Packaging module of broadband detector and preparation method thereof

Abstract

The invention provides a packaging module of a broadband detector and a preparation method thereof, and relates to the technical field of optoelectronic devices, and the packaging module of the broadband detector comprises a housing which is internally provided with an accommodation space, and one side of the housing is provided with a radio frequency port; the heat sink is arranged in the accommodating space; the detection module is arranged on the heat sink, and the detection module comprises a detector chip which comprises a first electrode and a second electrode and is suitable for converting an externally input optical signal into a radio frequency signal; the signal transmission line is suitable for receiving the radio frequency signal and outputting the radio frequency signal to an external circuit through the radio frequency port; the matching circuit comprises a matching resistor, a protection resistor and a bypass capacitor; and the connecting end parts of at least one part of the lead between the first electrode and the signal transmission line, the lead between the first electrode and the matched resistor, the lead between the matched resistor and the ground, the lead between the second electrode and the protective resistor and the lead between the upper electrode of the bypass capacitor and the protective resistor are coplanar.

Description

Technical Field

[0001] This disclosure relates to the technical field of optoelectronic devices, and more specifically, to a packaging module for a broadband detector and a method for its fabrication. Background Technology

[0002] In 5G / 6G communication systems, high-bandwidth and high-flatness detectors have become indispensable core components for building high-performance optical radio frequency links. High bandwidth enables single-channel direct generation and transmission of data streams up to several Gbps or even tens of Gbps, supporting signals in millimeter-wave and even terahertz bands. Flatness is crucial for ensuring the fidelity of complex broadband modulation signals (such as high-order QAM-OFDM). It ensures balanced gain for all frequency components across the entire broad spectrum from baseband to millimeter-wave, minimizing signal waveform distortion caused by amplitude-frequency distortion and meeting the stringent requirements of 6G for extreme spectral efficiency and ultra-low bit error rate. Therefore, advanced detectors combining these two characteristics are the fundamental physical support driving the evolution of future wireless networks towards higher frequency bands, larger capacity, lower power consumption, and higher intelligence.

[0003] However, detector bandwidth is not only related to chip structure, but also to parasitic parameters introduced by packaging structure and process, especially bond wire inductance and package distributed capacitance, which severely restrict the high-frequency performance of the detector. These parasitic elements, together with the intrinsic junction resistance and capacitance of the detector, form a low-pass filter network, becoming the main bottleneck limiting bandwidth improvement and causing high-frequency response roll-off. At the same time, parasitic inductance and capacitance may resonate at certain frequencies, causing peaks and valleys in the frequency response curve, deteriorating flatness, and causing signal amplitude-frequency distortion. Therefore, how to balance the bandwidth and flatness of the detector from the perspective of the package parasitic network has become a key technical problem that urgently needs to be solved. Summary of the Invention

[0004] To address at least one of the technical problems in the prior art, this disclosure provides a packaging module for a broadband detector and a method for its fabrication. By making the connection ends of at least a portion of the leads between the first electrode and the signal transmission line, the first electrode and the matching resistor, the matching resistor and ground, the second electrode and the protection resistor, and the upper electrode of the bypass capacitor and the protection resistor coplanar, the length of the leads can be reduced, thereby reducing parasitic inductance and increasing the bandwidth of the broadband detector.

[0005] This disclosure provides a broadband detector packaging module, comprising: a housing having an accommodating space therein, and a radio frequency (RF) port disposed on one side of the housing; a heat sink disposed in the accommodating space; and a detection module disposed on the heat sink, the detection module comprising: a detector chip including a first electrode and a second electrode, adapted to convert an externally input optical signal into an RF signal; a signal transmission line adapted to receive the RF signal and output it from the RF port to an external circuit; and a matching circuit including a matching resistor, a protection resistor, and a bypass capacitor, wherein at least a portion of the leads of the first electrode and the signal transmission line, the first electrode and the matching resistor, the matching resistor and ground, the second electrode and the protection resistor, and the lead of the upper electrode of the bypass capacitor and the protection resistor are coplanar.

[0006] According to some embodiments of this disclosure, the outer side of the lead between the matching resistor and ground is covered with conductive adhesive.

