Thin film circuit with beam lead and applied to high-frequency radio-frequency chip packaging and preparation method of thin film circuit

Abstract

The invention discloses a thin film circuit with a beam lead applied to high-frequency radio-frequency chip packaging and a preparation method of the thin film circuit with the beam lead applied to high-frequency radio-frequency chip packaging. The thin film circuit is a thin film circuit with a beam lead structure. The preparation method comprises the following steps: adhering a substrate material with the thickness of less than 127 microns to a quartz, silicon or silicon carbide gasket with the thickness of 200-1000 microns by adopting a temporary adhesive; manufacturing alignment marks and scribing marks of all subsequent steps on the substrate material by adopting a photoetching method; scribing according to the size of the circuit design; spin-coating a thick film photoresist, filling and leveling up the cutting channel, and grinding off the redundant photoresist by adopting a mechanical polishing process to expose the surface of the substrate; spin-coating thin film photoresist on the surface; manufacturing a metal seed layer; performing second photoetching on the seed layer to make all structures of the circuit; and the circuit structure with the beam lead is obtained. And a beam type lead structure is used for replacing a gold wire bonding process, so that the module packaging design is more compact, flexible and reliable.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor radio frequency chip packaging technology, and in particular to a packaging solution for millimeter wave, submillimeter wave and terahertz frequency doubling, mixing and amplification monolithic integrated chips using beam lead technology, and specifically to a thin film circuit with beam leads used for high-frequency radio frequency chip packaging and a preparation method thereof. Background Art

[0002] The terahertz frequency band has great application potential in many fields such as communication, imaging, and security inspection. As a key component in the terahertz system, the performance of terahertz solid-state devices is crucial to the entire system. However, there are many problems with the existing high-frequency RF chip packaging technology.

[0003] The traditional packaging method uses gold wire bonding technology to connect the chip and the probe. In the millimeter wave, submillimeter wave and terahertz frequency bands above 60GHz, large parasitic parameters such as inductance and capacitance will be introduced. These parasitic parameters will seriously affect the transmission quality of the terahertz signal, resulting in signal distortion and gain reduction. It is difficult to meet the requirements of RF chips for signal transmission, stability and reliability in the high frequency band. At high frequencies, the signal is easily distorted and there is a mismatch between the packaging structure and the integrated chip. New packaging technology is urgently needed to solve these problems. Summary of the invention

[0004] In view of the technical problems pointed out in the above background technology, the purpose of the present invention is to provide a thin film circuit with beam leads for high-frequency radio frequency chip packaging and a preparation method thereof.

[0005] To achieve the purpose of the present invention, the technical solution provided by the present invention is as follows:

[0006] First aspect

[0007] The present application provides a thin film circuit with beam leads for high-frequency radio frequency chip packaging, wherein the thin film circuit is a thin film circuit with a beam lead structure.

[0008] Second aspect

[0009] The present application provides a method for preparing a thin film circuit with beam leads for high-frequency radio frequency chip packaging, comprising the following steps:

[0010] Step 1: Using a temporary adhesive, a quartz, semi-insulating gallium arsenide or silicon carbide substrate material with a thickness of less than 127 μm is bonded to a quartz, silicon or silicon carbide spacer with a thickness of 200 μm to 1000 μm;

[0011] Step 2: Using a photolithography method to make alignment marks and scribe marks for all subsequent steps on a quartz, semi-insulating gallium arsenide or silicon carbide substrate material;

[0012] Step 3: Use high-speed grinding wheel cutting method to cut the slices according to the size of the circuit design, and the cutting depth is slightly greater than the thickness of the slice;

[0013] Step 4: Spin-coat thick film photoresist according to the thickness of the wafer to fill the cut path, and use mechanical polishing process to grind off the excess photoresist to expose the substrate surface;

[0014] Step 5: Spin-coat a thin film of photoresist on the surface and use a photolithography method to make the bottom layer of the circuit;

[0015] Step 6: Make a metal seed layer on the wafer in the previous step;

[0016] Step 7: Perform a second photolithography on the seed layer to make all the structures of the circuit, and use electroplating to thicken the pattern;

[0017] Step 8: After electroplating, remove the photoresist, etch the excess seed layer, remove the wax and the bottom pattern photoresist, and obtain a circuit structure with beam leads.

[0018] Wherein, the thick film photoresist adopts one or more of the following: SF15, SF11, NR9-3000.

[0019] Wherein, the thin film photoresist adopts AZ1500.

[0020] Wherein, in step six, a metal seed layer is prepared by magnetron sputtering or evaporation.

[0021] Compared with the prior art, the beneficial effect of adopting the above technical solution is that the semiconductor RF chip packaging technology provided by the present invention uses a beam lead structure to replace the gold wire bonding process, making the module packaging design more compact, flexible and reliable, effectively reducing parasitic parameters, reducing the problem of signal distortion at high frequencies, and enabling the signals of millimeter wave, submillimeter wave and terahertz frequency multiplication, mixing and amplification monolithic integrated chips to be effectively transmitted from input to output and work stably and efficiently at high frequencies. It provides strong support for high-frequency RF chips to achieve high gain, low loss, high frequency response and other performances. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The figure shows a state schematic diagram corresponding to step 1 in a method for preparing a thin film circuit with beam-type leads for high-frequency radio frequency chip packaging provided by this embodiment;

[0023] Figure 2 The figure shows a schematic diagram of the states corresponding to steps 2, 3 and 4 in a method for preparing a thin film circuit with beam leads for high-frequency radio frequency chip packaging provided by this embodiment;

[0024] Figure 3The figure shows a state schematic diagram corresponding to step 5 in a method for preparing a thin film circuit with beam leads for high-frequency radio frequency chip packaging provided by this embodiment;

[0025] Figure 4 The figure shows a schematic diagram of the states corresponding to steps six and seven in a method for preparing a thin film circuit with beam leads for high-frequency radio frequency chip packaging provided by this embodiment;

[0026] Figure 5 FIG. 1 is a top view structural schematic diagram a of a thin film circuit with beam leads applied to high-frequency radio frequency chip packaging provided by this embodiment;

[0027] Figure 6 The figure shows a side structural schematic diagram b of a thin film circuit with beam leads for high-frequency radio frequency chip packaging provided by the present embodiment. DETAILED DESCRIPTION

[0028] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the drawings 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.

