A microwave semiconductor chip assembly and a microwave semiconductor device

Abstract

The application discloses a microwave semiconductor chip assembly and belongs to the technical field of semiconductor chip assembly. The existing microwave chip adopts a two-dimensional paving form, and has the problems of large volume and low integration density. The microwave semiconductor chip assembly comprises a plurality of microwave semiconductor chips and special-shaped gaskets. The special-shaped gasket is located between every two adjacent upper and lower chips, the upper surface of the special-shaped gasket is gold-plated, the upper surface of the special-shaped gasket is electrically connected with the upper chip, and the lower surface of the special-shaped gasket is insulated from the lower chip. The lower surface of the chip is electrically connected with the upper surface of the substrate or the special-shaped gasket. The bonding point of the chip is electrically interconnected with the bonding point of the substrate or other chips through a lead wire. The bottom surface of the substrate is further provided with a bump or a pin. The microwave semiconductor chip assembly realizes the three-dimensional assembly of the multilayer microwave semiconductor chip and has high integration density.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor chip assembly technology, and particularly relates to a microwave semiconductor chip assembly and a microwave semiconductor device. Background Technology

[0002] The improved adaptability of precision-guided weapons requires more complex functions in the seeker subsystem. The contradiction between the complex and multifunctional integration requirements of radar systems and their miniaturization and weight reduction is becoming increasingly prominent. While ensuring performance, improving the system integration per unit volume is an effective way to solve this contradiction.

[0003] Traditional radar microwave systems require microwave grounding on the back of the microwave chips, so they use a two-dimensional flat arrangement of microwave chips. This method results in large size and low integration density. Summary of the Invention

[0004] Based on the above analysis, the present invention aims to provide a microwave semiconductor chip assembly and microwave semiconductor device to solve the following technical problems: existing microwave chips adopt a two-dimensional flat form, which has a large volume and low integration density.

[0005] The objective of this invention is mainly achieved through the following technical solutions:

[0006] This invention provides a microwave semiconductor chip assembly, which includes multiple microwave semiconductor chips and irregularly shaped spacers. The irregularly shaped spacers are located between every two adjacent upper and lower chips. The upper surface of the irregularly shaped spacers is gold-plated and electrically connected to the upper chips. The lower surface of the irregularly shaped spacers is insulated from the lower chips. The lower surface of the chips is electrically connected to the substrate or the upper surface of the irregularly shaped spacers. The bonding points of the chips are electrically interconnected with the bonding points of the substrate or other chips through leads. The bottom surface of the substrate is also provided with bumps or pins.

[0007] Furthermore, both the upper and lower layer chips are bare chips, and the back of the bare chips is gold-plated.

[0008] Furthermore, the size of the upper-layer chip is smaller than the size of the irregularly shaped pad.

[0009] Furthermore, the leads are made of gold or aluminum wire.

[0010] Furthermore, the irregularly shaped gasket includes an upper plate and a support component below the upper plate.

[0011] Furthermore, there are multiple supporting components.

[0012] Furthermore, the irregularly shaped pads are designed to avoid the circuit patterns on the surface of the underlying chip.

[0013] Furthermore, irregularly shaped gaskets are prepared by silicon etching on silicon wafers.

[0014] Furthermore, the processing flow for irregularly shaped gaskets includes:

[0015] Step 1: Grow silicon dioxide on the upper surface of a silicon wafer using chemical vapor deposition.

[0016] Step 2: Grow a Ti layer as an adhesion layer using physical vapor deposition.

[0017] Step 3: Use physical vapor deposition to grow an Au layer as the top conductive layer to form an electrical connection with the upper chip.

[0018] Step 4: Apply a protective layer to the gold layer surface and use silicon deposition etching to form a height-controllable groove on the lower surface of the silicon wafer;

[0019] Step 5: Remove the protective layer from the top surface;

[0020] Step 6: Divide the sheet to form a single irregularly shaped gasket.

[0021] Furthermore, in step 3, the thickness of the Au layer is the same as the thickness of the gold layer on the back of the upper chip.

[0022] The present invention also provides a microwave semiconductor device, including a housing and a microwave semiconductor chip assembly disposed within the housing.

