Multifunctional MIC test fixture

Abstract

The utility model discloses a multifunctional MIC test fixture, including fixture carrier plate, fixture upper die, fixture lower die and plugging cylinder assembly, the fixture carrier plate is used for fixedly connecting piece FPC board, the fixture upper die is located the upper of fixture carrier plate, is used for pressing FPC board, and simultaneously ensures that the sound hole of MIC is in alignment with the sound source sound channel hole on the fixture carrier plate, the upper side of fixture lower die is used for fixing the fixture carrier plate, and the downside is used for installing plugging cylinder assembly, and the plugging of MIC sound hole is realized through the lifting of plugging cylinder assembly or opening, to realize the airtight test or audio test of MIC. Its through a set of fixture combination automatic switching core design, will improve the test efficiency by more than 30%, and the fixture cost reduces 50%, and the production efficiency and cost pressure of enterprise are relieved greatly.

Description

Technical Field

[0001] This utility model relates to the field of MIC performance testing technology, specifically to a multifunctional MIC testing fixture. Background Technology

[0002] In the field of flexible printed circuit board (FPC) manufacturing, especially in applications such as consumer electronics and medical devices where product reliability requirements are extremely high, the performance of the integrated microphone (MIC) in the FPC, as a core connection component, directly determines the communication quality and user experience of the end product. As a core functional component of communication equipment, the audio performance of the MIC affects the clarity, sensitivity, and frequency response of sound acquisition, while its airtightness relates to the stability and lifespan of the MIC under complex environments (such as humidity, dust, and air pressure changes). Therefore, FPCs must undergo MIC audio profile testing and airtightness profile testing before leaving the factory; these two tests are crucial steps in ensuring product qualification.

[0003] As the consumer electronics industry rapidly evolves towards thinner, lighter, and more multifunctional designs, mobile phones, tablets, laptops, and other terminal products commonly employ multi-microphone (MIC) designs to achieve complex functions such as noise reduction, 3D sound effects, and voice wake-up. This trend places higher demands on the MIC testing process in FPC production: it must meet the efficiency requirements of simultaneous testing of multiple MICs while controlling testing costs and production space usage. However, current industry-standard testing solutions suffer from numerous intractable technical flaws. In existing technologies, audio curve testing and airtightness curve testing require two separate fixtures: the first is an open-hole fixture for audio curve testing with the MIC inlet hole open; the second is a closed-hole fixture for airtightness curve testing with the MIC inlet hole sealed. This separate testing mode introduces a series of problems:

[0004] First, the testing efficiency is extremely low. During the testing process, the operator must first fix the continuous FPC to the opening fixture to complete the test, and then disassemble the product and reposition it to the plugging fixture for the airtightness test. For FPCs with multiple MICs, the positioning, disassembly, and installation steps are repeated for the two tests, and a single fixture can usually only test 1-2 pieces of the product, resulting in a lengthy testing cycle.

[0005] Secondly, testing costs are high. The design, manufacturing, and calibration of both sets of fixtures require separate investments. The combined material, processing, and maintenance costs of these fixtures double the investment in testing equipment for a single production line. Furthermore, the two sets of fixtures require twice the production space, further increasing production costs given the rising cost of factory rents. In addition, separate testing requires more operators for fixture switching and product transfer, increasing labor costs accordingly.

[0006] Secondly, test accuracy is difficult to guarantee. During the two tests, the product needs to undergo two positioning operations. Positioning deviations caused by manual operation may reduce the alignment accuracy between the microphone inlet and the sound source channel of the fixture, thus affecting the sensitivity of the audio curve test and the sealing performance of the airtightness curve test. This positioning error is amplified in multi-aperture testing, potentially leading to misjudgments of some products, reducing the product yield rate, and increasing rework costs.

