TWM671609U - Stacked die optocoupler packaging structure by secondary plastic encapsulation - Google Patents

Abstract

A secondary plastic-encapsulated stacked-chip optical coupler packaging structure includes: a first lead pin; a second lead pin adjacent to the first lead pin; a photoelectric unit arranged on the first lead pin; a light-transmitting insulating block arranged on the photoelectric unit; a light-emitting unit arranged on the light-transmitting insulating block; and a reflective colloid covering the photoelectric unit, the light-transmitting insulating block and the light-emitting unit.

Description

Secondary plastic encapsulation stacked die optocoupler package structure

The present disclosure relates to a double-molded stacked die optical coupler packaging structure.

Optocouplers, also known as photocouplers, optical isolators, and photoisolators, are devices that transmit electrical signals using visible light or infrared light as a medium. Optocouplers have the characteristic of electrically isolating the input circuit from the output circuit.

The general stacked-crystal optical coupler package structure has a light-emitting unit, a light-transmitting insulating block, and a photoelectric unit, and the above components are sealed with black plastic at one time to complete the package. When the light-emitting unit emits light, the light can penetrate the light-transmitting insulating block and then be received by the photoelectric unit. In this way, the effect of the optical coupler is achieved.

However, the light emitted by the light-emitting unit of the general stacked-crystal optical coupler package structure may be emitted from the side wall of the light-transmitting insulating block and absorbed by the black glue, so that part of the light is not received by the photoelectric unit, resulting in poor energy conversion rate between the light emitted by the light-emitting unit and the light received by the photoelectric unit. If the driving power of the light-emitting unit is increased in order to allow the photoelectric unit to receive enough light, it will cause a waste of electric energy.

In view of this, how to improve the energy conversion rate between the light-emitting unit and the photoelectric unit of the stacked-chip optical coupler package structure is one of the problems that need to be solved urgently.

The present disclosure provides a secondary plastic-encapsulated stacked-chip optical coupler package structure, which can improve the energy conversion rate between the light-emitting unit and the photoelectric unit of the stacked-chip optical coupler package structure.

The present disclosure provides a secondary plastic-encapsulated stacked-chip optical coupler packaging structure, comprising: a first lead pin; a second lead pin adjacent to the first lead pin; a photoelectric unit disposed on the first lead pin; a light-transmitting insulating block disposed on the photoelectric unit; a light-emitting unit disposed on the light-transmitting insulating block; and a reflective colloid covering the photoelectric unit, the light-transmitting insulating block and the light-emitting unit.

In certain embodiments, the reflective colloid includes titanium dioxide.

In some embodiments, the color of the reflective colloid is substantially white.

In some embodiments, the reflective colloid is reflective within the operating spectrum of the light-emitting unit.

In some embodiments, the reflectivity is a reflectivity greater than or equal to 50%.

In some embodiments, the secondary plastic encapsulation stacked die optical coupler packaging structure further includes: a packaging colloid covering a portion of the first lead, a portion of the second lead, the optoelectronic unit, a light-transmitting insulating block, a light-emitting unit, and a reflective colloid.

In some embodiments, the color of the encapsulation colloid is substantially black.

In some embodiments, the encapsulation colloid is opaque relative to the operating spectrum of the light-emitting unit.

In some embodiments, opacity means a transmittance of less than or equal to 10%.

In some embodiments, the light-transmitting insulating block is sandwiched between the photovoltaic unit and the light-emitting unit.

As mentioned above, the secondary plastic-encapsulated stacked-chip optocoupler package structure disclosed herein converts the input electrical signal source into an optical signal and then into an electrical signal, and maintains electrical isolation, thus having good electrical insulation and anti-interference capabilities. Adding the secondary plastic-encapsulated stacked-chip optocoupler package structure disclosed herein to the circuit can prevent the rear-end circuit components from being damaged by imperfect input electrical signal sources, lightning, electrostatic discharge, electromagnetic interference, and switching pulses. The first lead can support the optoelectronic unit through the light-transmitting insulating block, so the optoelectronic unit does not need to be set on other supporting structures.

