A coaxial structure suitable for millimeter wave BGA package module testing

Abstract

This invention discloses a coaxial structure suitable for testing millimeter-wave BGA packaged modules, including an upper metal panel and a lower metal panel. A second air-matching cavity is formed on the upper metal panel, and a first fixing cavity is formed above the second air-matching cavity. A third air-matching cavity is formed on the lower metal panel, and a second fixing cavity is formed below the third air-matching cavity. A spring probe is positioned with its upper end in the first fixing cavity and its lower end passing through the second and third air-matching cavities and then positioned in the second fixing cavity. The spring probe is used to match the millimeter-wave BGA packaged module. An upper epoxy resin layer is poured into the first fixing cavity, covering the upper tip and upper end of the spring probe. A lower epoxy resin layer is poured into the second fixing cavity, covering the lower tip and lower end of the spring probe. This invention enables multi-channel stable testing of BGA packaged modules.

Description

Technical Field

[0001] This invention relates to the field of radio frequency microwave device testing technology, specifically to a coaxial structure for testing millimeter-wave BGA packaged modules. Background Technology

[0002] With the rapid development of the RF module field, especially the increasing operating frequencies and channel numbers of BGA packaged modules, higher demands are placed on the accuracy, consistency, and durability of testing the RF performance of each channel of the BGA packaged module. The key to accurately measuring the performance of millimeter-wave BGA packaged modules lies in solving the technical problems of bandwidth limitation and excessive loss. Therefore, excellent impedance matching design, dimensional accuracy of the coaxial structure, assembly accuracy, and structural reliability are crucial. To address this, a new coaxial testing structure was designed using impedance matching technology to achieve stable multi-channel testing of BGA packaged modules. Summary of the Invention

[0003] Purpose of the invention: The purpose of this invention is to provide a coaxial structure for testing millimeter-wave BGA packaged modules, which can realize multi-channel stable testing of BGA packaged modules.

[0004] Technical Solution: The present invention provides a coaxial structure suitable for testing millimeter-wave BGA packaging modules, comprising an upper metal panel and a lower metal panel; the upper metal panel has a second air matching cavity formed upward from the center of its bottom surface, and a first fixing cavity coaxially formed above the second air matching cavity; the lower metal panel has a third air matching cavity formed downward from the center of its top surface, coaxial with the second air matching cavity, the second air matching cavity and the third air matching cavity are connected, and a second fixing cavity coaxially formed below the third air matching cavity; the upper end of a spring probe is placed in the first fixing cavity, and the lower end passes through the second and third air matching cavities and is placed in the second fixing cavity, the spring probe being used to match the millimeter-wave BGA packaging module; the first fixing cavity is used to inject an upper epoxy resin layer, the upper epoxy resin layer wrapping the upper needle tip and upper end of the spring probe, and the second fixing cavity is used to inject a lower epoxy resin layer, the lower epoxy resin layer wrapping the lower needle tip and lower end of the spring probe.

[0005] Furthermore, multiple first air matching cavities are evenly distributed around the outer periphery of the first and second fixed cavities for impedance matching; the first air matching cavities in the upper metal panel and the first air matching cavities in the lower metal panel correspond one-to-one; the upper epoxy resin adhesive layer and the lower epoxy resin adhesive layer are both exposed in the first air matching cavities.

[0006] Furthermore, the plurality of first air matching cavities are connected to the second air matching cavity and the third air matching cavity.

[0007] Furthermore, a stepped hole is provided at the top of the upper epoxy resin adhesive layer and at the bottom of the lower epoxy resin adhesive layer, and the spring probe is restricted between the two stepped holes to limit the longitudinal movement of the spring probe.

[0008] Furthermore, the first fixing cavity has multiple first through holes along the longitudinal direction on its outer periphery, each first through hole penetrating the upper metal panel; the second fixing cavity has multiple second through holes along the longitudinal direction on its outer periphery, each second through hole penetrating the lower metal panel; the multiple first through holes and the multiple second through holes correspond one-to-one, and after the upper metal panel and the lower metal panel are spliced ​​together, the multiple first through holes and the multiple second through holes are connected to form multiple pinholes, and a spring probe is placed in each pinhole.

[0009] Furthermore, under the constraint of the pinhole, the spring probe in the pinhole only moves up and down.

[0010] Furthermore, the upper spring needle of the spring probe is fixed in place, while the lower needle moves.

[0011] Furthermore, the spring probe inside the pinhole serves as a reinforced grounding pin, and the spring probe, which is wrapped by the upper and lower epoxy resin layers, is used for signal transmission.

