A resin plug hole processing device and method for a high aspect ratio circuit board via hole

Abstract

The application discloses a resin plug hole processing equipment for a high thickness-diameter ratio circuit board through hole and belongs to the technical field of circuit board processing. The equipment comprises a machine table, a limiting unit is arranged at the top of the machine table, a plug hole mechanism is arranged above the limiting unit, the plug hole mechanism comprises a mounting frame, a plurality of plug hole execution units are arranged at the bottom of the mounting frame, the plug hole execution unit comprises a mandrel, an exhaust flow channel is arranged in the mandrel, and an annular glue inlet assembly is arranged at the top edge of the mandrel. The mandrel occupies the through hole center space, the resin only flows along the annular gap, the convex flow front is geometrically eliminated, air is discharged through the exhaust flow channel, the problems of middle hollowing and bottom air pocket generated during resin plug hole of the high thickness-diameter ratio through hole are effectively solved, synchronous filling during pulling out is realized, the process is simplified, and yield is improved.

Description

Technical Field

[0001] This invention relates to the field of circuit board processing technology. Specifically, it includes a resin-filled hole processing device for through-holes in high aspect ratio circuit boards. Background Technology

[0002] Resin plugging is a critical process in PCB manufacturing, used to protect the hole walls and improve heat dissipation and mechanical strength. With the development of high-speed and high-density products such as 5G and servers, PCBs are showing a trend of smaller holes, thicker boards, and larger aspect ratios. The resin plugging process is becoming increasingly difficult, and the plugging quality of high aspect ratio through holes has become a pain point in the industry.

[0003] Currently, the main methods used for hole plugging include traditional scraping, vacuum-assisted hole plugging, multiple injections of adhesive, and parameter optimization. Scraping hole plugging is prone to insufficient bottom filling and central voids when the thickness-to-diameter ratio is large; vacuum-assisted hole plugging equipment is expensive and has a long cycle time, and it is still difficult to ensure complete filling of the bottom of deep holes with ultra-thickness-to-diameter ratios; multiple injections of adhesive are cumbersome and the interlayer interface bonding strength is insufficient.

[0004] The aforementioned existing dispensing heads all have a single flow channel and a single outlet structure. When the resin is filled, the fluid front exhibits a convex shape with a faster flow rate at the center and a slower flow rate at the edges. In deep holes with a large thickness-to-diameter ratio, the central flow front reaches the bottom of the hole first and seals the outlet, trapping air and forming cavities. This defect is inherent to the flow channel structure and cannot be eliminated by adjusting parameters. Furthermore, the cavity created when the dispensing head is pulled out also becomes a new source of air trapping, requiring additional treatment. Summary of the Invention

[0005] The purpose of this invention is to provide a resin plugging equipment and method for high aspect ratio circuit board through holes, so as to solve the technical problem in the prior art that the single-channel integral glue injection structure causes the central convex flow front to be generated during resin filling, resulting in central hollowing.

[0006] The technical problem to be solved by the present invention can be achieved through the following technical solution: a resin plugging processing device for through holes of high aspect ratio circuit boards, comprising a machine base, wherein a limiting unit is provided on the top of the machine base for limiting and fixing the circuit board, the limiting unit being used to limit the circuit board and seal the bottom of the through holes thereon; a plugging mechanism is provided above the limiting unit, the plugging mechanism comprising a mounting frame, wherein a plurality of plugging execution units are provided at the bottom of the mounting frame, the plurality of plugging execution units being respectively provided with a plurality of through holes; the plugging execution unit comprising a mandrel, wherein an exhaust channel is provided inside the mandrel, and an annular glue injection component is provided on the top edge of the mandrel for injecting glue into the position of fitting the inner wall of the through hole; the diameter of the mandrel is smaller than the diameter of the through hole, such that after the mandrel is inserted into the through hole, an annular gap is formed with the inner wall of the through hole, and the output end of the annular glue injection component is provided with the top of the annular gap corresponding to the top of the annular gap.

[0007] Preferably, the bottom of the mandrel is recessed upward to form an arc-shaped concave surface, and the top of the arc-shaped concave surface is connected to the exhaust channel.