[0023] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0024] a) The microwave semiconductor chip assembly of the present invention uses irregularly shaped spacers, which are located between every two adjacent upper and lower chips. The upper surface of the irregularly shaped spacers is gold-plated and electrically connected to the upper chip. The lower surface of the irregularly shaped spacers is insulated from the lower chip. This achieves three-dimensional assembly of multilayer microwave semiconductor chips with high integration density.

[0025] b) The microwave semiconductor chip assembly of the present invention uses irregularly shaped pads between every two adjacent upper and lower chips, and then the bonding points of the chips are electrically interconnected with the bonding points of the substrate or other chips through leads. There is no need to design a special chip structure for three-dimensional packaging. Existing commercially available ordinary chips can be used, which is low cost.

[0026] c) The assembly method of the microwave semiconductor chip assembly of the present invention is based on fully automatic / semi-automatic chip mounting equipment. Through reasonable process flow, strict process parameter control and effective tooling guarantee, the alignment accuracy of irregularly shaped pads is better than ±5um, and finally the three-dimensional assembly of multilayer microwave semiconductor chips is realized.

[0027] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings. Attached Figure Description

[0028] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0029] Figure 1 This is a schematic diagram of the overall structure of the microwave semiconductor chip assembly of the present invention;

[0030] Figure 2 This is a cross-sectional view of a portion of the structure of the microwave semiconductor chip assembly of the present invention;

[0031] Figure 3 This is one of the overall structural schematic diagrams of the microwave semiconductor chip assembly of the present invention;

[0032] Figure 4 This is a schematic diagram of the adhesive application fixture of the present invention;

[0033] Figure 5 This is a process flow diagram of the present invention.

[0034] Figure label:

[0035] 1-Jig base, 2-Groove, 3-Push block, 4-First lead, 5-Second lead, 6-Third lead, 7-Substrate, 8-Lower chip, 9-Fourth lead, 10-Irregularly shaped pad, 1001-Upper board, 1002-Support component, 11-Upper chip, 12-Insulating adhesive. Detailed Implementation

[0036] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of the present invention and, together with the embodiments of the present invention, serve to illustrate the principles of the present invention.

[0037] This invention provides a microwave semiconductor chip assembly, such as... Figure 1 As shown, the microwave semiconductor chip assembly includes multiple microwave semiconductor chips and irregularly shaped spacers 10. The irregularly shaped spacers 10 are located between every two adjacent upper and lower chips. The upper surface of the irregularly shaped spacers 10 is gold-plated and electrically connected to its upper chip. The lower surface of the irregularly shaped spacers 10 is insulated from the lower chip. The lower surface of the chip is electrically connected to the substrate 7 or the upper surface of the irregularly shaped spacers 10. The bonding points of the chip are electrically interconnected with the bonding points of the substrate 7 or other chips through leads.

[0038] Specifically, both the upper and lower layer chips are bare chips. The material of the bare chips can be GaAs or GaN. The bare chips undergo back gold plating, that is, gold plating on the back of the bare chips.

[0039] Compared with the prior art, the microwave semiconductor chip assembly of the present invention uses irregularly shaped spacers, which are located between every two adjacent upper and lower chips. The upper surface of the irregularly shaped spacers is gold-plated and electrically connected to their upper chips, while the lower surface of the irregularly shaped spacers is insulated from the lower chips. This achieves three-dimensional assembly of multilayer microwave semiconductor chips with high integration density.

[0040] Specifically, the lead wire is made of gold or aluminum wire.

[0041] Specifically, the irregularly shaped gasket 10 includes an upper plate 1001 and a support component 1002 below the upper plate.

[0042] Specifically, the support component 1002 can be plate-shaped or cylindrical.

[0043] To ensure the support effect, the number of support components 1002 can be multiple.

[0044] Specifically, considering that the upper surface of the lower-layer chip contains a microstrip structure, its characteristic impedance is highly sensitive to the dielectric constant of the chip surface mount material. Furthermore, the chip surface often contains air bridge structures. Therefore, the irregularly shaped pad 10 must avoid causing the air bridges to collapse when supporting the upper-layer chip. Thus, the shape design and material selection of the irregularly shaped pad 10 should avoid the circuit patterns on the surface of the lower-layer chip, while minimizing its impact on the transmission line impedance characteristics of the lower-layer chip.

