JPH11163394A - Semiconductor relay - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor relay capable of making a relay compact and thin, while improving yield of mounting. SOLUTION: A photoelectromotive element 3 is flip-chip mounted on a wiring pattern of a circuit substrate 1 through a bump 4, so as to cover a recessed portion 2 and an opening of the recessed portion 2 in a circuit substrate 1 formed by the recessed portion 2 and wiring pattern made into a predetermined shape, and MOSFETs 5a, 5b are flip-chip mounted via the bumps 3 at the photoelectromotive element 3 mounting surface side of the circuit substrate 1. At the surface side where the recessed portion 2 of the photoelectromotive element 3 is formed, a wireless mounting type LED6 directly surface mounted by a conductive material 7. Then a transparent resin 8 which transmits light is filled between the photoelectromotive element 3 and the circuit substrate 1, and the entire surface side of each chip mounting of the circuit substrate 1 is encapsulated by a light-proof resin 9, such as epoxy resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor relay using isolation by optical coupling, and more particularly to a photomos relay.

[0002]

2. Description of the Related Art FIG. 4 is a circuit diagram of a photomos relay according to a conventional example. Between the relay input terminals 12a and 12b, a light emitting diode (LED: Light Em
The LED 13 has a photodiode array 14 optically coupled thereto.

The anode of the photodiode array 14 has an M-channel output for an N-channel enhancement mode.
The gates are connected to the OSFETs 5a and 5b, and the cathodes are connected to the sources of the MOSFETs 5a and 5b via the resistor R.

A drain-source of an N-channel depletion mode driving MOSFET 15 is connected between the gates and sources of the output MOSFETs 5a and 5b. The gate of the driving MOSFET 15 is connected to the cathode of the photodiode array 14.

The drains of the MOSFETs 5a and 5b are connected to the relay output terminals 16a and 16b, respectively.
The sources of the ETs 5a and 5b are connected to the relay output terminal 16c.

The operation of the conventional photomos relay will be described below with reference to FIG. Relay input terminals 12a,
When an input current flows between 12b, LED 13 generates a light signal. Receiving this optical signal, the photodiode array 1
4 generate current. This current flows to the resistor R via the drive MOSFET 15 which is always on, and when the voltage generated by the resistor R exceeds the threshold voltage of the drive MOSFET 15, the drive MOSFET 15 is turned off. Thus, the current from the photodiode array 14 is
When the charged voltage between the gates and sources of the output MOSFETs 5a and 5b exceeds the threshold voltage of the output MOSFETs 5a and 5b, the output MOSFETs 5a and 5b are turned on and the relay output terminals 16a to 16c are turned on. Becomes conductive. Thereafter, a small current flows through the resistor R via the drain and source of the driving MOSFET 15, and the driving MOSFET 15 is held at a high impedance by the bias voltage generated at the resistor R.

Next, when the current between the relay input terminals 12a and 12b is cut off and the light signal from the LED 13 disappears,
The current from the photodiode array 14 disappears. Therefore, the voltage between the gate and the source of the driving MOSFET 15 decreases, and the driving MOSFET 15 is turned on, so that the electric charge accumulated between the gate and the source of the output MOSFETs 5a and 5b is replaced by the driving MOSFET 15. Discharges rapidly. As a result, the output MOSFETs 5a and 5b are turned off, and the relay output terminals 16a to 16c are shut off.

In the circuit described above, the output MOSFETs 5a, 5
In the steady state where b is on, the driving MOSF
Even if the current flowing through the ET 15 is small, it is possible to obtain a bias voltage sufficient to hold the driving MOSFET 15 in the off state by increasing the value of the resistor R.

FIG. 7 is a schematic sectional view showing the entire structure of a photomos relay according to a conventional example. Lead frame 17
The MOSFETs 5a and 5b and the photovoltaic element 3 are die-bonded on Ag, using Ag paste or the like, and wire-bonded. Here, the photovoltaic element 3 refers to
This is an element in which the photodiode array 14, the driving MOSFET 15 and the resistor R are integrated into one chip.

