Antenna module and method for producing the same

Abstract

The present invention provides an antenna module comprising a first flexible circuit board, a second flexible circuit board electrically connected to the first flexible circuit board, a radio frequency front-end chip soldered to the second flexible circuit board, and an antenna. The antenna is fixed to the first flexible circuit board and electrically connected to the radio frequency front-end chip. A solder pad is provided on a side of the first flexible circuit board adjacent to the second flexible circuit board, and the radio frequency front-end chip is flip-chip soldered to the pad. The antenna module of the present invention can improve antenna reception sensitivity, reduce power consumption, and extend battery life. Compared with current designs, it can save 15% of area, eliminate a substrate layer, reduce the metal shielding cover, and reduce the height of the radio frequency front-end circuit by approximately 0.5 mm.

Description

Technical Field

[0001] The present invention relates to an antenna module and a method for producing the antenna module. Background Art

[0002] The built-in antenna is a key piece of hardware in smartphones. It enables functions like phone calls, internet access, Bluetooth transmission, and GPS positioning. As phones become smaller and thinner, more demands are placed on the antenna's size and signal transmission and reception capabilities. Dr. Yuan Tao improved the antenna structure in many papers, such as Zhang, X., Tan, TY, Wu, QS, Zhu, L., Zhong, S., & Yuan, T. (2021). Pin-loaded patch antenna fed with a dual-mode SIW resonator for bandwidth enhancement and stable high gain. IEEE Antennas and Wireless Propagation Letters, 20(2), 279-283., Huang, GL, Sim, CYD, Liang, SY, Liao, WS, & Yuan, T. (2018). Low-profile flexible UHF RFID tag design for wristbands applications. Wireless Communications and Mobile Computing, 2018., Li, GX, Zhang, X., Hong, KD, Zhu, L., & Yuan, T. (2020, December). Differentially-Fed Circular Patch Antenna under Dual High-order Modes for Enhanced Bandwidth and Stable High Gain.In 2020IEEE Asia-Pacific MicrowaveConference(APMC)(pp.66-68).IEEE., Han, CZ, Huang, GL, Yuan, T., & Hong, W. (2018). A frequency-reconfigurable tuner-loaded coupled-fed frame-antenna for all-metal-shell handsets. IEEE Access,6,64041-64049., Huang, GL, Zhou, SG, Chio, TH, & Yuan, T. (2017).Lightweight perforated waveguide structure realized by 3-D printing for RF applications. IEEE Transactions on Antennas and Propagation, 65(8), 3897-3904. .

[0003] With the increase in frequency bands and the widespread use of MIMO and CA, the number and complexity of components in the RF front-end and antenna of 5G mobile phones have increased significantly. The demand for extreme appearance and large-capacity batteries has further compressed the space required for the RF front-end and antenna. The urgent need for small size and high performance is driving the development of antennas and RF front-ends towards modularization.

[0004] In view of this, it is necessary to improve the existing antenna module to solve the above problems. Summary of the Invention

[0005] The object of the present invention is to provide an antenna module to solve the problem in the prior art that the radio frequency front end and the antenna occupy a large space.

[0006] To achieve the above-mentioned objectives, the present invention provides an antenna module, which includes a first flexible circuit board, a second flexible circuit board electrically connected to the first flexible circuit board, a radio frequency front-end chip soldered in the second flexible circuit board, and an antenna. The antenna is fixed on the first flexible circuit board and electrically connected to the radio frequency front-end chip. A solder pad is provided on one side of the first flexible circuit board close to the second flexible circuit board, and the radio frequency front-end chip is soldered on the solder pad in a bare chip flip-chip manner.

[0007] As a further improvement of the present invention, the first flexible circuit board and the second flexible circuit board are FPC circuit boards or LCP circuit boards.

[0008] As a further improvement of the present invention, the first flexible circuit board and the second flexible circuit board are electrically connected by ball planting.

[0009] As a further improvement of the present invention, one or more of capacitors, resistors, and inductors are embedded in the second flexible circuit board.

[0010] As a further improvement of the present invention, a receiving cavity and a glue injection hole connected to the receiving cavity for injecting glue into the receiving cavity are opened in the second flexible circuit board, and the RF front-end chip is received in the receiving cavity.

[0011] As a further improvement of the present invention, the antenna is in the form of a loop antenna, a monopole antenna, an IFA antenna, a PIFA antenna, a MIMO antenna, and an array antenna.