[0029] This application invents a thin film circuit with a beam lead structure. The beam lead structure can make the module packaging design more compact, flexible and reliable. Its lead has a suitable length, width and thickness, which can effectively reduce the parasitic inductance and capacitance during the terahertz signal transmission process. This lead structure can maintain good signal transmission characteristics at high frequencies and reduce signal distortion.

[0030] Compared with the gold wire bonding process, the new RF chip packaging method provided by the present invention adopts a beam lead structure, which can effectively reduce the parasitic parameters introduced in the millimeter wave, submillimeter wave and terahertz frequency bands, thereby reducing the difference loss and improving the signal distortion at high frequencies, thereby ensuring the stable and efficient operation of the RF chip at high frequencies.

[0031] Example 1

[0032] like Figure 1 and Figure 6 As shown, this embodiment provides a thin film circuit with beam leads for high-frequency radio frequency chip packaging, and the thin film circuit is a thin film circuit with a beam lead structure.

[0033] Example 2

[0034] like Figure 1 and Figure 6As shown, this embodiment provides a method for preparing a thin film circuit with Liang's leads for high-frequency radio frequency chip packaging, comprising the following steps:

[0035] Step 1: Using a temporary adhesive, a substrate material such as quartz, semi-insulating gallium arsenide or silicon carbide with a thickness of less than 127 μm is bonded to a spacer such as quartz, silicon or silicon carbide with a thickness of 200 μm to 1000 μm;

[0036] Step 2: Use photolithography to make alignment marks and scribe marks for all subsequent steps on thin quartz, semi-insulating gallium arsenide or silicon carbide;

[0037] Step 3: Use high-speed grinding wheel cutting method to cut the slices according to the size of the circuit design, and the cutting depth is slightly greater than the thickness of the slice;

[0038] Step 4: Spin-coat thick film photoresists such as SF15, SF11, NR9-3000 according to the thickness of the wafer to fill the cut path, and use mechanical polishing process to grind off the excess photoresist to expose the substrate surface;

[0039] Step 5: Spin-coat a thin film photoresist such as AZ1500 on the surface and use a photolithography method to make the bottom layer pattern of the circuit.

[0040] Step 6: Prepare a metal seed layer on the wafer in the previous step by magnetron sputtering or evaporation;

[0041] Step 7: Perform a second photolithography on the seed layer to make all the structures of the circuit, and use electroplating to thicken the pattern;

[0042] Step 8: After electroplating, remove the photoresist, etch the excess seed layer, remove the wax and the bottom pattern photoresist, and obtain a circuit structure with beam leads.

[0043] The beneficial effect of adopting the above technical solution is that the beam lead structure can directly overlap the probe transition structure with the coplanar waveguide structure of the high-frequency RF chip, eliminating the gold wire bonding process and the loss caused by parasitic parameters such as excess inductance and capacitance introduced by the gold wire.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate and explain the present invention, and are not intended to limit the present invention to the scope of the described embodiments. In addition, those skilled in the art can understand that the present invention is not limited to the above embodiments, and more variations and modifications can be made according to the teachings of the present invention, and these variations and modifications all fall within the scope of the protection claimed by the present invention.

Claims

1. A thin film circuit with beam leads for high-frequency radio frequency chip packaging, characterized in that: The thin film circuit is a thin film circuit with a beam lead structure.

2. A method for preparing a thin film circuit with beam leads for high-frequency radio frequency chip packaging, characterized in that: The steps include: Step 1: Using a temporary adhesive, a quartz, semi-insulating gallium arsenide or silicon carbide substrate material with a thickness of less than 127 μm is bonded to a quartz, silicon or silicon carbide spacer with a thickness of 200 μm to 1000 μm; Step 2: Using a photolithography method to make alignment marks and scribe marks for all subsequent steps on a quartz, semi-insulating gallium arsenide or silicon carbide substrate material; Step 3: Use high-speed grinding wheel cutting method to cut the slices according to the size of the circuit design, and the cutting depth is slightly greater than the thickness of the slice; Step 4: Spin-coat thick film photoresist according to the thickness of the wafer to fill the cut path, and use mechanical polishing process to grind off the excess photoresist to expose the substrate surface; Step 5: Spin-coat a thin film of photoresist on the surface and use a photolithography method to make the bottom layer of the circuit; Step 6: Make a metal seed layer on the wafer in the previous step; Step 7: Perform a second photolithography on the seed layer to make all the structures of the circuit, and use electroplating to thicken the pattern; Step 8: After electroplating, remove the photoresist, etch the excess seed layer, remove the wax and the bottom pattern photoresist, and obtain a circuit structure with beam leads.

3. The method for preparing a thin film circuit with beam leads for high-frequency radio frequency chip packaging according to claim 2, characterized in that: The thick film photoresist is one or more of the following: SF15, SF11, NR9-3000.

4. The method for preparing a thin film circuit with beam leads for high-frequency radio frequency chip packaging according to claim 2, characterized in that: The thin film photoresist is AZ1500.

5. The method for preparing a thin film circuit with beam leads for high-frequency radio frequency chip packaging according to claim 2, characterized in that: In step six, a metal seed layer is formed by magnetron sputtering or evaporation.

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