[0045] Specifically, in order to ensure the high-frequency performance of the underlying chip, the substrate of the irregularly shaped pad 10 can preferably be silicon material. In this way, the impact of the irregularly shaped pad 10 on the transmission line impedance characteristics of the underlying chip is within 5%.

[0046] Specifically, considering that if the height of the support component 1002 is too low, it will affect the electrical performance of the underlying chip, such as worsening the standing wave ratio and causing uneven gain; if it is too high, it will reduce the strength of the microwave semiconductor chip assembly. Therefore, the ratio of the height of the support component 1002 to the height of the upper plate 1001 is controlled to be 0.8:1 to 1.5:1. Preferably, the ratio of the height of the support component 1002 to the height of the upper plate 1001 is 1:1.

[0047] Specifically, the height of the control support component 1002 is 100 to 200 micrometers.

[0048] Specifically, the height of the upper plate 1001 is 100-150 micrometers.

[0049] Specifically, to prevent cracking during the bonding process of the upper-layer chip, the size of the upper-layer chip is smaller than the size of the upper board 1001.

[0050] Specifically, the size of the upper board 1001 is smaller than the size of the lower layer chip.

[0051] Specifically, in order to ensure the strength of the irregularly shaped gasket 10, the surface area of ​​the contact part between the support component 1002 and the lower chip accounts for more than 50% of the surface area of ​​the upper surface of the lower chip.

[0052] Specifically, the bottom surface of substrate 7 is also provided with bumps to facilitate the routing of circuit I / O ports. The bumps can be formed by BGA ball mounting.

[0053] Alternatively, the substrate 7 can be soldered to a leaded housing to complete the circuit I / O port lead-out.

[0054] Specifically, the irregularly shaped pad 10 can be prepared by silicon etching on a silicon wafer.

[0055] Specifically, the processing flow of the irregularly shaped gasket 10 includes:

[0056] Step 1: Grow silicon dioxide on the upper surface of a silicon wafer using chemical vapor deposition.

[0057] Step 2: Grow a Ti layer as an adhesion layer using physical vapor deposition.

[0058] Step 3: Use physical vapor deposition to grow an Au layer as the top conductive layer to form an electrical connection with the upper chip.

[0059] Step 4: Apply a protective layer to the gold layer surface and use silicon deposition etching to form a height-controllable groove on the lower surface of the silicon wafer;

[0060] Step 5: Remove the protective layer from the top surface;

[0061] Step 6: Divide the sheet to form a single irregularly shaped gasket 10.

[0062] Specifically, in step 3 above, if the Au layer is too thick, the cost will be too high; if the thickness is too thin, the bonding strength when bonding with the upper chip will be too low, affecting the wire bonding strength and thus the grounding effect. Therefore, the thickness of the Au layer should be controlled to be consistent with the thickness of the gold layer on the back of the upper chip.

[0063] The microwave semiconductor chip assembly of the present invention employs a method of placing irregularly shaped pads between every two adjacent upper and lower chips, and then electrically interconnecting the chip bonding points with the substrate or other chip bonding points through leads. This eliminates the need for designing a special chip structure for three-dimensional packaging, and allows the use of existing commercially available chips. The microwave semiconductor chip assembly is three-dimensionally assembled, resulting in a small size and high density.

[0064] The present invention also provides a method for assembling a microwave semiconductor chip assembly, comprising the following steps:

[0065] S1. The lower surface of the lower-layer chip is electrically connected to the substrate;

[0066] S2. The bonding points of the lower-layer chip are electrically interconnected by bonding with the bonding points of the substrate through wires.

[0067] S3. The lower surface of the irregularly shaped pad is assembled with the underlying chip through insulating adhesive;

[0068] S4. The upper surface of the irregularly shaped pad is electrically connected to the lower surface of the upper chip, and the irregularly shaped pad is bonded to the grounding bonding point of the substrate through a lead wire.

[0069] S5. The bonding points of the upper-layer chip are electrically interconnected with the bonding points of the lower-layer chip or the bonding points of the substrate through wire bonding.

[0070] Specifically, in S1 and S4, conductive adhesive or solder is used for conductive connection. The conductive adhesive or solder pad is applied using a fully automatic / semi-automatic chip mounter or manually. The conductive adhesive is baked and cured in a curing oven or the solder pad is melted and welded in a hot plate / vacuum brazing oven.

