Optical relay and its packaging structure

Abstract

A photoelectric relay and its packaging structure are disclosed. The photoelectric relay includes: a light-emitting chip, a photoelectric generator chip, and a driving transistor, wherein: the light-emitting chip is adapted to emit an optical signal; the photoelectric generator chip is adapted to convert the optical signal into a corresponding electrical signal; the light-emitting chip is stacked on top of the photoelectric generator chip, and an insulating and light-transmitting layer is disposed between the light-emitting chip and the photoelectric generator chip; the driving transistor is coupled to the photoelectric generator chip and adapted to conduct or disconnect under the action of the electrical signal; the driving transistor and the photoelectric generator chip are integrated in an output integrated chip. The photoelectric relay provided by the above solution occupies a small circuit area.

Description

Technical Field

[0001] This utility model relates to the field of photoelectric conversion technology, and in particular to a photoelectric relay and its packaging structure. Background Technology

[0002] Traditional optocouplers use optocouplers for input / output isolation and input control signal transmission. A typical optocoupler includes a light-emitting chip, a photoelectric generator chip, and two MOSFET output modules. The light-emitting chip converts the input electrical signal into a corresponding optical signal, and the photoelectric generator chip converts the optical signal back into an electrical signal, driving the two MOSFET output modules to turn on and off.

[0003] In the existing technology, the light-emitting chip, the photoelectric generator chip, and the two MOSFET output modules are four independent chips, which have a large circuit area and are difficult to miniaturize. Utility Model Content

[0004] The purpose of this invention is at least to provide a miniaturized optical relay that occupies a smaller circuit area.

[0005] In a first aspect, this utility model provides an optical relay, comprising: a light-emitting chip, a photoelectric generator chip, and a driving transistor, wherein: the light-emitting chip is adapted to emit an optical signal; the photoelectric generator chip is adapted to convert the optical signal into a corresponding electrical signal; the light-emitting chip is stacked on top of the photoelectric generator chip, and an insulating and light-transmitting layer is disposed between the light-emitting chip and the photoelectric generator chip; the driving transistor is coupled to the photoelectric generator chip and is adapted to conduct or disconnect under the action of the electrical signal; the driving transistor and the photoelectric generator chip are integrated in an output-end integrated chip.

[0006] The light-emitting chip is stacked on top of the photoelectric generator chip, and the driving transistor and the photoelectric generator chip are integrated into an output integrated chip. Therefore, compared to having the driving transistor and the photoelectric generator chip independently, the circuit area of ​​the photorelay can be effectively reduced.

[0007] Optionally, the light-emitting chip is stacked above the photosensitive area of ​​the photoelectric generating chip, and the light-emitting chip is fixedly disposed to the photosensitive area through the insulating light-transmitting layer.

[0008] Optionally, the driving transistor includes a first driving transistor and a second driving transistor; in the output integrated chip, the first driving transistor is disposed on a first side of the photoelectric generator chip, and the second driving transistor is disposed on a second side of the photoelectric generator chip; the first side and the second side are parallel in a first direction.

[0009] Optionally, in the output integrated chip, the drain of the first driving transistor is coupled to the lead frame; the drain of the second driving transistor is coupled to the lead frame.

[0010] Optionally, in the output integrated chip, the gates of the first driving transistor and the second driving transistor are both coupled to the electrical signal output terminal of the photoelectric generator chip; the first driving transistor and the second driving transistor are turned on or off under the action of the electrical signal output by the photoelectric generator chip.

[0011] Optionally, the output integrated chip is fixedly mounted on the lead frame.

[0012] Optionally, the material of the insulating and light-transmitting layer may include light-transmitting epoxy resin or light-transmitting silicone.

[0013] Optionally, the light-emitting chip includes an LED light-emitting chip.

[0014] Optionally, the photorelay is encapsulated with opaque epoxy resin.

