CN212305767U

CN212305767U - Anti-crosstalk device and circuit with same

Info

Publication number: CN212305767U
Application number: CN202022117948.9U
Authority: CN
Inventors: 张拥健; 吴邦嘉; 王志勇; 陈奔; 朱宇
Original assignee: Hengtong Rockley Technology Co Ltd
Current assignee: Suzhou Zhuoyu Photon Technology Co ltd
Priority date: 2020-09-24
Filing date: 2020-09-24
Publication date: 2021-01-05
Anticipated expiration: 2030-09-24

Abstract

The utility model discloses an anti-crosstalk device and have this anti-crosstalk device's circuit, this anti-crosstalk device include body (40), body (40) include a plurality of connection feet (40a), adjacent two connect and form shielding chamber (41) that have electromagnetic shield effect between foot (40a), shielding chamber (41) cover is located on bonding wire (62) of circuit. The utility model has the advantages that the shielding cavity covering the bonding wire of the signal channel is arranged, the radiation of the bonding wire is limited, and the electromagnetic radiation crosstalk between the bonding wires is prevented, so that the mutual interference between the signal channels is greatly reduced, and the reliable transmission of signals in each signal channel is effectively ensured; meanwhile, the shielding cavity can enable the impedance reference surface of the bonding wire to be placed at a position close to the bonding wire, so that the impedance control effect is achieved, the signal integrity quality can be improved, and the performance of the whole system is improved.

Description

Anti-crosstalk device and circuit with same

Technical Field

The utility model relates to a little equipment technical field, in particular to anti cross talk device and have device's circuit.

Background

The micro-assembly technology plays a crucial role in modern communication systems, gold wire bonding is a key process in the micro-assembly technology, and the quality of bonding quality directly influences the reliability and the electrical property stability of products. Gold wire bonding is a commonly used process in a multi-chip microwave module, and refers to a technique of bonding extremely fine gold wires having excellent ductility and conductivity between a substrate and a chip, or between chips to realize mutual correlation of electrical characteristics.

As shown in fig. 1, fig. 1 shows a schematic diagram of a circuit bonded by gold wire in the prior art, which includes a first substrate 1 and a second substrate 10, wherein a plurality of gold-plated conductive layers 11 and gold-plated ground planes 12 are disposed on each of the first substrate 1 and the second substrate 10, specifically, two conductive layers 11 and three ground planes 12 are disposed on each substrate shown in fig. 1 at intervals. The conductive layers 11 and the ground layers 12 on the first substrate 1 and the second substrate 10 correspond to each other and are bonded by gold wires 13, thereby forming a first signal path 14, a second signal path 15, and three ground lines 16.

The above scheme has the following disadvantages: 1. the crosstalk among the channels is serious, when one signal channel transmits signals, the other channel is greatly interfered, and the closer channel lines are, the more the interference among the adjacent channel lines is, the difficulty in reliable transmission of the signals is caused; 2. the gold wire impedance is difficult to control, so that the channel impedance discontinuity is high, and the signal integrity is poor; 3. two adjacent substrates are connected through a fragile gold wire, and the connection reliability and stability are poor.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to the above-mentioned defect among the prior art, provide an anti device of crosstalking and have device's circuit, this anti device of crosstalking can effectively reduce the crosstalking between the signal channel, improves signal transmission's reliability.

In order to realize the above-mentioned utility model purpose, on the one hand, the utility model provides an anti device that disturbs, it includes the body, the body includes a plurality of connection feet, adjacent two connect and form the shielding chamber that has electromagnetic shield effect between the foot, shielding chamber cover is located on the bonding wire.

Further, the body (40) is made of metal.

Furthermore, the surface of the shielding cavity is provided with a shielding layer, and the shielding layer is made of a metal material.

Furthermore, the surface of the connecting pin is provided with an electric connecting layer, and the electric connecting layer is connected with the shielding layer.

Furthermore, the shielding layer and the electrical connection layer are both made of metal.

Further, the shielding cavity comprises a plurality of planes, and the planes are connected to form a semi-enclosed structure.

Further, the shielding cavity comprises a first plane, and a second plane and a third plane which are symmetrically arranged on two sides of the first plane.

