An electrical interconnection component

Abstract

The present invention proposes an electrical interconnection component, including a ceramic circuit board and a main control circuit board. The front end of the ceramic circuit board extends out in a duckbill style, and cooperates with the blind groove of the main control circuit board, and is assisted by the alignment marks on it to control the position deviation of the two. The ceramic circuit board is welded on the main control circuit board, and a ground pad 1 and a signal pad 1 are provided on the ceramic circuit board. The main control circuit board is provided with a ground pad 2 of equal length and width for welding with the ground pad 1, and the main control circuit board is provided with a signal pad 2 of equal length and width for welding with the signal pad 1. The ground pad 1 is 0.6-1.0mm long and 0.25-0.35mm wide; the signal pad 1 is 0.6-1.0mm long and 0.15-0.25mm wide. The present invention improves the crosstalk, insertion loss and return loss performance of the entire product by setting the pad sizes of the ceramic circuit board and the main control circuit board.

Description

Technical Field

[0001] The present invention relates to the field of optical communication, and in particular to an electrical interconnection component. Background Art

[0002] Optical communication is the backbone and foundation of the entire communication network, with the advantages of large communication capacity, long transmission distance, low signal crosstalk, and anti-electromagnetic interference. Optical modules are optoelectronic devices that realize the functions of photoelectric conversion and electro-optical conversion during optical signal transmission. They are an important part of optical communication systems and the core components of data transmission and data interconnection.

[0003] The optical engine is an important part of the optical module. Simply put, it separates the device part of the traditional optical module and encapsulates all optical device materials on the sub-board of the optical engine. Its main function is to establish the optical system in the optical module. Silicon-based optoelectronic technology uses silicon or other materials compatible with silicon technology to develop micro-nano information functional devices with photons and electrons as carriers, and integrates them on the same silicon substrate on a large scale to form a complete new chip unit with comprehensive functions. The silicon photonic engine uses silicon photonic chips as optoelectronic modulation chips to achieve the purpose of higher speed and higher density data transmission.

[0004] Flexible materials are relatively fragile, with a large loss in production yield, and are easily damaged during use, which can easily lead to appearance and performance degradation. Flexible materials are different from the materials of the optical engine circuit board and the main control circuit board, and the material properties are quite different. Therefore, using flexible materials as the electrical connection medium for the optical engine circuit board and the main control circuit board will cause a mismatch in material properties, which is specifically reflected in the mismatch and fluctuation of link impedance, resulting in increased link insertion loss, which in turn causes the signal strength of the entire link to attenuate, affecting the signal quality. Summary of the invention

[0005] The present invention provides an electrical interconnection component, which solves the problems of poor signal quality, large signal loss and large channel crosstalk in the interconnection between the son and mother circuit boards in the prior art.

[0006] The technical solution of the present invention is implemented as follows: an electrical interconnection component, comprising a ceramic circuit board and a main control circuit board, the ceramic circuit board is welded on the main control circuit board, a ground pad 1 and a signal pad 1 are provided on the ceramic circuit board, a ground pad 2 of equal length and width for welding with the ground pad 1 is provided on the main control circuit board, a signal pad 2 of equal length and width for welding with the signal pad 1 is provided on the main control circuit board, the ground pad 1 is 0.6-1.0mm long and 0.25-0.35mm wide; the signal pad 1 is 0.6-1.0mm long and 0.15-0.25mm wide.

[0007] Furthermore, the length of the ground pad 1 is 0.8 mm and the width is 0.3 mm; the length of the signal pad 1 is 0.8 mm and the width is 0.2 mm.

[0008] Furthermore, a silicon photonic engine is installed on the ceramic circuit board, and the silicon photonic engine includes a transmitting silicon photonic chip, a laser, a lens, a transmitting optical fiber array, a receiving silicon photonic chip, a receiving optical fiber array and a transimpedance amplifier. The optical fibers of the transmitting optical fiber array and the receiving optical fiber array are connected to the same pin body, the positive and negative electrodes of the laser are connected to the ceramic circuit board through gold wires, the RF signal pads and the power pads of the transmitting silicon photonic chip are connected to the ceramic circuit board through gold wires, the RF signal pads and the power pads of the transimpedance amplifier are connected to the ceramic circuit board through gold wires, and the receiving silicon photonic chip and the transimpedance amplifier are electrically connected through gold wires.