[0015] Secondly, this utility model embodiment also provides a packaging structure for an optical relay, wherein the optical relay described above is packaged. Attached Figure Description

[0016] Figure 1 This is a block diagram of the principle of an optical relay;

[0017] Figure 2 This is a cross-sectional schematic diagram of an optical relay according to an embodiment of this utility model;

[0018] Figure 3 yes Figure 2 A top view of a corresponding optical relay;

[0019] Figure 4 This is a schematic diagram of the layout of an output-end integrated chip in an embodiment of this utility model;

[0020] Figure 5 This is a schematic diagram of the internal structure of an output-end integrated chip in an embodiment of this utility model;

[0021] Figure 6 This is a cross-sectional schematic diagram of an existing optical relay;

[0022] Figure 7 yes Figure 6 Top view of the corresponding photorelay. Detailed Implementation

[0023] like Figure 1 The diagram shows the principle block diagram of a traditional optical relay. Figure 1 In this optical relay, there are four independent chips: an LED chip, a photoelectric generator chip, and two MOSFETs. An isolation region is provided between the LED chip and the photoelectric generator chip, and this isolation region is typically filled with transparent epoxy resin.

[0024] In existing technologies, photorelays have a large circuit area, making miniaturization difficult.

[0025] In this embodiment of the invention, the driving transistor and the photoelectric generator chip are integrated into an integrated chip at the output end. Therefore, compared to having the driving transistor and the photoelectric generator chip independently configured, the circuit area of ​​the photorelay can be effectively reduced.

[0026] To make the above-mentioned objectives, features and beneficial effects of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0027] This utility model provides an optical relay. (Refer to...) Figure 2 A cross-sectional schematic diagram of an optical relay according to an embodiment of this utility model is provided. (Refer to...) Figure 3 It gave Figure 2 The top view of the corresponding photorelay. (The following is combined with...) Figure 2 and Figure 3 Please provide an explanation.

[0028] In this embodiment of the invention, the photoelectric relay may include a light-emitting chip 1, a photoelectric generator chip 2, and a driving transistor.

[0029] In a specific implementation, the light-emitting chip 1 is adapted to emit a corresponding light signal when it receives an electrical signal. In some embodiments, the light-emitting chip 1 can be an LED chip, which may include a plurality of LED beads to emit light signals.

[0030] Specifically, the specific structure and working principle of the LED chip can be referred to the existing LED chip. This embodiment of the utility model does not modify the specific structure or working process of the LED chip.

[0031] In practical implementation, the photoelectric generator chip 2 is adapted to receive optical signals and convert the received optical signals into corresponding electrical signals. The driving transistor can be coupled to the photoelectric generator chip 2, receive the electrical signals output by the photoelectric generator chip 2, and conduct under the action of the electrical signals.

[0032] In a specific implementation, the photoelectric generator chip 2 can be stacked on top of the lead frame 3. The light-emitting chip 1 can be stacked on top of the photoelectric generator chip 2, and an insulating light-transmitting layer can be provided between the light-emitting chip 1 and the photoelectric generator chip 2. Through the insulating light-transmitting layer, the photoelectric generator chip 2 can receive the light signal emitted by the light-emitting chip 1.

[0033] In this embodiment of the invention, the photoelectric generator chip 2 may include a photosensitive area, through which the photoelectric generator chip 2 can receive the light signal emitted by the light-emitting chip 1.

[0034] In some embodiments, the light-emitting chip 1 can be stacked on top of the photosensitive area of ​​the photoelectric generating chip 2, and the light-emitting chip 1 is fixedly disposed with the photosensitive area through an insulating light-transmitting layer.

[0035] In a specific implementation, the driving transistor can be coupled to the electrical signal output terminal of the photoelectric generator chip 2, and turn on after receiving the optical signal output by the photoelectric generator chip 2.

[0036] In this embodiment of the invention, the driving transistor and the photoelectric generator chip 2 can be integrated into a single output integrated chip.

[0037] In a specific implementation, the driving transistor may include a first driving transistor and a second driving transistor. The gates of both the first and second driving transistors can be coupled to the electrical signal output terminal of the photoelectric generator chip 2 to receive the electrical signal output by the photoelectric generator chip 2. The first and second driving transistors are turned on or off under the action of the electrical signal.

[0038] In some embodiments, the first driving transistor and the second driving transistor described above are MOSFET transistors.

