Packaging structure for multi-channel light coupling device

Abstract

A packaging structure of a multi-channel light coupling device includes a lead frame, at least two light emitting chips and at least two photoelectric conversion chips, wherein the lead frame includes a first base island, a second base island and a third base island; a first side lead frame of the first base island on which the first light emitting chip is arranged is bent to form a first shielding structure; a second side lead frame of the second base island on which the second light emitting chip is arranged is bent to form a second shielding structure; the lead frame of the third base island is bent to form at least one third shielding structure, and adjacent first photoelectric conversion chip and second photoelectric conversion chip are arranged on two sides of the third shielding structure; and a plastic packaging structure covers the lead frame, the light emitting chip and the photoelectric conversion chip. The above scheme reduces the light crosstalk while the size of the packaging structure of the multi-channel light coupling device is small.

Description

Technical Field

[0001] This utility model relates to the field of optical coupling device technology, and in particular to a packaging structure for a multi-channel optical coupling device. Background Technology

[0002] Optical coupling devices are semiconductor devices that use optical signal transmission to achieve electrical isolation, and are widely used in power management, signal isolation, industrial control, and communication systems. With the increasing demand for high integration and miniaturization, multi-channel optical coupling devices have gradually appeared on the market, which integrate two or more LED chips and corresponding photoelectric conversion chips in the same plastic package structure.

[0003] Because multiple LED chips and photoelectric conversion chips in a multi-channel optical coupling device are housed in the same plastic package structure, optical crosstalk can easily occur during transmission of light signals emitted by different LED chips. This means that non-corresponding photoelectric conversion chips receive interference light emitted by other LED chips, leading to output errors or performance degradation.

[0004] To address the optical crosstalk problem, existing technologies typically employ black epoxy resin, ceramic separators of a certain thickness, or light-absorbing layers to isolate different optical paths. However, existing multi-channel optical coupling devices have relatively large package sizes. Utility Model Content

[0005] The purpose of this invention is to provide at least one packaging structure for a multi-channel optical coupling device that reduces optical crosstalk while maintaining a small package size.

[0006] To achieve the above objectives, this utility model provides a packaging structure for a multi-channel optical coupling device, comprising: a lead frame, at least two light-emitting chips and at least two photoelectric conversion chips, wherein: the lead frame includes a first base island, a second base island, and a third base island; the first light-emitting chip and the second light-emitting chip are disposed on different base islands; the lead frame on the first side of the first base island where the first light-emitting chip is located is bent to form a first shielding structure; the lead frame on the second side of the second base island where the second light-emitting chip is located is bent to form a second shielding structure; the first shielding structure and the second shielding structure are arranged parallel to each other, and the first shielding structure and the second shielding structure are located between the first base island and the second base island; the lead frame on the third base island is bent to form at least one third shielding structure, and adjacent first photoelectric conversion chips and second photoelectric conversion chips are disposed on both sides of a third shielding structure; a first optical path is formed between the first light-emitting chip and the first photoelectric conversion chip, and a second optical path is formed between the second light-emitting chip and the second photoelectric conversion chip; and a plastic encapsulation structure covering the lead frame, the light-emitting chips, and the photoelectric conversion chips.

[0007] The first side lead frame of the first base island is bent to form a first shielding structure, and the second side lead frame of the second base island is bent to form a second shielding structure. The first shielding structure blocks the light emitted by the first light-emitting chip to avoid optical crosstalk to the light emitted by the second light-emitting chip. The second shielding structure blocks the light emitted by the second light-emitting chip to avoid optical crosstalk to the light emitted by the first light-emitting chip. Therefore, it is unnecessary to additionally set a black epoxy resin of a certain width and thickness between the first and second optical paths as a light-shielding structure, thus not significantly increasing the size of the multi-channel optocoupler's packaging structure, which is beneficial for the miniaturization of the multi-channel optocoupler.

[0008] Optionally, the height of the first shielding structure relative to the base plate is not lower than the height of the first light-emitting chip relative to the base plate; the lead frame is disposed on the base plate.

[0009] Optionally, the second side lead frame of the first base island is bent to form a fourth shielding structure, and the first shielding structure is arranged parallel to the fourth shielding structure.

[0010] Optionally, the height of the first shielding structure is equal to the height of the fourth shielding structure.

[0011] Optionally, the height of the second shielding structure relative to the base plate is not lower than the height of the second light-emitting chip relative to the base plate; the lead frame is disposed on the base plate.

[0012] Optionally, the first side lead frame of the second base island is bent to form a fifth shielding structure, and the second shielding structure is arranged parallel to the fifth shielding structure.