[0007] According to some embodiments of this disclosure, the packaging module of the broadband detector further includes: a DC circuit board disposed on the heat sink, the DC circuit board including: a power supply layer formed on the DC circuit board, adapted to apply a reverse bias voltage to the detector chip, so that the detector chip converts the optical signal into the radio frequency signal, the protection resistor is electrically connected between the power supply layer and the second electrode, and the bypass capacitor is electrically connected between the power supply layer and ground.

[0008] According to some embodiments of this disclosure, the heat sink includes: a first step suitable for supporting the DC circuit board; a second step, the height of which is higher than the height of the first step, the second step being suitable for supporting the matching resistor, the protection resistor, and the bypass capacitor; and a third step, the height of which is higher than the height of the second step, the third step being suitable for supporting the detector chip and the signal transmission line, such that the optical signal input from the outside irradiates the detector chip.

[0009] According to some embodiments of this disclosure, one end of the matching resistor is electrically connected to the first electrode, and the other end of the matching resistor is grounded to match the output impedance of the first electrode with the impedance of the signal transmission line; one end of the protection resistor is electrically connected to the second electrode; the upper electrode of the bypass capacitor is electrically connected to the other end of the protection resistor, and the lower electrode of the bypass capacitor is attached to the heat sink.

[0010] According to some embodiments of this disclosure, the matching resistor and the protection resistor are bonded to the heat sink with UV adhesive to insulate the bottom of the matching resistor and the protection resistor from the surface of the heat sink.

[0011] According to some embodiments of this disclosure, a boss is formed on the second step, the other end of the matching resistor is grounded through the boss, and the surface of the boss is coplanar with the other end of the matching resistor.

[0012] According to some embodiments of this disclosure, the DC circuit board further includes a ground layer formed on the DC circuit board and arranged at a distance from the power supply layer.

[0013] According to some embodiments of this disclosure, the matching circuit further includes a decoupling capacitor, one end of which is electrically connected to the power supply layer, and the other end of which is connected to the ground layer.

[0014] According to some embodiments of another aspect of this disclosure, a method for fabricating the packaging module of the broadband detector is provided, comprising: mounting a heat sink in the accommodating space of a housing; mounting a DC circuit board on a first step of the heat sink, mounting a bypass capacitor on a second step of the heat sink, and mounting a detector chip and a signal transmission line on a third step of the heat sink, wherein the height of the second step is higher than the height of the first step, and the height of the third step is higher than the height of the second step; electrically connecting the signal transmission line to an RF port using conductive adhesive; mounting a matching resistor and a protection resistor on the second step using UV adhesive; and electrically connecting the first electrode of the detector chip to the signal transmission line, the first electrode to the matching resistor, the matching resistor to a boss on the second step, the second electrode of the detector chip to the protection resistor, the upper electrode of the bypass capacitor to the protection resistor, and the upper electrode of the bypass capacitor to the power supply layer of the DC circuit board by wire bonding.

[0015] The packaging module of the broadband detector according to an embodiment of this disclosure includes a housing, a heat sink, and a detection module. The housing has an accommodating space, and an RF port is provided on one side of the housing. The heat sink is disposed in the accommodating space. The detection module is disposed on the heat sink and includes a detector chip, a signal transmission line, and a matching circuit. The detector chip includes a first electrode and a second electrode, and is adapted to convert an externally input optical signal into an RF signal. The signal transmission line is adapted to receive and output the RF signal from the RF port to an external circuit. The matching circuit includes a matching resistor, a protection resistor, and a bypass capacitor. By making at least a portion of the connection ends of the leads between the first electrode and the signal transmission line, the first electrode and the matching resistor, the matching resistor and ground, the second electrode and the protection resistor, and the upper electrode of the bypass capacitor and the protection resistor coplanar, the length of the leads can be reduced, thereby reducing parasitic inductance and improving the bandwidth of the broadband detector. Attached Figure Description

[0016] Figure 1 This is a perspective view of a packaging module for a broadband detector according to an illustrative embodiment of the present disclosure;

[0017] Figure 2 This is an exploded perspective view of a broadband detector packaging module according to an illustrative embodiment of the present disclosure, with the cover plate removed;

[0018] Figure 3 This is a partially enlarged view of a detection module according to an illustrative embodiment of the present disclosure;

[0019] Figure 4 This is a partially enlarged perspective view of a detection module according to an illustrative embodiment of the present disclosure;

[0020] Figure 5 This is a flowchart illustrating a method for fabricating a packaging module of a broadband detector according to an illustrative embodiment of the present disclosure;

[0021] Figure 6 This is a comparison diagram of the frequency response curves S21 of the broadband detector before and after optimization according to an illustrative embodiment of the present disclosure.

