EML substrate for optical module, EML COC assembly and optical module

Abstract

The utility model discloses an EML substrate used for an optical module, an EML COC assembly and the optical module, the EML substrate used for the optical module comprises a substrate body, the substrate body is provided with a common grounding area, the surface of the common grounding area is provided with a gold-tin solder area used for fixedly connecting an EML laser, and the surface of the common grounding area is provided with a copper-tin solder area used for fixedly connecting the copper-tin solder area. The substrate body is also provided with a high-frequency signal input line and a high-frequency signal impedance adjusting line which are independent from each other. When the EML substrate needs high high-frequency signal input line impedance, the high-frequency signal input line and the high-frequency signal impedance adjusting line do not need to be connected through a gold bonding wire, and when the EML substrate needs low high-frequency signal input line impedance, the high-frequency signal input line and the high-frequency signal impedance adjusting line are connected in parallel through the gold bonding wire. The EML substrate may have at least two impedances. By adopting the scheme of the EML substrate, even if the EML substrate is manufactured, the impedance of the high-frequency signal input line of the EML substrate can still be changed.

Description

Technical Field

[0001] The utility model relates to the technical field of optical communication, in particular to an EML substrate for an optical module, an EML COC component and an optical module. Background Art

[0002] At present, 400G and 800G optical modules generally use EML lasers as light sources. EML lasers are usually eutectic on an EML substrate (the area where the EML laser contacts the EML substrate is plated with gold-tin alloy solder). Figure 1 This is a schematic diagram of the EML laser eutectic onto the EML substrate. As the speed of optical modules increases to single-wavelength 100G and single-wavelength 200G, the bandwidth requirements for EML substrates are getting higher and higher. How to reduce the loss on the high-frequency signal transmission link and improve the transmission quality of high-frequency signals is becoming more and more important.

[0003] Figure 1 This is a typical schematic diagram of an EML substrate with an EML laser attached. Figure 1 The impedance of the high-frequency signal input line is designed to a fixed value (such as 50 ohms) according to actual needs. Due to the differences in the impedance of the high-frequency signal transmission link in actual applications, such as the impedance of the PCBA high-frequency line and the impedance of the EML laser, the impedance does not match the impedance of the high-frequency signal input line of the EML substrate, thereby increasing the loss of the high-frequency signal and causing the high-frequency signal transmission quality to become very poor, thus affecting the performance of the product. Since the EML substrate is designed according to the designed value, there is no way to change the impedance once it is manufactured. If there is a mismatch, the EML substrate can only be redesigned. Utility Model Content

[0004] The utility model aims to solve at least one of the technical problems existing in the prior art, and proposes an EML substrate for an optical module, an EML COC component and an optical module.

[0005] The technical solution of the utility model is implemented as follows: the utility model discloses an EML substrate for an optical module, including a substrate body, a common grounding area is provided on the substrate body, a solder area for fixing and connecting the EML laser is provided on the surface of the common grounding area, and independent high-frequency signal input circuits and high-frequency signal impedance adjustment circuits are also provided on the substrate body.

[0006] Furthermore, the high-frequency signal input circuit is connected in parallel with the high-frequency signal impedance adjustment circuit.

[0007] Furthermore, the high-frequency signal input circuit and the high-frequency signal impedance adjustment circuit are connected in parallel through gold-plated wires.

[0008] Furthermore, the first end of the high-frequency signal input circuit is connected to the first end of the high-frequency signal impedance adjustment circuit through at least one first gold wire, and the second end of the high-frequency signal input circuit is connected to the second end of the high-frequency signal impedance adjustment circuit through at least one second gold wire.