[0013] Optionally, the height of the second shielding structure is equal to the height of the fifth shielding structure.

[0014] Optionally, the height of the third shielding structure relative to the base plate is not lower than the height of the first photoelectric conversion chip relative to the base plate; the lead frame is disposed on the base plate.

[0015] Optionally, the first side lead frame of the third base island is bent to form a sixth shielding structure; and / or, the second side lead frame of the third base island is bent to form a seventh shielding structure; the sixth shielding structure is arranged parallel to the third shielding structure, and the seventh shielding structure is arranged parallel to the third shielding structure.

[0016] Optionally, the packaging structure of the multi-channel optical coupling device may further include an eighth shielding structure disposed between the first optical path and the second optical path.

[0017] By setting an eighth shielding structure of a certain thickness between the first and second optical paths, optical crosstalk between the two paths can be more effectively isolated. Furthermore, since the first and second shielding structures are already in place, the light leaking from the first optical path that causes optical crosstalk to the second optical path is weaker. Therefore, the thickness of the eighth shielding structure can be set to be thinner, thus avoiding excessively increasing the width of the multi-channel optical coupling device's package structure.

[0018] Optionally, the eighth shielding structure is formed of black opaque resin. Attached Figure Description

[0019] Figure 1 This is a top view of the packaging structure of a multi-channel optical coupling device according to an embodiment of this utility model;

[0020] Figure 2 This is a top view of the packaging structure of another multi-channel optical coupling device in this embodiment of the present invention;

[0021] Figure 3 This is a top view of the packaging structure of another multi-channel optical coupling device in this embodiment of the present invention;

[0022] Figure 4 This is a cross-sectional view of a third base island in an embodiment of this utility model;

[0023] Figure 5 This is a top view of a third base island in an embodiment of this utility model;

[0024] Figure 6 This is a top view of the packaging structure of an existing multi-channel optical coupling device. Detailed Implementation

[0025] As described in the background section, to address the optical crosstalk problem, existing technologies typically employ black epoxy resin, ceramic separators, or light-absorbing layers of a certain thickness to isolate different optical paths. However, existing multi-channel optical coupling devices have relatively large package structures.

[0026] In this embodiment of the invention, the first side lead frame of the first base island is bent to form a first shielding structure, and the second side lead frame of the second base island is bent to form a second shielding structure. The first shielding structure blocks the light emitted by the first light-emitting chip to avoid optical crosstalk to the light emitted by the second light-emitting chip. The second shielding structure blocks the light emitted by the second light-emitting chip to avoid optical crosstalk to the light emitted by the first light-emitting chip. Therefore, it is unnecessary to additionally provide a black epoxy resin of a certain width and thickness as a light-shielding structure between the first and second optical paths, thus not significantly increasing the size of the multi-channel optical coupling device's packaging structure, which is beneficial for the miniaturization of the multi-channel optical coupling device.

[0027] 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.

[0028] In this embodiment of the invention, the packaging structure of the multi-channel optical coupling device may include: a lead frame, at least two light-emitting chips and at least two photoelectric conversion chips, and a plastic encapsulation structure. The plastic encapsulation structure covers the lead frame, at least two light-emitting chips, and at least two photoelectric conversion chips.

[0029] In some embodiments, a multi-channel optical coupling device may include two light-emitting chips and photoelectric conversion chips arranged in a one-to-one correspondence with the two light-emitting chips. In other embodiments, the multi-channel optical coupling device includes three or more light-emitting chips, and correspondingly, the multi-channel optical coupling device also includes a number of photoelectric conversion chips equal to the number of light-emitting chips, with a one-to-one correspondence between the photoelectric conversion chips and the light-emitting chips. The optical path between each light-emitting chip and its corresponding photoelectric conversion chip can also be referred to as an optical path.

[0030] In this embodiment of the invention, the lead frame may include multiple base islands, different light-emitting chips may be disposed on different base islands, and different photoelectric conversion chips may be disposed on the same base island.

[0031] In a specific implementation, the lead frame may include at least a first base island, a second base island, and a third base island. At least two light-emitting chips, including a first light-emitting chip and a second light-emitting chip, are respectively disposed on the first and second base islands, and at least two photoelectric conversion chips are both disposed on the third base island.

[0032] For a first base island equipped with a first light-emitting chip, its first side lead frame is bent to form a first shielding structure; for a second base island equipped with a second light-emitting chip, its second side lead frame is bent to form a second shielding structure. The first shielding structure and the second shielding structure are arranged in parallel, and the first shielding structure and the second shielding structure are located between the first base island and the second base island.

