Pin-free packaged stacked optical coupling device
Through a stacked design with pinless package, the conductive parts and contact pads are used for electrical connection, which solves the problem that the optocoupler is limited by the conductive frame in the miniaturized design, and achieves a smaller circuit layout area and longer Service life.
Patent Information
- Application Number
- CN202421114282.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Priority Date
- 2023-06-08
- Filing Date
- 2024-05-21
- Publication Date
- 2025-02-14
- Estimated Expiration
- 2034-05-21
AI Technical Summary
When pursuing a miniaturized design, existing optocouplers are limited by the physical limits of the conductive frame, making it difficult to further reduce the volume. At the same time, the exposed power supply pins occupy a large circuit layout area.
The stacked optical coupling device with a pinless package is adopted. By providing a first optical element, an insulating light transmitting layer and a second optical element on the substrate, and electrically connecting a plurality of conductive parts and contact pads, the optical coupling function is realized. No exposed pins are required.
The optocoupler is reduced to a greater extent, the circuit layout area is reduced, and the design trend is light, thin and small. At the same time, the service life of the device is extended through the use of thermal pads.
Smart Images
Figure CN222483389U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to an optical coupling device, in particular to a stacked optical coupling device without pin packaging. Background Art
[0002] With the development of technology, many electronic products have been pursuing miniaturized designs in order to meet the public's preferences. Optocouplers are widely used components in various electronic products. Therefore, if the size of the optocoupler can be effectively reduced, the size of the electronic product can also be reduced accordingly.
[0003] In the prior art, an optocoupler is provided with a light emitting element and a receiving element by means of a conductive frame. Since there is a distance between the conductive frames, there is also a distance between the light emitting element and the receiving element, thereby achieving the design purpose of electrical isolation of the optocoupler.
[0004] In order to meet the trend of electronic products moving towards lighter, thinner and smaller designs, optocouplers must also be significantly reduced in size. In addition to considering the issue of electrical isolation, they will also be limited by the physical limitations of the conductive frame.
[0005] Therefore, in another prior art, there is a stacking design that eliminates the use of a conductive frame inside the optical coupler, which can achieve the purpose of improving the physical limitations of the conductive frame and being unable to reduce the volume. Utility Model Content
[0006] However, the stacked design still uses technologies such as Small Out-line Package (SOP) or Quad Flat Package (QFP) to package the optocoupler into an optocoupler device. In the aforementioned packaging technologies, the power supply pins of the optocoupler are exposed and extend out of the package shell of the optocoupler device, resulting in the problem that the optocoupler device occupies a larger circuit layout area.
[0007] In order to solve the above problems, the purpose of the utility model is to provide a stacked optical coupling device with a pinless package, including: a stacked optical coupling module, including: a substrate; a first optical element, arranged on the substrate; an insulating light-transmitting layer, covering the first optical element; a second optical element, matched with the first optical element, and the second optical element is arranged outside the insulating light-transmitting layer; and a plurality of conductive parts, arranged between the substrate and the second optical element, and one end of the plurality of conductive parts is electrically connected to the substrate, and the other end is electrically connected to the second optical element; a molded packaging shell, covering the stacked optical coupling module; and a plurality of contact pads, electrically connected to the plurality of conductive parts; wherein the plurality of contact pads are exposed from the molded packaging shell and are flush with the outer surface of the molded packaging shell.
[0008] In some embodiments, the leadless package is a Dual Flat No leads (DFN) package or a Quad Flat No leads (QFN) package.
[0009] In some embodiments, a thermal conductive pad is further included, which contacts the plurality of contact pads and the substrate of the stacked optical coupling module.
[0010] In some embodiments, the first optical element includes: a first top surface disposed away from the substrate; and a first bottom surface disposed opposite to the first top surface and electrically connected to the substrate.
[0011] In some embodiments, the second optical element includes: a second top surface disposed away from the insulating light-transmitting layer; a second bottom surface disposed opposite to the second top surface and covering the insulating light-transmitting layer, and disposed corresponding to the first top surface.
[0012] In some embodiments, the insulating light-transmitting layer includes: an upper surface away from the first optical element and supporting the second bottom surface; and a side surface, one end of which is adjacent to the substrate and the other end of which is connected to the upper surface.
[0013] In some embodiments, the first optical element is a light emitter and the second optical element is a light detector.
[0014] In some embodiments, the first top surface is a light emitting surface, and the second bottom surface is a light receiving surface.