Furthermore, the secondary plastic-encapsulated stacked-chip optical coupler packaging structure disclosed in the present invention has a reflective colloid, which increases the path of light transmission to the photoelectric unit, thereby improving the energy conversion rate between the light emitted by the light-emitting unit and the light received by the photoelectric unit, achieving the effect of power saving.

Furthermore, the disclosed secondary plastic-encapsulated stacked-die optical coupler packaging structure can prevent light outside the secondary plastic-encapsulated stacked-die optical coupler packaging structure from penetrating the packaging resin and irradiating the optoelectronic unit, thereby preventing external light from interfering with the optoelectronic unit and also preventing induced erroneous signals from being sent to the optoelectronic unit.

The detailed description and technical contents of the present disclosure are described below with reference to the accompanying drawings. However, the accompanying drawings are only provided for reference and description and are not intended to limit the present disclosure.

As used herein, terms such as "first" and "second" describe various elements, components, regions, layers and/or parts, which should not be limited by these terms. These terms can only be used to distinguish one element, component, region, layer or part from another. Unless the context clearly indicates, the terms such as "first" and "second" used in this document do not imply a sequence or order.

FIG1 is a side cross-sectional diagram of the double-molded stacked die optical coupler package structure disclosed in the present invention. Referring to FIG1 , the double-molded stacked die optical coupler package structure 1 of the present embodiment includes a first lead pin 21, a second lead pin 22, a photoelectric unit 31, a light-transmitting insulating block 32, a light-emitting unit 33 and a reflective colloid 41.

The material of the first lead pin 21 can be, for example, conductive materials such as silver, copper, gold, and aluminum. The first lead pin 21 can support other components and enable the secondary plastic-encapsulated stacked-chip optical coupler package structure 1 to be electrically connected to an external circuit. The first lead pin 21 can have, for example, more than two pins.

The second lead pin 22 is adjacent to the first lead pin 21. The second lead pin 22 can be located on the same side or the opposite side of the first lead pin 21. The material of the second lead pin 22 can be, for example, a conductive material such as silver, copper, gold, and aluminum. The second lead pin 22 enables the secondary plastic-encapsulated stacked-chip optical coupler package structure 1 to be electrically connected to an external circuit. The second lead pin 22 can, for example, have more than two pins.

The photoelectric unit 31 is disposed on the first lead 21. The photoelectric unit 31 can directly contact the first lead 21, so that the photoelectric unit 31 is electrically connected to the first lead 21. The photoelectric unit 31 may not contact the first lead 21, but may be electrically connected to the first lead 21 through a wire. The first lead 21 may support the photoelectric unit 31. The first lead 21 may also lead out an electrical signal of the photoelectric unit 31.

In some embodiments, the photoelectric unit 31 includes a photosensitive integrated circuit, a photoresistor, a phototransistor, a photodiode, or a photo three-terminal bidirectional AC switch. A photosensitive integrated circuit is an integrated circuit that integrates photoelectric components on a single chip. A photosensitive integrated circuit is an integrated circuit that can use photons to perform signal processing and transmission functions. A photoresistor may include, for example, cadmium sulfide or lead sulfide. A photoresistor may change its resistance value with light intensity. A phototransistor may include, for example, a bipolar junction transistor (BJT), a field effect transistor (FET), or a metal oxide semiconductor field effect transistor (MOSFET). A photodiode may include, for example, silicon or germanium. Photodiodes can generate photocurrent under light and provide corresponding current signals according to the light intensity. Photo TRIAC, also known as photo-controlled silicon, is a semiconductor component that combines the functions of a triode AC semiconductor switch with the characteristics of a photosensitive element.

