CN210835350U

CN210835350U - TO-CAN detector based on positive spherical lens tube cap

Info

Publication number: CN210835350U
Application number: CN201921916294.7U
Authority: CN
Inventors: 温永阔; 龚成文; 胡靖�; 邓刚; 龚雪萍
Original assignee: Wuhan East Feiling Technology Co ltd
Current assignee: Wuhan East Feiling Technology Co ltd
Priority date: 2019-11-08
Filing date: 2019-11-08
Publication date: 2020-06-23
Anticipated expiration: 2029-11-08

Abstract

The utility model discloses technical problem TO adopting aspheric surface lens pipe cap among the prior art with high costs, that the lead period is long provides a TO-CAN detector based on positive spherical lens pipe cap, including tube socket, pipe cap, lens and many pins, many pins are worn TO locate in the tube socket, pipe cap and lens package in proper order at the upper surface of tube socket, lens are positive spherical lens, positive spherical lens's refracting index is 2.0, positive spherical lens's diameter is 1.5mm TO guarantee the coupling responsivity and the return loss of detector, tube socket, pipe cap and positive spherical lens three keep coaxial setting. The utility model discloses technical scheme's detector makes the high rate product can use the just sphere pipe cap of localization to replace the aspheric surface pipe cap of import, is applicable to two-way subassembly of double fiber (ROSA) and uses, can be about the cost reduction of detector pipe cap is original one-third after the use, reaches the purpose with the cost.

Description

TO-CAN detector based on positive spherical lens tube cap

Technical Field

The utility model belongs TO the optical fiber communication trade relates TO TO-CAN detector packaging technology, especially relates TO a TO-CAN detector of reducible cost.

Background

As is well known, a TO-CAN detector applied TO optical fiber communication has a function of converting an optical signal into an electrical signal, and is implemented mainly by using a photodiode provided therein as a photoelectric conversion unit. In some application scenarios with high transmission rate, we will generally use an aspheric lens cap to encapsulate the detector, which has two benefits: firstly, the light signal convergence effect is better, and the light signal with larger proportion is converged on the photosensitive surface of the photodiode, so that the responsivity (A/W) of the detector is improved; secondly, the application scene of the detector can be a single-fiber bidirectional component (BOSA) and a dual-fiber bidirectional component (ROSA), wherein the single-fiber bidirectional component (BOSA) has a longer requirement on the focal length of the detector (generally about 2.5 mm), and the dual-fiber bidirectional component (ROSA) does not limit the requirement on the focal length of the detector, so that the two components can be compatible at the same time by adopting an aspheric lens pipe cap to make the focal length 2.5 mm.

Although the prior art has advantages, the tube cap of the aspheric lens is usually manufactured by adopting a die pressing process, and the processing difficulty is high, so that the tube cap of the current aspheric lens is all imported, the price is high, and the delivery period is long, so that a TO-CAN detector with a cost reduction scheme needs TO be researched, and the cost is reduced while the functional requirements are met.

SUMMERY OF THE UTILITY MODEL

In view of this, the utility model provides a TO-CAN detector based on positive spherical lens pipe cap aims at solving and adopts aspheric lens TO regard as the TO-CAN detector of pipe cap with high costs among the above-mentioned prior art problem.

In order to achieve the technical purpose, the utility model adopts the following technical proposal:

the utility model provides a pair of TO-CAN detector based on positive spherical lens pipe cap, the key lies in two points: firstly, selecting a positive spherical lens with proper refractive index to meet the coupling responsivity same as that of the tube cap of the aspheric lens; secondly, select suitable positive spherical lens diameter to satisfy the return loss requirement the same with aspheric surface lens pipe cap, based on this, the technical scheme of the utility model is that:

the utility model provides a TO-CAN detector based on positive spherical lens pipe cap, its external member includes tube socket, pipe cap, lens and many pins, many pins wear TO locate in the tube socket, pipe cap and lens encapsulate in proper order in the upper surface of tube socket, lens adopt positive spherical lens TO positive spherical lens's refracting index is 2.0 and positive spherical lens's diameter is 1.5mm, just so CAN guarantee the coupling responsivity and the return loss of detector and the same with the coupling responsivity and the return loss of non-spherical lens pipe cap, simultaneously, tube socket, pipe cap and positive spherical lens three need keep coaxial setting.

Furthermore, after the technical scheme is adopted, the focal length between the positive spherical lens and the incident light source of the optical fiber ferrule is set to be 1.1mm, so that the return loss can be further reduced.

And simultaneously, as photoelectric conversion's electronic component, the utility model discloses a detector, its inside part is including setting up at the inside TIA chip (transimpedance amplifier chip, hereinafter "TIA chip"), PD chip (photodiode chip, hereinafter "PD chip") and electric capacity of pipe cap, TIA chip paste dress is in the upper surface center of tube socket, PD chip paste dress is in the surface of TIA chip, electric capacity paste dress is in on the other position that is close to the VCC end of TIA chip.

