High-speed substrate for electro-absorption modulator

Abstract

The utility model relates to a high-speed substrate for an electro-absorption modulator, which comprises a composite substrate, a radio frequency electrode is arranged on one side above the composite substrate, and the radio frequency electrode is connected with an electrode of the electro-absorption modulator through a gold wire; a resistance region is arranged on the other side above the composite substrate, and the resistance region comprises a first lead region and at least one resistance unit; wherein each resistor unit comprises a thin-film resistor and a second lead area; the resistor units are connected end to end, and the thin-film resistor of the resistor unit located in the head area is connected with the first lead area. According to the utility model, through the reasonable layout of the radio frequency electrode and the resistance region, various matching resistors required by the electro-absorption modulator can be simply and efficiently met, and the cost and period of product development are obviously reduced.

Description

Technical Field

[0001] This utility model relates to the field of laser technology, and in particular to a high-speed substrate for an electroabsorption modulator. Background Technology

[0002] With the rapid development of global optical communication and the increasing demand for transmission bandwidth from data centers and artificial intelligence, communication equipment places increasingly higher demands on optical emission chips, especially on the performance and integration of laser chips. To adapt to this trend, traditional single-chip lasers (such as DFB lasers) are transitioning to EML laser chips that integrate two functions. EML laser chips, by integrating an electroabsorption modulator (EAM) with the laser chip on the same chip, achieve higher data transmission rates, lower power consumption, and smaller size, showing great promise for future applications.

[0003] Integrated chips need to be multifunctionally integrated according to the requirements of communication equipment to adapt to the needs of optical communication development. At the same time, the packaging process for multifunctional integrated optical transmitter chips requires consideration of numerous parameters, making packaging more complex. To meet the packaging requirements of different integrated chips or different models of the same type of chip, researchers have begun to focus on and study the compatibility of optical transmitter chip packaging accessories to save costs and simplify the packaging forms of various integrated chips. However, current matching resistor design methods often require separate design for each different specification of electro-absorption modulator, increasing the complexity and cost of production and testing. Furthermore, fixed resistor matching methods lack flexibility and are difficult to cope with diverse product demands and market changes.

[0004] Therefore, there is a need for a high-speed substrate for electroabsorption modulators that can be compatible with multiple types of electroabsorption modulators on the same high-speed substrate, and can simply and efficiently meet the requirements of various matching resistors of different specifications required by electroabsorption modulators. Utility Model Content

[0005] In view of this, it is necessary to provide a high-speed substrate for electroabsorption modulators to solve the technical problems in the prior art that require the design of a separate high-speed substrate for each electroabsorption modulator of different specifications, making it impossible to be compatible with multiple types of electroabsorption modulators through a single high-speed substrate, resulting in poor packaging versatility and increased complexity and cost of production and testing.

[0006] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:

[0007] This invention provides a high-speed substrate for an electro-absorption modulator, comprising a composite substrate. A radio frequency (RF) electrode is disposed on one side of the composite substrate, and the RF electrode is connected to the electrode of the electro-absorption modulator via gold wires. A resistive region is disposed on the other side of the composite substrate, the resistive region including a first lead region and at least one resistive unit. Each resistive unit includes a thin-film resistor and a second lead region. The resistive units are connected end-to-end, and the thin-film resistor of the resistive unit located in the first region is connected to the first lead region.

[0008] Furthermore, the composite substrate has a layered structure, with aluminum nitride ceramic as the base layer, and tungsten and gold layers stacked sequentially on the base layer.

[0009] Furthermore, the composite substrate has the following dimensions: length 2000 micrometers, width 1800 micrometers, and thickness 300 micrometers.

[0010] Furthermore, the distance between the outer edge of the radio frequency electrode and the edge of the composite substrate is 200 micrometers, and the total width of the radio frequency electrode is 150 micrometers.

[0011] Furthermore, the dimensions of the first lead region are: 250 micrometers in length and 150 micrometers in width.

[0012] Furthermore, the dimensions of the second lead region are: 250 micrometers in length and 100 micrometers in width.

[0013] Furthermore, the dimensions of the thin-film resistor are: 200 micrometers in length and 100 micrometers in width.

[0014] Furthermore, the thin-film resistor is a tantalum nitride thin-film resistor with a resistance of 1-10 ohms.

[0015] Furthermore, the distance between the outer edge of the resistive region and the edge of the composite substrate is 150 micrometers, and the dimensions are: 1250 micrometers in length and 350 micrometers in width.