[0009] Furthermore, the high-frequency signal input circuit and the high-frequency signal impedance adjustment circuit are straight-line type, the length of the high-frequency signal input circuit is equal to the length of the high-frequency signal impedance adjustment circuit, the width of the high-frequency signal input circuit is greater than the width of the high-frequency signal impedance adjustment circuit, the high-frequency signal input circuit and the high-frequency signal impedance adjustment circuit are arranged side by side, and a gap is provided between the high-frequency signal input circuit and the high-frequency signal impedance adjustment circuit. Furthermore, the high-frequency signal impedance adjustment circuit is one or more.

[0010] Furthermore, the substrate body is a ceramic substrate.

[0011] The utility model also discloses an EML COC component, comprising an EML laser and the EML substrate as described above, wherein the EML laser is fixedly connected to the gold-tin solder area of ​​the EML substrate, the EML laser is connected to the laser pin pad arranged on the EML substrate through a gold wire, and the EML laser is connected to the high-frequency signal input circuit through a gold wire.

[0012] Furthermore, the EML COC component of the utility model also includes a matching resistor, which is arranged on the EML substrate, wherein one end of the matching resistor is connected to the common ground area, and the other end of the matching resistor is connected to the wire bonding pad, and the wire bonding pad is connected to the EML laser through a gold wire.

[0013] The utility model also discloses an optical module, which adopts the EML COC component as described above.

[0014] Compared with the prior art, the utility model has the following beneficial effects: due to the adoption of the EML substrate for optical modules of the utility model, when the EML substrate requires a higher high-frequency signal input line impedance, the high-frequency signal input line and the high-frequency signal impedance adjustment line do not need to be connected by gold wires, and when the EML substrate requires a lower high-frequency signal input line impedance, the high-frequency signal input line and the high-frequency signal impedance adjustment line are connected in parallel by gold wires, so that the EML substrate can have at least two impedances, such as 47 ohms and 53 ohms, or 50 ohms and 53 ohms, etc. By adopting the EML substrate solution of the utility model, the high-frequency signal input line impedance of the EML substrate can still be changed even after the EML substrate is manufactured. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of the structure of an EML substrate for an optical module provided in the related art;

[0016] Figure 2 A schematic diagram of the structure of an EML substrate for an optical module provided by an embodiment of the utility model;

[0017] Figure 3 This is a schematic diagram of the gold wire connection between the high-frequency signal input circuit and the high-frequency signal impedance adjustment circuit of the utility model.

[0018] In the accompanying drawings, 1 is the substrate body, 2 is the gold-tin solder area, 3 is the first common grounding area, 4 is the second common grounding area, 5 is the third common grounding area, 6 is the high-frequency signal input circuit, 7 is the high-frequency signal impedance adjustment circuit, 8 is the laser pin pad, 9 is the EML laser, 10 is the matching resistor, 11 is the first gold wire, 12 is the second gold wire, and 13 is the wire bonding pad. DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Embodiment 1

[0021] See also Figure 2 The embodiment of the utility model discloses an EML substrate for an optical module, including a substrate body 1, on which a common grounding area is provided, and on the surface of the common grounding area a gold-tin solder area 2 for fixing and connecting an EML laser 9 is provided, and on the substrate body 1, independent high-frequency signal input circuits 6 and high-frequency signal impedance adjustment circuits 7 are also provided.

[0022] Specifically, a gold-plated layer is provided in the common grounding area, and gold-tin solder is provided on the gold-plated layer.

[0023] The utility model adds one or more high-frequency signal impedance adjustment circuits 7 beside the high-frequency signal input circuit 6, so that an EML substrate can adapt to at least two impedances.

[0024] Further, the common grounding area includes a first common grounding area 3, a second common grounding area 4 and a third common grounding area 5, a spacing is provided between the first common grounding area 3 and the second common grounding area 4 along the first direction, the high-frequency signal input line 6 and the high-frequency signal impedance adjustment line 7 are located between the first common grounding area 3 and the second common grounding area 4, the signal paths of the high-frequency signal input line 6 and the high-frequency signal impedance adjustment line 7 extend along the second direction, the third common grounding area 5 is located at at least one end of the high-frequency signal input line 6 and the high-frequency signal impedance adjustment line 7, and a third gap is provided between the third common grounding area 5 and the high-frequency signal input line 6 and the high-frequency signal impedance adjustment line 7. The third common grounding area 5 connects the first common grounding area 3 with the second common grounding area 4.