[0007] Finally, there is a lack of adaptability and flexibility. Most existing separate fixtures are customized designs, designed for specific specifications of FPC and MIC quantities. When the end product is updated or the FPC specifications or MIC quantities change, two new fixtures need to be redesigned and manufactured, which not only increases the R&D cycle, but also cannot meet the production needs of multiple varieties and small batches. Utility Model Content

[0008] The present invention aims to overcome at least one of the defects of the prior art and provide a multifunctional MIC test fixture to achieve high testing efficiency and reduced costs.

[0009] Specifically, this utility model discloses the core structural components and basic functions of each structure of a multifunctional MIC test fixture: the fixture carrier plate serves as a support base for fixing the continuous FPC board, providing a stable product positioning platform for subsequent testing; the upper mold of the fixture is set above the fixture carrier plate, on the one hand fixing the FPC board through a pressing action to prevent product displacement during testing, and on the other hand ensuring precise alignment between the MIC inlet hole on the FPC board and the sound source channel hole on the fixture carrier plate, providing a prerequisite for audio signal transmission; the upper side of the lower mold of the fixture is used to fix the fixture carrier plate, ensuring the stability of the carrier plate position, while the lower side is equipped with a hole-blocking cylinder assembly, providing an actuator for switching test states; the hole-blocking cylinder assembly can block or open the MIC inlet hole through a lifting action. In the open state, the sound source signal can enter the MIC through the channel to complete the audio test; in the blocked state, the inlet hole forms a sealed environment to complete the airtightness test, ultimately realizing the integration of two testing functions in one fixture. This invention directly addresses the shortcomings of existing technologies that require separate testing with two sets of fixtures. Through structural integration and motion linkage, it solves the core problems of low testing efficiency and high fixture costs. Therefore, manual fixture switching and secondary product clamping are eliminated, significantly shortening the testing cycle and improving testing efficiency by more than 30% compared to separate testing. Simultaneously, one fixture replaces two dedicated fixtures, reducing fixture design, procurement, and maintenance costs by 50%, and avoiding positioning deviations caused by secondary clamping, thus improving the consistency of test data. It is suitable for scenarios with high FPC reliability requirements, such as consumer electronics and medical devices.

[0010] Furthermore, the fixture features multiple upper mold pressing blocks on its inner side, the number of which matches the number of microphones on the continuous FPC board. Each upper mold pressing block is positioned one-to-one with the corresponding microphone position, ensuring that each microphone can be precisely pressed. This avoids the problems of "partial microphone not being pressed" or "pressing misalignment" that may occur with traditional single-block pressing. It guarantees that all microphones remain stable and fixed during testing, preventing sound source channel alignment deviations caused by microphone displacement. Simultaneously, precise one-to-one pressing prevents the pressing blocks from causing pressure damage to other electronic components on the FPC board, protecting product integrity and improving the product pass rate during batch testing.

[0011] Furthermore, the upper mold pressing block consists of an integrally molded fixing head and a square column pressing column. The fixing head is used for a stable connection with the upper mold of the fixture, while the square column pressing column directly contacts the MIC. This structural design combines the testing fixture's requirements for pressing stability and precision. The integral molding process ensures that the overall structure of the pressing block is robust and not prone to loosening or breakage due to long-term pressing. Compared with the round pressing column, the square column pressing column can more accurately match the installation area of ​​the MIC when in contact with it, reducing the risk of pressing block displacement. The top length and width of the fixing head are greater than the length and width of the pressing column.

[0012] Furthermore, the positioning pins on the fixture carrier plate are matched with the positioning holes on the continuous FPC board, limiting the position of the continuous FPC board on the fixture carrier plate through the "pin-hole" engagement. Operators only need to fit the positioning holes of the FPC board into the positioning pins to quickly complete product positioning, significantly shortening clamping time. Compared to traditional manual positioning adjustments, clamping efficiency is improved by more than 60%. Simultaneously, the "pin-hole" engagement effectively restricts the horizontal displacement of the FPC board, preventing displacement due to vibration or pressure during testing. This ensures consistent testing conditions for multiple microphones, improves the comparability of batch test data, and reduces the test misjudgment rate caused by positioning deviations.

