Optical modules and communication equipment

Abstract

The present invention discloses an optical module and communication equipment, wherein the optical module includes a substrate, an electric chip, a high-speed signal line and a capacitor, wherein the electric chip, the high-speed signal line and the capacitor are arranged on the substrate, the capacitor is connected between the electric chip and the high-speed signal line, the capacitor includes a first electrode plate and a second electrode plate, the first electrode plate is connected to the corresponding pad of the electric chip through a signal bonding wire, and the second electrode plate is connected to the high-speed signal line. Since the electric chip is directly connected to the capacitor through a bonding wire, and the capacitor is then connected to the high-speed signal line, rather than being connected to the high-speed signal line through a bonding wire and the capacitor is arranged in the middle of the path of the high-speed signal line, the impedance discontinuity point on the high-speed signal transmission path is reduced, and the integrity of the high-speed signal is improved.

Description

Technical Field

[0001] The present invention relates to the field of optical communication technology, and in particular to an optical module and communication equipment. Background Art

[0002] With the rapid development of modern fiber-optic communications, the optical transmission rate is increasing rapidly. Especially under the demand of 5G systems, the signal rate of optical devices is getting higher and higher, and at the same time, the optical devices are required to have lower power consumption and lower prices. Therefore, optical modules with COB (CHIP ON BOARD) structure have become popular. The characteristic of COB optical module structure is simplicity. All optical and electrical components are placed on the substrate (the substrate can be a circuit board or a metal plate). This saves the box and process of encapsulating OSA, greatly simplifying the structure. However, the overly simple structure brings new problems. No matter what the structure is, there is a transmission between high-speed electrical signals and electrical chips inside the optical module, and gold wire bonding (commonly known as gold wire bonding) is often used to build high-speed electrical signals. For example Figure 2 This is an application of gold wire bonding. With the increase of modern communication speed, high-speed lines for signal transmission have higher and higher signal integrity requirements, that is, the requirement for complete and error-free signal transmission. For high-speed electrical signals to achieve this, the signal transmission path must have impedance continuity and consistency. Gold wires, as connecting parts, are often the place where impedance continuity and consistency are destroyed. The length of gold wires has a great impact on impedance discontinuity, so it is usually required that the gold wires on high-speed lines be as short as possible. Please refer to Figure 1 and Figure 2 , which are respectively the traditional BOX packaging structure and the COB structure. It can be seen that in the BOX packaging structure, due to the step structure 101 inside the BOX, the height of the electrical chip 102 and the gold wire pad 103 can be basically flush, so that the length of the gold wire 104 can be extremely short; while in the COB structure (taking the substrate as the circuit board 200 as an example), the wire pad 203 is on the surface of the circuit board 200, and the chip 202 is also attached to the circuit board 200, so that the wire pad 205 on the chip 202 has a height difference with the wire pad 203 on the circuit board 200. Due to the process characteristics of the gold wire 204, this height difference is bound to increase the length of the gold wire 204, which in turn affects the impedance continuity of the high-speed line and causes signal integrity problems. In terms of the overall performance of the optical module, it exhibits poor eye diagrams and reduced sensitivity. Figure 2 In the high-speed signal line path of the optical module with a typical COB structure shown, both sides of the bonding wire 204 and both sides of the capacitor 206 are locations where impedance discontinuities are generated, which will endanger signal integrity. Summary of the invention

[0003] The object of the present invention is to provide an optical module capable of reducing impedance discontinuities on a high-speed signal transmission path and improving the integrity of the high-speed signal.

[0004] Another object of the present invention is to provide a communication device that can reduce impedance discontinuities on a high-speed signal transmission path and improve the integrity of the high-speed signal.

[0005] To achieve the above-mentioned purpose, the present invention provides an optical module, including a substrate, an electrical chip, a high-speed signal line and a capacitor, wherein the electrical chip, the high-speed signal line and the capacitor are arranged on the substrate, and the capacitor is connected between the electrical chip and the high-speed signal line. The capacitor includes a first electrode plate and a second electrode plate, wherein the first electrode plate is connected to a corresponding pad of the electrical chip through a signal bonding wire, and the second electrode plate is connected to the high-speed signal line.

[0006] Preferably, two capacitor pads corresponding to the capacitor are provided on the substrate, one of the two capacitor pads is connected to the high-speed signal line, and the first electrode plate and the second electrode plate of the capacitor are respectively welded to the two capacitor pads.

[0007] Preferably, a capacitor pad corresponding to the capacitor and connected to the high-speed signal line is provided on the substrate, the second electrode plate of the capacitor is welded on the capacitor pad, and the first electrode plate of the capacitor faces upward.

[0008] Preferably, the first electrode plate of the capacitor is arranged close to the electric chip.