[0022] List of reference numerals in the attached diagram:

[0023] 1. Shell;

[0024] 10. Radio frequency port;

[0025] 2. Heat sink;

[0026] 21. The first step;

[0027] 22. The second step;

[0028] 221. Boss;

[0029] 23. The third step;

[0030] 3. Detection module;

[0031] 31. Inclined optical fiber;

[0032] 32. Detector chip;

[0033] 321. Main body;

[0034] 322. Photosensitive surface;

[0035] 323. First electrode;

[0036] 324. Second electrode;

[0037] 33. Signal transmission line;

[0038] 34. Matching circuit;

[0039] 341. Matching resistor;

[0040] 342. Protective resistor;

[0041] 343. Bypass capacitor;

[0042] 344. Decoupling capacitor;

[0043] 4. DC circuit board;

[0044] 41. Power supply layer;

[0045] 42. Grounding layer;

[0046] 5. Lead wire;

[0047] 6. Power supply pins;

[0048] 7. Cover plate. Detailed Implementation

[0049] The embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the disclosure. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the present disclosure for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.

[0050] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0051] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0052] When using expressions such as "at least one of A, B, and C," the expression should generally be interpreted in accordance with the meaning commonly understood by a person skilled in the art (e.g., "a system having at least one of A, B, and C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.). When using expressions such as "at least one of A, B, or C," the expression should generally be interpreted in accordance with the meaning commonly understood by a person skilled in the art (e.g., "a system having at least one of A, B, or C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.).

[0053] Figure 1 This is a perspective view of a packaging module for a broadband detector according to an illustrative embodiment of the present disclosure. Figure 2 This is an exploded perspective view of a broadband detector packaging module according to an illustrative embodiment of the present disclosure, with the cover plate removed. Figure 3 This is a partially enlarged view of a detection module according to an illustrative embodiment of the present disclosure. Figure 4 This is a partially enlarged perspective view of a detection module according to an illustrative embodiment of the present disclosure.

[0054] A broadband detector packaging module provided according to embodiments of this disclosure, such as... Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, the broadband detector's packaging module includes a housing 1, a heat sink 2, and a detection module 3. The housing 1 has an accommodating space, and an RF port 10 is located on one side of the housing 1. The heat sink 2 is disposed within the accommodating space. The detection module 3 is disposed on the heat sink 2 and includes a detector chip 32, a signal transmission line 33, and a matching circuit 34. The detector chip 32 includes a first electrode 323 and a second electrode 324, and is suitable for converting externally input optical signals into RF signals. The signal transmission line 33 is suitable for receiving and outputting RF signals from the RF port 10 to external circuits. The matching circuit 34 includes a matching resistor 341, a protection resistor 342, and a bypass capacitor 343. The connection ends of at least a portion of the leads 5 between the first electrode 323 and the signal transmission line 33, between the first electrode 323 and the matching resistor 341, between the matching resistor 341 and ground, between the second electrode 324 and the protection resistor 342, and between the upper electrode of the bypass capacitor 343 and the protection resistor 342 are coplanar.

[0055] As an example, the housing 1 can be made of metal.

[0056] As an example, the protection resistor 342 has a resistance of 150Ω and the bypass capacitor 343 has a capacitance of 33pF.

[0057] In some illustrative embodiments, the heat generated by the detection module 3 is transferred to the outside of the housing 1 via the heat sink 2.

[0058] In some illustrative embodiments, the detection module 3 further includes a beveled optical fiber 31 adapted to receive optical signals input from an external source. The detector chip 32 also includes a body 321 and a photosensitive surface 322. The photosensitive surface 322 is disposed on the body 321 and is adapted to receive optical signals from the beveled optical fiber 31.