[0009] Furthermore, after the laser starts to work and emits light, the lens couples the optical signal of the laser into the waveguide of the transmitting silicon photonic chip. After the optical signal is processed by the built-in modulator of the transmitting silicon photonic chip, it is coupled by the transmitting optical fiber array to transmit the optical signal from the optical fiber to the pin body and the external receiving component for reception. The pin body transmits the received optical signal to the receiving optical fiber array via the optical fiber. After the receiving optical fiber array is coupled with the receiving silicon photonic chip, the optical signal is amplified by a transimpedance amplifier. An isolator is provided between the lens and the transmitting silicon photonic chip to prevent reflected light from affecting the performance of the system and improve the return loss performance.

[0010] Furthermore, the front end of the ceramic circuit board extends out in a duckbill shape, the thickness of the extending portion of the front end of the ceramic circuit board is 0.3-0.4 mm, the width of the extending portion of the ceramic circuit board is 1.5-2.0 mm, and the length of the extending portion of the ceramic circuit board is 16-21 mm.

[0011] Furthermore, a blind groove is provided on the main control circuit board, and the front end protruding part of the ceramic circuit board is connected to the blind groove. The thickness of the front end protruding part of the ceramic circuit board is the same as the depth of the blind groove. The difference between the length of the blind groove and the length of the protruding part of the ceramic circuit board is between 0-0.1mm, and the width of the blind groove is 1.25-1.5mm.

[0012] Furthermore, positioning marks with plus signs are provided on the ceramic circuit board and the main control circuit board, and the plus signs include horizontal lines and vertical lines.

[0013] Furthermore, at least two plus marks are provided on the protruding part of the front end of the ceramic circuit board, at least two plus marks are provided on the left and right sides of the blind groove, and at least two plus marks are provided above the blind groove. The horizontal lines of the plus signs marked on the ceramic circuit board are aligned with the horizontal lines of the plus signs marked on the left and right sides of the blind groove to complete the horizontal position alignment of the ceramic circuit board and the main control circuit board; the vertical lines of the plus signs marked on the ceramic circuit board are aligned with the vertical lines of the plus signs marked above the blind groove to complete the vertical position alignment of the ceramic circuit board and the main control circuit board.

[0014] Furthermore, the surface of the protruding portion of the ceramic circuit board is copper-plated with a width of at least 1 mm, and a through hole is made inside the ceramic circuit board at the copper-plated position.

[0015] Furthermore, the ceramic circuit board and the main control circuit board are welded by reflow welding or laser welding.

[0016] The beneficial effects of the present invention are: the electrical interconnection component of the present invention has high integration, high material thermal conductivity, and good heat dissipation performance.

[0017] The present invention improves the crosstalk, insertion loss and return loss performance of the entire product by setting the size of the pads of the ceramic circuit board and the main control circuit board. The front end of the ceramic circuit board extends out in a duckbill style, cooperates with the blind groove of the main control circuit board, and is assisted by the alignment mark on it to control the position deviation of the two, accurately control the relative position of the pads of the ceramic circuit board and the main control circuit board, and improve the insertion loss and return loss performance of the product. By copper plating on the surface of the ceramic circuit board, the heat on the surface can be quickly transferred to the pad to achieve fast welding, and the temperature difference of all pads is very small, so that the consistency of welding can be ensured, and the cold solder joint caused by uneven welding temperature can be prevented.