On the other hand, the utility model also provides a circuit, it includes first base plate, second base plate, a plurality of signal channel and as above anti crosstalking device, signal channel including set up in first conducting layer on the first base plate, set up in second conducting layer on the second base plate and connect first conducting layer with bonding wire between the second conducting layer, anti crosstalking device's shielding chamber cover is located on the bonding wire.

Further, the circuit further comprises a plurality of ground wires arranged at intervals with the signal channels, the ground wires comprise a first ground wire layer arranged on the first substrate and a second ground wire layer arranged on the second substrate, and connecting pins of the crosstalk prevention device are connected between the first ground wire layer and the second ground wire layer.

Furthermore, the connecting pins are adhered to the first ground plane and the second ground plane through conductive adhesives, or adhered to the first ground plane and the second ground plane through metal brazing, hot pressing or ultrasonic welding.

Compared with the prior art, the utility model has the advantages of:

1. the shielding cavity which covers the bonding wire of the signal channel is arranged, so that the radiation of the bonding wire is limited, and the electromagnetic radiation crosstalk between the bonding wires is prevented, thereby greatly reducing the mutual interference between the signal channels and effectively ensuring the reliable transmission of signals in each signal channel;

2. the shielding cavity is arranged in a mode that a plurality of planes are connected, so that a reference plane can be provided for the bonding wire, the impedance of the bonding wire can be controlled, the impedance discontinuity of a channel is reduced, and the integrity quality of signals is improved;

3. the ground wire layers on the two substrates are connected through the crosstalk resisting device, compared with a traditional mode that the ground wire layers are connected through bonding wires, the contact area can be greatly increased, and the connection stability and the connection reliability of the ground wire layers are ensured;

4. the utility model discloses an it is continuous through the conducting resin bonding between anti crosstalk device and the ground plane, and it is very convenient to install.

Drawings

Fig. 1 is a schematic diagram of a circuit in the prior art.

Fig. 2 is a schematic diagram of the circuit of the present invention.

Fig. 3 is an exploded view of the circuit of the present invention.

Fig. 4 is a side view of the circuit of the present invention.

Fig. 5 is an enlarged view of a portion I in fig. 4.

Fig. 6 is a simulation diagram of electric field strength of a circuit in the prior art.

Fig. 7 is an electric field intensity simulation diagram of the middle circuit of the present invention.

Fig. 8 is a graph of return loss of the transmission channel and near-end, far-end crosstalk strength of the disturbed channel for a prior art circuit.

Fig. 9 is a graph of return loss for the transmission channel of the circuit of the present invention and the near-end and far-end crosstalk strength for the disturbed channel.

Fig. 10 is a graph of the TDR impedance of the transmission channel of the prior art circuit.

Fig. 11 is a TDR impedance curve diagram of the transmission channel of the middle circuit of the present invention.

Fig. 12 is a graph of transmission channel insertion loss for a prior art circuit.

Fig. 13 is a graph of the transmission channel insertion loss of the circuit of the present invention.

Detailed Description

The following non-limiting detailed description of the present invention is provided in connection with the preferred embodiments and accompanying drawings.

As shown in fig. 2 and 3, the circuit according to a preferred embodiment of the present invention includes a first substrate 2, a second substrate 3, and an anti-crosstalk apparatus 4 connected between the first substrate 2 and the second substrate 3.

The first substrate 2 and the second substrate 3 may be PCB substrates or ceramic substrates, etc.

The circuit further comprises a plurality of ground wires 5 and signal channels, wherein the number of the ground wires 5 is three, the number of the signal channels is two, the two ground wires are respectively a first signal channel 6 and a second signal channel 7, and the two sides of the first signal channel 6 and the two sides of the second signal channel 7 are both the ground wires 5.

The ground line 5 comprises a first ground plane 50 disposed on the first substrate 2 and a second ground plane 51 disposed on the second substrate 3, wherein the first ground plane 50 and the second ground plane 51 are disposed correspondingly, generally in a straight line, and are connected through the anti-crosstalk device 4, and the connection manner will be described below.