[0033] For a third base island equipped with at least two photoelectric conversion chips, its corresponding lead frame is bent to form at least one third shielding structure. The first photoelectric conversion chip and the second photoelectric conversion chip of the at least two photoelectric conversion chips are disposed on opposite sides of a third shielding structure. A first optical path is formed between the first light-emitting chip and the first photoelectric conversion chip, and a second optical path is formed between the second light-emitting chip and the second photoelectric conversion chip.

[0034] If there are two photoelectric conversion chips, that is, a first photoelectric conversion chip and a second photoelectric conversion chip, then a third shielding structure can be formed on the third base island, with the first and second photoelectric conversion chips positioned on either side of the third shielding structure. The third shielding structure can be located in the central region of the third structure.

[0035] Reference Figure 1 The present invention provides a top view of a packaging structure 10 for a multi-channel optical coupling device according to an embodiment of the present invention.

[0036] Figure 1 In the package structure 10 of the multi-channel optical coupling device, there are two light-emitting chips and two photoelectric conversion chips. The first side lead frame of the first base island 41 is adjacent to the second side lead frame of the second base island 42, and the first side lead frame of the first base island 41 is bent to form a first shielding structure 51, and the second side lead frame of the second base island 42 is used to form a second shielding structure 52.

[0037] The third base island 43 is provided with a first photoelectric conversion chip 31 and a second photoelectric conversion chip 32, and a third shielding structure 53 is provided between the first photoelectric conversion chip 31 and the second photoelectric conversion chip 32.

[0038] The first light-emitting chip 21 can be coupled to the first power supply frame 44 in the lead frame, and the second light-emitting chip 22 can be coupled to the second power supply frame 45 in the lead frame. The first photoelectric conversion chip 31 can be coupled to the ground frame 46 and the first signal output frame 47 in the lead frame, and the second photoelectric conversion chip 32 can be coupled to the ground frame 46 and the second signal output frame 48 in the lead frame.

[0039] It should be noted that the connection relationships between the first light-emitting chip 21, the second light-emitting chip 22, the first photoelectric conversion chip 31, the second photoelectric conversion chip 32, and the lead frame, specifically how the first light-emitting chip 21 and the second light-emitting chip 22 input electrical signals through the lead frame, and how the first photoelectric conversion chip 31 and the second photoelectric conversion chip 32 are grounded and output electrical signals through the lead frame, can all be referred to existing multi-channel optocouplers.

[0040] In a specific implementation, the packaging structure 10 of the multi-channel optical coupling device may also include a base plate, and the lead frame may be set on the base plate.

[0041] In this embodiment of the invention, the height of the first shielding structure 51 relative to the base plate can be no less than the height of the first light-emitting chip 21 relative to the base plate. Therefore, the first shielding structure 51 can block the light emitted by the first light-emitting chip 21, thereby reducing optical crosstalk caused by the light emitted by the first light-emitting chip 21 to the light emitted by the second light-emitting chip 22.

[0042] The height of the second shielding structure 52 relative to the base plate can also be no less than the height of the second light-emitting chip 22 relative to the base plate. Therefore, the second shielding structure 52 can block the light emitted by the second light-emitting chip 22, thereby reducing optical crosstalk caused by the light emitted by the second light-emitting chip 22 to the light emitted by the first light-emitting chip 21.

[0043] Therefore, by setting a first blocking structure 51 at a certain height, the light emitted by the first light-emitting chip 21 will hardly illuminate the second optical path under the blocking effect of the first blocking structure 51, thus effectively blocking the light emitted by the first light-emitting chip 21. Correspondingly, by setting a second blocking structure 52 at a certain height, the light emitted by the second light-emitting chip 22 will hardly illuminate the first optical path under the blocking effect of the second blocking structure 52, thus effectively blocking the light emitted by the second light-emitting chip 22. The aforementioned first optical path is the optical path between the first light-emitting chip 21 and the first photoelectric conversion chip 31, and the second optical path is the optical path between the second light-emitting chip 22 and the second photoelectric conversion chip 32.

[0044] As can be seen, by setting the first blocking structure 51, the light emitted by the first light-emitting chip 21 can hardly cause optical crosstalk to the second optical path. Correspondingly, by setting the second blocking structure 52, the light emitted by the second light-emitting chip 22 can hardly cause optical crosstalk to the first optical path.