[0009] Preferably, the signal bonding wire is bonded to the upper surface of the first electrode plate of the capacitor.

[0010] Preferably, the optical module is a COB optical module.

[0011] Preferably, the end of the high-speed signal line opposite to the capacitor is connected to an optical chip or a connector.

[0012] Preferably, a metal ground is also provided on the substrate, and the electrical chip is bonded to the metal ground via a ground bonding wire.

[0013] To achieve the above another objective, the present invention provides a communication device, comprising the above optical module.

[0014] Compared with the prior art, the capacitor of the optical module of the present invention is connected between the electric chip and the high-speed signal line, the first plate of the capacitor is connected to the pad of the electric chip through the signal bonding wire, and the second plate of the capacitor is connected to the high-speed signal line. That is to say, in the present invention, the electric chip is directly connected to the capacitor through the bonding wire, and the capacitor is then connected to the high-speed signal line, rather than being connected to the high-speed signal line through the bonding wire and arranging the capacitor in the middle of the path of the high-speed signal line, thereby reducing the impedance discontinuity points on the high-speed signal transmission path and improving the integrity of the high-speed signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The present invention is a three-dimensional structural schematic diagram of an optical module with an existing BOX packaging structure.

[0016] Figure 2 The present invention is a three-dimensional structural schematic diagram of an optical module with an existing COB packaging structure.

[0017] Figure 3 It is a schematic diagram of the three-dimensional structure of the optical module according to an embodiment of the present invention.

[0018] Figure 4 yes Figure 3 Enlarged schematic diagram of part A in the middle.

[0019] Figure 5 It is a schematic diagram of the three-dimensional structure of an optical module according to another embodiment of the present invention.

[0020] Figure 6 yes Figure 5 Enlarged schematic diagram of part B in the middle. DETAILED DESCRIPTION

[0021] In order to explain the technical content and structural features of the present invention in detail, further description will be given below in combination with the implementation modes and the accompanying drawings.

[0022] See also Figures 3 to 6 The present invention discloses an optical module, including a substrate 1, an electric chip 2, a high-speed signal line 3 and a capacitor 4 / 5, wherein the electric chip 2, the high-speed signal line 3 and the capacitor 4 / 5 are arranged on the substrate 1, and the capacitor 4 / 5 is connected between the electric chip 2 and the high-speed signal line 3, and the capacitor 4 / 5 includes a first electrode 41 / 51 and a second electrode 42 / 52, wherein the first electrode 41 / 51 is connected to the corresponding pad 21 of the electric chip 2 through a signal bonding wire 6, and the second electrode 42 / 52 is connected to the high-speed signal line 3. Generally speaking, the signal bonding wire 6 is bonded to the upper surface of the first electrode 41 / 51, but is not limited thereto. In the example shown in the accompanying drawings, the optical module includes two high-speed signal lines 3, and capacitors 4 / 5 are respectively connected between the two high-speed signal lines 3 and the corresponding pads 21 of the electric chip 2. In addition, the "optical module" here can be a COB optical module, an optical module with a BOX packaging structure, etc., which is not limited here.

[0023] The electric chip 2 of the optical module of the present invention is directly connected to the capacitor 4 / 5 through the bonding wire 6, and the capacitor 4 / 5 is then connected to the high-speed signal line 3, rather than being connected to the high-speed signal line 3 through the bonding wire 6 and arranging the capacitor 4 / 5 in the middle section of the path of the high-speed signal line 3 (equivalent to removing a section of the high-speed signal line 3 between the capacitor 4 / 5 and the signal bonding wire 6), thereby reducing the impedance discontinuity points on the high-speed signal transmission path and improving the integrity of the high-speed signal.

[0024] See also Figure 3 and Figure 4 In some embodiments, two capacitor pads 7 corresponding to the capacitor 4 are provided on the substrate 1, one of the two capacitor pads 7 is connected to the high-speed signal line 3, and the first electrode plate 41 and the second electrode plate 42 of the capacitor 4 are respectively welded on the two capacitor pads 7. Figure 5 In the example shown, since capacitors 4 are respectively connected between the two high-speed signal lines 3 and the electrical chip 2 , two capacitor pads 7 are correspondingly provided on the substrate 1 for each of the two capacitors 4 .

[0025] See also Figure 5 and Figure 6 In other embodiments, a capacitor pad 8 corresponding to the capacitor 5 and connected to the high-speed signal line 3 is provided on the substrate 1, the second electrode 52 of the capacitor 5 is welded on the capacitor pad 8, and the first electrode 51 of the capacitor 5 faces upward. Figure 6 In the example shown, since capacitors 5 are respectively connected between the two high-speed signal lines 3 and the electrical chip 2 , a capacitor pad 8 is correspondingly provided on the substrate 1 for each of the two capacitors 5 .