[0013] Furthermore, the plugging cylinder assembly consists of a cylinder and a plugging guide post. The cylinder serves as the power source, driving the plugging guide post to achieve lifting and lowering movements. When the plugging guide post rises, it blocks the microphone inlet, meeting the sealing requirements of the airtightness test; when the plugging guide post falls, the microphone inlet opens, meeting the signal transmission requirements of the audio test. The cylinder-driven automated lifting and lowering action replaces the traditional manual switching of the plugging components, achieving automatic switching of test states without manual intervention, further shortening the test process time. The stable power output of the cylinder ensures that the lifting and lowering movements of the plugging guide post are precise and responsive, avoiding reduced test efficiency due to switching delays, while ensuring the consistency of the plugging guide post's position during each switch, reducing test errors caused by unstable switching movements.

[0014] Preferably, a sealing gasket is provided at the top of the plugging guide post, and the size of the sealing gasket is compatible with that of the sound source channel. When the plugging guide post rises, the sealing gasket can fit tightly against the sound source channel, achieving a complete seal. This solves the problem of incomplete sealing that may occur with traditional plugging structures. Its advantages are that the sealing gasket ensures reliable sealing during airtightness testing, preventing external air from entering or internal air pressure from leaking due to poor sealing. This allows the airtightness curve test data to more accurately reflect the airtightness performance of the MIC, reducing test pass rate deviations caused by sealing problems. Simultaneously, the sealing gasket is made of wear-resistant and aging-resistant material, capable of withstanding long-term lifting and pressing actions, reducing the frequency of gasket replacement, lowering fixture maintenance costs, and extending the continuous service life of the fixture.

[0015] More preferably, the bottom of the molding block on the fixture is provided with a silicone buffer layer with a thickness of 0.3-0.5mm. The silicone material is soft and elastic, and plays a cushioning role when the molding block presses the MIC. The silicone buffer layer can effectively absorb the impact force when the molding block is pressed, avoiding scratches, indentations or damage to internal components caused by direct contact between the hard molding block and the MIC. Actual tests have reduced the MIC test damage rate from more than 3% to less than 0.5%. At the same time, the elastic properties of silicone can evenly distribute the pressing force on the MIC surface, avoiding MIC deformation caused by excessive local pressure, ensuring the integrity of the MIC sound inlet shape, and not affecting the normal transmission of audio signals. In addition, the 0.3-0.5mm thickness design can ensure the cushioning effect without reducing the pressing positioning accuracy due to excessive thickness, thus balancing the needs of protection and testing accuracy.

[0016] Preferably, the upper surface of the fixture carrier plate is provided with anti-slip textures with a depth of 0.1-0.2mm. This increases the friction between the carrier plate and the FPC board, improving the stability of the FPC board on the carrier plate. This design addresses the issue of large-area, multi-cavity testing of continuous FPC boards, which is prone to slippage, by supplementing the fixing effect of the positioning pins. Its beneficial effects are that the anti-slip textures effectively prevent the FPC board from slipping due to vibration, pressing, or slight displacement during testing, especially during simultaneous testing of multiple cavities, ensuring the stability of all FPC boards and avoiding inconsistent testing conditions caused by the slippage of some FPC boards; the 0.1-0.2mm depth design ensures sufficient friction without scratching the FPC board surface due to excessively deep textures, protecting the integrity of the FPC board's circuitry and components; at the same time, the presence of anti-slip textures reduces reliance on positioning pins. Even if the positioning pins experience slight wear, the friction of the textures can still maintain the stability of the FPC board, improving the fixture's fault tolerance.