[0059] Specifically, the photosensitive surface 322 excites electron-hole pairs under the illumination of a light signal. A first electrode 323 is disposed on the main body 321 and electrically connected to one end of the signal transmission line 33 via a lead 5. A second electrode 324 is disposed on the main body 321 and arranged at a distance from the first electrode 323. The electrons and holes in the electron-hole pairs are separated under the combined action of the built-in electric field formed between the first electrode 323 and the second electrode 324, and the reverse bias voltage (provided by the power supply layer 41 of the DC circuit board 4, which will be described in detail below), generating a radio frequency (RF) signal, which is output from the first electrode 323. For example, the first electrode 323 is the p-electrode of the detector chip 32, and the second electrode 324 is the n-electrode of the detector chip 32.

[0060] In some illustrative embodiments, the other end of the signal transmission line 33 is electrically connected to the radio frequency port 10. The signal transmission line 33 receives the radio frequency signal from the first electrode 323 and outputs the radio frequency signal to the external circuit through the radio frequency port 10.

[0061] As an example, the signal transmission line 33 can be a quartz substrate transmission line. Using a quartz substrate transmission line enables low-loss transmission of radio frequency signals from the first electrode 323 of the detector chip 32 to the radio frequency port 10.

[0062] According to embodiments of this disclosure, the length of the lead 5 is reduced by making the connection ends of at least a portion of the leads 5 between the first electrode 323 and the signal transmission line 33, between the first electrode 323 and the matching resistor 341, between the matching resistor 341 and ground, between the second electrode 324 and the protection resistor 342, and between the upper electrode of the bypass capacitor 343 and the protection resistor 342 coplanar. Since the parasitic inductance generated by the lead 5 is proportional to the length of the lead 5, reducing the length of the lead 5 can reduce the parasitic inductance, thereby increasing the bandwidth of the broadband detector.

[0063] As an example, at least some or all of the following wires may be gold wires: the lead 5 between the first electrode 323 and the signal transmission line 33; the lead 5 between the first electrode 323 and the matching resistor 341; the lead 5 between the matching resistor 341 and ground; the lead 5 between the second electrode 324 and the protection resistor 342; and the lead 5 between the upper electrode of the bypass capacitor 343 and the protection resistor 342.

[0064] In some other illustrative embodiments, a plurality of radio frequency ports 10 may be provided on one side of the housing 1, and the packaging module of the broadband detector may include a plurality of detection modules 3, which are spaced apart on the heat sink 2. The other ends of the signal transmission lines 33 of the plurality of detection modules 3 are electrically connected to the plurality of radio frequency ports 10 respectively, so as to output radio frequency signals to external circuits through the radio frequency ports 10 respectively.

[0065] According to an embodiment of this disclosure, the outer side of the lead 5 between the matching resistor 341 and ground is covered with conductive adhesive.

[0066] In this implementation, the conductive adhesive coating on the outer side of the lead 5 between the matching resistor 341 and ground forms a distributed capacitance, which reduces the parasitic inductance generated by the lead 5. Furthermore, the conductive adhesive coating increases the transmission cross-sectional area of ​​the lead 5 between the matching resistor 341 and ground, reducing conductor loss and improving the bandwidth of the broadband detector while reducing unevenness.

[0067] According to embodiments of this disclosure, such as Figure 2 and Figure 3 As shown, the broadband detector's packaging module also includes a DC circuit board 4. The DC circuit board 4 is disposed on the heat sink 2 and includes a power supply layer 41. The power supply layer 41 is formed on the DC circuit board 4 and is adapted to apply a reverse bias voltage to the detector chip 32, causing the detector chip 32 to convert the optical signal into a radio frequency signal. A protection resistor 342 is electrically connected between the power supply layer 41 and the second electrode 324, and a bypass capacitor 343 is electrically connected between the power supply layer 41 and ground.

[0068] In some illustrative embodiments, the power supply layer 41 is adapted to apply a reverse bias voltage to the second electrode 324 via an external DC power supply, so that the detector chip 32 converts the optical signal into a radio frequency signal.

[0069] Specifically, such as Figure 2 As shown, the broadband detector's packaging module also includes a power supply pin 6. One end of the power supply pin 6 is electrically connected to an external DC power supply, and the other end of the power supply pin 6 passes through the housing 1 and is electrically connected to the power supply layer 41 via wire bonding, so as to apply a reverse bias voltage to the second electrode 324 through the power supply layer 41.