The light-transmitting insulating block 32 is disposed on the photoelectric unit 31. In some embodiments, the light-transmitting insulating block 32 can be sandwiched between the photoelectric unit 31 and the light-emitting unit 33 to serve as a medium for light transmission and electrically isolate the photoelectric unit 31 from the light-emitting unit 33. In other words, the current and voltage at the input end will not directly act on the output end, and the current and voltage at the output end will not directly act on the input end. The material of the light-transmitting insulating block 32 can be, for example, a light-transmitting and insulating material such as acrylic plate, glass, polycarbonate, resin or plastic, but it is not restrictive.

The light-emitting unit 33 is disposed on the light-transmitting insulating block 32 and is electrically connected to the second lead 22. The light-transmitting insulating block 32 can transmit the light emitted by the light-emitting unit 33. When the second lead 22 is connected to an appropriate input electrical signal source, the input electrical signal source changes the light emitted by the light-emitting unit 33. The light-emitting unit 33 can be a light-emitting diode, a light bulb or a fluorescent tube.

In some embodiments, the light-emitting unit 33 is a light-emitting diode, for example, a red light-emitting diode, a yellow light-emitting diode, a green light-emitting diode, a blue light-emitting diode, a purple light-emitting diode, an infrared light-emitting diode or an ultraviolet light-emitting diode, but this is not limiting. The light-emitting diode can be an inorganic light-emitting diode or an organic light-emitting diode (OLED), but this is not limiting.

The reflective glue 41 covers the photoelectric unit 31, the light-transmitting insulating block 32 and the light-emitting unit 33. The reflective glue 41 can cover the photoelectric unit 31, the light-transmitting insulating block 32 and the light-emitting unit 33 by plastic packaging (or plastic packaging). In some embodiments, the reflective glue 41 can also cover a portion of the first lead 21 and the second lead 22. The reflective glue 41 can reflect the light escaping from the side wall of the light-transmitting insulating block 32 and reflect the light to the photoelectric unit 31.

In some embodiments, the reflective colloid 41 includes titanium dioxide. When titanium dioxide is dispersed in the reflective colloid 41, the whiteness of the reflective colloid 41 can be improved to increase the diffuse reflection effect.

In some embodiments, the color of the reflective colloid 41 is substantially white. The reflective colloid 41 may be, for example, white colloid. The reflective colloid 41 may be, for example, a colloid to which titanium dioxide, calcium carbonate, talcum powder, or zinc oxide is added, or a colloid to which white pigment is added, so that the reflective colloid 41 has a white appearance to facilitate light reflection.

In some embodiments, the reflective colloid 41 is reflective within the operating spectrum of the light emitting unit 33. The frequency of light that can be received by the photoelectric unit 31 has a certain range. For example, the photoelectric unit 31 can receive infrared bands and visible light bands. If the reflective colloid 41 is reflective in the infrared band and the visible light band, the energy conversion rate between the light emitted by the light emitting unit 33 and the light received by the photoelectric unit 31 can be increased. In other embodiments, if the light emitted by the light emitting unit 33 is in the visible light band, and the light that can be received by the photoelectric unit 31 is also in the visible light band, the reflective colloid 41 can be reflective in the visible light band to increase the energy conversion rate between the light emitted by the light emitting unit 33 and the light received by the photoelectric unit 31.

In some embodiments, the reflectivity is a reflectivity greater than or equal to 50%. Reflectance is a measure of the ratio of the incident light energy reflected by the surface of an object to the incident light energy, expressed as the ratio of the reflected light energy to the incident light energy. The reflectivity is related to the frequency of the incident light and the material of the object, and is usually between 0% and 100%. If the light emitted by the light-emitting unit 33 is in the visible light band, and the light that can be received by the photoelectric unit 31 is also in the visible light band, the reflectivity of the reflective colloid 41 in the visible light band can be greater than or equal to 50%. The reflectivity of the reflective colloid 41 can be, for example, 50%, 60%, 70%, 80%, 90% or 100%, but it is not restrictive.

In some embodiments, the reflective colloid 41 can protect the photoelectric unit 31, the light-transmitting insulating block 32, and the light-emitting unit 33 to prevent them from being damaged by mechanical force, corrosive substances, oxygen, moisture, or electricity.