[0015] In some embodiments, the first optical element is a light detector and the second optical element is a light emitter.
[0016] In some embodiments, the first top surface is a light receiving surface, and the second bottom surface is a light emitting surface.
[0017] In summary, the stacked optical coupling device with a pinless package of the present invention, through the structural design of the conductive part, the contact pad and the stacked optical coupling module, does not need to be additionally provided with independent conductive frames for the first optical element and the second optical element, thereby achieving the purpose of improving the physical limitations of the conductive frame and being unable to reduce the volume. In addition, because the multiple contact pads of the present invention are not exposed and extend out of the pin structure, the stacked optical coupling device with a pinless package of the present invention has a relatively small circuit layout area, thereby meeting the design trend of being light, thin and small. In addition, the thermal pad of the present invention can conduct the heat energy generated by the stacked optical coupling module, and cooperate with the heat sink to dissipate the heat energy, thereby extending the service life of the stacked optical coupling module. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 It is a schematic structural cross-sectional view of an embodiment of a stacked optical coupling device of a pinless package of the utility model.
[0019] Figure 2 It is a schematic structural cross-sectional view of another embodiment of the stacked optical coupling device of the utility model without pin package.
[0020] Figure 3 It is a schematic structural cross-sectional view of another embodiment of the stacked optical coupling device of the utility model without pin package.
[0021] Figure 4 It is a schematic structural cross-sectional view of yet another embodiment of the stacked optical coupling device of the utility model without pin package.
[0022] Reference numerals
[0023] 10 substrate
[0024] 20 First optical element
[0025] 21 First top surface
[0026] 22 First bottom surface
[0027] 30 Insulation and light-transmitting layer
[0028] 32 Insulation and light-transmitting layer
[0029] 34 Upper surface
[0030] 36 Side surface
[0031] 40 Second optical element
[0032] 41 Second top surface
[0033] 42 Second bottom surface
[0034] 50 Conductive part
[0035] 52 Conductive part
[0036] 55 Contact pad
[0037] 57 Contact pad
[0038] 60 Molded Encapsulation Case
[0039] 70 Thermal Pad
[0040] 100 Leadless Package Stacked Optocoupler Device
[0041] 110 Leadless Package Stacked Optocoupler Device
[0042] 120 Leadless Package Stacked Optocoupler Device
[0043] 130 Leadless Package Stacked Optocoupler Device
[0044] 150 stacked optical coupling module
[0045] 155 stacked optical coupling module DETAILED DESCRIPTION
[0046] Please refer to Figure 1 , is a schematic structural cross-sectional view of an embodiment of a stacked optical coupling device of a pinless package of the present invention. The stacked optical coupling device of a pinless package 100 comprises: a stacked optical coupling module 150, a molded package housing 60 and a plurality of contact pads 55. Figure 1 Two contact pads 55 are used as an example for illustration, but the invention is not limited thereto. The leadless package may be, for example, a double flat leadless package or a quad flat leadless package.
[0047] The stacked optical coupling module 150 includes a substrate 10, a first optical element 20, an insulating light-transmitting layer 30, a second optical element 40 and a plurality of conductive parts 50. Figure 1 Two conductive parts 50 are used as an example for illustration, but the invention is not limited thereto.
[0048] The first optical element 20 is disposed on the substrate 10. The first optical element 20 may be a light emitter (eg, a light emitting diode) or a light detector (eg, a photoelectric crystal).
[0049] The insulating light-transmitting layer 30 covers the first optical element 20 . The insulating light-transmitting layer 30 may be, for example, titanium oxide, silicon oxide, silicon nitride or other insulating light-transmitting materials. The insulating light-transmitting layer 30 may be used to electrically isolate the first optical element 20 from the second optical element 40 .
[0050] The second optical element 40 is matched with the first optical element 20, and the second optical element 40 is arranged outside the insulating light-transmitting layer 30. The second optical element 40 can be a light emitter (e.g., a light emitting diode) or a light detector (e.g., a photoelectric crystal). In this embodiment, the first optical element 20 and the second optical element 40 are matched elements to each other. For example, if the first optical element 20 is a light emitter, the second optical element 40 matched with the first optical element 20 is a light detector. In other embodiments, if the first optical element 20 is a light detector, the second optical element 40 is a light emitter.