[0008] Preferably, the top of the mandrel is provided with an exhaust control component for the exhaust channel. The exhaust control component includes a mounting cover, a discharge hole is provided on one side of the mounting cover, and a miniature direct-acting solenoid valve is fixedly installed on the inner wall of the mounting cover. The on / off switching between the discharge hole and the exhaust channel is realized through the miniature direct-acting solenoid valve.

[0009] Preferably, an air inlet is provided on one side of the exhaust channel, and an air inlet is fixedly connected to the inner wall of the air inlet. One end of the air inlet is connected to the output end of an external air supply device.

[0010] Preferably, the annular glue inlet assembly includes an annular sleeve, the annular sleeve having a temporary storage cavity inside, an output groove fixedly connected to the bottom of the inner wall of the annular sleeve, a guide plate fixedly connected to the inner wall of the output groove, one side of the guide plate being inclined, a plurality of glue inlet pipes arranged at equal intervals fixedly connected to the edge of the temporary storage cavity, one end of each of the plurality of glue inlet pipes being connected to an external glue supply device, and a lifting push rod for driving the lifting and lowering movement of the mandrel being provided above the mandrel.

[0011] Preferably, an adjusting ring is slidably disposed on the inner wall of the temporary storage cavity, a sealing gasket is fixedly connected to the edge of the adjusting ring, and a capacity control component for adjusting the displacement of the adjusting ring is disposed above the adjusting ring.

[0012] Preferably, the capacity control component includes an upper pressure ring, a plurality of lower pressure push rods are fixedly connected to the bottom of the upper pressure ring, a lower pressure rod is fixedly connected to the output end of each of the plurality of lower pressure push rods, the bottom of each of the plurality of lower pressure rods is fixedly connected to the top of an adjusting ring, and a rigid sleeve is fixedly connected between the plurality of lower pressure rods; a plurality of fixing rods are fixedly connected between the bottom of the upper pressure ring and the top of the annular sleeve.

[0013] Preferably, the limiting unit includes a conveyor belt, which is rotatably mounted on the top of the machine platform. Several limiting trays are fixedly mounted on the surface of the conveyor belt, and several positioning blocks are fixedly connected to the top of the limiting trays.

[0014] Preferably, a clean room is provided at the top center of the machine, and an observation window is fixedly installed on one side of the clean room.

[0015] Preferably, a scraping collar is fitted on the upper outer wall of the mandrel, the scraping collar is fixedly connected to the mounting bracket, a scraping cleaning pad is fixedly connected to the top of the inner wall of the scraping collar, a negative pressure suction port is opened at the bottom of the inner wall of the scraping collar, a guide ring is fixedly connected to the bottom of the negative pressure suction port near the mandrel, the bottom of the guide ring is inclined upward, a suction tube is fixedly connected to the bottom of the negative pressure suction port, and one end of the suction tube is connected to an external negative pressure suction device.

[0016] Preferably, a positioning drive assembly is provided above the mounting frame. The positioning drive assembly is used to drive the mounting frame to move up and down. Its specific structure can be implemented with reference to existing technical means. It includes at least a linear motor, and the output end of the linear motor is fixedly connected to the top of the mounting frame.

[0017] A method for resin plugging of through holes in high aspect ratio circuit boards includes the following steps;

[0018] Step 1: Place the circuit board on the machine platform, so that the bottom of the through hole on the circuit board is closed by the limiting unit, and insert the mandrel of the plugging execution unit into the through hole of the circuit board.

[0019] Step 2: Inject resin into the annular glue injection assembly located at the top edge of the mandrel. The resin flows down the inner wall of the through hole and fills the annular gap between the mandrel and the inner wall of the through hole. The air in the through hole is squeezed by the resin and gathers in the gap between the bottom of the mandrel and the bottom of the through hole, and then is discharged through the exhaust channel inside the mandrel.

[0020] Step 3: After the resin fills the annular gap, pull the mandrel upwards. At the same time, the annular glue injection assembly continuously injects resin into the through hole and seals the exhaust channel, so that the injected resin synchronously fills the space left after the mandrel is pulled out.

[0021] Step 4: Stop applying glue after the mandrel is completely pulled out, and the plugging process of the through hole is completed.