[0017] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0018] This utility model's multifunctional MIC testing fixture, through integrated structural design and detailed optimization, fundamentally solves the deficiency of separating MIC audio testing and airtightness testing in existing technologies. Overall, by combining a single fixture with an automatic switching core design, it improves testing efficiency by over 30% and reduces fixture costs by 50%, significantly alleviating production efficiency and cost pressures for enterprises. Simultaneously, detailed structural details such as positioning pins, anti-slip textures, and a silicone buffer layer ensure accurate product positioning, stable testing processes, and no damage to the MIC, improving the accuracy of test data and product pass rate. Furthermore, the fixture is compatible with multi-MIC FPC boards, supporting simultaneous testing of 4-8 pieces of products, and is suitable for both manual and automated production lines, possessing wide applicability. In summary, this utility model excels in improving production efficiency, reducing costs, ensuring test quality, and enhancing adaptability, meeting the high reliability requirements of FPC production scenarios such as consumer electronics and medical equipment, and has significant practical value and promotional significance. Attached Figure Description

[0019] Figure 1 This is a three-dimensional structural diagram of the multifunctional MIC testing fixture of this utility model.

[0020] Figure 2 This is a three-dimensional structural diagram of the multifunctional MIC testing fixture of this utility model after the upper mold of the hidden fixture is concealed.

[0021] Figure 3 This is a side view of the multifunctional MIC testing fixture of this utility model. Detailed Implementation

[0022] The accompanying drawings illustrate the technical solutions of this utility model in more detail. Throughout the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions. The described embodiments are only some, not all, of the embodiments of this utility model. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model. The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0023] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0024] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application. Example

[0025] The multifunctional MIC test fixture of this embodiment is composed of a fixture carrier plate 1, a fixture upper mold 2, a fixture lower mold 3, a hole-blocking cylinder assembly 4, an upper mold pressure block 21, a positioning pin 11, a sealing gasket 43, a silicone buffer layer, anti-slip texture, a sound source channel, and test probes. All components work together to achieve integrated audio testing and airtightness testing of multiple microphones on the continuous FPC board 5. The lower mold 3 of the fixture serves as the basic support component of the entire fixture. The fixture carrier plate 1 and the hole-blocking cylinder assembly 4 are respectively installed on the upper and lower sides of the lower mold 3. The upper mold 2 of the fixture is correspondingly set above the fixture carrier plate 1. The upper mold pressure block 21 is integrated into the inner side of the upper mold 2. The positioning pin 11, anti-slip texture, and sound source channel are all set on the fixture carrier plate 1. The sealing gasket 43 is assembled on the top of the hole-blocking guide post 42 of the hole-blocking cylinder assembly 4. The silicone buffer layer is attached to the bottom of the upper mold pressure block 21. The test probe is installed on the upper side of the lower mold 3 and corresponds to the test PID position of the FPC board 5.

[0026] The lower mold 3 of the fixture can be made of cast iron and has an overall rectangular plate structure, serving as the load-bearing foundation of the entire fixture. Located at the bottom of the fixture, it provides stable support for all other components. The upper side of the lower mold 3 is fixedly connected to the fixture carrier plate 1 by bolts, and the lower side is bolted to the plugging cylinder assembly 4 via two L-shaped mounting seats. Additionally, the upper side also has a probe mounting seat for mounting the test probe. Its function is to withstand the pressure during testing, preventing overall deformation of the fixture, and providing fixed mounting positions for the fixture carrier plate 1, the plugging cylinder assembly 4, and the test probe, ensuring the relative stability of each component.

[0027] The fixture carrier plate 1 has a rectangular structure, its dimensions match the continuous FPC board 5, and its position is on the upper side of the fixture lower mold 3 and aligned with it. It is fixed by bolts on the upper side of the fixture lower mold 3. Simultaneously, through holes adapted to the plugging guide post 42 are formed on the fixture carrier plate 1, allowing the plugging guide post 42 to pass through. The upper surface of the fixture carrier plate 1 is machined with anti-slip textures with a depth between 0.1 mm and 0.2 mm to increase the friction between the FPC board 5 and the fixture carrier plate 1, preventing the FPC board 5 from sliding. Positioning pins 11, made of stainless steel, are also installed on the carrier plate and are adapted to the positioning holes 51 on the continuous FPC board 5 to limit the position of the FPC board 5 on the carrier plate, ensuring accurate installation. Furthermore, a through-hole sound source channel is machined inside the carrier plate. One end of the sound source channel connects to an external sound source device, and the other end corresponds to the microphone inlet hole on the FPC board 5, used to transmit signals required for audio testing.