[0039] In a specific implementation, in the integrated chip at the output end, the first driving transistor can be disposed on the first side of the photoelectric generator chip 2, and the second driving transistor can be disposed on the second side of the photoelectric generator chip 2. The aforementioned first side and second side are parallel in a first direction.

[0040] In some embodiments, the first direction described above may be a vertical direction. In other embodiments, the first direction described above may be a horizontal direction.

[0041] like Figure 4 As shown, a layout diagram of an output-end integrated chip is presented. Figure 4 In the process, the first driving transistor MOSFET1 is located on the left side of the photoelectric generator chip 2, and the second driving transistor MOSFET2 is located on the right side of the photoelectric generator chip 2.

[0042] In a specific implementation, the drain D of the first driving transistor MOSFET1 is coupled to the lead frame 3, and the drain D of the second driving transistor MOSFET2 is coupled to the lead frame 3.

[0043] In practice, the output integrated chip can be fixedly mounted on the lead frame 3. The light-emitting chip 1 is positioned above the photosensitive area of ​​the photoelectric generating chip 2.

[0044] Since the first driving transistor, the second driving transistor, and the photoelectric generator chip 2 are integrated in the output-end integrated chip, the gates of the first driving transistor and the second driving transistor can be electrically connected to the photoelectric generator chip 2 in the output-end integrated chip. Therefore, the output-end integrated chip only needs two output pins to be connected to the lead frame 3.

[0045] Reference Figure 5 The present invention provides a schematic diagram of the internal structure of an output-end integrated chip in an embodiment of the present invention.

[0046] like Figure 5 As shown, in the integrated output chip, the output terminal Vout of the photoelectric generator chip 2 is coupled to the gate G of the first driving transistor MOSFET1 and the gate G of the second driving transistor MOSFET2, respectively. The ground terminal GND of the photoelectric generator chip 2 is coupled to the source S of the first driving transistor MOSFET1 and the source S of the second driving transistor MOSFET2, respectively. The two output terminals of the integrated output chip are the drain D of the first driving transistor MOSFET1 and the drain D of the second driving transistor MOSFET2, which are also the two output pins of the integrated output chip.

[0047] The packaging process of the optical relay provided by this utility model will be described below.

[0048] Step 1), apply conductive silver paste to the lead frame;

[0049] Step 2), place the output integrated chip on the conductive silver paste;

[0050] Step 3) Apply insulating adhesive to the photosensitive area of ​​the integrated chip at the output end. The insulating adhesive can be made of silicone or epoxy resin.

[0051] Step 4), stack the light-emitting chip on the photosensitive area of ​​the output integrated chip;

[0052] Step 5), perform wire bonding on the placed chip;

[0053] Step 6) The lead frame is encapsulated with opaque epoxy resin to obtain the optical relay provided in this embodiment of the present invention.

[0054] The working process of the photorelay provided in this embodiment of the utility model is as follows: After receiving the electrical signal, the light-emitting chip converts the electrical signal into an optical signal and emits it; in the output integrated chip, the photosensitive area of ​​the photoelectric generator chip 2 receives the optical signal and converts the optical signal into a corresponding electrical signal; in the output integrated chip, the integrated first driving transistor and the second driving transistor are turned on or off after receiving the electrical signal output by the photoelectric generator chip.

[0055] Reference Figure 6 The paper presents an existing packaging structure for an optical relay. Figure 6 The packaging structure is a traditional top-and-bottom opposed split packaging structure. (Refer to...) Figure 7 It gave Figure 6 The front view of the corresponding packaging structure.

[0056] like Figure 6 As shown, the photorelay consists of a light-emitting chip, a photoelectric generator chip, and an output MOSFET 4. The light-emitting chip is an LED chip. Transparent epoxy resin is filled between the light-emitting chip and the photoelectric generator chip to isolate the input and output.

[0057] like Figure 6 and Figure 7 The photorelay shown in the diagram converts an electrical signal into a light signal and emits it after the LED chip receives the signal. The light signal passes through the transparent epoxy resin and reaches the photosensitive area of ​​the photoelectric generator chip. The photoelectric generator chip receives the light signal, generates a voltage through the internal photoelectric effect, and converts the light signal back into an electrical signal. The electrical signal is output to the control terminal of the output MOSFET to control the output MOSFET to turn on or off, thereby achieving input-output isolation.