[0070] like Figure 3As shown, the protection resistor 342 is electrically connected between the power supply layer 41 and the second electrode 324 to prevent damage to the detector chip 32 from abnormal situations such as current surges or electrostatic discharges caused by the external DC power supply. The upper electrode of the bypass capacitor 343 is electrically connected to the power supply layer 41 by wire bonding, and the lower electrode of the bypass capacitor 343 is attached to the heat sink 2. The bypass capacitor 343 is electrically connected between the power supply layer 41 and ground.

[0071] According to embodiments of this disclosure, such as Figure 4 As shown, the heat sink 2 includes a first step 21, a second step 22, and a third step 23. The first step 21 is suitable for carrying the DC circuit board 4. The second step 22 is higher than the first step 21 and is suitable for carrying the matching resistor 341, the protection resistor 342, and the bypass capacitor 343. The third step 23 is higher than the second step 22 and is suitable for carrying the detector chip 32 and the signal transmission line 33, so that the light signal input from the outside can illuminate the detector chip 32.

[0072] Specifically, the heat sink 2 is designed with steps of varying heights to match the thickness of each component. The second step 22 is higher than the first step 21, and the third step 23 is higher than the second step 22. One end of the angled optical fiber 31 passes through the optical fiber port on the side wall of the housing 1 and is mounted on the DC circuit board 4, which is mounted on the first step 21. The detector chip 32 and the signal transmission line 33 are both mounted on the third step 23, allowing the light signal emitted from the angled optical fiber 31 to illuminate the photosensitive surface 322 of the detector chip 32.

[0073] In some illustrative embodiments, the third step 23 has a protrusion on the side closer to the second step 22, which is generally "convex" in shape. The protrusion is suitable for carrying the detector chip 32, so that the detector chip 32 and the signal transmission line 33 are coplanar.

[0074] Based on this, due to the thickness of the matching resistor 341, the protection resistor 342, and the bypass capacitor 343 themselves, by placing the matching resistor 341, the protection resistor 342, and the bypass capacitor 343 on the second step 22, the bonding planes of the detector chip 32, the signal transmission line 33, the matching resistor 341, the protection resistor 342, and the bypass capacitor 343 can be kept at approximately the same height. This ensures that at least a portion of the connection ends of the leads 5 between the first electrode 323 and the signal transmission line 33, between the first electrode 323 and the matching resistor 341, between the matching resistor 341 and ground, between the second electrode 324 and the protection resistor 342, and between the upper electrode of the bypass capacitor 343 and the protection resistor 342 are coplanar. Furthermore, by placing the first electrode 323 and the second electrode 324 of the detector chip 32 close to each other with the signal transmission line 33, and by placing the matching resistor 341 and the protection resistor 342 located on both sides of the detector chip 32 close to each other with the detector chip 32, and by placing the bypass capacitor 343 close to the protection resistor 342, the length of the lead wire 5 can be minimized, while reducing the dispensing gap and the amount of conductive adhesive used.

[0075] According to embodiments of this disclosure, such as Figure 3 and Figure 4 As shown, one end of the matching resistor 341 is electrically connected to the first electrode 323, and the other end of the matching resistor 341 is grounded to match the output impedance of the first electrode 323 with the impedance of the signal transmission line 33. One end of the protection resistor 342 is electrically connected to the second electrode 324. The upper electrode of the bypass capacitor 343 is electrically connected to the other end of the protection resistor 342, and the lower electrode of the bypass capacitor 343 is in contact with the heat sink 2.

[0076] In this implementation, the upper electrode of the bypass capacitor 343 is electrically connected to the other end of the protection resistor 342 via wire bonding (and is also electrically connected to the power supply layer 41 via wire bonding), and the lower electrode of the bypass capacitor 343 is attached to the second step 22 of the heat sink 2 and thus grounded. Therefore, the second electrode 324 has both the reverse bias voltage applied by the power supply layer 41 and excellent RF grounding can be achieved through the bypass capacitor 343.