[0012] Furthermore, each of the first through holes has a step at the top and each of the second through holes has a step at the bottom.

[0013] Furthermore, the upper metal panel and the lower metal panel are joined together to form a cylindrical structure.

[0014] Beneficial effects: Compared with the prior art, the significant technical effects of the present invention are as follows:

[0015] This invention uses an upper epoxy resin adhesive layer attached to the first fixing cavity of the upper metal panel, and a lower epoxy resin adhesive layer attached to the second fixing cavity of the lower metal panel. The upper and lower metal panels and the upper and lower epoxy resin adhesive layers are considered as one unit. The entire coaxial matching structure is precision machined to achieve extremely high dimensional consistency and ensure that no displacement, deflection, or jitter occurs during repeated use. The spring probe installed in the first and second fixing cavities fits tightly with the upper and lower epoxy resin adhesive layers to reduce the amount of movement error and maximize the consistency and durability of radio frequency performance. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0017] Figure 2 for Figure 1 A longitudinal sectional view;

[0018] Figure 3 for Figure 2 The front view;

[0019] Figure 4 This is a schematic diagram of the upper metal panel in this invention;

[0020] Figure 5 This is a schematic diagram of the upper metal panel from another perspective in this invention;

[0021] Figure 6 for Figure 5 Top view;

[0022] Figure 7 This is a schematic diagram of the structure of the lower metal panel in this invention;

[0023] Figure 8 for Figure 7 Top view;

[0024] Figure 9 This is a schematic diagram of the lower epoxy resin adhesive layer inside the lower metal panel in this invention;

[0025] Figure 10 This is a schematic diagram of the spring probe in this invention;

[0026] Figure 11 This is a simulation curve diagram of the present invention. Detailed Implementation

[0027] The technical solution of the present invention will now be described in detail with reference to specific embodiments and accompanying drawings.

[0028] like Figure 1-10 As shown, a coaxial structure suitable for testing millimeter-wave BGA packaged modules according to the present invention includes an upper metal panel 101, a spring probe 102, a lower metal panel 103, an upper epoxy resin adhesive layer 104, a lower epoxy resin adhesive layer 105, a stepped hole 106, a first air matching cavity 107, a pinhole 108, a second air matching cavity 109, a third air matching cavity 110, a first fixing cavity 201, and a second fixing cavity 301.

[0029] like Figure 1 As shown, the upper metal panel 101 and the lower metal panel 103 are joined together to form a cylindrical structure. The upper metal panel 101 and the lower metal panel 103 are provided with corresponding pinhole sections, fixed cavity sections and air cavity sections, and the upper metal panel 101 and the lower metal panel 103 work together to form a complete functional cavity.

[0030] like Figure 2-3 and Figure 5-6 As shown, a second air matching cavity 109 is formed from the center of the bottom surface of the upper metal panel 101 upwards, and a first fixing cavity 201 is formed coaxially above the second air matching cavity 109. The second air matching cavity 109 communicates with the first fixing cavity 201, as shown below. Figure 2As shown.

[0031] like Figure 2-3 and Figure 7-8 As shown, a third air matching cavity 110, coaxial with the second air matching cavity 109, is formed from the center of the top surface of the lower metal panel 103. The second air matching cavity 109 and the third air matching cavity 110 are connected. A second fixing cavity 301 is coaxially formed below the third air matching cavity 110. The third air matching cavity 110 communicates with the second fixing cavity 301, as shown... Figure 2 As shown.

[0032] like Figure 2-3 As shown, the upper end of the spring probe 102 is placed in the first fixed cavity 20, and the lower end passes through the second air matching cavity 109 and the third air matching cavity 110 and is placed in the second fixed cavity 301. The spring probe 102 is used to match the millimeter-wave BGA package module.

[0033] like Figure 2-3 As shown, the first fixing cavity 201 is used to inject the upper epoxy resin adhesive layer 104, which covers the upper needle and upper end of the spring probe 102. The second fixing cavity 301 is used to inject the lower epoxy resin adhesive layer 105, which covers the lower needle and lower end of the spring probe 102.

[0034] like Figure 2 , Figure 6 and Figure 8 As shown, multiple first air matching cavities 107 are evenly distributed around the outer periphery of the first fixing cavity 201 and the second fixing cavity 301 for impedance matching. The first air matching cavities 107 in the upper metal panel 101 and the first air matching cavities 107 in the lower metal panel 103 correspond one-to-one. In this embodiment, four first air matching cavities 107 are provided around the outer periphery of the first fixing cavity 201, and four first air matching cavities 107 are also provided around the outer periphery of the second fixing cavity 301. The upper epoxy resin adhesive layer 104 and the lower epoxy resin adhesive layer 105 are both exposed within the first air matching cavities 107.