[0058] like Figure 6 and Figure 7 The packaging process for the photorelay shown may include the following steps:

[0059] Step 1), apply conductive silver paste to the lead frames of each input and output terminal;

[0060] Step 2), place all chips (LED chip, photoelectric generator chip, output MOSFET chip) on conductive silver paste;

[0061] Step 3), after chip placement is complete, wire bonding is performed;

[0062] Step 4), stack the lead frames of the input / output terminals and encapsulate them with epoxy resin that has light-transmitting properties;

[0063] Step 5) Encapsulate the photoresist from step 4) with opaque epoxy resin to obtain the encapsulated photoresist.

[0064] Will Figure 2 and Figure 6 To make a comparison, Figure 3 and Figure 7 In comparison, it can be seen that, compared to existing photorelays where a large amount of translucent epoxy resin is filled between the light-emitting chip 1 and the photoelectric generator chip 2, the photorelay provided in this embodiment of the invention places the light-emitting chip on top of the photoelectric generator chip, thus effectively reducing the thickness of the photorelay. Furthermore, the photorelay provided in this embodiment of the invention integrates the driving transistor and the photoelectric generator chip into an integrated chip at the output end. Therefore, compared to the independent arrangement of the driving transistor and the photoelectric generator chip, the circuit area of ​​the photorelay can be effectively reduced.

[0065] And, as Figure 7 As shown, the two driving transistors 4 also need to be electrically connected to the photoelectric generator chip via wires. However, in this embodiment of the invention, since the driving transistors and the photoelectric generator chip are integrated in the same output terminal integrated chip, the number of wires in the circuit can be reduced, and the desoldering caused by a large number of wires can be avoided.

[0066] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A photoelectric relay, characterized in that, include: The components include a light-emitting chip, a photoelectric generator chip, and a driver transistor, among which: The light-emitting chip is suitable for emitting light signals; The photoelectric generating chip is adapted to convert the optical signal into a corresponding electrical signal; the light-emitting chip is stacked on top of the photoelectric generating chip, and an insulating light-transmitting layer is provided between the light-emitting chip and the photoelectric generating chip; The driving transistor is coupled to the photoelectric generator chip and is adapted to be turned on or off under the action of the electrical signal; the driving transistor and the photoelectric generator chip are integrated in the output integrated chip.

2. The optical relay as described in claim 1, characterized in that, The light-emitting chip is stacked on top of the photosensitive area of ​​the photoelectric generating chip, and the light-emitting chip is fixed to the photosensitive area through the insulating light-transmitting layer.

3. The optical relay as described in claim 1, characterized in that, The driving transistor includes a first driving transistor and a second driving transistor; in the output integrated chip, the first driving transistor is disposed on a first side of the photoelectric generator chip, and the second driving transistor is disposed on a second side of the photoelectric generator chip; the first side and the second side are parallel in a first direction.

4. The optical relay as described in claim 3, characterized in that, In the output-terminal integrated chip, the drain of the first driving transistor is coupled to the lead frame; the drain of the second driving transistor is coupled to the lead frame.

5. The optical relay as described in claim 3, characterized in that, In the integrated chip at the output terminal, the gates of the first driving transistor and the second driving transistor are both coupled to the electrical signal output terminal of the photoelectric generator chip; the first driving transistor and the second driving transistor are turned on or off under the action of the electrical signal output by the photoelectric generator chip.

6. The optical relay as described in claim 1, characterized in that, The output integrated chip is fixedly mounted on the lead frame.

7. The optical relay as described in claim 1, characterized in that, The insulating and light-transmitting layer is made of light-transmitting epoxy resin or light-transmitting silicone.

8. The optical relay as described in claim 1, characterized in that, The light-emitting chip includes: an LED light-emitting chip.

9. The optical relay as described in claim 1, characterized in that, The photorelay is encapsulated with opaque epoxy resin.

10. A packaging structure for an optical relay, characterized in that, It includes an optical relay as described in any one of claims 1 to 9.

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