The signal path includes a first conductive layer 60 disposed on the first substrate 2 and a second conductive layer 61 disposed on the second substrate 3, and the first conductive layer 60 and the second conductive layer 61 are disposed correspondingly and generally in a straight line. The signal path further includes a bond wire 62 that is bonded between the first conductive layer 60 and the second conductive layer 61.

The ground planes (the first ground plane 50 and the second ground plane 51), the conductive layers (the first conductive layer 60 and the second conductive layer 61), and the bonding wires 62 are made of conductors, and the material of the conductors may be a metal material such as gold, silver, copper, etc. The ground plane, the conductive layer and the bonding wire 62 may be made of the same material or different materials, preferably made of the same material, and more preferably made of metal gold.

As shown in fig. 4 and 5, the crosstalk prevention apparatus 4 includes a body 40 and a plurality of shielding cavities 41 formed on the body 40, where a plurality of connecting pins 40a are disposed on the body 40, and the shielding cavities 41 are formed between two adjacent connecting pins 40 a; the connecting pin 40a is arranged corresponding to the ground wire, and is used for connecting a first ground wire layer 50 and a second ground wire layer 51 of each ground wire; the shielding cavity 41 is disposed corresponding to the bonding wire 62, and covers the bonding wire 62. In the present embodiment, the number of the ground lines 5 and the bonding wires 62 is three and two, respectively, and thus the number of the connecting pins 40a and the shield cavities 41 is also three and two, respectively.

The body 40 and the connecting legs 40a thereof are preferably integrally formed, and may be directly made of a material having an electromagnetic shielding effect, or may be made of a material having no electromagnetic shielding effect (such as ceramic, silicon material, etc.) and a layer of a material having an electromagnetic shielding effect is plated on the shielding cavity 41, that is, a shielding layer 42 is disposed on the surface of the shielding cavity 41. The material with electromagnetic shielding effect may be a metal material, such as gold, silver, copper, etc., but other materials with similar or same effect may also be used.

Due to the limitation of the installation position, the size of the crosstalk prevention device 4 is small, and is usually millimeter-sized, so that the body 40 is preferably formed by etching a silicon material, and the processing is more convenient; in other embodiments, it may also be made of ceramic or other materials.

The connection pin 40a is connected between the first ground layer 50 and the second ground layer 51, and is used to conduct the first ground layer 50 and the second ground layer 51. The connection pins 40a may be made of a conductive material, or an insulating material may be used, and an electrical connection layer 43 made of a conductive material is disposed on the bottom surface of the connection pins 40a, and the material of the electrical connection layer 43 is preferably the same as that of the shielding layer 42.

The electrical connection layer 43 is connected to the shielding layer 42 to make the grounding more reliable and improve the shielding effect.

The connection between the connection pin 40a and the ground plane is preferably made by gluing, and specifically, the conductive glue 44 is disposed on the bottom surface of the connection pin 40a, and is adhered to the ground by the conductive glue 44, so as to electrically connect the first ground plane 50 and the second ground plane 51. The conductive paste 44 may be, for example, silver paste. The connection is realized in an adhesive mode, so that the convenience of installation is greatly improved. Or the connecting foot 40a is adhered with the first ground layer (50) and the second ground layer (51) by means of metal brazing, hot pressing or ultrasonic welding.

Compare in the conduction mode who uses the gold thread bonding between traditional ground plane, the utility model discloses a mode that ground plane was pasted to conducting resin 44 can increase the area of contact between electric connection layer 43 and the ground plane, the stability of better assurance connection.

After the crosstalk prevention apparatus 4 is mounted on the first substrate 2 and the second substrate 3, the bonding wires 62 are accommodated in the shielding cavities 41, and preferably, the bonding wires 62 are completely accommodated in the shielding cavities 41 in the length direction, and other parts of the first conductive layer 60 and the second conductive layer 61 are also located in the shielding cavities 41. Through the shielding effect of the shielding cavity 41 on the electromagnetic signals of the bonding wires, the mutual interference between the signal channels can be effectively reduced, and the crosstalk resistance of the signal channels is greatly improved. It will be appreciated that the longer the length of the conductive layer within the shielded cavity 41, the better its anti-crosstalk effect.