[0035] like Figure 2 As shown, multiple first air matching cavities 107 are connected to second air matching cavities 109 and third air matching cavities 110. The first air matching cavities 107, second air matching cavities 109, and third air matching cavities 110, together with the upper epoxy resin adhesive layer 104 and the lower epoxy resin adhesive layer 105, form a complete coaxial air compensation section for impedance matching of the entire coaxial structure.

[0036] like Figure 2-3As shown, a stepped hole 106 is provided at the top of the upper epoxy resin layer 104 and at the bottom of the lower epoxy resin layer 105. The spring probe 102 is confined between the two stepped holes 106, thereby limiting the longitudinal movement of the spring probe 102. Specifically, the upper epoxy resin layer 104 has a stepped hole 106 for fixing the upper tip and part of the upper end of the spring probe 102; the lower epoxy resin layer 105 also has a stepped hole 106 for fixing the lower tip and part of the lower end of the spring probe 102. Both the upper epoxy resin layer 104 and the lower epoxy resin layer 105 are insulating layers. The spring probe 102, which plays a signal transmission role, is confined in the two stepped holes 106 in the upper epoxy resin layer 104 and the lower epoxy resin layer 105.

[0037] like Figure 2 and Figure 6 As shown, a plurality of first through holes are longitudinally formed on the outer periphery of the first fixing cavity 201, each first through hole penetrating the upper metal panel 101; in this embodiment, the number of first through holes is 8. Figure 2 and Figure 8 As shown, a plurality of second through holes are longitudinally formed on the outer periphery of the second fixing cavity 301, each second through hole penetrating the lower metal panel 103; in this embodiment, the number of second through holes is 8. Figure 2 and Figure 3 As shown, multiple first through holes correspond one-to-one with multiple second through holes. After the upper metal panel 101 and the lower metal panel 103 are spliced ​​together, the multiple first through holes and multiple second through holes are connected to form multiple pinholes 108. A spring probe 102 is placed in each pinhole 108. The pinhole is used to position the spring probe 102. Under the constraint of the pinhole 108, the spring probe 102 in the pinhole 108 can only move up and down.

[0038] like Figure 2 and Figure 3 As shown, each first through hole has a step at the top, and each second through hole also has a step at the bottom.

[0039] like Figure 10 As shown, the upper spring needle of the spring probe 102 is fixed, while the lower needle can spring. In this design, the spring probe 102 is disposed in the internal holes of the upper and lower epoxy resin layers and the pin holes of the upper and lower metal panels. The spring probe 102 inside the pin hole 108 serves as a reinforcing grounding pin, and the spring probe 102, which is wrapped by the upper epoxy resin layer 104 and the lower epoxy resin layer 105, is used for signal transmission.

[0040] In the coaxial structure of this invention, the central part serves as the core pathway for impedance matching. Fixed cavities (i.e., the first fixed cavity 201 and the second fixed cavity 301) are provided in the upper and lower metal panels for injecting the upper and lower epoxy resin insulating layers. The upper epoxy resin layer 104 and the lower epoxy resin layer 105 each have stepped holes 106 milled according to the spring probe 102. These holes cooperate to restrict the upper end and upper needle tip and the lower end and lower needle tip of the spring probe 102, respectively, ensuring the consistency of the position and spring displacement of the spring probe 102 as a connector. A first air matching cavity 107 is arranged at the center of the outer layer of the upper epoxy resin layer 104 and the upper metal panel 101, and a first air matching cavity 107 is also arranged at the center of the outer layer of the lower epoxy resin layer 105 and the lower metal panel 103. The first air matching cavity 107 is used for link matching, optimizing the RF performance of the entire coaxial structure.

[0041] The upper epoxy resin adhesive layer 104 and the upper metal panel 101 are considered as one unit, and the lower epoxy resin adhesive layer 105 and the lower metal panel 103 are considered as one unit structure. The entire coaxial matching section structure is integrally formed by precision machining process, resulting in an overall microwave coaxial structure with extremely high dimensional accuracy and consistency and no peeling of the insulating adhesive layer. This greatly ensures the RF performance and durability reliability of the entire coaxial structure during testing and use.

[0042] like Figure 11 The figure shows the S-parameter simulation results of the RF coaxial structure of the present invention in the HFSS environment. The upper curve in the figure represents the insertion loss (S21), and the lower curve represents the return loss (S11). Within the operating bandwidth of DC-40GHz, the S11 curve remains below -25.5dB throughout, indicating that the reflected signal is well suppressed. The S21 curve has a high flatness and does not exceed 0.06dB throughout, indicating that the energy attenuation during signal transmission is extremely small. This demonstrates that the structure has the dual advantages of ultra-wideband matching and low energy attenuation.