On the other hand, an LED is mounted on the lead frame 17b.
13 is die-bonded with an Ag paste or the like, and wire-bonded, and the lead frames 17a and 17b are
D13 and photovoltaic element 3 are arranged so as to face each other.

The space between the LED 13 and the photovoltaic element 3 is filled with a light-transmitting resin 8 that transmits light, and the whole is molded by a package 18 made of a light-shielding resin. At this time, the lead frame 1 is
One end of each of 7a and 17b protrudes.

Here, if the MOSFETs 5a and 5b are mounted on two chips, both can be used as DC / AC, but if one chip is used, only DC is used due to the diode characteristics of the MOSFET.

[0013]

However, in the semiconductor relay having the above-mentioned structure, each chip is die-bonded on a lead frame and wire-bonded, so that the LED and the photovoltaic element are arranged to face each other. However, there has been a problem that it is difficult to realize a reduction in thickness and size.

Further, when the whole is molded by the package 18, the lead frames 17a and 17b may be bent by the flow of the resin to be molded, which makes it difficult to secure a facing distance between the LED 13 and the photovoltaic element 3. ,
There is a problem that the mounting yield is deteriorated.

The present invention has been made in view of the above points, and an object of the present invention is to provide a semiconductor relay which can be reduced in size and thickness and can improve a mounting yield. is there.

[0016]

According to the first aspect of the present invention,
A MOSFET and a photovoltaic element are mounted on one substrate, a light emitting element of a wireless mounting type is surface-mounted on the photovoltaic element, and the photovoltaic element and the light emitting element are optically coupled. It is characterized by comprising.

According to a second aspect of the present invention, in the semiconductor relay of the first aspect, a concave portion and a wiring pattern are formed on the substrate, and the photovoltaic element is flip-chip mounted on the substrate so as to cover the concave portion opening. Mounted on the substrate,
On the photovoltaic element mounting surface side and / or on a different surface side
The MOSFET is flip-chip mounted or wire-bonded, the light emitting element is surface mounted on the concave part forming surface side of the photovoltaic element, and a light transmitting resin is provided so as to cover the light receiving part and the light emitting element of the photovoltaic element. And wherein the photovoltaic element mounting surface side of the substrate is sealed with a light-shielding resin.

According to a third aspect of the present invention, in the semiconductor relay of the first aspect, a concave portion and a wiring pattern are formed in the substrate, and the photovoltaic element is die-bonded to the bottom surface of the concave portion by wire bonding. On the photovoltaic element mounting surface side and / or on a different surface side of the substrate
The MOSFET is flip-chip mounted or wire-bonded, the light emitting element is surface mounted on the photovoltaic element, and a light transmitting resin is provided so as to cover a light receiving portion and the light emitting element of the photovoltaic element, The photovoltaic element mounting surface side of the substrate is sealed with a light-shielding resin.

According to a fourth aspect of the present invention, there is provided the semiconductor relay according to the second or third aspect, wherein:
A recess is provided in at least one of the locations where the MOSFET is formed, and the MOSFET is flip-chip mounted or wire-bonded to the bottom of the recess.

According to a fifth aspect of the present invention, in the semiconductor relay according to any one of the first to fourth aspects, the recessed portion is formed in a color that easily reflects light, or a reflecting member that reflects light is provided. It is characterized by having been provided.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. The circuit configuration of the photo MOS relay according to the present embodiment is the same as the circuit configuration of the photo MOS relay shown in FIG. 4 as a conventional example. Further, in the present embodiment, a case where an N-channel type is used as the MOSFETs 5a, 5b, 15 will be described, but the present invention can be applied to a case where a P-channel type is used. In this case, the photodiode array 14 is connected such that the polarity of the photodiode array 14 is reversed.
Further, the same reference numerals are given to the same components as those of the photo MOS relay shown in FIG. 5 as a conventional example, and the description is omitted.