[0071] Specifically, in S3, on the stage of the fully automatic / semi-automatic placement machine, after the irregularly shaped pad is adsorbed by the placement machine suction head, a certain thickness of insulating adhesive is applied.

[0072] The positioning system of the pick and place machine enables the alignment and mounting of irregularly shaped spacers and underlying chips;

[0073] The irregularly shaped gasket is bonded and fixed to the underlying chip through a curing oven.

[0074] Specifically, in S3 above, the irregularly shaped gasket is dipped in insulating adhesive using an adhesive-dipping fixture; such as Figure 3 The diagram shows the structure of the adhesive application fixture, which includes a fixture base 1, a groove 2, and a pressing block 3.

[0075] The tooling base 1 has a groove 2 of a certain depth in the center; the push block 3 is installed on the tooling base 1, and the insulating glue is applied to the groove 2; the insulating glue 12 in the groove 2 is pushed by the push block 3 to obtain glue of a certain thickness.

[0076] Specifically, in S3 above, the adhesive applicator is placed on the stage of the fully automatic / semi-automatic pick and place machine. After the irregularly shaped pad 10 is adsorbed by the pick and place machine suction head, it is pressed into the groove 2 of the adhesive applicator to pick up the insulating adhesive 12.

[0077] The microwave semiconductor chip assembly of this invention employs a method of placing irregularly shaped spacers between every two adjacent upper and lower layer chips, wherein the irregularly shaped spacers are aligned and mounted with the lower layer chips. To achieve this alignment, the irregularly shaped spacers are picked up by a pick-and-place machine nozzle, coated with a certain thickness of insulating adhesive, and then aligned and mounted using a pick-and-place machine alignment system. Finally, a curing oven is used to bond and fix the irregularly shaped spacers to the lower layer chips. In this invention, the shape of the irregularly shaped spacers needs to avoid the circuit patterns on the surface of the lower layer chips; therefore, the shape of the irregularly shaped spacers varies depending on the circuit patterns on the surface of the lower layer chips, resulting in different contact surfaces between the irregularly shaped spacers and the lower layer chips. Ensuring the consistency of the amount and uniformity of adhesive applied to the contact surfaces of the irregularly shaped spacers and the lower layer chips during adhesive application is of great importance. This is because when the amount of adhesive applied to the contact surface between the irregularly shaped gasket and the underlying chip is different or uneven, it will affect the bonding strength and assembly accuracy of the product, and at the same time affect the quality and extent of the adhesive bonding surface.

[0078] To improve adhesive uniformity, an ultrasonic generator is installed below the adhesive application fixture of this invention. This ultrasonic generator is detachably and fixedly mounted on the stage of a fully automatic / semi-automatic chip mounter. Before or during adhesive application, the ultrasonic generator is activated. Under its action, the adhesive undergoes a slight flow, which helps to eliminate residual air bubbles in the adhesive, ensuring that the applied adhesive is bubble-free and thus improving the adhesion between the shaped pad and the underlying chip. Furthermore, it promotes a reasonable and uniform distribution of the adhesive, avoiding differences in adhesive application amount and uniformity caused by variations in the adhesive surface force due to differences in the structure and contact surface shape of the shaped pad when it enters the adhesive. The power of the ultrasonic generator can be set according to actual needs, as long as it effectively removes air bubbles from the adhesive.

[0079] For applications requiring precise control of adhesive application, an adhesive thickness detection device can be installed. One possible design utilizes optical equipment for this purpose. Specifically, optical imaging is used to measure the distance between the beginning and end of the adhesive application, thus achieving accurate thickness measurement. This optical equipment includes cameras, video cameras, and other imaging devices. To improve resolution and ensure measurement accuracy, invisible light imaging devices, such as ultraviolet imaging devices, are used to image the adhesive applied to the irregularly shaped gasket using specific invisible light. If the adhesive itself has invisible light absorption capabilities, it can be imaged directly. If the adhesive does not have these capabilities, an invisible light absorber that does not affect its properties can be added. Based on the data collected by the imaging device, the distance between the beginning and end of the adhesive application on the irregularly shaped gasket is calculated, thus yielding the adhesive thickness value. To facilitate the real-time acquisition of the adhesive thickness, an imaging device is installed on one side of the adhesive-dipping fixture. After the irregularly shaped pad is dipped in adhesive, it passes vertically through the imaging area of ​​the imaging device. The vertical distance between the beginning and end of the adhesive dipped in the irregularly shaped pad is obtained by comparing the positions of the beginning and end of the adhesive, thereby obtaining the thickness value of the dipped adhesive.