[0026] See also Figures 3 to 6 As a preferred embodiment, the first plate 41 / 51 of the capacitor 4 / 5 is arranged close to the electric chip 2. Generally speaking, there is a small gap between the capacitor 4 / 5 and the electric chip 2 to avoid mutual influence. Of course, it is not ruled out that the capacitor 4 / 5 and the electric chip 2 are in contact with each other. As long as the influence between the capacitor 4 / 5 and the electric chip 2 can be controlled, they can be as close as possible. Since the first plate 41 / 51 of the capacitor 4 / 5 is arranged close to the electric chip 2, and the capacitor 4 / 5 itself has a certain height, when the corresponding pad 21 of the electric chip 2 and the first plate 41 / 51 of the capacitor 4 / 5 are connected by the signal bonding wire 6, the bonding position of the signal bonding wire 6 on the first plate 41 / 51 can have a certain height relative to the substrate 1, which is conducive to reducing the height difference between the corresponding pad 21 of the electric chip 2 and the bonding position on the first plate 41 / 51, thereby shortening the length of the signal bonding wire 6. Generally speaking, the signal bonding wire 6 is bonded to the upper surface of the first electrode plate 41 / 51 of the capacitor 4 / 5 to facilitate the bonding operation of the signal bonding wire 6 and reduce the height difference of the bonding wire, but not limited thereto.

[0027] Specifically, the optical module is a COB optical module, but is not limited thereto.

[0028] See also Figure 3 and Figure 5 In some embodiments, the end of the high-speed signal line 3 opposite to the capacitor 4 / 5 is connected to an optical chip (not shown) or a connector (not shown). In the specific example shown in the accompanying drawings, the end of the high-speed signal line 3 opposite to the capacitor 4 / 5 is connected to a gold finger 9 to connect to the connector through the gold finger 9.

[0029] See also Figures 3 to 6 In some embodiments, a metal ground 10 is further provided on the substrate 1 , and the electrical chip 2 is bonded to the metal ground 10 via a ground bonding wire 11 .

[0030] Please combine Figures 3 to 6 The present invention also discloses a communication device, comprising the optical module as described above.

[0031] In summary, the capacitor 4 / 5 of the optical module of the present invention is connected between the electric chip 2 and the high-speed signal line 3, the first plate 41 / 51 of the capacitor 4 / 5 is connected to the pad 21 of the electric chip 2 through the signal bonding wire 6, and the second plate 42 / 52 of the capacitor 4 / 5 is connected to the high-speed signal line 3. That is to say, in the present invention, the electric chip 2 is directly connected to the capacitor 4 / 5 through the bonding wire 6, and the capacitor 4 / 5 is then connected to the high-speed signal line 3, rather than being connected to the high-speed signal line 3 through the bonding wire 6 and arranging the capacitor 4 / 5 in the middle of the path of the high-speed signal line 3, thereby reducing the impedance discontinuity points on the high-speed signal transmission path and improving the integrity of the high-speed signal. Moreover, the implementation method of the present invention is simple and easy to implement.

[0032] The above disclosure is only a preferred embodiment of the present invention, which cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are all within the scope of the present invention.

Claims

1. An optical module, characterized in that: The device comprises a substrate, an electric chip, a high-speed signal line and a capacitor, wherein the electric chip, the high-speed signal line and the capacitor are arranged on the substrate, the capacitor is connected between the electric chip and the high-speed signal line, the capacitor comprises a first electrode plate and a second electrode plate, the first electrode plate is connected to a corresponding pad of the electric chip through a signal bonding wire, and the second electrode plate is connected to the high-speed signal line; The substrate is provided with two capacitor pads corresponding to the capacitor, one of the two capacitor pads is connected to the high-speed signal line, the first electrode plate and the second electrode plate of the capacitor are respectively welded on the two capacitor pads, the first electrode plate of the capacitor is arranged close to the electric chip, and the signal bonding wire is bonded to the upper surface of the first electrode plate of the capacitor; or A capacitor pad corresponding to the capacitor and connected to the high-speed signal line is provided on the substrate, the second electrode plate of the capacitor is welded on the capacitor pad, the first electrode plate of the capacitor faces upward, the first electrode plate of the capacitor is arranged close to the electrical chip, and the signal bonding wire is bonded to the upper surface of the first electrode plate of the capacitor.

2. The optical module according to claim 1, wherein: The optical module is a COB optical module.

3. The optical module according to claim 1, wherein: An end of the high-speed signal line opposite to the capacitor is connected to an optical chip or a connector.

4. The optical module according to claim 1, wherein: A metal ground is also provided on the substrate, and the electric chip is bonded to the metal ground via a ground bonding wire.

5. A communication device, characterized in that: The optical module comprises the optical module as claimed in any one of claims 1 to 4.

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