[0051] The plurality of conductive parts 50 are disposed between the substrate 10 and the second optical element 40, and one end of each of the plurality of conductive parts 50 is electrically connected to the substrate 10. The other end of each of the plurality of conductive parts 50 is electrically connected to the second optical element 40. The plurality of conductive parts 50 can be made of a metal or a composite metal selected from silver, copper, gold, aluminum, tin, iron, etc.
[0052] The stacked optical coupling module 150 is disposed in the molded package housing 60. The molded package housing 60 can be used as a protective housing for the stacked optical coupling module 150 to block air, impurities or moisture, etc. The molded package housing 60 can be made of insulating materials such as epoxy resin or other resins.
[0053] The plurality of contact pads 55 are disposed adjacent to the substrate 10 and are electrically connected to the plurality of conductive portions 50 through the substrate 10, respectively. Thus, when the first optical element 20 is a light emitter and the second optical element 40 is a light detector, an external power circuit (not shown) can transmit an electrical signal to the first optical element 20 through the plurality of contact pads 55 and the substrate 10 to emit light, and the second optical element 40 generates an output signal by photoelectric conversion according to the light, and transmits the output signal to the external circuit (not shown) through the plurality of conductive portions 50, the substrate 10, and the plurality of contact pads 55. When the first optical element 20 is a light detector and the second optical element 40 is a light emitter, the external power circuit transmits an electrical signal to the second optical element 40 through the plurality of contact pads 55, the substrate 10, and the plurality of conductive portions 50 to emit light, and the first optical element 20 generates an output signal by photoelectric conversion according to the light, and transmits the output signal to the external circuit through the substrate 10 and the plurality of contact pads 55. In this way, the first optical element 20 and the second optical element 40 share the substrate 10 and the plurality of contact pads 55, so that the stacked optical coupling module 150 can be designed as a stacked structure (i.e., the second optical element 40 is matched with the first optical element 20), without the need to set up independent conductive frames for the first optical element 20 and the second optical element 40 to transmit electrical signals. Furthermore, the plurality of contact pads 55 are exposed to the molded package shell 60 and are flush with the outer surface of the molded package shell 60. In this way, the stacked optical coupling device 100 with a pinless package has no exposed and extended pin structure, so the stacked optical coupling device 100 with a pinless package has a relatively small circuit layout area, which conforms to the design trend of being light, thin, and small. The plurality of contact pads 55 are conductive materials. The plurality of contact pads 55 can be selected from metals or composite metals such as silver, copper, gold, aluminum, tin, and iron. In other embodiments, the plurality of contact pads 55 can have the same material as the plurality of conductive parts 50. In other embodiments, the plurality of contact pads 55 may form an integral structure with the plurality of conductive parts 50 .
[0054] Please refer to Figure 2 , is a schematic structural cross-sectional view of another embodiment of the stacked optical coupling device of the present invention without pins. The stacked optical coupling device 110 of the stacked optical coupling device without pins includes: a stacked optical coupling module 150, a molded packaging shell 60, a plurality of contact pads 57 and a thermal pad 70. This embodiment Figure 2Two contact pads 57 are used as an example for illustration, but the invention is not limited thereto. The leadless package may be, for example, a double flat leadless package or a quad flat leadless package.
[0055] Figure 2 Example and Figure 1 The difference of the embodiment is that the contact pad 57 is used instead of Figure 1 The contact pad 55 is provided, and the structure shape of the contact pad 57 (such as L-shaped) is different from the structure shape of the contact pad 55 (such as square shape), and a thermal conductive pad 70 is added, and the remaining modules or components are the same. Figure 1 The embodiments are not described in detail here.
[0056] The thermal pad 70 contacts one end of the stacked optical coupling module 150. More specifically, the upper surface (not shown) of the thermal pad 70 contacts the lower surface (not shown) of the substrate 10 and a portion of the inner surface of the contact pad 57 to conduct the heat energy generated by the stacked optical coupling module 150. In other embodiments, the thermal pad 70 may also cooperate with a heat sink (not shown) to dissipate the aforementioned heat energy to the outside of the pinless packaged stacked optical coupling device 110. In this way, the stacked optical coupling module 150 is prevented from being affected by the aforementioned heat energy and shortening its service life. In addition, in order to match the size of the thermal pad 70, the structural shape of the contact pad 57 is adjusted (for example, if the area of the thermal pad 70 is larger or smaller than the area of the substrate 10, the structural shape of the contact pad 57 can be adjusted to an L-shape; if the area of the thermal pad 70 is equal to the area of the substrate 10, the structural shape of the contact pad 57 can be adjusted to a square or L-shape), but it is still exposed to the molded packaging shell 60 and is flush with the outer surface of the molded packaging shell 60.