Embodiment 1 FIG. 1 is a schematic sectional view showing the entire configuration of a photo MOS relay according to an embodiment of the present invention. The photomos relay according to the present embodiment has a photovoltaic element so as to cover the opening of the recess 2 of the circuit board 1 in which the recess 2 and a wiring pattern (not shown) patterned in a predetermined shape are formed. 3
Are flip-chip mounted on the wiring pattern of the circuit board 1 via bumps 4 such as solder, and MOSFETs 5a and 5b are flip-chip mounted on the photovoltaic element 3 mounting surface side of the circuit board 1 via the bumps 4.

In this embodiment, the circuit board 1
In order to mount the MOSFETs 5a and 5b on the flip chip,
As the MOSFETs 5a and 5b, for example, an LDMOSFET (La MOSFET) in which gate, source and drain electrodes exist on the same plane of the chip
teral Double Diffused MOSFET).

A light emitting diode (LED: Light Emi)
tting Diode) 6 is a conductive material 7 such as solder or Ag paste.
By direct surface mounting.

The space between the photovoltaic element 3 and the circuit board 1 is filled with a light-transmitting resin 8 that transmits light.
The entire chip mounting surface side is sealed with a light-shielding resin 9 such as an epoxy resin for shielding light.

In this embodiment, the space between the photovoltaic element 3 and the circuit board 1 is filled with the translucent resin 8, but at least the light receiving portion (not shown) of the photovoltaic element 3 is filled. ) And the LED 6 as long as the translucent resin 8 is formed.

Therefore, in the present embodiment, the photovoltaic element 3, the MOSFETs 5a and 5b and the LE
Since D6 is arranged and the photovoltaic element 3 and the MOSFETs 5a and 5b are flip-chip mounted, there is no need to form a pad for wire bonding on the circuit board 1, and the photoMOS relay can be made thinner. , And can be downsized.

Also, since the LED 6 is directly surface-mounted on the photovoltaic element 3, the light-shielding resin 9 for sealing makes it possible to use the LE6.
The opposing distance between D6 and the photovoltaic element 3 does not change, and the mounting yield can be improved.

Further, the photovoltaic element 3 and the MOSFETs 5a, 5
Since b is flip-chip mounted, highly accurate positioning is possible.

In this embodiment, the MOSFET 5
Although a and 5b are flip-chip mounted, the present invention is not limited to this, and wire bonding may be used.

Embodiment 2 FIG. 2 is a schematic sectional view showing the entire configuration of a photo MOS relay according to another embodiment of the present invention. In the photo MOS relay according to the present embodiment, a photovoltaic element 3 is made of an Ag paste on the bottom surface of a concave portion 2 of a circuit board 1 in which a concave portion 2 and a wiring pattern (not shown) patterned in a predetermined shape are formed. The MOSFETs 5a and 5b are flip-chip mounted via bumps 4 on the photovoltaic element 3 mounting surface side of the circuit board 1 by die bonding.

A wireless mounting type LED 6 is directly surface-mounted on the photovoltaic element 3 by a conductive material 7 such as solder or Ag paste, and a light receiving portion (not shown) of the photovoltaic power element 3 and The LED 6 is covered with a translucent resin 8. The entire chip mounting surface side of the circuit board 1 is sealed with a light-shielding resin 9.

Therefore, in the present embodiment, the photovoltaic element 3, the MOSFETs 5a, 5b and the LE
Since the D6 is arranged and the MOSFETs 5a and 5b are flip-chip mounted, there is no need to form a pad for wire bonding on the circuit board 1, and the photoMOS relay can be made thinner and smaller. it can.

Further, since the LED 6 is directly surface-mounted on the photovoltaic element 3, the light-shielding resin 9 for sealing allows the LE
The opposing distance between D6 and the photovoltaic element 3 does not change, and the mounting yield can be improved.