[0022] Compared with the prior art, the beneficial effects of this application are as follows:

[0023] 1. The mandrel of the present invention occupies the central space of the through hole, so that the resin can only pass through the annular gap between the mandrel and the hole wall. Geometrically, it eliminates the formation condition of the resin flow front having a central convex surface in the traditional solution. Combined with the exhaust channel, the air in the hole is reliably discharged, which effectively solves the problems of central cavitation and bottom air cavitation caused when resin is plugged in through holes with a high thickness-to-diameter ratio, and significantly improves the filling quality.

[0024] 2. The core inventive concept of this invention lies in: by occupying the central space of the through hole with a mandrel, and in conjunction with an independent exhaust channel and annular glue injection assembly, the filling mode is reconstructed from the flow channel geometry at the glue injection execution end, so that the resin flows along the wall along the annular gap, and the air is squeezed out through the exhaust channel. Thus, a filling effect close to vacuum glue injection can be achieved under normal atmospheric conditions without the need for a large vacuum chamber. At the same time, it solves the two contradictory indicators of central voids and bottom air pockets. Furthermore, by combining the mandrel pull-out action with synchronous filling, the process is simplified and the yield is improved.

[0025] 3. The annular glue injection assembly of the present invention guides the resin towards the inner wall of the through hole through the inclined guide plate, ensuring that the resin flows downward in a wall-adhering mode, reducing the contact area between the resin and air, and reducing the probability of air bubbles being mixed in; at the same time, the setting of the adjusting ring and the capacity control assembly makes the effective volume of the temporary storage chamber adjustable, and can accurately control the glue injection amount according to the through hole size, thereby improving the accuracy of process control. Attached Figure Description

[0026] Figure 1 This is a perspective view of the present invention;

[0027] Figure 2 This is a front cross-sectional view of the present invention;

[0028] Figure 3 This is a schematic diagram of the internal structure of the cleanroom of the present invention;

[0029] Figure 4 This is a perspective view of the hole-plugging execution unit of the present invention;

[0030] Figure 5 This is a cross-sectional schematic diagram of the hole-plugging execution unit of the present invention;

[0031] Figure 6 This is a cross-sectional schematic diagram of the annular glue inlet assembly of the present invention;

[0032] Figure 7 This is a cross-sectional schematic diagram of the scraping collar of the present invention;

[0033] Figure 8 This is a cross-sectional schematic diagram of the exhaust control component of the present invention;

[0034] Figure 9 This is a schematic diagram of the working state of the plugging and dispensing of adhesive according to the present invention.

[0035] Explanation of reference numerals in the attached figures:

[0036] 100. Machine base; 200. Limiting unit; 201. Limiting tray; 202. Positioning stop; 203. Conveyor belt; 204. Intermediate support rod; 300. Hole plugging mechanism; 301. Clean room; 302. Observation window; 303. Linear motor; 310. Mounting bracket; 320. Hole plugging actuator; 321. Spindle; 322. Exhaust channel; 323. Lifting push rod; 324. Arc-shaped concave surface; 326. Mounting cover; 32 7. Discharge port; 328. Miniature direct-acting solenoid valve; 330. Inflation tube; 331. Annular sleeve; 332. Temporary storage chamber; 333. Output slot; 334. Fixing rod; 335. Inlet tube; 336. Adjusting ring; 337. Upper pressure ring; 338. Lower pressure push rod; 339. Lower pressure rod; 350. Scraping collar; 351. Negative pressure suction port; 352. Guide ring; 353. Scraping cleaning pad; 4. Circuit board; 401. Through hole. Detailed Implementation

[0037] The specific embodiments of the present invention will be described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0038] Example 1

[0039] Existing resin plugging processes for high aspect ratio circuit board through-holes mostly employ a single-channel integral injection structure. When the resin fills the hole from top to bottom, the flow front exhibits a convex shape with a faster flow rate at the center and a slower flow rate at the edges. In deep holes, this can easily lead to bridging and closure of the flow front, trapping air and creating defects such as central cavitation and bottom air pockets. Conventional vacuum-assisted solutions require large vacuum chambers, resulting in high equipment costs, long process flows, and slow single-station intermittent mass production cycles. These solutions cannot fundamentally eliminate the causes of air trapping and mass production compatibility defects.