[0080] Specifically, to protect the aforementioned microwave semiconductor chip assembly from environmental changes such as temperature and humidity, and to prevent damage caused by mechanical vibration and impact, the assembly method for the aforementioned microwave semiconductor chip assembly further includes:

[0081] S6. Encapsulate the components obtained in step S5.

[0082] Specifically, the encapsulation process can employ liquid colloid filling under vacuum conditions or gas-tight packaging.

[0083] Specifically, the assembly method for the aforementioned microwave semiconductor chip components also includes:

[0084] S7. After liquid colloid filling and encapsulation under vacuum conditions, bumps are formed on the bottom surface of substrate 7 by BGA ball implantation.

[0085] The method of this invention, through reasonable process flow, strict process parameter control, and effective tooling guarantee, enables the alignment accuracy of irregularly shaped gaskets to be better than ±5µm, and ultimately realizes the three-dimensional assembly of multilayer microwave semiconductor chips.

[0086] The method of this invention is based on fully automatic / semi-automatic chip mounting equipment. It has formulated a scientific and reasonable process scheme for three-dimensional assembly of microwave semiconductor chips using irregularly shaped spacers, and finally obtained a method that can effectively achieve three-dimensional assembly of multilayer microwave semiconductor chips.

[0087] Example 1

[0088] This embodiment provides a microwave semiconductor chip assembly, such as... Figure 1-3 The diagram shows a schematic of a microwave semiconductor chip assembly. In this embodiment, the microwave semiconductor chip assembly includes, from bottom to top, a substrate 7, a lower chip 8, a shaped pad 10, and an upper chip 11. The shaped pad 10 is located between the upper chip 11 and the lower chip 8. The upper surface of the shaped pad 10 is gold-plated. The upper surface of the shaped pad 10 is electrically connected to the lower surface of the upper chip 11, and the lower surface of the shaped pad 10 is insulated from the lower chip 8. The lower surface of the lower chip 8 is electrically connected to the substrate 7. The bonding points of the upper chip 11 are electrically interconnected with the bonding points of the substrate 7 via a first lead 4. The shaped pad 10 is bonded to the grounding pad point of the substrate 7 via a second lead 5 to achieve good grounding. The bonding points of the lower chip 8 are electrically interconnected with the bonding points of the substrate 7 via a third lead 6. The bonding points of the upper chip 11 are electrically interconnected with the bonding points of the lower chip 8 via a fourth lead 9.

[0089] Specifically, BGA ball bearings are applied to the bottom surface of substrate 7 to form bumps, thereby completing the lead-out of the circuit I / O ports.

[0090] Specifically, both the upper-layer chip 11 and the lower-layer chip 8 are bare chips. The material of the bare chips is GaAs, and the bare chips undergo back gold treatment.

[0091] Specifically, the first to fourth leads are all made of gold wire.

[0092] Specifically, the irregularly shaped gasket 10 includes an upper plate 1001 and a support component 1002 below the upper plate; three support components 1002 are provided, and the support components 1002 are plate-shaped. The height of the upper plate 1001 is 150 micrometers, and the height of the support component 1002 is 100 micrometers.

[0093] Specifically, the shape of the irregular pad 10 is designed to avoid the circuit pattern on the surface of the underlying chip 8.

[0094] Specifically, the irregularly shaped spacer 10 has less than 5% impact on the transmission line impedance characteristics of the underlying chip.

[0095] The size of the upper-layer chip is smaller than the size of the upper board 1001.

[0096] Specifically, the size of the upper board 1001 is smaller than the size of the lower layer chip.

[0097] Specifically, in order to ensure the strength of the irregularly shaped gasket 10, the surface area of ​​the contact part between the support component 1002 and the lower chip accounts for 60% of the surface area of ​​the upper surface of the lower chip.

[0098] Specifically, the processing flow of the irregularly shaped gasket 10 includes:

[0099] Step 1: Grow silicon dioxide on the upper surface of a silicon wafer using chemical vapor deposition.

[0100] Step 2: Grow a Ti layer as an adhesion layer using physical vapor deposition.