[0018] By using a ceramic circuit board as a carrier board and taking advantage of the stacking characteristics of the ceramic circuit board and the ability to have a metal coating on the surface, the circuit of the silicon photonic engine can be built inside the ceramic circuit board. At the same time, the other components of the silicon photonic engine can be encapsulated on the ceramic circuit board to form a highly integrated silicon photonic engine with high integration, a small number of components, and cost savings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0020] Figure 1 A schematic diagram of the three-dimensional structure of a ceramic circuit board of a silicon light engine of an electrical interconnection component of the present invention;

[0021] Figure 2 It is a structural schematic diagram of the protruding portion of a ceramic circuit board of an electrical interconnection component of the present invention;

[0022] Figure 3 A rear view schematic diagram of a ceramic circuit board of a silicon photonic engine of an electrical interconnection component of the present invention;

[0023] Figure 4 It is a schematic diagram of the main structure of an electrical interconnection component of the present invention;

[0024] Figure 5 It is a schematic diagram of the three-dimensional structure of an electrical interconnection component of the present invention;

[0025] Figure 6 A crosstalk comparison diagram of different pad widths of an electrical interconnect component of the present invention;

[0026] Figure 7 A crosstalk comparison diagram of different pad sizes of an electrical interconnect component of the present invention;

[0027] Figure 8 This is a comparison diagram of insertion losses of different signal pad widths of an electrical interconnect component of the present invention.

[0028] Fig. 9 This is a comparison diagram of return losses of different signal pad widths of an electrical interconnect component of the present invention.

[0029] Fig.10 This is a comparison diagram of insertion losses of different signal pad sizes of an electrical interconnect component of the present invention.

[0030] Fig.11 This is a comparison diagram of return losses of different signal pad sizes of an electrical interconnect component of the present invention.

[0031] In the attached figure: 1- silicon photonic engine ceramic circuit board; 2- main control circuit board; 111- pin body; 112- optical fiber; 113- power pad; 114- ceramic circuit board; 115- receiving end silicon photonic chip; 116- transimpedance amplifier; 117- transmitting end silicon photonic chip; 118- isolator; 119- lens; 120- laser; 121- micro central processing unit; 122- transmitting end optical fiber array; 123- receiving end optical fiber array. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments 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.

[0033] like Figure 1 As shown, the silicon photonic engine ceramic circuit board of the present invention uses a ceramic circuit board 114 as a carrier, and the transmitting end includes a transmitting silicon photonic chip 117, a laser 120, a lens 119, an isolator 118, and a transmitting fiber array 122. The receiving end includes a transimpedance amplifier 116, a receiving silicon photonic chip 115, and a receiving fiber array 123. At the same time, the optical fibers of the transmitting fiber array 122 and the receiving fiber array 123 are connected to the same pin body 111. The positive and negative electrodes of the laser 120 are connected to the ceramic circuit board 114 through gold wires, and the RF signal pads and power pads of the transmitting silicon photonic chip 117 are also connected to the ceramic circuit board 114 through gold wires. Similarly, the RF signal pads and power pads of the transimpedance amplifier 116 are connected to the ceramic circuit board 114 through gold wires, and the receiving silicon photonic chip 115 and the transimpedance amplifier 116 are also circuit-connected through gold wires. Signal transmission: Transmitting end: After the laser 120 starts to work and emits light, the optical signal of the laser 120 is coupled to the waveguide of the transmitting silicon photonic chip 117 through the lens 119. After the optical signal is processed by the built-in modulator of the transmitting silicon photonic chip 117, it is coupled by the transmitting fiber array 122 to transmit the optical signal from the optical fiber 112 to the pin body 111 and the external receiving device. At the receiving end, the pin body 111 transmits the received optical signal to the receiving fiber array 123 via the optical fiber. After the receiving fiber array 123 and the receiving silicon photonic chip 115 are coupled, the optical signal is amplified by the transimpedance amplifier 116. The isolator 118 is arranged between the lens 119 and the transmitting silicon photonic chip 117. The function of the isolator 118 is to allow the forward incident linear polarized light to pass through, while preventing the reverse incident linear polarized light from passing through, so as to prevent the light reflected back on the optical path from affecting the signal quality of the input light. Four power pads 113 are arranged on the ceramic circuit board 114. A micro central processing unit 121 is mounted on the ceramic circuit board 114 to implement parameter monitoring and integrated circuit bus communication functions during the silicon photonic engine manufacturing process.