[0040] like Figures 1 to 9In this embodiment, a resin-filled hole processing device for high aspect ratio circuit board through holes includes a machine base 100. A limiting unit 200 is provided on the top of the machine base 100 for limiting and fixing the circuit board 4. The limiting unit 200 is used to limit the circuit board 4 and close the bottom of the through holes 401 on it. A hole-filling mechanism 300 is provided above the limiting unit 200. The hole-filling mechanism 300 includes a mounting frame 310. A plurality of hole-filling execution units 320 are provided at the bottom of the mounting frame 310. The plurality of hole-filling execution units 320 are respectively connected to the plurality of through holes 401. 01 Corresponding settings; The plugging execution unit 320 includes a spindle 321, the spindle 321 has an exhaust channel 322 inside, and the top edge of the spindle 321 is provided with an annular glue injection component for injecting glue into the inner wall of the fitting through hole 401; the diameter of the spindle 321 is smaller than the diameter of the through hole 401; so that after the spindle 321 is inserted into the through hole 401, it forms an annular gap with the inner wall of the through hole 401, and the output end of the annular glue injection component is correspondingly set with the top of the annular gap; a lifting push rod 323 is provided above the spindle 321 for driving the spindle 321 to move up and down.

[0041] The limiting unit 200 includes a conveyor belt 203, with several intermediate support rods 204 rotatably mounted in the middle of the conveyor belt 203. The conveyor belt 203 is rotatably mounted on the top of the machine base 100. Several limiting trays 201 are fixedly mounted on the surface of the conveyor belt 203, and several positioning blocks 202 are fixedly connected to the top of the limiting trays 201. A clean room 301 is set at the center of the top of the machine base 100, and an observation window 302 is fixedly mounted on one side of the clean room 301.

[0042] The working principle of this embodiment is as follows: Figures 1-3 The circuit board 4 is placed on the limiting tray 201 of the machine tool 100, and the clamping and limiting are completed by the positioning block 202, so that the bottom of the through hole 401 on the circuit board 4 is closed. The conveyor belt 203 carries the circuit board 4 into the processing area of ​​the clean room 301. The mandrel 321 of the hole plugging execution unit 320 is inserted into the through hole 401 of the circuit board 4. Resin is injected through the annular glue injection assembly set on the top edge of the mandrel 321, so that the resin flows down along the inner wall of the through hole 401 and fills the space between the mandrel 321 and the inner wall of the through hole 401. An annular gap exists between the mandrel 321 and the through hole 401. The air inside the through hole 401 is compressed by the resin and gathers in the gap between the bottom of the mandrel 321 and the bottom of the through hole 401. The air is then discharged through the exhaust channel 322 inside the mandrel 321. When the resin fills the annular gap, the mandrel 321 is pulled out upwards. At the same time, the annular glue injection assembly continuously injects resin into the through hole 401 and seals the exhaust channel 322, so that the injected resin synchronously fills the space left after the mandrel 321 is pulled out. After the mandrel 321 is completely pulled out, the glue injection stops, and the plugging process of the through hole 401 is completed.

[0043] It should be emphasized that the core improvement of this embodiment lies in the fact that by reconstructing the annular filling channel through the mandrel 321, the formation conditions of the central convex surface of the resin front are eliminated from the geometric shape. Combined with the central independent exhaust channel 322, directional and orderly exhaust is achieved, solving the problems of central bridging and voids and bottom cavitation in the high thickness-to-diameter ratio through hole 401. At the same time, the mandrel 321 pull-out action is combined with synchronous filling, turning the disadvantage of structural occupancy into a link in the filling process. The entire process of hole plugging can be completed in a single station without the need for a large vacuum chamber, which balances mass production efficiency and finished product yield, and significantly reduces the overall operating cost of the equipment.

[0044] It should be noted that, such as Figure 3 A positioning drive assembly is provided above the mounting bracket 310. The positioning drive assembly is used to drive the mounting bracket 310 to move up and down. Its specific structure can be implemented with reference to existing technical means. It includes at least a linear motor 303. The output end of the linear motor 303 is fixedly connected to the top of the mounting bracket 310.

[0045] It should be noted that, such as Figure 1 The observation window 302 is made of transparent and sealed material, which allows observation of the processing status without damaging the internal environment of the clean room 301.

[0046] Example 2

[0047] It is understandable that in Embodiment 1, the bottom of the mandrel 321 is a flat end face, and the inlet of the exhaust channel 322 is located at the center of the end face. When the resin flows down along the annular gap to the bottom of the hole, it will inevitably contact the edge of the end face first and gradually close towards the center, quickly sealing the inlet of the exhaust channel 322 to form a liquid seal and air lock. This results in the residual air at the bottom of the hole being unable to be discharged, forming a bottom cavitation defect and weakening the actual effect of the exhaust structure of the mandrel 321.