Furthermore, the photosensitive surface of the PD chip is arranged in an eccentric 60-micron mode relative to the positive spherical lens, and the TIA chip, the PD chip and the capacitor are connected with a plurality of pins through gold wires with the diameter of 25 microns to form a circuit.

The utility model has the advantages that:

compared with the prior art, the utility model provides a TO-CAN detector based on positive spherical lens pipe cap through adopting positive spherical lens as the pipe cap TO adopt the positive spherical lens of glass material of 2.0 refracting indexes, CAN make the light signal that optic fibre sent better assemble a bit, set the focus between the incident light source of positive spherical lens and optic fibre lock pin TO 1.1mm, CAN improve the coupling responsivity, CAN satisfy the same coupling responsivity with aspheric lens pipe cap; the positive spherical lens with the diameter of 1.5mm is adopted, and the PD chip of the detector deviates from the axis of the positive spherical lens by 60 microns for mounting, so that the return loss can be reduced, the return loss requirement identical to that of an aspheric lens tube cap can be met, the positive spherical lens is adopted as the tube cap to achieve the coupling responsivity and the return loss identical to that of the aspheric lens tube cap, and the positive spherical lens is low in cost and short in delivery cycle, so that the positive spherical lens can be used on high-speed products instead of the imported aspheric lens tube cap. Because two-way subassembly of two fibre (ROSA) are not restricted to the focus of detector, so the utility model discloses technical scheme's detector only is applicable to two-way subassembly of two fibres (ROSA) and uses, can reduce the cost of detector pipe cap to about the original one-third after the use, reaches the purpose with the cost.

Drawings

Fig. 1 is a schematic view of the appearance structure of the detector of the present invention.

Fig. 2 is a plan view of the internal chip of the detector of the present invention.

Fig. 3 is an enlarged view of the PD chip mounting position in fig. 2.

Fig. 4 is a schematic view of the focal length between the center of the cap lens and the incident light source of the detector of the present invention.

Fig. 5 is an optical diagram of the detector of the present invention.

Shown in the figure:

1-tube seat, 2-tube cap, 3-lens, 4-pin, 5-TIA chip, 6-PD chip, 7-capacitor,

the focal length between the center of the H-positive spherical lens and the incident light source of the optical fiber ferrule,

the eccentricity of the photosensitive surface of the M-PD chip relative to the center of the positive spherical lens,

a-the incident light source of the fiber stub.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail with reference to the accompanying drawings and specific embodiments. It is to be understood that the specific embodiments described herein are for purposes of illustration only and are not to be construed as limitations of the invention.

The embodiment provides a TO-CAN detector based on a spherical lens tube cap, the external structure of which is shown in figure 1, and the TO-CAN detector comprises a tube seat 1, a tube cap 2, a

lens

3 and 5 pins 4, wherein the 5 pins 4 are all pins

The probe comprises a

tube seat

1, 5 pins 4 are arranged in the tube seat 1 in a penetrating mode, a tube cap 2 and a lens 3 are sequentially packaged on the upper surface of the tube seat 1 and ensure that the tube seat 1, the tube cap 2 and the lens 3 are coaxial, the lens 3 adopts a positive spherical lens, the refractive index of the positive spherical lens 3 is 2.0, and the diameter of the positive spherical lens 3 is 1.5mm so as to ensure that the coupling responsivity and the return loss of the probe are the same as those of the aspheric lens tube cap.

Meanwhile, according TO the TO-CAN detector based on the positive spherical lens tube cap provided by the embodiment, the internal core components comprise a TIA chip 5, a PD chip 6 and a capacitor 7, the TIA chip 5, the PD chip 6 and the capacitor 7 are included in the tube cap 2, the specific mounting modes are shown as an internal chip plane layout diagram in fig. 2 and a PD chip mounting position enlarged diagram in fig. 3, the TIA chip 5 is mounted at the center of the upper surface of the tube seat 1 in a silver adhesive die bonding mode, the PD chip 6 is mounted on the surface of the TIA chip 5 in a silver adhesive die bonding mode, and the electrode of the PD chip 6 is close TO the corresponding electrode of the TIA chip 5 as much as possible, so that the distance between the two chips CAN be shortened, the connecting gold wire is shorter, and the transmission impedance is further reduced; the capacitor 7 is attached to a position close to a VCC end beside the TIA chip 5, the PD chip 6 and the capacitor 7 are connected with 5 pins 4 through 25-micron gold wires to form a circuit, and then the tube cap 2 and the tube seat 1 are hermetically welded together in a resistance welding mode in a high-purity nitrogen environment.

Further, in the detector of the present embodiment, the photosensitive surface of the PD chip 6 is disposed off-center by 60 μm with respect to the positive spherical lens 3 to reduce the return loss.

Further, when the detector of the present embodiment is implemented specifically, as shown in fig. 4, since the diameter of the positive spherical lens 3 is relatively small and is 1.5mm, under the condition that other conditions are not changed, the focal length H between the positive spherical lens 3 and the incident light source a of the optical fiber ferrule can be reduced to about 1.1mm, and the positive spherical lens 3 adopts glass with a refractive index of 2.0, so that the same coupling responsivity as that of the aspheric lens can be ensured.