[0034] like Figure 2 As shown, the ceramic circuit board 114 of this embodiment adopts a duckbill design, the thickness of the front end extending is D1 of 0.3-0.4mm, and the width H1 of the extending part is 1.5-2.0mm, so as to make electrical connection with the main control circuit board 2. Through the 2.5D packaging process, the high-speed signal line on the surface of the ceramic circuit board is passed through the bottom of the extending part of the ceramic circuit board, and a pad design is made at the bottom of the extending part. The ceramic circuit board 114 and the main control circuit board 2 are welded together by reflow soldering or laser welding to form a complete optical module. The advantage of using this welding process is that the impedance and capacitance of the welding point can be controlled by controlling the design size of the pad, thereby reducing the circuit return loss and insertion loss caused by the welding process.

[0035] The pad sizes of the ceramic circuit board 114 and the main control circuit board 2 of the present invention are optimized to improve the crosstalk, insertion loss and return loss performance of the entire product. Figure 3 As shown, the length L4 of the ground pad is 0.6-1.0 mm, preferably 0.8 mm in this embodiment, and the width H3 is 0.25-0.35 mm, preferably 0.3 mm. The length of the signal pad is 0.6-1.0 mm, preferably 0.8 mm, and the width H4 is 0.15-0.25 mm, preferably 0.2 mm. The ground pads of the ceramic circuit board 114 and the main control circuit board 2 are of equal length and width, and the signal pads of the ceramic circuit board 114 and the main control circuit board 2 are of equal length and width, and correspond to each other.

[0036] The relative positions of the pads of the ceramic circuit board and the main control circuit board need to be precisely controlled. Different positional relationships and offsets between the pads of the ceramic circuit board and the pads of the main control circuit board will affect the electrical performance of the link and thus the performance of the entire optical module.

[0037] In order to accurately control the positional relationship between the ceramic circuit board and the main control circuit board, the method used is:

[0038] like Figure 4 As shown, first of all, in terms of visual alignment, positioning marks "+" are designed on the surface of the ceramic circuit board and the surface of the main control circuit board respectively. The alignment method is to align the horizontal direction "-" of the "+" mark on the ceramic circuit board with the horizontal direction "-" of the "+" mark on the main control circuit board, so that the "-" of the four "+" marks on the left and right sides of the horizontal direction are on the same horizontal line, and the horizontal position alignment of the ceramic circuit board and the main control circuit board is completed. Similarly, in the vertical direction, align the vertical direction "|" of the "+" mark on the ceramic circuit board with the vertical direction "|" of the "+" mark on the main control circuit board, so that the "|" of the four "+" marks on the left and right sides of the vertical direction are on the same vertical line, and the vertical position alignment of the ceramic circuit board and the main control circuit board is completed.

[0039] In terms of mechanical limiting, the protruding part of the front end of the ceramic circuit board can be used to limit the main control circuit board. A blind groove is designed on the main control circuit board. The depth D2 of the blind groove is kept consistent with the thickness D1 of the protruding part of the front end of the ceramic circuit board. In this embodiment, the thickness of the protruding part of the ceramic circuit board is 0.3mm, so the depth of the blind groove on the main control circuit board is also 0.3mm, and the width H2 of the blind groove is 1.25-1.5mm. When the ceramic circuit board is welded to the main control circuit board, the surfaces of the two can be kept flat, which is conducive to subsequent shell assembly and heat dissipation treatment.

[0040] like Figure 5As shown, an assembly tolerance of 0.05 mm is reserved on both sides of the blind groove (Y direction). In this example, the length L2 of the protruding part of the ceramic circuit board is 17.2 mm. In this embodiment, the length L1 of the other side of the ceramic circuit board is 19.5 mm, the thickness D3 is 0.7 mm, and the difference D4 between D3 and D1 is 0.4 mm. Therefore, the length L3 of the blind groove is designed to be 17.3 mm. The maximum deviation in the Y direction during welding of the ceramic circuit board is 0.05 mm. The deviation in the Y direction not exceeding 0.05 mm has no significant effect on the performance of the product.