[0048] like Figures 4 to 5 To solve the above problems, based on the entire structure of Embodiment 1, the bottom of the mandrel 321 is recessed upward to form an arc-shaped concave surface 324, and the top of the arc-shaped concave surface 324 is connected to the exhaust channel 322; the top of the mandrel 321 is provided with an exhaust control component for the exhaust channel 322, the exhaust control component includes a mounting cover 326, one side of the mounting cover 326 is provided with an exhaust hole 327, and a miniature direct-acting solenoid valve 328 is fixedly installed on the inner wall of the mounting cover 326, and the on / off switching between the exhaust hole 327 and the exhaust channel 322 is realized through the miniature direct-acting solenoid valve 328; one side of the exhaust channel 322 is provided with an air inlet, and an air inlet is fixedly connected to the inner wall of the air inlet, one end of the air inlet 330 is connected to the output end of an external air supply device.

[0049] It should be emphasized that the core improvement of this embodiment is: by constructing an air collection space at the bottom of the hole through the arc-shaped concave surface 324 at the bottom of the mandrel 321, the dead corners of air accumulation are eliminated, and the speed at which the resin blocks the exhaust inlet is slowed down, leaving sufficient exhaust windows for the air at the bottom of the hole. This structurally alleviates the industry pain point of easy liquid sealing of small-diameter exhaust channels. The matching exhaust control component and air filling pipe 330 can not only close the exhaust channel during the filling stage to maintain the pressure inside the hole and ensure the filling density, but also clean the residual resin in the pipeline through positive pressure backflushing, which greatly improves the stability of continuous production and the process adaptability range.

[0050] It should be noted that, such as Figure 8 The miniature direct-acting solenoid valve 328 can automatically switch on and off states according to the processing sequence. During the upward pulling stage of the mandrel 321, the exhaust channel 322 is sealed to avoid the problem of external airflow being introduced due to the negative pressure of the pulling operation.

[0051] It should be noted that the pressure of the clean gas introduced through the air inlet pipe 330 can be adjusted according to process requirements to adapt to the backflushing cleaning needs of resins with different viscosities.

[0052] Example 3

[0053] It is understandable that in Embodiment 2, the mandrel 321 needs to be inserted into liquid resin and then pulled out to complete the synchronous filling. This insertion and pulling action will inevitably cause a layer of resin to adhere to the outer wall of the mandrel 321. During the retraction process, the adhered resin is prone to stringing and dripping, contaminating the plate surface and the orifice, damaging the flatness of the orifice, and the solidification of the residual resin will affect the coaxiality and venting effect of the mandrel 321 in subsequent processing. This is an inevitable derivative problem of the insert-and-pull filling structure of the mandrel 321.

[0054] like Figures 5 to 7 To solve the above problems, based on the entire structure of Embodiment 2, a scraping collar 350 is sleeved on the upper outer wall of the mandrel 321. The scraping collar 350 is fixedly connected to the mounting bracket 310. A scraping cleaning pad 353 is fixedly connected to the top of the inner wall of the scraping collar 350. A negative pressure suction port 351 is opened at the bottom of the inner wall of the scraping collar 350. A guide ring 352 is fixedly connected to the bottom of the negative pressure suction port 351 near the mandrel 321. The bottom of the guide ring 352 is inclined upward. A suction tube is fixedly connected to the bottom of the negative pressure suction port 351. One end of the suction tube is connected to an external negative pressure suction device.

[0055] It should be emphasized that the core improvement of this embodiment lies in the following: the adoption of a purely mechanical structure with a fixed collar for scraping resin, which automatically scrapes the outer wall resin during the removal of the mandrel 321, completely avoiding the contamination of the board surface and orifices by stringing and dripping resin; the matching negative pressure suction and guide ring 352 structure collects and processes the scraped resin in a centralized manner, eliminating the need for manual cleaning during machine shutdown, greatly improving continuous production efficiency and cleanliness consistency, while reducing the risk of particulate contamination in the clean environment, forming a complete functional closed loop with the mandrel 321 insertion and filling structure.