[0012] As a further improvement of the present invention, the RF front-end chip includes a transceiver module, which includes a first antenna tuning chip electrically connected to the antenna, a first RF switch electrically connected to the antenna, a duplexer electrically connected to the first RF switch, a power amplifier electrically connected to the duplexer, and a first low-noise amplifier.

[0013] As a further improvement of the present invention, the RF front-end chip includes a receiving module, and the receiving module includes a second antenna tuning chip electrically connected to the antenna, a second RF switch electrically connected to the antenna, a filter electrically connected to the second RF switch, and a second low-noise amplifier electrically connected to the filter.

[0014] The present invention also provides a production method for forming the antenna module as described above, comprising the following steps:

[0015] S1: providing a first flexible circuit board, fixing the antenna on the first flexible circuit board, providing a second flexible circuit board, and defining a receiving cavity and a glue injection hole connected to the receiving cavity for injecting glue into the receiving cavity on the second flexible circuit board;

[0016] S2: soldering the RF front-end chip onto the first flexible circuit board chip in a bare chip flip-chip manner;

[0017] S3: electrically connecting the first flexible circuit board and the second flexible circuit board by ball planting, and accommodating the RF front-end chip in the accommodating cavity;

[0018] S4: injecting resin into the receiving cavity through the glue injection hole.

[0019] As a further improvement of the present invention, the second flexible circuit board provided in step S1 is embedded with one or more of capacitors, resistors, and inductors, and is produced by a lamination process.

[0020] As a further improvement of the present invention, step S0 is also included before step S1: designing the antenna and the RF front-end chip according to product requirements, and performing simulation based on the parameters of the antenna and the RF front-end chip.

[0021] The beneficial effects of the present invention are: the antenna module of the present invention can improve the sensitivity of antenna reception, reduce power consumption, and increase battery life; compared with the current design, it can save 15% of the area, save a layer of substrate, reduce the metal shielding cover, and the height of the RF front-end circuit can be reduced by about 0.5mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the antenna module of the present invention;

[0023] Figure 2 This is a schematic diagram of the radio frequency front-end chip and antenna structure of the antenna module of the present invention;

[0024] Figure 3 It is a flow chart of the production method of the antenna module of the present invention. DETAILED DESCRIPTION

[0025] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0026] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0027] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internal communication between two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0028] like Figures 1 to 2 As shown, the present invention provides an antenna module 100 for use in a communication device, which is connected to a transceiver chip 201 on a motherboard 200 in the communication device via a radio frequency cable 202. The antenna module 100 includes a first flexible circuit board 1, a second flexible circuit board 2 electrically connected to the first flexible circuit board 1, a radio frequency front-end chip 3 soldered to the second flexible circuit board 2, and an antenna 4.

[0029] The first and second flexible circuit boards 1 and 2 are used to embed circuits and components. They can be either FPCs or LCPs. LCPs offer a low dielectric constant and minimal high-frequency current loss, while FPCs offer lower costs.

[0030] The first flexible circuit board 1 has a pad 11 on one side and the antenna 4 is fixed on the other side. The side with the pad 11 faces the second flexible circuit board 2, and the RF front-end chip 3 is soldered on the pad 11 in a bare chip flip-chip manner.

[0031] The RF front-end chip 3 is fixed in the form of a bare chip, so only one packaging is required, which reduces the thickness and size of the antenna module 100 and has better performance than two packaging.

[0032] In this embodiment, the RF front-end chip 3 includes a transceiver module 31, and the transceiver module 31 includes a first antenna tuning chip 311 electrically connected to the antenna 4, a first RF switch 312 electrically connected to the antenna 4, a duplexer 313 electrically connected to the first RF switch 312, and a power amplifier 314 and a first low-noise amplifier 315 electrically connected to the duplexer 313.

[0033] In other embodiments, the RF front-end chip 3 also includes a receiving module 32, which includes a second antenna tuning chip 321 electrically connected to the antenna 4, a second RF switch 322 electrically connected to the antenna 4, a filter 323 electrically connected to the second RF switch 322, and a second low-noise amplifier 324 electrically connected to the filter 323.

[0034] Antenna 4 is a loop antenna, a monopole antenna, an IFA antenna, a PIFA antenna, a MIMO antenna, or an array antenna. It is used to receive and radiate wireless signals. Signals transmitted from the RF transmit front-end chip 3 are radiated through antenna 4; wireless signals in space are received by antenna 4 and transmitted to the RF receive front-end chip 3.