[0041] In the welding process, in order to make the ceramic circuit board and the main control circuit board better welded, copper plating is performed within the range of 1mm on the surface width D5 of the protruding part of the ceramic circuit board, and a through hole is made inside the ceramic circuit board in this area, so that the heat on the surface can be quickly transferred to the pad to achieve fast welding, and the temperature difference of all pads is very small, thereby ensuring the consistency of welding and preventing cold solder joints caused by uneven welding temperature.

[0042] When the ground pad length L4 is 0.8mm, the crosstalk results of different ground pad widths H3, 0.1mm, 0.2mm and 0.3mm are compared. Figure 6 As shown. It can be seen that the width of the ground pad has a greater impact on the crosstalk of the product. This is because the wider the pad, the better the isolation of the signal transmission of the adjacent pad. Secondly, widening the pad can increase the capacitive reactance of the link, thereby improving the high-frequency performance of the link and reducing the link crosstalk. In this embodiment, a width of 0.3mm is used, and its crosstalk at the 30GHz frequency point is -58dB, while the crosstalk of the pad width of 0.1mm and 0.2mm is -37dB and -50dB respectively, which is quite different from the crosstalk of 0.3mm width. Secondly, the linearity of the crosstalk results of 0.1mm and 0.2mm widths in the frequency range of 20-40GHz is much worse than that of the crosstalk results of 0.3mm width.

[0043] At the same time, a comparative analysis of the crosstalk results of different ground pad sizes was also done, such as Figure 7 As shown, it can be seen that as the size of the ground pad increases, the crosstalk performance also improves. There are certain differences in the crosstalk of different ground pad sizes designed in this embodiment, but the difference is not large and has no effect on the performance of the component. When the ground pad size is 0.6mm long and 0.25mm wide, the crosstalk result at 30GHz is -55dB, while the ground pad size is 0.8mm long and 0.3mm wide at 30GHz The crosstalk is -58dB, and the ground pad size is 1.0mm long and 0.35mm wide at 30GHz The crosstalk is -60dB.

[0044] Secondly, in terms of link insertion loss and return loss performance, it is mainly reflected in the optimization design of the signal pad size. When the pad length is 0.8mm, the insertion loss and return loss results of different signal pad widths H4, 0.1mm, 0.2mm and 0.3mm are compared. Figure 8 and Fig. 9 As shown. It can be seen that the width of the signal pad has a great influence on the insertion loss and return loss of the product. This is because, the wider the signal pad, the smaller its capacitive reactance, the greater the impedance, and the greater the insertion loss and return loss. At the 30GHz frequency point, the insertion losses of signal pads with widths of 0.1mm, 0.2mm and 0.3mm are 0.79dB, 0.86dB and 1.0dB respectively, and the return losses are -13dB, -12.3dB and -10.2dB respectively. The insertion loss and return loss performance of signal pads with widths of 0.1mm and 0.2mm are relatively close, and 0.1mm is better, but considering the welding process and operability, the signal pad width of 0.2mm is the optimal design.

[0045] Comparison of insertion loss and return loss results for different signal pad sizes: 0.6mm length x 0.15mm width, 0.8mm length x 0.2mm width, and 1.0mm length x 0.25mm width. Fig.10 and Fig.11 As shown in the figure, within the designed signal pad size range, the insertion loss is not much different. At 30GHz, the insertion loss of the three sizes is 0.83dB, 0.86dB and 0.91dB respectively. The return loss is -13.2dB, -12.3dB and -11.8dB respectively. The insertion loss and return loss results of the three sizes are relatively close, and the performance difference is not much.