Also, since the MOSFETs 5a and 5b are flip-chip mounted, highly accurate alignment is possible.

In this embodiment, the MOSFET 5
Although a and 5b are flip-chip mounted, the present invention is not limited to this, and wire bonding may be used.

Embodiment 3 = FIG. 3 is a schematic sectional view showing the entire configuration of a photomos relay according to another embodiment of the present invention. In the photo MOS relay according to the present embodiment, in the photo MOS relay shown in FIG. 1 as the first embodiment, and in the photo MOS relay shown in FIG. 1 as the first embodiment, the concave portion 11 is formed in the circuit board 1 where the MOSFETs 5a and 5b are mounted. And MOSFET on the bottom of the recess 11
In this configuration, 5a and 5b are die-bonded with an Ag paste or the like, and wire-bonded with an Au wire 10 or the like.

Therefore, in the present embodiment, the photovoltaic element 3, the MOSFETs 5a, 5b and the LE
Since the D6 is arranged and the photovoltaic element 3 is flip-chip mounted, there is no need to form a pad for wire bonding on the circuit board 1, and the photoMOS relay is made thinner and smaller. be able to.

Further, since the LED 6 is directly surface-mounted on the photovoltaic element 3, the light-shielding resin 9 for sealing is used for LE.
The opposing distance between D6 and the photovoltaic element 3 does not change, and the mounting yield can be improved.

Further, since the photovoltaic element 3 is flip-chip mounted, highly accurate alignment is possible.

In this embodiment, the MOSFET 5
Although a and 5b are wire-bonded, the present invention is not limited to this, and flip-chip mounting may be performed via bumps 4. In this case, it is necessary to form a pad for wire bonding. Gone
Further downsizing can be achieved.

In all of the above embodiments, the MO
The SFETs 5a and 5b are mounted on the surface of the circuit board 1 on which the photovoltaic element 3 is mounted. However, the present invention is not limited to this. One, or two MOSFETs may be mounted.

In the first and third embodiments, the material of the circuit board 1 is a color that is easily reflected such as white or the like.
If a reflective material etc. that reflects light is provided on the side surface of
Light transmission efficiency can be improved.

In all the above embodiments, the MO
Although the case where two SFETs are mounted has been described, the present invention is not limited to this, and only one MOSFET may be mounted only for DC.

[0045]

According to the first aspect of the present invention, on one substrate,
A MOSFET and a photovoltaic element are mounted, and a wireless mounting type light emitting element is surface-mounted on the photovoltaic element,
Since the photovoltaic element and the light emitting element are optically coupled, the opposing distance between the light emitting element and the photovoltaic element does not change due to sealing, and the size and thickness are reduced, and the mounting yield is improved. The semiconductor relay which can be provided.

According to a second aspect of the present invention, in the semiconductor relay of the first aspect, a concave portion and a wiring pattern are formed in the substrate, and the photovoltaic element is flip-chip mounted on the substrate so as to cover the concave portion opening. The MOSFET is flip-chip mounted or wire-bonded on the photovoltaic element mounting surface side and / or on a different surface side, the light emitting element is surface mounted on the concave forming surface side of the photovoltaic element, and the light receiving section of the photovoltaic element And a light-transmitting resin is provided to cover the light-emitting element, and the photovoltaic element mounting surface side of the substrate is sealed with a light-blocking resin, so that the size and thickness can be reduced.
The sealing distance does not change the facing distance between the light emitting element and the photovoltaic element, and the mounting yield can be improved.
Since each element is flip-chip mounted, high-accuracy alignment is possible.