[0035] The first antenna tuning chip 311 and the second antenna tuning chip 321 are used to optimize the performance of the antenna 4 and are located between the antenna 4 and the RF front-end chip. By switching between different states, the performance of the antenna 4 is optimized.

[0036] The first RF switch 312 and the second RF switch 322 are used to select RF signals and are generally located between the RF front-end chip and the first tuner chip 311 or antenna 4 / the second tuner chip 311 or antenna 4. The corresponding signal is selected according to the operating frequency requirement.

[0037] The duplexer 313 is located between the first RF switch 312 and the power amplifier 314 and is used for filtering received / transmitted signals and isolating received and transmitted signals.

[0038] The filter 323 is located between the second RF switch 322 and the second low noise amplifier 324 and is used for filtering the received signal.

[0039] The power amplifier 314 is electrically connected to the duplexer 313 and is used to amplify the transmission signal.

[0040] The transceiver module 31 integrates a duplexer 313 or power amplifier 314 into the antenna module 100. Signals received by the antenna 4 are routed through the first RF switch 312, selecting the appropriate duplexer 313 or first low-noise amplifier 315 based on the received signal's channel. After being amplified by the first low-noise amplifier 315, the weak signal enters the RF cable 202 for transmission to the transceiver chip 201 of the communication device, effectively improving reception sensitivity. This eliminates the power loss caused by the signal passing directly through the RF cable 202. The first antenna tuning chip 311 is electrically connected to the antenna 4 to enhance its performance.

[0041] The small transmit signal output by transceiver chip 201 is transmitted over RF cable 202, with significantly less energy loss than the amplified signal. This topology reduces cable length, brings it closer to antenna 4, reduces energy loss, improves receiver sensitivity, reduces power consumption, and increases battery life for the communication device.

[0042] The transceiver module 31 and the receiving module 32 have the same working principle. By reducing the intermediate loss during transmission and reception, the receiving sensitivity can be effectively improved, and the transmission and reception performance can be improved, resulting in better call and data communication effects.

[0043] One or more of a capacitor 22, a resistor 21, and an inductor 23 are embedded in the second flexible circuit board 2. In this embodiment, the capacitor 22, the resistor 21, and the inductor 23 are embedded in the second flexible circuit board 2 at the same time.

[0044] A receiving cavity and a glue injection hole connected to the receiving cavity for injecting glue into the receiving cavity are defined in the second flexible circuit board 2 .

[0045] The opening of the receiving cavity faces the first flexible circuit board 1. When the second flexible circuit board 2 is connected to the first flexible circuit board 1, the RF front-end chip 3 is received in the receiving cavity. Glue is then injected into the receiving cavity through the glue injection hole to achieve the effect of encapsulating the RF front-end chip 3.

[0046] The first flexible circuit board 1 and the second flexible circuit board 2 are electrically connected by ball planting 12. That is, interconnection ports are provided on the first flexible circuit board 1 and the second flexible circuit board 2 to achieve electrical connection between the first flexible circuit board 1 and the second flexible circuit board 2.

[0047] The production method of the antenna module 100 of the present invention includes the following steps:

[0048] S0: Design the antenna 4 and the RF front-end chip 3 according to product requirements, and perform simulations based on the parameters of the antenna 4 and the RF front-end chip 3 to determine the topology and matching.

[0049] S1: Provide a first flexible circuit board 1, secure the antenna 4 to the first flexible circuit board 1, provide a second flexible circuit board 2, and define a receiving cavity and a glue injection hole connected to the receiving cavity for injecting glue into the receiving cavity. The second flexible circuit board 2 provided in step S1 has one or more of a capacitor 22, a resistor 21, and an inductor 23 embedded therein and is produced using a lamination process. The second flexible circuit board 2 includes an electromagnetic shield.

[0050] The method of burying the resistor 21 is as follows: the resistor 21 material is embedded in the second flexible circuit board 2, and the corresponding flexible circuit board dielectric material layer is thinned. After the flexible circuit board is pressed together, the function of the resistor 21 is realized, and the resistor 21 with different resistance values ​​is realized by adjusting the amount of the resistor 21 material.

[0051] The method of embedding the capacitor 22 is as follows: the metal of adjacent layers of the second flexible circuit board 2 and the dielectric therebetween are used to realize the function of the capacitor 22 , and the capacitance of the capacitor 22 is adjusted by controlling the size of the metal area, the thickness and characteristics of the dielectric.