[0045] In a specific implementation, the second side lead frame of the first base island 41 can also be bent to form a fourth shielding structure 54, with the first shielding structure 51 and the fourth shielding structure 54 arranged in parallel.

[0046] In some embodiments, the height of the first blocking structure 51 may be equal to the height of the fourth blocking structure 54.

[0047] In a specific implementation, the first side lead frame of the second base island 42 can also be bent to form the fifth shielding structure 55, with the second shielding structure 52 and the fifth shielding structure 55 arranged in parallel.

[0048] In some embodiments, the height of the second shielding structure 52 may be equal to the height of the fifth shielding structure 55.

[0049] like Figure 2 The figure shows a top view of the packaging structure 10 of another multi-channel optical coupling device in an embodiment of the present invention.

[0050] Figure 2 In, with Figure 1 The difference is that the second side lead frame of the first base island 41 is bent to obtain the fourth shielding structure 54; and the first side lead frame of the second base island 42 is bent to obtain the fifth shielding structure 55.

[0051] In specific implementations, the first side lead frame of the third base island 43 can be bent to form the sixth shielding structure 56, and / or the second side lead frame of the third base island 43 can be bent to form the seventh shielding structure 57. On the third base island 43, the sixth shielding structure 56 can be arranged parallel to the third shielding structure 53, and the seventh shielding structure 57 can be arranged parallel to the third shielding structure 53.

[0052] In some embodiments, only the first side lead frame of the third base island 43 may be bent to form the sixth shielding structure 56, or only the second side lead frame of the third base island 43 may be bent to form the seventh shielding structure 57.

[0053] In other embodiments, such as Figure 2 As shown, the first side lead frame of the third base island 43 is bent to form the sixth shielding structure 56, and the second side lead frame of the third base island 43 is bent to form the seventh shielding structure 57.

[0054] In specific implementation, such as Figure 1and Figure 2 As shown, there is a certain distance between the first base island 41 and the third base island 43, meaning that a portion of the first optical path is open. Correspondingly, there is also a certain distance between the second base island 42 and the third base island 43, meaning that a portion of the second optical path is also open. In practical applications, optical crosstalk may still exist between the first and second optical paths.

[0055] In this embodiment of the invention, an eighth shielding structure 58 may be provided between the first optical path and the second optical path. The eighth shielding structure 58 may be formed of black opaque resin, thereby avoiding optical crosstalk between the first optical path and the second optical path.

[0056] Reference Figure 3 The present invention provides another packaging structure 10 for a multi-channel optical coupling device in an embodiment of the present invention.

[0057] Figure 3 In this configuration, an eighth blocking structure 58 is provided between the first optical path and the second optical path. The eighth blocking structure 58 blocks the area between the first optical path and the second optical path, thereby further avoiding optical crosstalk between the first optical path and the second optical path.

[0058] Since the first and second shielding structures are respectively set on the first and second base islands, the light leakage from the first optical path that causes optical crosstalk to the second optical path is relatively weak, and the light leakage from the second optical path that causes optical crosstalk to the first optical path is also relatively weak. Therefore, the thickness of the eighth shielding structure set between the first and second optical paths can be relatively thin, thus not excessively increasing the width of the package structure of the multi-channel optical coupling device.

[0059] The third shielding structure 53 formed on the third base island 43 will be described below.

[0060] Reference Figure 4 A cross-sectional view of a third base island according to an embodiment of this utility model is provided. Figure 4 In the middle, the third shielding structure 53 is formed by bending the middle region of the third base island 43.

[0061] like Figures 1-4 As shown, two photoelectric conversion chips are installed on the third base island 43.

[0062] As mentioned above, three or more photoelectric conversion chips can be installed on the third base island 43.

[0063] If there are three or more photoelectric conversion chips, a third shielding structure 53 is provided on the third base island 43 between adjacent photoelectric conversion chips, and two adjacent photoelectric conversion chips are arranged on both sides of the corresponding third shielding structure 53.

[0064] For example, if there are three photoelectric conversion chips, then two third shielding structures 53 are formed on the third base island 43. A first third shielding structure 53 is provided between the first photoelectric conversion chip 31 and the second photoelectric conversion chip 32, and a second third shielding structure 53 is provided between the second photoelectric conversion chip 32 and the third photoelectric conversion chip.

[0065] Reference Figure 5 The present invention provides a top view of a third base island in an embodiment of the present invention. Figure 5 In the middle, a first photoelectric conversion chip 31, a second photoelectric conversion chip 32, and a third photoelectric conversion chip are disposed on the third base island 43. A first third shielding structure 53 is disposed between the first photoelectric conversion chip 31 and the second photoelectric conversion chip 32, and a third shielding structure 53 is disposed between the second photoelectric conversion chip 32 and the third photoelectric conversion chip.