[0077] According to an embodiment of this disclosure, the matching resistor 341 and the protection resistor 342 are bonded to the heat sink 2 with UV adhesive to insulate the bottoms of the matching resistor 341 and the protection resistor 342 from the surface of the heat sink 2.

[0078] In this embodiment, the matching resistor 341 and the protection resistor 342 are bonded to the second step 22 with UV adhesive. The UV adhesive can insulate the bottom of the matching resistor 341 and the protection resistor 342 from the surface of the second step 22, thus avoiding the formation of parasitic capacitance between the surface electrodes and the surface of the second step 22 due to the small size of the matching resistor 341 and the protection resistor 342.

[0079] According to embodiments of this disclosure, such as Figure 4 As shown, a boss 221 is formed on the second step 22. The other end of the matching resistor 341 is grounded through the boss 221, and the surface of the boss 221 is coplanar with the other end of the matching resistor 341.

[0080] In this implementation, the surface of the boss 221 is coplanar with the other end of the matching resistor 341, so that the length of the lead 5 between the other end of the matching resistor 341 and the boss 221 is as short as possible, reducing the parasitic inductance generated by the lead 5, thereby improving the bandwidth of the broadband detector.

[0081] According to embodiments of this disclosure, such as Figure 2 As shown, the DC circuit board 4 also includes a ground layer 42. The ground layer 42 is formed on the DC circuit board 4 and is arranged at a distance from the power supply layer 41.

[0082] According to embodiments of this disclosure, such as Figure 2 As shown, the matching circuit 34 also includes a decoupling capacitor 344, one end of which is electrically connected to the power supply layer 41, and the other end of which is connected to the ground layer 42.

[0083] As an example, the decoupling capacitor 344 has a capacitance of 100nF.

[0084] In this implementation, the decoupling capacitor 344 is attached to the DC circuit board 4, and one end of the decoupling capacitor 344 is electrically connected to the power supply layer 41, while the other end of the decoupling capacitor 344 is connected to the ground layer 42, which can filter out noise from the current flowing in from the external DC power supply.

[0085] Figure 5 This is a flowchart illustrating a method for fabricating a packaging module of a broadband detector according to an illustrative embodiment of the present disclosure.

[0086] According to another embodiment of this disclosure, a method for preparing the packaging module of the broadband detector described above is provided, such as... Figures 1 to 5 As shown, the preparation method includes the following steps S1 to S5.

[0087] Step S1: Attach the heat sink 2 into the accommodating space of the housing 1.

[0088] In some illustrative embodiments, conductive adhesive is used to tightly bond the heat sink 2 to the side wall of the housing 1 where the radio frequency port 10 is located.

[0089] Step S2: Mount the DC circuit board 4 on the first step 21 of the heat sink 2, mount the bypass capacitor 343 on the second step 22 of the heat sink 2, and mount the detector chip 32 and the signal transmission line 33 on the third step 23 of the heat sink 2.

[0090] According to an embodiment of this disclosure, the height of the second step 22 is higher than the height of the first step 21, and the height of the third step 23 is higher than the height of the second step 22.

[0091] In some illustrative embodiments, the adhesive used for bonding the DC circuit board 4 to the first step 21 of the heat sink 2, the bypass capacitor 343 to the second step 22 of the heat sink 2, and the detector chip 32 and signal transmission line 33 to the third step 23 of the heat sink 2 is conductive adhesive.

[0092] In some illustrative embodiments, the decoupling capacitor 344 is mounted on the DC circuit board 4 using conductive adhesive.

[0093] Step S3: Use conductive adhesive to electrically connect the signal transmission line 33 to the radio frequency port 10.

[0094] Step S4: Mount the matching resistor 341 and the protection resistor 342 onto the second step 22 using UV adhesive.

[0095] Step S5: Connect the first electrode 323 of the detector chip 32 to the signal transmission line 33, the first electrode 323 to the matching resistor 341, the matching resistor 341 to the boss 221 on the second step 22, the second electrode 324 of the detector chip 32 to the protection resistor 342, the upper electrode of the bypass capacitor 343 to the protection resistor 342, and the upper electrode of the bypass capacitor 343 to the power supply layer 41 of the DC circuit board 4 by wire bonding.