[0056] It should be noted that, such as Figure 7 The cleaning pad 353 is flexibly attached to the outer wall of the spindle 321, which ensures the scraping effect without scratching the surface of the spindle 321.

[0057] It should be noted that the inclined structure of the guide ring 352 can guide the negative pressure airflow to form a converging flow field, thereby improving the collection efficiency of resin debris.

[0058] Example 4

[0059] It is understandable that in Embodiment 1, if the annular glue inlet assembly adopts a basic structure with a single annular opening and a single glue inlet, the resin will enter the annular cavity from one side and the circumferential flow resistance will be different. This will inevitably lead to uneven circumferential glue outlet pressure and flow rate. If the local resin flow rate is too fast, it will be easy to prematurely close and bridge towards the center, which will instead offset the anti-dampening effect of the mandrel 321 occupying the annular flow channel.

[0060] like Figures 5 to 6 To solve the above problems, based on the entire structure of Embodiment 1, the annular glue inlet assembly includes an annular sleeve 331. The annular sleeve 331 has a temporary storage cavity 332 inside. An output groove 333 is fixedly connected to the bottom of the inner wall of the annular sleeve 331. A guide plate is fixedly connected to the inner wall of the output groove 333. One side of the guide plate is inclined. A plurality of glue inlet pipes 335 are fixedly connected to the edge of the temporary storage cavity 332. One end of each of the plurality of glue inlet pipes 335 is connected to an external glue supply device.

[0061] It should be emphasized that the core improvement of this embodiment is: the annular temporary storage cavity 332, in conjunction with multiple equidistant glue inlet tubes 335, achieves circumferential pressure equalization and flow stabilization, buffers glue supply pressure pulsation, and ensures a stable and consistent glue flow rate throughout the entire circle; the inclined guide vane forces the resin to adhere to the wall for output, further regulates the flow pattern, and avoids premature bridging of local resin from the source, fully releasing the anti-drumping effect of the mandrel 321 occupying the annular flow channel.

[0062] It should be noted that the tilt angle of the guide plate matches the opening angle of the output groove 333, which can smoothly guide the resin to the inner wall of the through hole 401.

[0063] Example 5

[0064] It is understandable that in Embodiment 4, the temporary storage cavity 332 inside the annular sleeve 331 is a fixed volume structure, while the amount of glue required for through holes 401 with different apertures and plate thicknesses varies. The fixed volume cannot accurately match the amount of glue injected into a single hole. If external flow metering and control are used, it will be greatly affected by resin viscosity and temperature fluctuations, which will inevitably lead to problems such as overfilling of glue in small holes and insufficient filling in large holes, and cannot meet the flexible processing requirements of through holes 401 with multiple specifications.

[0065] like Figures 5 to 6 To address the aforementioned issues, based on the entire structure of Embodiment 4, an adjusting ring 336 is slidably provided on the inner wall of the temporary storage cavity 332. A sealing gasket is fixedly connected to the edge of the adjusting ring 336. A capacity control component for adjusting the displacement of the adjusting ring 336 is provided above the adjusting ring 336. The capacity control component includes an upper pressure ring 337. Several lower pressure push rods 338 are fixedly connected to the bottom of the upper pressure ring 337. A lower pressure rod 339 is fixedly connected to the output end of each of the several lower pressure push rods 338. The bottom of each of the several lower pressure rods 339 is fixedly connected to the top of the adjusting ring 336. A rigid sleeve is fixedly connected between the several lower pressure rods 339. Several fixing rods 334 are fixedly connected between the bottom of the upper pressure ring 337 and the top of the annular sleeve 331.

[0066] It should be emphasized that the core improvement of this embodiment is: an adjustable volume structure is added to the flow equalization temporary storage cavity 332, and the effective volume of the temporary storage cavity 332 is changed by mechanical displacement, so that volumetric metering replaces flow metering, the dispensing accuracy is not affected by resin viscosity and temperature fluctuations, and the applicability range is wider; at the same time, the multi-rod rigid linkage ensures that the adjustment ring 336 moves synchronously in the circumference, avoiding skew and jamming, and the efficiency of changeover adjustment is significantly improved.

[0067] It should be noted that the multiple pressure rods 339, together with the rigid sleeve, can ensure circumferential synchronization during the translation of the adjusting ring 336, and avoid unilateral tilting and jamming.