[0101] Step 3: Use physical vapor deposition to grow an Au layer as the top conductive layer to form an electrical connection with the upper chip.

[0102] Step 4: Apply a protective layer to the gold layer surface and use silicon deposition etching to form a height-controllable groove on the lower surface of the silicon wafer;

[0103] Step 5: Remove the protective layer from the top surface;

[0104] Step 6: Divide the sheet to form a single irregularly shaped gasket 10.

[0105] Example 2

[0106] This embodiment provides a method for assembling microwave semiconductor chip components, such as... Figure 5 As shown, it includes:

[0107] S1. The lower surface of the lower chip 8 and the upper surface of the substrate 7 are electrically connected by using conductive adhesive or soldering.

[0108] S2. The bonding pads of the lower chip 8 are electrically interconnected with the bonding pads of the substrate 7 through the third lead 6.

[0109] S3. The lower surface of the irregularly shaped pad 10 is assembled with the lower chip 8 through insulating adhesive;

[0110] S4. The upper surface of the irregularly shaped pad 10 is electrically connected to the lower surface of the upper chip 11, and the irregularly shaped pad 10 is bonded to the grounding bonding point of the substrate 7 through the second lead 5.

[0111] S5. The bonding point of the upper chip 11 is electrically interconnected with the bonding point of the lower chip 8 through the fourth lead 9, and the bonding point of the upper chip 11 is electrically interconnected with the bonding point of the substrate 7 through the first lead 4.

[0112] Specifically, in S1 and S4, conductive adhesive or solder is used for conductive connection. The conductive adhesive or solder pad is applied using a fully automatic / semi-automatic chip mounter or manually. The conductive adhesive is baked and cured in a curing oven or the solder pad is melted and welded in a hot plate / vacuum brazing oven.

[0113] Specifically, in S3, on the stage of the fully automatic / semi-automatic placement machine, after the irregularly shaped pad is adsorbed by the placement machine suction head, a certain thickness of insulating adhesive is applied.

[0114] The positioning system of the pick and place machine enables the alignment and mounting of irregularly shaped spacers and underlying chips;

[0115] The irregularly shaped gasket is bonded and fixed to the underlying chip through a curing oven.

[0116] Specifically, in S3 above, the irregularly shaped gasket is dipped in insulating adhesive using an adhesive-dipping fixture; such as Figure 4 The diagram shows the structure of the adhesive application fixture, which includes a fixture base 1, a groove 2, and a pressing block 3.

[0117] The tooling base 1 has a groove 2 of a certain depth in the center; the push block 3 is installed on the tooling base 1, and the insulating glue is applied to the groove 2; the insulating glue 12 in the groove 2 is pushed by the push block 3 to obtain glue of a certain thickness.

[0118] Specifically, in S3 above, the adhesive applicator is placed on the stage of the fully automatic / semi-automatic pick and place machine. After the irregularly shaped pad 10 is adsorbed by the pick and place machine suction head, it is pressed into the groove 2 of the adhesive applicator to pick up the insulating adhesive 12.

[0119] Specifically, to protect the aforementioned microwave semiconductor chip assembly from environmental changes such as temperature and humidity, and to prevent damage caused by mechanical vibration and impact, the assembly method for the aforementioned microwave semiconductor chip assembly further includes:

[0120] S6. The components obtained in step S5 are encapsulated using liquid colloid filling under vacuum conditions.

[0121] S7. Bumps are formed on the bottom surface of substrate 7 by BGA ball placement.

[0122] Example 3

[0123] This embodiment provides a microwave semiconductor device, including a housing and a microwave semiconductor chip assembly disposed within the housing. This microwave semiconductor device can be used in radar systems or aircraft. When used in aircraft, the microwave semiconductor device will inevitably be subjected to certain impacts during flight or landing. To improve the device's vibration resistance, the microwave semiconductor device also includes a shock-resistant structure, through which the microwave semiconductor chip assembly is connected to the housing.

[0124] The seismic-resistant structure includes a first curved rod, a connecting sleeve, and a second curved rod. One end of the first curved rod is slidably connected to one end of the second curved rod via the connecting sleeve. The other ends of the first and second curved rods are connected to the housing. The microwave semiconductor chip assembly is mounted on the connecting sleeve. In this way, on the one hand, since both the first and second curved rods are arc-shaped, they can undergo a certain degree of elastic deformation when the microwave semiconductor chip assembly is subjected to impact, thus providing a buffering effect. On the other hand, the slidable connection between one end of the first curved rod and one end of the second curved rod via the connecting sleeve causes their ends to move closer together during elastic deformation, increasing their elastic deformation and further buffering the impact.