In some embodiments, the secondary plastic encapsulation stacked-chip optical coupler package structure 1 further includes a packaging gel 42 covering a portion of the first lead 21, a portion of the second lead 22, the optoelectronic unit 31, the light-transmitting insulating block 32, the light-emitting unit 33, and the reflective gel 41. The packaging gel 42 can be, for example, epoxy or hot melt adhesive. The packaging gel 42 can protect the internal electronic components from being damaged by mechanical force, corrosive substances, oxygen, moisture, or electricity. A portion of the first lead 21 and the second lead 22 are covered by the packaging gel 42, and another portion of the first lead 21 and the second lead 22 can be used as pins connected to an external circuit.

In some embodiments, the color of the packaging colloid 42 is substantially black. The packaging colloid 42 may be, for example, black colloid. The packaging colloid 42 may be, for example, a colloid with carbon or iron oxide added or a colloid with black pigment added, so that the packaging colloid 42 has a black appearance. This helps to shield the light outside the secondary plastic-encapsulated stacked-chip optical coupler packaging structure 1.

In some embodiments, the packaging resin 42 is opaque relative to the operating spectrum of the light emitting unit 33. The frequency of light that can be received by the light emitting unit 33 has a certain range. For example, the photoelectric unit 31 can receive infrared bands and visible light bands. The packaging resin 42 is opaque in the infrared band and the visible light band to prevent the infrared and visible light outside the secondary plastic-encapsulated stacked-crystal optical coupler packaging structure 1 from penetrating the packaging resin 42 and irradiating the photoelectric unit 31.

In some embodiments, opacity means a transmittance of less than or equal to 10%. Transmittance is a measure of the ratio of transmitted light energy to incident light energy when light passes through a material, and is expressed as the ratio of reflected light energy to incident light energy. Transmittance is related to the frequency of the incident light and the material of the object, and is usually between 0% and 100%. If the light emitted by the light-emitting unit 33 is in the visible light band, and the light that can be received by the photoelectric unit 31 is also in the visible light band, then the transmittance of the encapsulation colloid 42 in the visible light band can be less than or equal to 10%. The transmittance of the encapsulation colloid 42 can be, for example, 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9% or 10%, but it is not restrictive.

Therefore, when the second lead 22 of the secondary plastic-encapsulated stacked-chip optical coupler package structure 1 is connected to the input electrical signal source, the light-emitting unit 33 can emit light, and the light can directly pass through the light-transmitting insulating block 32, or the light can pass through the light-transmitting insulating block 32 after being reflected by the reflective colloid 41, and the photoelectric unit 31 can receive the light and generate an electrical signal. In other words, the input electrical signal source changes the light emitted by the light-emitting unit 33, and the light change causes the photoelectric unit 31 to generate an electrical signal such as a voltage signal or a current signal, and outputs it from the first lead 21, thereby achieving the function of the optical coupler.

In summary, the secondary plastic-encapsulated stacked-die optocoupler package structure disclosed herein converts the input electrical signal source into an optical signal and then into an electrical signal, and maintains electrical isolation, thus having good electrical insulation and anti-interference capabilities. Adding the secondary plastic-encapsulated stacked-die optocoupler package structure disclosed herein to the circuit can prevent the rear-end circuit components from being damaged by imperfect input electrical signal sources, lightning, electrostatic discharge, electromagnetic interference, and switching pulses. The first lead can support the optoelectronic unit through the light-transmitting insulating block, so the optoelectronic unit does not need to be set on other supporting structures.

Furthermore, the secondary plastic-encapsulated stacked-chip optical coupler packaging structure disclosed in the present invention has a reflective colloid, which increases the path of light transmission to the photoelectric unit, thereby improving the energy conversion rate between the light emitted by the light-emitting unit and the light received by the photoelectric unit, achieving the effect of power saving.

Furthermore, the disclosed secondary plastic-encapsulated stacked-die optical coupler packaging structure can prevent light outside the secondary plastic-encapsulated stacked-die optical coupler packaging structure from penetrating the packaging resin and irradiating the optoelectronic unit, thereby preventing external light from interfering with the optoelectronic unit and also preventing induced erroneous signals from being sent to the optoelectronic unit.