[0068] The working principle of this invention is as follows: The working principle of the resin-filled hole processing device for 4-hole 401 high aspect ratio circuit boards is as follows:

[0069] Before processing, based on the diameter and thickness of the through hole 401 to be processed, the adjusting ring 336 is driven by the downward push rod 338 to move along the inner wall of the temporary storage cavity 332, adjusting the effective glue injection volume of the temporary storage cavity 332, and completing the pre-setting of process parameters. The circuit board 4 is placed on the limiting tray 201 of the conveyor belt 203, and the positioning block 202 rigidly limits the circuit board 4, so that the bottom of the through hole 401 is closed by the limiting tray 201; the conveyor belt 203 drives the circuit board 4 into the processing station in the clean room 301. The positioning drive assembly drives the mounting frame 310 to descend as a whole, so that each plugging execution unit 320 is coaxially aligned with the corresponding through hole 401; the lifting push rod 323 drives the mandrel 321 to insert downward into the through hole 401, and an annular gap is formed between the outer wall of the mandrel 321 and the inner wall of the through hole 401, with the lower end of the mandrel 321 close to the bottom of the through hole 401, at which point the state is as follows. Figure 9 (a);

[0070] An external glue supply device supplies resin into the temporary storage chamber 332 of the annular sleeve 331 through multiple glue inlet pipes 335. After the temporary storage chamber 332 is stabilized, the resin flows out through the output groove 333, is guided by the guide plate, and then adheres to the inner wall of the through hole 401, flowing smoothly from top to bottom along the annular gap. At this time, the state is as follows: Figure 9 (b); The air inside the through hole 401 is gradually compressed by the resin, gathers in the arc-shaped concave area 324 at the bottom of the mandrel 321, and is then discharged outward through the exhaust channel 322 inside the mandrel 321 and the discharge hole 327 of the exhaust control component. At this time, the state is as follows: Figure 9 (c);

[0071] When the resin in the annular gap fills to the set height, the miniature direct-acting solenoid valve 328 actuates, sealing the passage between the exhaust channel 322 and the discharge hole 327; the lifting push rod 323 drives the spindle 321 to retract upwards at a uniform speed, at which point the state is as follows. Figure 9 (d) At the same time, the annular glue injection assembly continuously injects resin into the through hole 401, and the resin synchronously fills the central space left after the mandrel 321 is withdrawn upward.

[0072] During the upward retraction of the mandrel 321, the scraping collar 350 fixed on the mounting bracket 310 remains stationary, and the scraping cleaning pad 353 adheres to the outer wall of the mandrel 321, continuously scraping off the resin adhering to the outer wall; the scraped resin flows along the guide ring 352 into the negative pressure suction port 351, and is collected and processed by the external negative pressure suction equipment through the suction tube.

[0073] After the spindle 321 is completely withdrawn from the through hole 401, the state is as follows: Figure 9 (e) The glue injection action stops, and the positioning drive assembly drives the mounting frame 310 to rise and reset; the conveyor belt 203 drives the processed circuit board 4 out of the clean room 301 to complete the hole plugging process of a single circuit board 4.

[0074] The basic principles, main features, and advantages of this application have been described above. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely the principles of this application. Various changes and modifications can be made to this application without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed application.

Claims

1. A resin-filled hole processing device for high aspect ratio circuit board through holes, characterized in that, The system includes a machine base (100), the top of which is provided with a limiting unit (200) for limiting and fixing a circuit board (4). The limiting unit (200) is used to limit the circuit board (4) and close the bottom of its through hole (401). Above the limiting unit (200) is a hole-plugging mechanism (300), which includes a mounting frame (310). The bottom of the mounting frame (310) is provided with several hole-plugging execution units (320), which are respectively provided with several through holes (401). The hole-plugging execution unit (320) includes a spindle (321), the inside of which is provided with an exhaust channel (322). The top edge of the spindle (321) is provided with an annular glue injection component for injecting glue into the inner wall of the through hole (401).

2. The resin plugging equipment for high aspect ratio circuit board through holes as described in claim 1, characterized in that, The bottom of the mandrel (321) is recessed upward to form an arc-shaped concave surface (324), and the top of the arc-shaped concave surface (324) is connected to the exhaust channel (322).