[0016] Furthermore, the first pad in the first lead area for gold wire connection with the electrode of the absorption modulator, the second pad for gold wire connection between the radio frequency electrode and the electrode of the absorption modulator, and the electrode of the absorption modulator are arranged on the same straight line.

[0017] Compared with existing technologies, the advantages of this invention include: Through a reasonable layout of the resistor and lead areas, the same high-speed substrate can be compatible with various EAM specifications, and can easily and efficiently meet the various matching resistor requirements of electro-absorption modulators, making the packaging more universal. Compared to a matching resistor with a single resistance value, it effectively reduces the types of high-speed substrates that can be designed and manufactured, avoids the cumbersome steps of designing matching resistors individually for each different specification of electro-absorption modulator, simplifies the production process, and improves the efficiency and accuracy of testing. Attached Figure Description

[0018] Figure 1 A schematic diagram of one embodiment of a high-speed substrate for an electroabsorption modulator provided by this utility model;

[0019] Figure 2 A schematic diagram of the hierarchical structure of the laser provided by this utility model during the manufacturing process;

[0020] In the figure: 1-composite substrate, 2-RF electrode, 3-first lead region, 4-thin film resistor, 5-second lead region, 6-resistance region, 7-electro-absorption modulator, 8-electrode of electro-absorption modulator. Detailed Implementation

[0021] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0022] In the description of this application, "multiple" means two or more, unless otherwise expressly and specifically defined.

[0023] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the present invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0024] This invention provides a high-speed substrate for an electroabsorption modulator. Please refer to [link / reference]. Figure 1The high-speed substrate includes a composite substrate 1. An RF electrode 2 is disposed on one side of the composite substrate 1, and the RF electrode 2 is connected to the electrode of an electro-absorption modulator via gold wires. A resistor region 6 is disposed on the other side of the composite substrate 1. The resistor region includes a first lead region 3 and at least one resistor unit. Each resistor unit includes a thin-film resistor 4 and a second lead region 5. The resistor units are connected end-to-end, and the thin-film resistor 4 of the resistor unit located in the first region is connected to the first lead region 3. When the number of resistor units is greater than two, the first lead region 3 is connected to the first thin-film resistor 4. Multiple thin-film resistors 4 and multiple second lead regions 5 in different resistor units are alternately arranged, meaning that a second lead region 5 is disposed between two adjacent thin-film resistors 4.

[0025] This invention provides a high-speed substrate for electro-absorption modulators. Through a rational layout of the resistor and lead areas, an adjustable resistor region is designed. This layout not only facilitates signal conditioning but also ensures more uniform current distribution, reduces unnecessary electromagnetic radiation, and enhances the anti-interference capability of the electro-absorption modulator during high-speed operation. It also provides flexible resistor matching for different EAMs (Electronic Amplifiers). This avoids the cumbersome process of designing individual matching resistors for each electro-absorption modulator, simplifies the production process, and improves testing efficiency and accuracy. It meets the needs of different electro-absorption modulators with varying parallel matching resistor values, and can simply and efficiently meet the various matching resistor requirements of electro-absorption modulators. Compared to a single-value matching resistor, it effectively reduces the design and processing types of high-speed substrates, significantly lowering manufacturing costs.

[0026] In a preferred embodiment, the composite substrate has a layered structure, with aluminum nitride ceramic as the base layer, and titanium tungsten layer and gold layer stacked sequentially on the base layer.

[0027] Specifically, the thicknesses of the titanium-tungsten layer and the gold layer are 30 nm and 150 micrometers, respectively, covering the front, back, and side surfaces of the composite substrate.

[0028] Using aluminum nitride, a ceramic material with high thermal conductivity, as the base layer effectively aids in heat dissipation. For electronic devices (such as electro-absorption modulators), high thermal conductivity improves operational stability and extends lifespan, preventing performance degradation or damage due to excessive temperature. The titanium-tungsten layer primarily promotes a good bond between titanium and the aluminum nitride ceramic, enhancing the adhesion of metal layers (such as gold layers) to the composite substrate and preventing gold layer detachment or separation. The gold layer mainly achieves good electrical conductivity, especially in high-speed and high-frequency signal transmission, providing low-resistance electrical connections and reducing signal loss and interference.