[0125] Considering that all materials have a deformation limit, to prevent excessive deformation of the first and second bent rods leading to failure, the relative sliding displacement between the first and second bent rods needs to be appropriately limited. One end of the connecting sleeve is fitted onto the outer wall of the first bent rod, and the other end of the connecting sleeve is fitted onto the outer wall of the second arc-shaped tube. Limiting elements are provided between the connecting sleeve and the first bent rod, and between the connecting sleeve and the second bent rod. For example, the limiting elements include an outer ring provided on the outer wall of the first and second bent rods, and an inner ring provided on the inner wall of the connecting sleeve. The outer ring is a rigid ring, and the inner ring is an elastic ring. The inner diameter of the inner ring is smaller than the outer diameter of the outer ring, and the inner diameter of the multiple inner rings gradually decreases along the direction gradually approaching the midpoint of the connecting sleeve.

[0126] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A microwave semiconductor chip assembly, characterized in that, The microwave semiconductor chip assembly includes multiple microwave semiconductor chips and irregularly shaped spacers (10); the irregularly shaped spacers (10) are located between every two adjacent upper and lower chips, the upper surface of the irregularly shaped spacers (10) is gold-plated, and the upper surface of the irregularly shaped spacers (10) is electrically connected to its upper chips. The bonding points of the upper chips (11) are electrically interconnected with the bonding points of the substrate (7) through the first lead (4); the bonding points of the lower chips (8) are electrically interconnected with the bonding points of the substrate (7) through the third lead (6); the bonding points of the upper chips (11) are electrically interconnected with the bonding points of the substrate (7) through the third lead (6); The four leads (9) are electrically interconnected with the bonding point of the lower chip (8); the irregular pad (10) is grounded by bonding with the ground pad point of the substrate (7) through the second lead (5), and the lower surface of the irregular pad (10) is insulated from the lower chip; the lower surface of the upper chip (11) is electrically connected to the upper surface of the irregular pad (10), and the lower surface of the lower chip (8) is electrically connected to the upper surface of the substrate (7); the bottom surface of the substrate (7) is also provided with bumps or pins; both the upper chip and the lower chip are bare chips, and the back of the bare chip is gold plated. The irregularly shaped pad (10) includes an upper plate (1001) and a support member (1002) below the upper plate. The ratio of the height of the support member (1002) to the height of the upper plate (1001) is 0.8:1 to 1.5:

1. The height of the support member (1002) is 100 to 200 micrometers, and the height of the upper plate (1001) is 100 to 150 micrometers. The surface area of ​​the contact part between the support member (1002) and the lower chip accounts for more than 50% of the surface area of ​​the upper surface of the lower chip. The irregularly shaped pad (10) is prepared by silicon etching on a silicon wafer, and the processing flow includes: Step 1: Grow silicon dioxide on the upper surface of a silicon wafer using chemical vapor deposition. Step 2: Grow a Ti layer as an adhesion layer using physical vapor deposition. Step 3: Use physical vapor deposition to grow an Au layer as the top conductive layer to form an electrical connection with the upper chip. Step 4: Apply a protective layer to the gold layer surface and use silicon deposition etching to form a height-controllable groove on the lower surface of the silicon wafer; Step 5: Remove the protective layer from the top surface; Step 6: Divide the sheet to form a single irregularly shaped gasket (10).

2. The microwave semiconductor chip assembly according to claim 1, characterized in that, The size of the upper chip is smaller than the size of the irregular pad (10).

3. The microwave semiconductor chip assembly according to claim 1, characterized in that, The lead wire is made of gold or aluminum.

4. The microwave semiconductor chip assembly according to claim 1, characterized in that, The number of the support components (1002) is multiple.

5. The microwave semiconductor chip assembly according to claim 1, characterized in that, The shape of the irregular pad (10) is designed to avoid the circuit pattern on the surface of the underlying chip.

6. A microwave semiconductor device, characterized in that, Includes a housing and a microwave semiconductor chip assembly as described in any one of claims 1-5 disposed within the housing.

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