[0028] The upper mold 2 of the fixture adopts an aluminum alloy frame structure, and its overall size matches that of the fixture carrier plate 1. Positioned directly above the fixture carrier plate 1, it is connected to the lower mold 3 of the fixture via its own guide pillars and can move up and down along the guide pillars. Upper mold pressure blocks 21 are fixedly installed on the inner side of the upper mold 2 with screws. The number of upper mold pressure blocks 21 is consistent with the number of microphones on the connected FPC board 5. Their function is to press down on the FPC board 5 during testing, ensuring that the FPC board 5 is tightly attached to the fixture carrier plate 1 and preventing displacement during testing. Simultaneously, the upper mold pressure blocks 21 precisely press down on the microphones, ensuring that the microphone's sound inlet is perfectly aligned with the sound source channel on the fixture carrier plate 1, thus guaranteeing stable audio signal transmission.

[0029] The upper mold pressure block 21 is made of POM plastic and consists of a one-piece molded fixing head 211 and a square column pressure column 212. Each upper mold pressure block 21 corresponds to the position of one MIC on the FPC board 5. The bottom of the pressure column 212 is fitted with a silicone buffer layer with a thickness between 0.3 mm and 0.5 mm. The silicone buffer layer is made of food-grade silicone and can absorb the impact force during pressing, preventing the hard pressure block from damaging the surface or internal components of the MIC. At the same time, it can make the pressing force evenly distributed on the MIC and avoid MIC deformation affecting the test results.

[0030] The plugging cylinder assembly 4 consists of a cylinder 41 and a plugging guide post 42. The cylinder 41 is a double-acting cylinder, located below the lower mold 3 of the fixture. The bottom end of the plugging guide post 42 is threadedly connected to the piston rod of the cylinder 41 and moves up and down synchronously with the piston rod. The top end of the plugging guide post 42 is glued with a sealing gasket 43. The cylinder 41 drives the plugging guide post 42 to move up and down, thereby blocking or opening the MIC inlet hole: when the plugging guide post 42 rises, the sealing gasket 43 at the top fits against the sound source channel outlet, blocking the MIC inlet hole and meeting the sealing requirements of the airtightness test; when the guide post falls, the sealing gasket 43 disengages from the sound source channel outlet, and the MIC inlet hole opens, meeting the signal transmission requirements of the audio test.

[0031] The sealing gasket 43 is perfectly matched to the size of the sound source channel outlet on the fixture carrier plate 1. Its function is to fit tightly against the sound source channel outlet when the plugging guide post 42 rises, forming a sealed environment to prevent the entry of outside air or leakage of internal gas, thus ensuring the accuracy of the airtightness test data. The fluororubber material has wear-resistant and aging-resistant properties, and can withstand long-term lifting and squeezing actions, extending the service life of the sealing gasket 43 and reducing the frequency of maintenance and replacement.

[0032] The test probe can be mounted on the upper side of the lower mold 3 of the fixture, and is bolted to the lower mold 3 via a test probe mounting base. The tip of the probe corresponds to the test PID position on the FPC board 5 on the fixture carrier plate 1, and can extend and retract upwards with the pressing action of the upper mold 2 of the fixture. Its function is to establish an electrical connection when the upper mold 2 of the fixture is pressed down, so that the tip of the test probe contacts the test PID of the FPC board 5, and collects data from the MIC in real time during audio and airtightness tests, and transmits the data to external testing equipment to provide a basis for the analysis of test results. The gold-plated material reduces contact resistance and ensures stable data transmission, while the elastic extension and retraction design prevents the test PID from being damaged by excessive pressure of the probe.