[0029] In a preferred embodiment, the composite substrate has the following dimensions: 2000 micrometers in length, 1800 micrometers in width, and 300 micrometers in thickness. This size design meets the space requirements of specific devices while providing sufficient area for electrical connections and heat dissipation. The 300-micrometer thickness ensures structural strength without being excessively thick or heavy, thus minimizing impact on the overall volume and weight.

[0030] In a preferred embodiment, an RF electrode 2 is fabricated in a designated area of ​​the composite substrate 1 using photolithography and etching techniques. The distance between the outer edge of the RF electrode 2 and the edge of the composite substrate 1 is 200 micrometers, and the total width of the RF electrode 2 is 150 micrometers. This arrangement aims to minimize the connection length between the RF electrode 2 and the electrode 8 of the electroabsorption modulator, thereby reducing RF signal loss. Figure 2 As shown, Figure 2 The diagram shows the electroabsorption modulator with the electrodes connected by wires. The radio frequency electrode 2 is connected to the electrode 8 of the electroabsorption modulator by gold wire. The radio frequency electrode 2 is used to introduce radio frequency signals into the electrode 8 of the electroabsorption modulator.

[0031] In a preferred embodiment, multiple lead regions with adjustable series resistance are fabricated in the resistive region using deposition, photolithography, and etching techniques. These lead regions are divided into a first lead region 3 and a second lead region 5. The first lead region has dimensions of 250 micrometers in length and 150 micrometers in width. Since the first lead region 3 needs to provide a first pad for connection to the electrode of the absorption modulator, its width is larger than that of the second lead region 5, which helps ensure a reliable connection to the gold wire.

[0032] The dimensions of the second lead region 5 are: 250 micrometers in length and 100 micrometers in width. The smaller width helps to reduce the impact of excessive current density, thereby optimizing power consumption and system stability.

[0033] In a preferred embodiment, the thin-film resistor 4 has the following dimensions: 200 micrometers in length and 100 micrometers in width.

[0034] In a preferred embodiment, the thin-film resistor is a tantalum nitride thin-film resistor with a resistance of 1-10 ohms.

[0035] In some embodiments, each thin-film resistor is 10 ohms, and five thin-film resistors are connected in series; the thickness of the thin-film resistor 4 is set according to the actual required resistance value; the electrode 8 of the electroabsorption modulator is connected to the first lead area 3 of the resistor area 6 through gold wire, and multiple thin-film resistors 4 are selected according to the matching resistance value required by the different point absorption modulator 7, or the first lead area 3 is directly connected to ground.

[0036] Compared to a matching resistor with a fixed resistance value, the high-speed substrate of this invention, through the design and fabrication of an adjustable resistance structure, prepares a titanium-tungsten layer and a gold layer on a composite substrate; radio frequency electrodes are fabricated in designated areas using photolithography and etching techniques; and adjustable series resistors are fabricated in the resistive region using deposition, photolithography, and etching techniques. This can meet the needs of different electroabsorption modulators with varying parallel matching resistor values, effectively reducing the types of high-speed substrate designs and fabrications, and significantly lowering costs.

[0037] In a preferred embodiment, the distance between the outer edge of the resistive region 6 and the edge of the composite substrate 1 is 150 micrometers, and the dimensions are: 1250 micrometers in length and 350 micrometers in width.

[0038] In a preferred embodiment, the first pad in the first lead area 3 for gold wire connection with the electrode 8 of the absorption modulator, the second pad of the radio frequency electrode 2 for gold wire connection with the electrode 8 of the absorption modulator, and the electrode 8 of the absorption modulator are arranged on the same straight line.

[0039] By aligning the first pad, the second pad, and the electrodes of the absorption modulator in a straight line, this layout optimizes the signal transmission path, simplifies the manufacturing process, improves soldering reliability, reduces the risk of electrical mismatch, and decreases circuit complexity, ultimately enhancing system performance, stability, and maintainability. This is particularly important for high-precision RF circuits, ensuring efficient and stable operation.

[0040] In a specific embodiment, the manufacturing steps of the high-speed substrate provided by this utility model are as follows:

[0041] Step 1: Prepare a 30nm titanium-tungsten layer and a 150μm gold layer on a composite substrate 1, covering the front, back and sides. The dimensions of the composite substrate 1 are 2000μm long, 1800μm wide and 300μm thick.