[0052] The method of embedding the inductor 23 is as follows: a threaded metal wire is made on the metal layer of the second flexible circuit board 2, and different inductor 23 values ​​are achieved by adjusting parameters such as the length and spacing of the metal wire.

[0053] In this embodiment, the resistor 21 , the capacitor 22 , and the inductor 23 are all embedded in the middle layer of the second flexible circuit board 2 .

[0054] S2: soldering the RF front-end chip 3 onto the first flexible circuit board 1 chip in a bare chip flip-chip manner.

[0055] The RF front-end chip 3 is embedded in the first flexible circuit board 1 and the second flexible circuit board 2 in a bare chip flip-chip manner, and the RC and IR are embedded in the first flexible circuit board 1 and the second flexible circuit board 2 , so as to reduce the thickness of the antenna module 100 .

[0056] S3: The first flexible circuit board 1 and the second flexible circuit board 2 are electrically connected by ball planting 12, and the radio frequency front-end chip 3 is accommodated in the accommodation cavity.

[0057] S4: injecting resin into the receiving cavity through the glue injection hole.

[0058] The production method of the antenna module 100 of the present invention can effectively reduce the area and height of the antenna module 100, thereby saving more space in the communication device.

[0059] The antenna module 100 and the production method of the antenna module 100 of the present invention can improve the receiving sensitivity of the antenna 4, reduce power consumption, and increase battery life; compared with the current design, it can save 15% of the area, save a layer of substrate, reduce the metal shielding cover, and the height of the RF front-end circuit can be reduced by about 0.5 mm.

[0060] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0061] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. An antenna module, characterized in that: The antenna module includes a first flexible circuit board, a second flexible circuit board electrically connected to the first flexible circuit board, a radio frequency front-end chip soldered in the second flexible circuit board, and an antenna. The antenna is fixed on the first flexible circuit board and electrically connected to the radio frequency front-end chip. A soldering pad is provided on a side of the first flexible circuit board close to the second flexible circuit board. The radio frequency front-end chip is soldered on the soldering pad in a bare chip flip-chip manner. The first flexible circuit board and the second flexible circuit board are FPC circuit boards or LCP circuit boards. One or more of a capacitor, a resistor, and an inductor are embedded in the second flexible circuit board. The first flexible circuit board and the second flexible circuit board are electrically connected by ball planting. The second flexible circuit board is electrically connected to the first flexible circuit board by ball planting. A receiving cavity and a glue injection hole connected to the receiving cavity for injecting glue into the receiving cavity are provided in the flexible circuit board. The RF front-end chip is accommodated in the receiving cavity. The RF front-end chip includes a transceiver module. The transceiver module includes a first antenna tuning chip electrically connected to the antenna, a first RF switch electrically connected to the antenna, a duplexer electrically connected to the first RF switch, a power amplifier electrically connected to the duplexer, and a first low-noise amplifier. The RF front-end chip includes a receiving module. The receiving module includes a second antenna tuning chip electrically connected to the antenna, a second RF switch electrically connected to the antenna, a filter electrically connected to the second RF switch, and a second low-noise amplifier electrically connected to the filter.

2. The antenna module according to claim 1, wherein: The antenna type is one of a loop antenna, a monopole antenna, an IFA antenna, a PIFA antenna, a MIMO antenna, and an array antenna.

3. A method for producing the antenna module according to any one of claims 1 to 2, characterized in that: The steps include: S1: providing a first flexible circuit board, fixing the antenna on the first flexible circuit board, providing a second flexible circuit board, and defining a receiving cavity and a glue injection hole connected to the receiving cavity for injecting glue into the receiving cavity on the second flexible circuit board; S2: soldering the RF front-end chip onto the first flexible circuit board chip in a bare chip flip-chip manner; S3: electrically connecting the first flexible circuit board and the second flexible circuit board by ball planting, and accommodating the RF front-end chip in the accommodating cavity; S4: injecting resin into the receiving cavity through the glue injection hole.

4. The method for producing an antenna module according to claim 3, wherein: The second flexible circuit board provided in step S1 has one or more of capacitors, resistors, and inductors embedded therein and is produced using a lamination process.

5. The method for producing an antenna module according to claim 3, wherein: Before step S1, step S0 is also included: designing the antenna and the RF front-end chip according to product requirements, and performing simulation based on the parameters of the antenna and the RF front-end chip.

Images