[0057] Please refer to Figure 3 , is a schematic structural cross-sectional view of another embodiment of a stacked optical coupling device of a pinless package of the utility model. The stacked optical coupling device of a pinless package 120 comprises: a stacked optical coupling module 155, a molded package housing 60 and a plurality of contact pads 55. The pinless package may be, for example, a two-sided flat pinless package or a four-sided flat pinless package.
[0058] Figure 3 Example and Figure 1 The difference of the embodiment is that the stacked optical coupling module 155 is used instead of Figure 1 The stacked optical coupling module 150 is a stacked optical coupling module 155, and the same elements as those in the stacked optical coupling module 150 are represented by the same element symbols. The stacked optical coupling module 155 includes a substrate 10, a first optical element 20, an insulating light-transmitting layer 32, a second optical element 40, and a plurality of conductive portions 52. Figure 3The two conductive parts 52 are used as an example for illustration, but the invention is not limited thereto. The structural shape of the conductive part 52 (e.g., arc shape) is different from the structural shape of the conductive part 50 (e.g., strip shape), and the structural shape of the insulating light-transmitting layer 32 is different from the structural shape of the insulating light-transmitting layer 30. The other modules or components are the same. Figure 1 Embodiment: the same parts as described above will not be repeated here.
[0059] The first optical element 20 includes a first top surface 21 and a first bottom surface 22. The first top surface 21 is disposed away from the substrate 10, and the first bottom surface 22 is symmetrical to the first top surface 21 and is disposed on the substrate 10 and electrically connected to the substrate 10.
[0060] The second optical element 40 includes a second top surface 41 and a second bottom surface 42. The second top surface 41 is disposed away from the insulating light-transmitting layer 32. The second bottom surface 42 is symmetrical to the second top surface 41 and covers the insulating light-transmitting layer 32, and is disposed corresponding to the first top surface 21.
[0061] In this embodiment, the first optical element 20 and the second optical element 40 are matched elements. The first optical element 20 can be a light emitter, and the second optical element 40 is a light detector. In the aforementioned matching situation, the first top surface 21 is a light emitting surface, and the second bottom surface 42 is a light receiving surface. In other embodiments, the first optical element 20 can also be a light detector, and the second optical element 40 is a light emitter. In this case, the first top surface 21 is a light receiving surface, and the second bottom surface 42 is a light emitting surface.
[0062] The insulating light-transmitting layer 32 includes an upper surface 34, and the upper surface 34 is away from the first optical element 20 and supports the second bottom surface 42. The insulating light-transmitting layer 32 further includes a side surface 36, and one end of the side surface 36 is connected to the substrate 10 and the other end is connected to the upper surface 34.
[0063] The plurality of conductive portions 52 are disposed adjacent to the side surface 36. In this embodiment, the plurality of conductive portions 52 are disposed inwardly curved according to the arc shape of the side surface 36 of the insulating light-transmitting layer 32, so as to be adjacent to the insulating light-transmitting layer 32. In this way, the distance between the first optical element 20 and the second optical element 40 can be further shortened to further reduce the overall height of the stacked optical coupling module 155, which conforms to the design trend of being light, thin, and small. In other embodiments, the plurality of conductive portions 52 can also be disposed outwardly convexly according to the convex shape of the side surface 36 of the insulating light-transmitting layer 32.
[0064] Please refer to Figure 4, is a schematic structural cross-sectional view of another embodiment of a stacked optical coupling device of a pinless package of the utility model. The stacked optical coupling device of a pinless package 130 comprises: a stacked optical coupling module 155, a molded package housing 60, a plurality of contact pads 57 and a thermal pad 70. The pinless package may be, for example, a two-sided flat pinless package or a four-sided flat pinless package.
[0065] Figure 4 Example and Figure 3 The difference of the embodiment is that the contact pad 57 is used instead of Figure 3 The contact pad 55 is provided, and the structure shape of the contact pad 57 (such as L-shaped) is different from the structure shape of the contact pad 55 (such as square shape), and a thermal conductive pad 70 is added, and the remaining modules or components are the same. Figure 3 The embodiments are not described in detail here.