[0033] The core working principle of this multifunctional MIC test fixture is to achieve audio and airtightness testing of the MIC in a single clamping operation through integrated structural design and automated action switching. When the upper mold 2 of the fixture is pressed down, the FPC board 5 is fixed and the MIC inlet hole is aligned with the sound source channel. The test probe contacts the test PID to establish a data transmission channel. During the audio test, the plugging guide post 42 descends, and the sound source signal enters the MIC through the sound source channel. The test probe collects audio curve data. During the airtightness test, the plugging guide post 42 rises, the sealing gasket 43 seals the sound source channel, the sound source emits sound again, and the test probe collects airtightness curve data under the sealed state. The automatic switching of the test state is completed through the lifting and lowering action of the plugging cylinder assembly 4, without manual intervention or fixture replacement, which greatly improves the testing efficiency.

[0034] The above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to the preferred embodiments above, those skilled in the art should understand that modifications or equivalent substitutions to the technical solution of this utility model should not depart from the spirit and scope of this utility model. Those skilled in the art can also make other changes within the spirit of this utility model for its design, as long as they do not deviate from the technical effect of this utility model. These changes made according to the spirit of this utility model should all be included within the scope of protection claimed by this utility model.

Claims

1. A multifunctional MIC testing fixture, characterized in that, It includes a jig carrier plate (1), a jig upper mold (2), a jig lower mold (3), and a plugging cylinder assembly (4); The fixture carrier plate (1) is used to fix the continuous FPC board (5); The upper mold (2) of the fixture is located above the fixture carrier plate (1) and is used to press the FPC board (5) while ensuring that the sound inlet hole of the MIC is aligned with the sound source channel hole on the fixture carrier plate (1). The upper side of the lower mold (3) of the fixture is used to fix the fixture carrier plate (1), and the lower side is used to install the hole-blocking cylinder assembly (4); the hole-blocking cylinder assembly (4) is raised and lowered to block or open the MIC sound inlet hole, so as to realize the airtightness test or audio test of the MIC.

2. The multifunctional MIC test fixture according to claim 1, characterized in that, The upper mold (2) of the fixture has multiple upper mold pressing blocks (21) on its inner side. The number of upper mold pressing blocks (21) is the same as the number of MICs on the continuous FPC board (5), and the position of each upper mold pressing block (21) corresponds one-to-one with the position of the MIC.

3. The multifunctional MIC test fixture according to claim 2, characterized in that, The upper mold pressing block (21) includes an integrally formed fixing head (211) and a pressing column (212), the pressing column (212) being square column-shaped.

4. The multifunctional MIC test fixture according to claim 1, characterized in that, The fixture carrier plate (1) is provided with positioning pins (11), which are adapted to the positioning holes (51) of the continuous FPC board (5) to limit the position of the continuous FPC board (5) on the fixture carrier plate (1).

5. The multifunctional MIC test fixture according to claim 1, characterized in that, The plugging cylinder assembly (4) includes a cylinder (41) and a plugging guide post (42). The cylinder (41) drives the plugging guide post (42) to move up and down to open or block the MIC sound inlet.

6. The multifunctional MIC test fixture according to claim 5, characterized in that, The top of the plugging guide post (42) is provided with a sealing gasket (43), which is adapted to the sound source channel to achieve the sealing and plugging of the sound source channel.

7. The multifunctional MIC test fixture according to claim 1, characterized in that, The upper mold (2) of the fixture has a silicone buffer layer at the bottom of the upper mold pressing block (21). The thickness of the silicone buffer layer is 0.3-0.5mm, which is used to avoid damage to the MIC when pressing.

8. The multifunctional MIC test fixture according to claim 1, characterized in that, The upper surface of the fixture carrier plate (1) is provided with anti-slip texture, the depth of which is 0.1-0.2mm.

Images