Conventionally, the bond wire 62 is far from its impedance reference plane, so the impedance controllability is poor, and the bond wire 62 is the main factor of impedance discontinuity in the whole system. By providing the shielding cavity, the impedance reference plane of the bond wire 62 is located closer to the bond wire 62, which plays a role in impedance control, thereby improving the signal integrity quality and improving the performance of the entire system.

The cross-sectional shape of the shielding cavity 41 may be various, such as a semicircle, a semi-ellipse, a U-shape, or a polygon. In this embodiment, the shielding chamber 41 is enclosed by three planes to form a semi-enclosed shape, and specifically, the shielding chamber 41 includes a first plane 420 at the top and a second plane 421 and a third plane 422 symmetrically disposed at both sides of the first plane 420. By providing the shielding cavity 41 in a form of a plurality of planes connected, a reference plane can be provided for the bonding wire 62, so that the impedance of the bonding wire 62 can be controlled (for example, the impedance of the bonding wire 62 can be controlled by adjusting the depth a of the shielding cavity 41 and the width b of the opening thereof), the impedance discontinuity of the signal path is reduced, and the integrity and quality of the signal are improved.

The following simulation comparison between the circuit shown in fig. 1 in the prior art and the circuit shown in fig. 2 of the present invention shows the advantages of the present invention more clearly, and the software used for simulation is Ansys HFSS.

In the circuit for simulation test, the plating layers (including the ground plane, the conductive layer, the electric connection layer and the shielding layer) and the bonding wires are all made of metal gold, the conductive adhesive is silver adhesive, the depth a of the shielding cavity 41 is 0.15mm, and the width b of the opening is 0.36 mm. In the simulated circuit, the first signal channel 6 is taken as a signal transmission channel, the input signal frequency is 30GHz, and the second signal channel 7 is taken as an interfered channel.

Fig. 6 shows a simulation diagram of the electric field strength of the circuit of the prior art, and it can be seen from the diagram that the second signal channel 7 obviously receives the signal of the first signal channel 6, which shows that the signal is greatly interfered by the first signal channel 6, specifically, the electric field strength of the first signal channel 6 is about 3.4E +04V/m, and the electric field strength of the interfered second signal channel 7 is about 3.4E + 03V/m.

Corresponding to fig. 6, fig. 7 shows the simulation diagram of the electric field intensity of the circuit of the present invention, and it can be seen from the diagram that the signal received by the second signal channel 7 is obviously weakened, and the influence degree of the signal quality is obviously reduced. Specifically, the electric field strength of the first signal path 6 is about 8.6E +04V/m, and the electric field strength of the disturbed second signal path 7 is about 8.6E + 02V/m.

Fig. 8 shows a graph of the return loss of the transmission channel and the near-end and far-end crosstalk strengths of the interfered channel of the circuit in the prior art in the simulation test, in which a curve c, a curve d, and a curve e are schematic diagrams of the changes of the return loss of the first signal channel 6, the near-end crosstalk of the second signal channel 7, and the far-end crosstalk of the second signal channel 7 with frequency, respectively. Simulation results show that the return loss of a transmission channel is-10.32 dB, the near-end crosstalk is-38.16 dB, and the far-end crosstalk is-37.83 dB when the existing circuit structure is at 30 GHz.

Fig. 9 is a graph showing the return loss of the transmission channel of the circuit of the present invention and the strength of the near-end crosstalk and the far-end crosstalk of the interfered channel, and similarly, the graph shows that the values of the return loss of the first signal channel 6, the near-end crosstalk of the second signal channel 7 and the far-end crosstalk of the second signal channel 7 vary with the frequency according to the curve c, the curve d and the curve e. The graph shows that, compared with the prior circuit structure, the single-channel return loss is reduced to-16.82 dB from the original-10.32 dB, the near-end crosstalk is reduced to-58.4 dB from the original-38.16 dB, and the far-end crosstalk is reduced to-46.05 dB from the original-37.83 dB when the anti-crosstalk device of the utility model is used.

