 1, wherein a light-transmitting synthetic resin is filled in the through hole of the synthetic resin molded substrate made of the liquid crystal polymer.