As used herein and not otherwise defined, the terms "substantially" and "approximately" are used to describe and describe small variations. When used in conjunction with an event or circumstance, the terms may include the exact time at which the event or circumstance occurred, as well as the event or circumstance occurring to a close approximation. For example, when used in conjunction with a numerical value, the terms may include a variation range of less than or equal to ±10% of the numerical value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%.

The above summarizes the components of several embodiments so that those with ordinary knowledge in the art to which the present disclosure belongs can better understand the concepts of the embodiments of the present disclosure. Those with ordinary knowledge in the art to which the present disclosure belongs should understand that the embodiments of the present disclosure can be used as a basis to design or modify other processes and structures to achieve the same purpose and/or achieve the same benefits as the embodiments introduced herein. Those with ordinary knowledge in the art to which the present disclosure belongs should also understand that these equivalent structures do not deviate from the spirit and scope of the present disclosure, and various changes, substitutions and other options can be made here without departing from the spirit and scope of the present disclosure. Therefore, the scope of protection of the present disclosure shall be defined as the scope of the attached patent application.

1: Secondary plastic encapsulation stacked die optocoupler packaging structure 21: First lead 22: Second lead 31: Photoelectric unit 32: Transparent insulating block 33: Light-emitting unit 41: Reflective colloid 42: Packaging colloid

The details of one or more embodiments of the subject matter described in this specification are set forth in the following drawings and description. Other features, aspects and advantages of the subject matter of this specification will become apparent from the description, drawings and patent claims, including:

FIG. 1 is a schematic side cross-sectional view of a double-molded stacked-die optical coupler package structure according to an embodiment of the present disclosure.

1: Secondary plastic encapsulation stacked die optocoupler packaging structure

21: First lead

22: Second lead

31: Photoelectric unit

32: Translucent insulating block

33: Light-emitting unit

41: Reflective colloid

42: Packaging colloid

Claims (10)

A secondary plastic-encapsulated stacked-chip optical coupler packaging structure includes: a first lead pin; a second lead pin adjacent to the first lead pin; a photoelectric unit disposed on the first lead pin; a light-transmitting insulating block disposed on the photoelectric unit; a light-emitting unit disposed on the light-transmitting insulating block; and a reflective colloid covering the photoelectric unit, the light-transmitting insulating block and the light-emitting unit. A secondary plastic encapsulated stacked-chip optical coupler packaging structure as described in claim 1, wherein the reflective colloid includes titanium dioxide. A secondary plastic encapsulated stacked die optical coupler package structure as described in claim 1, wherein the color of the reflective glue is substantially white. A secondary plastic encapsulated stacked-chip optical coupler packaging structure as described in claim 1, wherein the reflective glue has a reflective property within an operating spectrum range of the light-emitting unit. A secondary plastic encapsulated stacked die optical coupler packaging structure as described in claim 4, wherein the reflectivity is a reflectivity greater than or equal to 50%. The secondary plastic encapsulated stacked-chip optical coupler packaging structure as described in claim 1 further includes: a packaging colloid covering a portion of the first lead pin, a portion of the second lead pin, the optoelectronic unit, the light-transmitting insulating block, the light-emitting unit and the reflective colloid. A secondary plastic encapsulated stacked die optocoupler package structure as described in claim 6, wherein the color of the packaging glue is substantially black. A secondary plastic-encapsulated stacked-chip optical coupler packaging structure as described in claim 6, wherein the packaging colloid has an opaque property relative to an operating spectrum range of the light-emitting unit. A secondary plastic encapsulated stacked die optical coupler packaging structure as described in claim 8, wherein the opacity is a transmittance less than or equal to 10%. The secondary plastic-encapsulated stacked-chip optical coupler packaging structure as described in claim 1, wherein the light-transmitting insulating block is sandwiched between the optoelectronic unit and the light-emitting unit.

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