According to a third aspect of the present invention, in the semiconductor relay according to the first aspect, a concave portion and a wiring pattern are formed in the substrate, and a photovoltaic element is die-bonded to the bottom surface of the concave portion and wire-bonded. A MOSFET is flip-chip mounted or wire-bonded on the surface on which the electromotive element is mounted and / or on a different side, and a light emitting element is surface mounted on the photovoltaic element so as to cover the light receiving portion and the light emitting element of the photovoltaic element. A light-transmitting resin is provided, and the photovoltaic element mounting surface side of the substrate is sealed with a light-blocking resin, so that the size and thickness can be reduced. Since the facing distance does not change, the mounting yield can be improved, and since each element is flip-chip mounted, highly accurate positioning can be performed.

According to a fourth aspect of the present invention, in the semiconductor relay according to the second or third aspect, a concave portion is provided in at least one of the MOSFET forming portions of the substrate, and the MOSFET is flip-chip mounted on the bottom surface of the concave portion. Alternatively, since it is formed by wire bonding, the size and thickness can be reduced, and the sealing distance does not change the facing distance between the light emitting element and the photovoltaic element, so that the mounting yield can be improved. Are mounted flip-chip, so that high-accuracy alignment is possible.

According to a fifth aspect of the present invention, in the semiconductor relay according to any one of the first to fourth aspects, the concave portion is formed in a color that easily reflects light, or a reflection member that reflects light is provided. Therefore, light transmission efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view illustrating an overall configuration of a photomos relay according to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view illustrating an overall configuration of a photo MOS relay according to another embodiment of the present invention.

FIG. 3 is a schematic cross-sectional view showing the entire configuration of a photo MOS relay according to another embodiment of the present invention.

FIG. 4 is a circuit diagram of a photo MOS relay according to a conventional example.

FIG. 5 is a schematic cross-sectional view showing the entire configuration of a photo MOS relay according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Circuit board 2 Concave part 3 Photovoltaic element 4 Bump Au wire 5a, 5b MOSFET 6 LED 7 Conductive material 8 Translucent resin 9 Light shielding resin 10 Au wire 11 Concave part 12a, 12b Relay input terminal 13 LED 14 Photodiode array 15 MOSFET 16a-16c Relay output terminal 17a, 17b Lead frame 18 Package R Resistance

Claims (5)

[Claims] 1. A MOSFET and a photovoltaic element are mounted on one substrate, and a wireless mounting type light emitting element is surface-mounted on the photovoltaic element, wherein the photovoltaic element and the light emitting element are mounted. And a light-coupled semiconductor relay. 2. A recess and a wiring pattern are formed on the substrate, and the photovoltaic element is flip-chip mounted on the substrate so as to cover the opening of the recess, and the photovoltaic element mounting surface side of the substrate. And / or MOSFET on different side
Is flip-chip mounted or wire bonded,
The light emitting element is surface-mounted on the concave part forming surface side of the photovoltaic element, and a light-transmitting resin is provided so as to cover a light receiving part of the photovoltaic element and the light emitting element. 2. The semiconductor relay according to claim 1, wherein the element mounting surface is sealed with a light-shielding resin. 3. A concave portion and a wiring pattern are formed on the substrate, and the photovoltaic device is die-bonded to the bottom surface of the concave portion and wire-bonded, and the photovoltaic device mounting surface side of the substrate and / or different portions are provided. MOSFET on the surface side
Is flip-chip mounted or wire bonded,
The light-emitting element is surface-mounted on the photovoltaic element, a light-transmitting resin is provided so as to cover a light-receiving portion of the photovoltaic element and the light-emitting element, and the photovoltaic element mounting surface side of the substrate is 2. The semiconductor relay according to claim 1, wherein the semiconductor relay is sealed with a light-shielding resin. 4. The semiconductor device according to claim 1, wherein:
At least one recess is provided, and the bottom surface of the recess is
4. The semiconductor relay according to claim 2, wherein the MOSFET is flip-chip mounted or wire-bonded. 5. The semiconductor relay according to claim 1, wherein the concave portion is formed in a color that easily reflects light, or a reflection member that reflects light is provided.