[0096] As an example, lead 5 can be a wedge-shaped gold wire to realize the transmission and interconnection of signals between the first electrode 323 of the detector chip 32 and the signal transmission line 33, the first electrode 323 and the matching resistor 341, the matching resistor 341 and the boss 221 on the second step 22, the second electrode 324 of the detector chip 32 and the protection resistor 342, the upper electrode of the bypass capacitor 343 and the protection resistor 342, and the upper electrode of the bypass capacitor 343 and the power supply layer 41 of the DC circuit board 4.

[0097] In some illustrative embodiments, conductive adhesive is used to optimize the dispensing of the lead 5 between the matching resistor 341 and the boss 221 on the second step 22.

[0098] After step S5, coupling is performed using a beveled optical fiber 31. Specifically, the beveled optical fiber 31 is mounted on the DC circuit board 4, so that the light signal emitted from the beveled optical fiber 31 illuminates the photosensitive surface 322 of the detector chip 32. After determining the position, UV adhesive is used to fill and fix it. Finally, parallel pressure welding technology is used to seal the housing 1 and the cover plate 7.

[0099] Figure 6 This is a comparison diagram of the frequency response curves S21 of the broadband detector before and after optimization according to an illustrative embodiment of the present disclosure.

[0100] like Figure 6 As shown, verification was performed with matching resistor 341 at 50Ω and 35Ω, respectively. Figure 6 The results are shown in two sets of curves, A and B (matching resistor 341 is 50Ω) and C and D (matching resistor 341 is 35Ω). Curves A and C represent the test results after the matching resistor 341 leads are grounded with adhesive after the fabrication method optimization, while curves B and D represent the test results before the fabrication method optimization, where the matching resistor 341 leads are grounded only. Each curve indicates the characteristic point where the bandwidth frequency response decreases by 3dB. The characteristic point before the fabrication method optimization is marked with a regular hexagon, and the characteristic point after the optimization is marked with a pentagram.

[0101] Comparing curves A and B, and curves C and D, it can be seen that the 3dB bandwidth of the optimized fabrication method is greater than 60 GHz, representing an improvement over the unoptimized method. Within the frequency response range from 0 to 3dB, the flatness of the unoptimized curve is approximately 6dB, while the optimized curve exhibits significantly reduced fluctuations and maintains an overall in-band flatness of 3dB, demonstrating a significant improvement in in-band flatness. These results indicate that the optimized fabrication method reduces the transmission loss of the broadband detector, increases its bandwidth, reduces parasitic inductance, and improves in-band flatness.

[0102] Those skilled in the art will understand that the features described in the various embodiments and / or claims of this disclosure can be combined or combined in various ways, even if such combinations or combinations are not explicitly described in this disclosure. In particular, the features described in the various embodiments and / or claims of this disclosure can be combined and / or combined in various ways without departing from the spirit and teachings of this disclosure. All such combinations and / or combinations fall within the scope of this disclosure.

[0103] It should also be noted that the directional terms mentioned in the embodiments, such as "up," "down," "front," "back," "left," and "right," are only for reference to the directions in the accompanying drawings and are not intended to limit the scope of protection of this disclosure. Throughout the drawings, the same elements are represented by the same or similar reference numerals. Conventional structures or constructions will be omitted where they may cause confusion in understanding this disclosure, and the shapes and dimensions of the components in the drawings do not reflect actual size and proportion, but are only schematic representations of the embodiments of this disclosure.

[0104] Unless otherwise stated, the numerical parameters in this specification and the appended claims are approximate values ​​and can be varied according to desired characteristics derived from the content of this disclosure. Specifically, all figures used in the specification and claims to indicate composition, reaction conditions, etc., should be understood to be modified by the term "about" in all cases. Generally, this means that a specific amount may vary by ±10% in some embodiments, ±5% in some embodiments, ±1% in some embodiments, and ±0.5% in some embodiments.

[0105] The use of ordinal numbers such as "first," "second," "third," etc., in the specification and claims to modify the corresponding elements does not imply that the element has any ordinal number, nor does it represent the order of one element with another element, or the order of manufacturing methods. The use of these ordinal numbers is only to enable a named element to be clearly distinguished from another element with the same name.