[0025] Furthermore, the high-frequency signal input circuit 6 is close to the first common grounding area 3 and has a first gap therebetween. The high-frequency signal impedance adjustment circuit 7 is close to the second common grounding area 4 and has a second gap therebetween.

[0026] The second common grounding area 4 and the third common grounding area 5 of the present invention may be, but are not limited to, rectangular areas.

[0027] Specifically, the AuSn solder region 2 is provided on the upper surface of the first common ground region 3 (common GND).

[0028] Furthermore, the high-frequency signal input circuit 6 is connected in parallel with the high-frequency signal impedance adjustment circuit 7 .

[0029] Furthermore, the high-frequency signal input circuit 6 and the high-frequency signal impedance adjustment circuit 7 are connected in parallel via gold wires.

[0030] Furthermore, the first end of the high-frequency signal input circuit 6 is connected to the first end of the high-frequency signal impedance adjustment circuit 7 through at least one first gold wire 11, and the second end of the high-frequency signal input circuit 6 is connected to the second end of the high-frequency signal impedance adjustment circuit 7 through at least one second gold wire 12.

[0031] Furthermore, the high-frequency signal input circuit 6 and the high-frequency signal impedance adjustment circuit 7 are straight-line types, the length of the high-frequency signal input circuit 6 is equal to the length of the high-frequency signal impedance adjustment circuit 7, the width of the high-frequency signal input circuit 6 is greater than the width of the high-frequency signal impedance adjustment circuit 7, the high-frequency signal input circuit 6 and the high-frequency signal impedance adjustment circuit 7 are arranged side by side, and a gap is provided between the high-frequency signal input circuit 6 and the high-frequency signal impedance adjustment circuit 7.

[0032] Specifically, the high-frequency signal input circuit 6 and the high-frequency signal impedance adjustment circuit 7 are long rectangular strips.

[0033] Furthermore, the high-frequency signal impedance adjustment circuit 7 is one or more.

[0034] The substrate body 1 is also provided with a laser pin pad 8 , and a gap is provided between the laser pin pad 8 and the common grounding area. Specifically, a gap is provided between the laser pin pad 8 and the first common grounding area 3 .

[0035] Furthermore, the substrate body 1 is a ceramic substrate.

[0036] This embodiment adds a high-frequency signal impedance adjustment circuit 7 next to the high-frequency signal input circuit 6, so that an EML substrate can adapt to two impedances. If a 50-ohm impedance is designed according to the conventional scheme, two impedances can be designed using the scheme of the present invention, such as 47 ohms and 53 ohms, or 50 ohms and 53 ohms, etc. Figure 3 As shown, when lower impedance is required, the high-frequency signal input circuit 6 is connected to the high-frequency signal impedance adjustment circuit 7. If the gold wire is removed, the impedance will increase. Whether wire bonding is required can be determined based on actual needs.

[0037] Embodiment 2

[0038] The utility model also discloses an EML COC component, comprising an EML laser 9 and the EML substrate as described in Example 1, wherein the EML laser 9 is fixedly connected to the gold-tin solder area 2 of the EML substrate, the EML laser 9 is connected to the laser pin pad 8 arranged on the EML substrate through a gold wire, and the EML laser 9 is connected to the high-frequency signal input circuit 6 through a gold wire.

[0039] Furthermore, the EML COC component of the utility model also includes a matching resistor 10, which is arranged on the upper surface of the EML substrate. The matching resistor 10 is arranged on the EML substrate, wherein one end of the matching resistor 10 is electrically connected to the common ground area, and the other end of the matching resistor 10 is electrically connected to the wire bonding pad 13, and the wire bonding pad 13 is connected to the EML laser 9 through a gold wire.