[0043] Based on the above Figure 11 Simulation data analysis shows that the coaxial structure proposed in this invention exhibits good impedance matching and extremely low loss within a wide bandwidth of DC-40GHz. Therefore, Figure 11 The simulation results fully verify that the test coaxial structure proposed in this invention can maintain signal integrity at a high level while ensuring broadband signal transmission, effectively solving the technical problems of limited bandwidth and excessive loss in the test of millimeter-wave BGA packaged modules in the background art.

Claims

1. A coaxial structure suitable for testing millimeter-wave BGA packaged modules, characterized in that: Includes an upper metal panel (101) and a lower metal panel (103). The upper metal panel (101) has a second air matching cavity (109) opened from the center of the bottom surface upwards, and a first fixing cavity (201) is opened coaxially above the second air matching cavity (109). The lower metal panel (103) has a third air matching cavity (110) that is coaxial with the second air matching cavity (109) and extends downward from the center of the top surface. The second air matching cavity (109) and the third air matching cavity (110) are connected. A second fixing cavity (301) is coaxially opened below the third air matching cavity (110). The upper end of the spring probe (102) is placed in the first fixed cavity (201), and the lower end passes through the second air matching cavity (109) and the third air matching cavity (110) and is placed in the second fixed cavity (301). The spring probe (102) is used to match the millimeter-wave BGA package module. An upper epoxy resin layer (104) is injected into the first fixing cavity (201), which covers the upper needle and upper end of the spring probe (102). A lower epoxy resin layer (105) is injected into the second fixing cavity (301), which covers the lower needle and lower end of the spring probe (102).

2. The coaxial structure for testing millimeter-wave BGA packaged modules according to claim 1, characterized in that: The first fixed cavity (201) and the second fixed cavity (301) are evenly distributed with a plurality of first air matching cavities (107) for impedance matching; the first air matching cavities (107) in the upper metal panel (101) and the first air matching cavities (107) in the lower metal panel (103) correspond one-to-one. Both the upper epoxy resin adhesive layer (104) and the lower epoxy resin adhesive layer (105) are exposed in the first air matching cavity (107).

3. The coaxial structure for testing millimeter-wave BGA packaged modules according to claim 1, characterized in that: The plurality of first air matching cavities (107) are connected to the second air matching cavity (109) and the third air matching cavity (110).

4. The coaxial structure for testing millimeter-wave BGA packaged modules according to claim 1, characterized in that: A stepped hole (106) is provided at the top of the upper epoxy resin adhesive layer (104) and at the bottom of the lower epoxy resin adhesive layer (105). The spring probe (102) is restricted between the two stepped holes (106) to limit the longitudinal movement of the spring probe (102).

5. The coaxial structure for testing millimeter-wave BGA packaged modules according to claim 1, characterized in that: Multiple first through holes are opened along the longitudinal direction on the outer periphery of the first fixing cavity (201), and each first through hole penetrates the upper metal panel (101). The second fixing cavity (301) has multiple second through holes along the longitudinal direction on its outer periphery, and each second through hole penetrates the lower metal panel (103). The plurality of first through holes correspond one-to-one with the plurality of second through holes. After the upper metal panel (101) and the lower metal panel (103) are spliced ​​together, the plurality of first through holes and the plurality of second through holes are connected to form a plurality of pinholes (108). A spring probe (102) is placed in each pinhole (108).

6. The coaxial structure for testing millimeter-wave BGA packaged modules according to claim 5, characterized in that: Under the constraint of the pinhole (108), the spring probe (102) in the pinhole (108) can only move up and down.

7. The coaxial structure for testing millimeter-wave BGA packaged modules according to claim 1, characterized in that: The upper part of the spring probe (102) is fixed, while the lower part is movable.

8. The coaxial structure for testing millimeter-wave BGA packaged modules according to claim 5, characterized in that: The spring probe (102) inside the pinhole (108) serves as a reinforced grounding pin. The spring probe (102), which is wrapped by the upper epoxy resin layer (104) and the lower epoxy resin layer (105), is used for signal transmission.

9. The coaxial structure for testing millimeter-wave BGA packaged modules according to claim 5, characterized in that: Each of the first through holes has a step at the top and each of the second through holes has a step at the bottom.

10. The coaxial structure for testing millimeter-wave BGA packaged modules according to claim 1, characterized in that: The upper metal panel (101) and the lower metal panel (103) are spliced ​​together to form a cylindrical structure.

Images