[0066] Reference Figure 6 A top view of the packaging structure of an existing multi-channel optocoupler is given. For example... Figure 6 As shown, to avoid optical crosstalk between different optical paths, a black epoxy resin of a certain width and thickness is provided as a light-shielding structure 60 between the different optical paths. Typically, the width of the light-shielding structure 60 is relatively large, which to some extent increases the size of the packaging structure of the multi-channel optical coupling device.

[0067] When the number of optical paths included in the package structure of a multi-channel optical coupling device increases, the size of the package structure of the multi-channel optical coupling device will further increase.

[0068] In this embodiment of the invention, since the lead frame of the base island is bent to form a shielding structure, there is no need to set an additional black epoxy resin of a certain width and thickness as a light-shielding structure, so the size of the packaging structure of the multi-channel optical coupling device will not be increased too much.

[0069] Under the same conditions of the number of optical paths, chip process, and packaging process, compared with the existing packaging structure of multi-channel optical coupling devices, the width of the packaging structure of the multi-channel optical coupling device provided in this embodiment can be reduced by 15%, which is beneficial to the miniaturization of optical coupling devices.

[0070] 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 packaging structure for a multi-channel optical coupling device, characterized in that, include: The lead frame comprises at least two light-emitting chips and at least two photoelectric conversion chips, wherein: The lead frame includes a first base island, a second base island, and a third base island; The first and second light-emitting chips in the at least two light-emitting chips are disposed on different base islands; the first side lead frame of the first base island where the first light-emitting chip is located is bent to form a first shielding structure; the second side lead frame of the second base island where the second light-emitting chip is located is bent to form a second shielding structure; the first shielding structure and the second shielding structure are arranged in parallel, and the first shielding structure and the second shielding structure are located between the first base island and the second base island; The lead frame of the third base island is bent to form at least one third shielding structure, and adjacent first photoelectric conversion chips and second photoelectric conversion chips are disposed on both sides of a third shielding structure; a first optical path is formed between the first light-emitting chip and the first photoelectric conversion chip, and a second optical path is formed between the second light-emitting chip and the second photoelectric conversion chip; A plastic encapsulation structure covers the lead frame, the light-emitting chip, and the photoelectric conversion chip.

2. The packaging structure of the multi-channel optical coupling device as described in claim 1, characterized in that, The height of the first shielding structure relative to the base plate is not lower than the height of the first light-emitting chip relative to the base plate; the lead frame is disposed on the base plate.

3. The packaging structure of the multi-channel optical coupling device as described in claim 2, characterized in that, The second side lead frame of the first base island is bent to form a fourth shielding structure, and the first shielding structure and the fourth shielding structure are arranged parallel to each other.

4. The packaging structure of the multi-channel optical coupling device as described in claim 3, characterized in that, The height of the first shielding structure is equal to the height of the fourth shielding structure.

5. The packaging structure of the multi-channel optical coupling device as described in claim 1, characterized in that, The height of the second shielding structure relative to the base plate is not lower than the height of the second light-emitting chip relative to the base plate; the lead frame is disposed on the base plate.

6. The packaging structure of the multi-channel optical coupling device as described in claim 5, characterized in that, The first side lead frame of the second base island is bent to form a fifth shielding structure, and the second shielding structure is arranged parallel to the fifth shielding structure.

7. The packaging structure of the multi-channel optical coupling device as described in claim 6, characterized in that, The height of the second shielding structure is equal to the height of the fifth shielding structure.

8. The packaging structure of the multi-channel optical coupling device as described in claim 1, characterized in that, The height of the third shielding structure relative to the base plate is not lower than the height of the first photoelectric conversion chip relative to the base plate; the lead frame is disposed on the base plate.

9. The packaging structure of the multi-channel optical coupling device as described in claim 8, characterized in that, The first side lead frame of the third base island is bent to form a sixth shielding structure; and / or, the second side lead frame of the third base island is bent to form a seventh shielding structure; the sixth shielding structure is arranged parallel to the third shielding structure, and the seventh shielding structure is arranged parallel to the third shielding structure.

10. The packaging structure of the multi-channel optical coupling device as described in claim 1, characterized in that, Also includes: The eighth shielding structure is disposed between the first optical path and the second optical path.

11. The packaging structure of the multi-channel optical coupling device as described in claim 10, characterized in that, The eighth shielding structure is formed of black opaque resin.

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