Further, when the detector of this embodiment is specifically implemented, an optical signal is emitted from the incident light source a of the optical fiber ferrule, and is converged by the positive spherical lens 3 and then irradiated onto the photosensitive surface of the PD chip 6, the PD chip 6 converts the optical signal into an electrical signal and transmits the electrical signal to the TIA chip 5, and the TIA chip 5 converts the electrical signal into a voltage signal and amplifies the voltage signal for differential output. As can be seen from the optical path diagram of fig. 5, the light-sensitive surface of the PD chip 6 is disposed eccentrically with respect to the spherical front lens 3, and the return area of the reflected light is significantly smaller than the return area of the reflected light when the light-sensitive surface of the PD chip 6 is disposed coaxially with the spherical front lens 3, so that the return loss can be reduced. Preferably, when the eccentricity M of the photosensitive surface of the PD chip with respect to the center of the positive spherical lens is set to 60 μ M, and the diameter of the positive spherical lens 3 is smaller than 1.5mm, the positive spherical lens 3 achieves the same return loss requirement as that of the aspheric lens.

Preferably, in the detector of the embodiment, the TIA chip 5 and the PD chip 6 are mounted in a stacked manner, so that the occupied space is reduced, the chip spacing is shortened, the package size is reduced, and the cost is reduced.

It should be noted that, since the focal length requirement of the single fiber bidirectional assembly (BOSA) for the detector is about 2.5mm, and the focal length requirement of the dual fiber bidirectional assembly (ROSA) for the detector is not limited, the TO-CAN detector based on the positive spherical lens cap provided by this embodiment is only applicable TO the dual fiber bidirectional assembly (ROSA). In specific implementation, the positive spherical lens 3 is used as a tube cap, and a glass material with the refractive index of 2.0 is adopted, so that optical signals emitted by the optical fiber can be better converged to one point; meanwhile, the diameter of the positive spherical lens 3 is set to be 1.5mm, so that the focal length H between the positive spherical lens 3 and the incident light source A of the optical fiber ferrule is reduced to about 1.1mm, and the coupling responsivity same as that of the pipe cap of the aspheric lens can be obtained; and when the eccentricity M of the photosensitive surface of the PD chip 6 of the detector relative to the center of the positive spherical lens 3 is set to 60 μ M, the same return loss requirement as that of the aspheric lens tube cap can be obtained, so that the positive spherical lens tube cap in this embodiment obtains the same effect as that of the aspheric lens, and the cost of the positive spherical lens is much lower than that of the aspheric lens, so that the detector provided in this embodiment achieves the purpose of reducing the cost while ensuring the use effect.

It is to be understood that no matter how much of this specification appears, such as in the prior art or common general knowledge. The present embodiment is only used for illustrating the present invention, and is not used to limit the scope of the present invention, and modifications such as equivalent replacement made by those skilled in the art to the present invention are all considered to fall within the protection scope of the claims of the present invention.

Claims

1. The utility model provides a TO-CAN detector based on positive spherical lens pipe cap, includes tube socket (1), pipe cap (2), lens (3) and many pins (4), many pins (4) wear TO locate in tube socket (1), the upper surface at tube socket (1), its characterized in that are encapsulated in proper order in pipe cap (2) and lens (3): the detector is characterized in that the lens (3) is a positive spherical lens, the refractive index of the positive spherical lens (3) is 2.0, the diameter of the positive spherical lens (3) is 1.5mm, so that the coupling responsivity and the return loss of the detector are guaranteed, and the tube seat (1), the tube cap (2) and the positive spherical lens (3) are coaxially arranged.

2. A positive spherical lens cap based TO-CAN probe according TO claim 1, wherein: and the focal length H between the positive spherical lens (3) and the incident light source of the optical fiber ferrule is 1.1 mm.

3. A positive spherical lens cap based TO-CAN probe according TO claim 2, wherein: the detector further comprises a TIA chip (5), a PD chip (6) and a capacitor (7) which are arranged inside the tube cap (2), wherein the TIA chip (5) is mounted at the center of the upper surface of the tube seat (1), the PD chip (6) is mounted on the surface of the TIA chip (5), and the capacitor (7) is mounted on the position, close to the VCC end, beside the TIA chip (5).

4. A positive spherical lens cap based TO-CAN probe according TO claim 3, wherein: the photosensitive surface of the PD chip (6) is arranged eccentrically by 60 mu m relative to the positive spherical lens (3).

5. A positive spherical lens cap based TO-CAN probe according TO claim 3, wherein: the TIA chip (5), the PD chip (6) and the capacitor (7) are connected with the pins (4) through gold wires to form a circuit.

6. A positive spherical lens tube cap based TO-CAN detector as claimed in claim 5, wherein: the specification of the gold wire is 25 μm.