[0106] Furthermore, unless specifically described or required to occur in a specific order, the order of the above steps is not limited to those listed above and can be varied or rearranged according to the desired design. Moreover, the above embodiments can be used in combination with each other or with other embodiments based on design and reliability considerations; that is, technical features from different embodiments can be freely combined to form more embodiments.

[0107] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. The scope of this disclosure is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. A packaging module for a broadband detector, characterized in that, include: A housing having an accommodating space inside, and an RF port provided on one side of the housing; A heat sink is disposed in the accommodating space; A detection module is disposed on the heat sink, and the detection module includes: The detector chip, including a first electrode and a second electrode, is suitable for converting externally input optical signals into radio frequency signals. A signal transmission line, suitable for receiving the radio frequency signal and outputting it from the radio frequency port to an external circuit; The matching circuit includes a matching resistor, a protection resistor, and a bypass capacitor. The connection ends of at least a portion of the leads between the first electrode and the signal transmission line, between the first electrode and the matching resistor, between the matching resistor and ground, between the second electrode and the protection resistor, and between the upper electrode of the bypass capacitor and the protection resistor are coplanar.

2. The packaging module of the broadband detector according to claim 1, characterized in that, The outer side of the lead between the matching resistor and ground is covered with conductive adhesive.

3. The packaging module of the broadband detector according to claim 1, characterized in that, Also includes: A DC circuit board is disposed on the heat sink, the DC circuit board comprising: A power supply layer, formed on the DC circuit board, is adapted to apply a reverse bias voltage to the detector chip, so that the detector chip converts the optical signal into the radio frequency signal. The protection resistor is electrically connected between the power supply layer and the second electrode, and the bypass capacitor is electrically connected between the power supply layer and ground.

4. The packaging module of the broadband detector according to claim 3, characterized in that, The heat sink includes: The first step is suitable for supporting the DC circuit board; The second step is higher than the first step, and the second step is suitable for carrying the matching resistor, the protection resistor and the bypass capacitor; The third step, which is higher than the second step, is designed to support the detector chip and the signal transmission line, so that the externally input light signal can illuminate the detector chip.

5. The packaging module of the broadband detector according to claim 4, characterized in that, One end of the matching resistor is electrically connected to the first electrode, and the other end of the matching resistor is grounded to match the output impedance of the first electrode with the impedance of the signal transmission line; One end of the protective resistor is electrically connected to the second electrode; The upper electrode of the bypass capacitor is electrically connected to the other end of the protection resistor, and the lower electrode of the bypass capacitor is attached to the heat sink.

6. The packaging module of the broadband detector according to claim 5, characterized in that, The matching resistor and the protective resistor are bonded to the heat sink with UV adhesive to insulate the bottom of the matching resistor and the protective resistor from the surface of the heat sink.

7. The packaging module of the broadband detector according to claim 4, characterized in that, A boss is formed on the second step, and the other end of the matching resistor is grounded through the boss, and the surface of the boss is coplanar with the other end of the matching resistor.

8. The packaging module of the broadband detector according to claim 3, characterized in that, The DC circuit board also includes: A grounding layer is formed on the DC circuit board and is spaced apart from the power supply layer.

9. The packaging module of the broadband detector according to claim 8, characterized in that, The matching circuit further includes: A decoupling capacitor, one end of which is electrically connected to the power supply layer and the other end of which is connected to the ground layer.

10. A method for preparing a packaging module for a broadband detector as described in any one of claims 1-9, characterized in that, include: The heat sink is attached to the housing space; A DC circuit board is mounted on the first step of the heat sink, a bypass capacitor is mounted on the second step of the heat sink, and a detector chip and signal transmission line are mounted on the third step of the heat sink. The height of the second step is higher than the height of the first step, and the height of the third step is higher than the height of the second step. The signal transmission line is electrically connected to the radio frequency port using conductive adhesive. The matching resistor and the protection resistor are attached to the second step using UV adhesive. The first electrode of the detector chip is electrically connected to the signal transmission line, the first electrode to the matching resistor, the matching resistor to the boss on the second step, the second electrode of the detector chip to the protection resistor, the upper electrode of the bypass capacitor to the protection resistor, and the upper electrode of the bypass capacitor to the power supply layer of the DC circuit board by wire bonding.

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