Fig. 10 shows a TDR impedance curve diagram of a transmission channel of a circuit in the prior art during the simulation test, and the simulation result shows that, in the prior circuit structure, the gold wire impedance jump is about 9 ohms.

Corresponding to fig. 10, fig. 11 shows the TDR impedance curve diagram of the transmission channel of the circuit of the present invention, in order to clearly show the effect of the sizes of the depth a and the width b of the opening of the different shielding cavities 41 on the impedance, three curves are obtained by modifying the size parameters of the depth a and the width b: the impedance jump of the three curves is about 6 ohms, 5 ohms and 4 ohms in sequence and is obviously smaller than that of a traditional circuit, and the impedance jump can be controlled by adjusting the distance between the shielding cavity 41 and the bonding wire 62.

Fig. 12 shows a graph of the insertion loss of the transmission channel in a prior art circuit, and simulation results show that the insertion loss of a single channel is 3.25dB at 30 GHz.

Corresponding with fig. 12, fig. 13 shows the utility model discloses a transmission channel insertion loss's curve graph in the circuit, and the simulation result shows, is using the utility model discloses an under the condition of anti-crosstalk device, compare current circuit structure, when 30GHz, single channel insertion loss is reduced to 2.6dB by original 3.25 dB.

It is understood that the signal channels in the present invention are not limited to two, but may be provided in three or more forms, and the ground line and the shielding cavity may be correspondingly added.

The utility model discloses possess following advantage at least:

It should be noted that the above-mentioned preferred embodiments are only for illustrating the technical concepts and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and to implement the present invention accordingly, and the protection scope of the present invention cannot be limited thereby. All equivalent changes and modifications made according to the spirit of the present invention should be covered by the protection scope of the present invention.

Claims

1. An anti-crosstalk apparatus, characterized by: the bonding wire comprises a body (40), wherein the body (40) comprises a plurality of connecting pins (40a), a shielding cavity (41) with electromagnetic shielding effect is formed between every two adjacent connecting pins (40a), and the shielding cavity (41) is covered on a bonding wire (62).

2. The crosstalk reduction apparatus of claim 1, wherein: the body (40) is made of metal materials.

3. The crosstalk reduction apparatus of claim 1, wherein: the surface of the shielding cavity (41) is provided with a shielding layer (42), and the shielding layer (42) is made of metal materials.

4. The crosstalk prevention apparatus of claim 3, wherein: the surface of the connecting pin (40a) is provided with an electric connection layer (43), and the electric connection layer (43) is connected with the shielding layer (42).

5. The crosstalk prevention apparatus of claim 4, wherein: the shielding layer (42) and the electric connection layer (43) are both made of metal.

6. The crosstalk prevention apparatus according to any of claims 1 to 5, wherein: the shielding cavity (41) comprises a plurality of planes which are connected to form a semi-enclosed structure.

7. The crosstalk reduction apparatus of claim 6, wherein: the shielding cavity (41) comprises a first plane (420) and a second plane (421) and a third plane (422) which are symmetrically arranged at two sides of the first plane (420).

8. A circuit, characterized by: comprising a first substrate (2), a second substrate (3), a number of signal paths and an anti-crosstalk apparatus according to any of claims 1 to 7, the signal paths comprising a first conductive layer (60) disposed on the first substrate (2), a second conductive layer (61) disposed on the second substrate (3), and a bonding wire (62) connected between the first conductive layer (60) and the second conductive layer (61), a shielding cavity (41) of the anti-crosstalk apparatus being covered on the bonding wire (62).

9. The circuit of claim 8, wherein: the anti-crosstalk device is characterized by further comprising a plurality of ground wires (5) arranged at intervals of the signal channels, wherein the ground wires (5) comprise a first ground wire layer (50) arranged on the first substrate (2) and a second ground wire layer (51) arranged on the second substrate (3), and connecting pins (40a) of the anti-crosstalk device are connected between the first ground wire layer (50) and the second ground wire layer (51).

10. The circuit of claim 9, wherein: the connecting pin (40a) is adhered to the first ground layer (50) and the second ground layer (51) through a conductive adhesive (44), or adhered to the first ground layer (50) and the second ground layer (51) through metal brazing, hot pressing or ultrasonic welding.