[0046] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An electrical interconnection component, characterized in that: The invention comprises a ceramic circuit board and a main control circuit board, wherein the ceramic circuit board is welded on the main control circuit board, a ground pad 1 and a signal pad 1 are arranged on the ceramic circuit board, a ground pad 2 of equal length and width for welding with the ground pad 1 is arranged on the main control circuit board, and a signal pad 2 of equal length and width for welding with the signal pad 1 is arranged on the main control circuit board, wherein the length of the ground pad 1 is 0.6-1.0 mm and the width is 0.25-0.35 mm; the length of the signal pad 1 is 0.6-1.0 mm and the width is 0.15-0.25 mm; a silicon light engine is installed on the ceramic circuit board, The silicon photonic engine includes a transmitting silicon photonic chip, a laser, a lens, a transmitting fiber array, a receiving silicon photonic chip, a receiving fiber array and a transimpedance amplifier. The optical fibers of the transmitting fiber array and the receiving fiber array are connected to the same pin body. The positive and negative electrodes of the laser are connected to the ceramic circuit board through gold wires. The RF signal pads and power pads of the transmitting silicon photonic chip are connected to the ceramic circuit board through gold wires. The RF signal pads and power pads of the transimpedance amplifier are connected to the ceramic circuit board through gold wires. The receiving silicon photonic chip and the transimpedance amplifier are electrically connected through gold wires.

2. The electrical interconnect assembly according to claim 1, characterized in that: The length of the ground pad 1 is 0.8 mm and the width is 0.3 mm; the length of the signal pad 1 is 0.8 mm and the width is 0.2 mm.

3. The electrical interconnect assembly according to claim 1, wherein: After the laser starts to work and emits light, the lens couples the optical signal of the laser into the waveguide of the transmitting silicon photonic chip. After the optical signal is processed by the built-in modulator of the transmitting silicon photonic chip, it is coupled by the transmitting optical fiber array to transmit the optical signal from the optical fiber to the pin body and the external receiving component for reception. The pin body transmits the received optical signal to the receiving optical fiber array via the optical fiber. After the receiving optical fiber array is coupled with the receiving silicon photonic chip, the optical signal is amplified by a transimpedance amplifier. An isolator is provided between the lens and the transmitting silicon photonic chip.

4. The electrical interconnect assembly according to claim 3, wherein: The front end of the ceramic circuit board extends out in a duckbill shape, the thickness of the extending portion of the front end of the ceramic circuit board is 0.3-0.4 mm, the width of the extending portion of the ceramic circuit board is 1.5-2.0 mm, and the length of the extending portion of the ceramic circuit board is 16-21 mm.

5. The electrical interconnect assembly according to claim 4, characterized in that: A blind groove is provided on the main control circuit board, and the front end protruding part of the ceramic circuit board is connected to the blind groove. The thickness of the front end protruding part of the ceramic circuit board is the same as the depth of the blind groove. The difference between the length of the blind groove and the length of the protruding part of the ceramic circuit board is between 0-0.1mm, and the width of the blind groove is 1.25-1.5mm.

6. The electrical interconnect assembly according to claim 5, characterized in that: Positioning marks with plus signs are arranged on the ceramic circuit board and the main control circuit board, and the plus signs include horizontal lines and vertical lines.

7. The electrical interconnect assembly according to claim 6, wherein: At least two plus signs are provided on the protruding portion of the front end of the ceramic circuit board, at least two plus signs are provided on the left and right sides of the blind groove, and at least two plus signs are provided above the blind groove. The horizontal lines of the plus signs marked on the ceramic circuit board are aligned with the horizontal lines of the plus signs marked on the left and right sides of the blind groove; the vertical lines of the plus signs marked on the ceramic circuit board are aligned with the vertical lines of the plus signs marked above the blind groove.

8. The electrical interconnect assembly according to claim 5, characterized in that: The surface of the extended portion of the ceramic circuit board is copper-plated, with a width of at least 1 mm, and a through hole is made inside the ceramic circuit board at the copper-plated position.

9. The electrical interconnect assembly according to claim 5, characterized in that: The ceramic circuit board and the main control circuit board are welded by reflow welding or laser welding.

Images