[0042] Step 2: Fabricate RF electrode 2 in a designated area of ​​composite substrate 1 using photolithography and etching techniques; RF electrode 2 is 150 micrometers wide, 200 micrometers away from the edge of composite substrate 1, and is placed parallel to each other. RF electrode 2 is designed on the electrode side of electroabsorption modulator 7; the purpose is to minimize the connection length between RF electrode 2 and the electrode 8 of electroabsorption modulator to reduce RF signal loss; RF signal is introduced into the modulator electrode 8 by connecting RF electrode 2 and the electrode 8 of electroabsorption modulator with a gold wire.

[0043] Step 3: Using deposition, photolithography, and etching techniques, an adjustable series resistor lead area is fabricated in resistor region 6. The size of the first lead area 3 is 250 μm * 150 μm, the size of the second lead area 5 is 250 μm * 100 μm, the size of each thin film resistor 4 is 200 μm * 100 μm, and each thin film resistor 4 is 150 μm away from the edge of resistor region 6, and is set parallel to the edge. The size of resistor region 6 is 350 μm * 1250 μm.

[0044] The thin-film resistor 4 is a tantalum nitride thin-film resistor, each with a resistance of 10 ohms, and five thin-film resistors are connected in series. The thickness of the thin-film resistor 4 is set according to the actual required resistance value. The electrode 8 of the electroabsorption modulator is connected to the first lead area 3 through a gold wire. The thin-film resistor is selected according to the matching resistance value required by different modulators, or the first lead area 3 is directly connected to ground.

[0045] In summary, this invention provides a high-speed substrate for electro-absorption modulators. Through a rational layout of the resistor and lead areas, the same high-speed substrate can be compatible with various EAM specifications, and can easily and efficiently meet the various matching resistor requirements of electro-absorption modulators, making the packaging more versatile. Compared to a single-value matching resistor, this effectively reduces the design and fabrication types of high-speed substrates, avoids the cumbersome steps of designing matching resistors individually for each different specification of electro-absorption modulator, simplifies the production process, and improves testing efficiency and accuracy.

[0046] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present utility model should be included within the protection scope of the present utility model.

Claims

1. A high-speed substrate for an electroabsorption modulator, characterized in that, The device includes a composite substrate, on one side of which a radio frequency electrode is disposed, and the radio frequency electrode is connected to the electrode of an electroabsorption modulator via gold wire; on the other side of which a resistive region is disposed, the resistive region includes a first lead region and at least one resistive unit; wherein, each resistive unit includes a thin film resistor and a second lead region; each of the resistive units is connected end to end, and the thin film resistor of the resistive unit located in the first region is connected to the first lead region.

2. The high-speed substrate for an electroabsorption modulator according to claim 1, characterized in that, The composite substrate has a layered structure, with aluminum nitride ceramic as the base layer, and titanium tungsten layer and gold layer stacked sequentially on the base layer.

3. The high-speed substrate for an electroabsorption modulator according to claim 1, characterized in that, The composite substrate has the following dimensions: length 2000 micrometers, width 1800 micrometers, and thickness 300 micrometers.

4. The high-speed substrate for an electroabsorption modulator according to claim 1, characterized in that, The distance between the outer edge of the radio frequency electrode and the edge of the composite substrate is 200 micrometers, and the total width of the radio frequency electrode is 150 micrometers.

5. The high-speed substrate for an electroabsorption modulator according to claim 1, characterized in that, The dimensions of the first lead region are: 250 micrometers in length and 150 micrometers in width.

6. The high-speed substrate for an electroabsorption modulator according to claim 1, characterized in that, The dimensions of the second lead region are: 250 micrometers in length and 100 micrometers in width.

7. The high-speed substrate for an electroabsorption modulator according to claim 1, characterized in that, The dimensions of the thin-film resistor are: 200 micrometers in length and 100 micrometers in width.

8. The high-speed substrate for an electroabsorption modulator according to claim 1, characterized in that, The thin-film resistor is a tantalum nitride thin-film resistor with a resistance of 1-10 ohms.

9. The high-speed substrate for an electroabsorption modulator according to claim 1, characterized in that, The distance between the outer edge of the resistive region and the edge of the composite substrate is 150 micrometers, and the dimensions are: 1250 micrometers in length and 350 micrometers in width.

10. The high-speed substrate for an electroabsorption modulator according to claim 1, characterized in that, The first pad in the first lead area for gold wire connection with the electrode of the absorption modulator, the second pad for gold wire connection between the radio frequency electrode and the electrode of the absorption modulator, and the electrode of the absorption modulator are arranged on the same straight line.

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