[0066] The thermal pad 70 contacts one end of the stacked optical coupling module 155. More specifically, the upper surface (not shown) of the thermal pad 70 contacts the lower surface (not shown) of the substrate 10 and a portion of the inner surface of the contact pad 57 to conduct the heat energy generated by the stacked optical coupling module 155. In other embodiments, the thermal pad 70 may also cooperate with a heat sink to dissipate the aforementioned heat energy to the outside of the stacked optical coupling device 130 of the pinless package. In this way, the stacked optical coupling module 155 is prevented from being affected by the aforementioned heat energy and shortening its service life. In addition, in order to match the size of the thermal pad 70, the structural shape of the contact pad 57 has been adjusted, but it is still exposed to the molded package shell 60 and is flush with the outer surface of the molded package shell 60.
[0067] In summary, the stacked optical coupling devices 100, 110 (120, 130) of the present invention with a pinless package, through the structural design of the conductive portion 50, the contact pad 55 and the stacked optical coupling module 150 (155), do not need to be additionally provided with independent conductive frames for the first optical element 20 and the second optical element 40, thereby achieving the purpose of improving the physical limit of the conductive frame and being unable to reduce the volume. In addition, since the multiple contact pads 55, 57 of the present invention do not have an exposed and extended pin structure, the stacked optical coupling device of the present invention with a pinless package has a relatively small circuit layout area, thereby meeting the design trend of being light, thin and small. In addition, the thermal pad 70 of the present invention can conduct the heat energy generated by the stacked optical coupling module 150 (155), and cooperate with the heat sink to dissipate the heat energy, thereby extending the service life of the stacked optical coupling module 150 (155).
[0068] The present invention has been disclosed in the above with a preferred embodiment, but those skilled in the art should understand that the embodiment is only used to describe the present invention and should not be interpreted as limiting the scope of the present invention. It should be noted that all changes and substitutions equivalent to the embodiment should be included in the scope of the present invention. Therefore, the protection scope of the present invention shall be based on the scope of the patent application.
Claims
1. A stacked optical coupling device with a pinless package, characterized in that: include: A stacked optical coupling module, comprising: a substrate; a first optical element, disposed on the substrate; an insulating light-transmitting layer, covering the first optical element; a second optical element, matched with the first optical element, and arranged outside the insulating light-transmitting layer; and A plurality of conductive parts are disposed between the substrate and the second optical element, and one end of each of the plurality of conductive parts is electrically connected to the substrate, and the other end is electrically connected to the second optical element; A molded packaging shell, in which the stacked optical coupling module is arranged; as well as a plurality of contact pads, electrically connected to the plurality of conductive parts respectively; The plurality of contact pads are exposed from the molded packaging shell and are flush with the outer surface of the molded packaging shell.
2. The stacked optical coupling device of the leadless package according to claim 1, characterized in that: The leadless package is a double flat no-lead package or a quad flat no-lead package.
3. The stacked optical coupling device of the leadless package according to claim 1, characterized in that: The invention also includes a heat conductive pad which contacts with the plurality of contact pads and the substrate of the stacked optical coupling module.
4. The stacked optical coupling device of the leadless package according to claim 1, characterized in that: The first optical element comprises: a first top surface, disposed away from the substrate; and A first bottom surface is symmetrical with the first top surface and is disposed on the substrate and electrically connected to the substrate.
5. The stacked optical coupling device of the leadless package according to claim 4, characterized in that: The second optical element comprises: a second top surface, disposed away from the insulating light-transmitting layer; and A second bottom surface is symmetrical with the second top surface and covers the insulating light-transmitting layer, and is disposed corresponding to the first top surface.
6. The stacked optical coupling device of the leadless package according to claim 5, characterized in that: The insulating light-transmitting layer comprises: an upper surface, away from the first optical element and supporting the second bottom surface; and A side surface has one end connected to the substrate and the other end connected to the upper surface.
7. The stacked optical coupling device of the leadless package according to claim 5 or 6, characterized in that: The first optical element is a light emitter, and the second optical element is a light detector.
8. The stacked optical coupling device of the leadless package according to claim 7, characterized in that: The first top surface is a light emitting surface, and the second bottom surface is a light receiving surface.
9. The stacked optical coupling device of the leadless package according to claim 5 or 6, characterized in that: The first optical element is a light detector, and the second optical element is a light emitter.
10. The stacked optical coupling device of the leadless package according to claim 9, characterized in that: The first top surface is a light receiving surface, and the second bottom surface is a light emitting surface.