[0040] The matching resistor 10 may be a thin film resistor, which is predetermined on the upper surface of the substrate.

[0041] Embodiment 3

[0042] The embodiment of the utility model further discloses an optical module, which adopts the EML COC component as described in the second embodiment.

[0043] When testing the optical module of the product made of EML substrate of this solution, the following tests are performed: Figure 3 and Figure 2There are two situations: gold wire punching and no gold wire punching, and then compare the performance of the two methods. If the performance is better with gold wire punching, then the same batch of products (PCBA and laser in the same batch) will adopt the gold wire punching solution. If the performance is better without gold wire punching, then the same batch of products will adopt the no gold wire punching solution.

[0044] The steps for making an optical module product using the EML board of this solution are as follows:

[0045] Eutectic the laser onto the EML substrate;

[0046] Completed the gold wire punching, pre-aging test, aging test, and post-aging test of the eutectic EML laser 9;

[0047] Attach the eutectic EML laser 9 to the device packaging shell;

[0048] Complete the mounting of other components of the optical module;

[0049] Complete the gold wire bonding and optical path coupling of the optical module;

[0050] Respectively Figure 3 The performance of the optical module is tested with and without gold wires as shown and the performance of the two cases is compared;

[0051] Decide whether to make gold wire according to the results of performance test;

[0052] Based on the performance test results, determine whether to use gold wire in the same batch or not.

[0053] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. An EML substrate for an optical module, comprising a substrate body, a common grounding area is provided on the substrate body, and a solder area for fixing and connecting an EML laser is provided on the surface of the common grounding area, characterized in that: The substrate body is also provided with a high-frequency signal input circuit and a high-frequency signal impedance adjustment circuit which are independent of each other.

2. The EML substrate according to claim 1, characterized in that: The high-frequency signal input circuit is connected in parallel with the high-frequency signal impedance adjustment circuit.

3. The EML substrate according to claim 2, characterized in that: The high-frequency signal input circuit and the high-frequency signal impedance adjustment circuit are connected in parallel through gold-plated wires.

4. The EML substrate according to claim 3, characterized in that: The first end of the high-frequency signal input circuit is connected to the first end of the high-frequency signal impedance adjustment circuit through at least one first gold wire, and the second end of the high-frequency signal input circuit is connected to the second end of the high-frequency signal impedance adjustment circuit through at least one second gold wire.

5. The EML substrate according to any one of claims 1 to 4, characterized in that: The high-frequency signal input line and the high-frequency signal impedance adjustment line are straight-line types, the length of the high-frequency signal input line is equal to the length of the high-frequency signal impedance adjustment line, the width of the high-frequency signal input line is greater than the width of the high-frequency signal impedance adjustment line, the high-frequency signal input line and the high-frequency signal impedance adjustment line are arranged side by side, and a gap is provided between the high-frequency signal input line and the high-frequency signal impedance adjustment line.

6. The EML substrate according to any one of claims 1 to 4, characterized in that: The number of the high-frequency signal impedance adjustment circuits is one or more.

7. The EML substrate according to claim 1, characterized in that: The substrate body is a ceramic substrate.

8. An EML COC assembly, characterized in that: It comprises an EML laser and an EML substrate as described in any one of claims 1 to 7, wherein the EML laser is fixedly connected to a gold-tin solder area of ​​the EML substrate, the EML laser is connected to a laser pin pad arranged on the EML substrate through a gold wire, and the EML laser is connected to a high-frequency signal input circuit through a gold wire.

9. The EML COC assembly according to claim 8, characterized in that: It also includes a matching resistor, which is arranged on the EML substrate, wherein one end of the matching resistor is connected to the common grounding area, and the other end of the matching resistor is connected to the wire bonding pad, and the wire bonding pad is connected to the EML laser through a gold wire.

10. An optical module, characterized in that: An EML COC assembly as claimed in claim 8 or 9 is used.

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