3. The resin plugging equipment for high aspect ratio circuit board through holes as described in claim 2, characterized in that, The top of the spindle (321) is provided with an exhaust control assembly for the exhaust channel (322). The exhaust control assembly includes a mounting cover (326). A discharge hole (327) is opened on one side of the mounting cover (326). A miniature direct-acting solenoid valve (328) is fixedly installed on the inner wall of the mounting cover (326). The on / off switching between the discharge hole (327) and the exhaust channel (322) is realized through the miniature direct-acting solenoid valve (328).

4. The resin plugging equipment for high aspect ratio circuit board through holes as described in claim 2, characterized in that, An air inlet is provided on one side of the exhaust channel (322), and an air inlet pipe (330) is fixedly connected to the inner wall of the air inlet.

5. The resin-filled hole processing equipment for high aspect ratio circuit board through holes as described in claim 1, characterized in that, The annular glue inlet assembly includes an annular sleeve (331), the annular sleeve (331) has a temporary storage cavity (332) inside, the bottom of the inner wall of the annular sleeve (331) is fixedly connected to an output groove (333), the inner wall of the output groove (333) is fixedly connected to a guide plate, one side of the guide plate is inclined, the edge of the temporary storage cavity (332) is fixedly connected to a plurality of glue inlet tubes (335) arranged at equal intervals, and a lifting push rod (323) for driving the lifting and lowering movement of the mandrel (321) is provided above the mandrel (321).

6. The resin-filled hole processing equipment for high aspect ratio circuit board through holes as described in claim 5, characterized in that, An adjusting ring (336) is slidably provided on the inner wall of the temporary storage cavity (332). A sealing gasket is fixedly connected to the edge of the adjusting ring (336). A capacity control component for shifting and adjusting the adjusting ring (336) is provided above the adjusting ring (336).

7. The resin plugging equipment for high aspect ratio circuit board through holes as described in claim 6, characterized in that, The capacity control component includes an upper pressure ring (337), with a plurality of lower pressure push rods (338) fixedly connected to the bottom of the upper pressure ring (337), and a lower pressure rod (339) fixedly connected to the output end of each of the lower pressure push rods (338). The bottom of each of the lower pressure rods (339) is fixedly connected to the top of an adjusting ring (336), and a rigid sleeve is fixedly connected between the lower pressure rods (339). A plurality of fixing rods (334) are fixedly connected between the bottom of the upper pressure ring (337) and the top of the annular sleeve (331).

8. The resin plugging equipment for high aspect ratio circuit board through holes as described in claim 1, characterized in that, The limiting unit (200) includes a conveyor belt (203), which is rotatably mounted on the top of the machine base (100). Several limiting trays (201) are fixedly mounted on the surface of the conveyor belt (203), and several positioning blocks (202) are fixedly connected to the top of the limiting trays (201).

9. The resin plugging equipment for high aspect ratio circuit board through holes as described in claim 5, characterized in that, The outer wall of the mandrel (321) is fitted with a scraping collar (350). A scraping cleaning pad (353) is fixedly connected to the top of the inner wall of the scraping collar (350). A negative pressure suction port (351) is opened at the bottom of the inner wall of the scraping collar (350). A guide ring (352) is fixedly connected to the bottom of the negative pressure suction port (351) near the mandrel (321). The bottom of the guide ring (352) is inclined upward. A suction tube is fixedly connected to the bottom of the negative pressure suction port (351).

10. A method for resin plugging of through-holes in high aspect ratio circuit boards, comprising using the resin plugging equipment for high aspect ratio circuit board through-holes as described in claim 1, characterized in that... Step 1: Place the circuit board (4) on the machine (100) so that the bottom of the through hole (401) on the circuit board (4) is closed by the limiting unit (200) and the spindle (321) of the plugging execution unit (320) is inserted into the through hole (401) of the circuit board (4); Step 2: Resin is injected into the annular glue injection assembly located at the top edge of the mandrel (321), so that the resin flows down along the inner wall of the through hole (401) and fills the annular gap between the mandrel (321) and the inner wall of the through hole (401). The air in the through hole (401) is squeezed by the resin and gathers in the gap between the bottom of the mandrel (321) and the bottom of the through hole (401), and then discharged through the exhaust channel (322) in the mandrel (321). Step 3: After the resin fills the annular gap, pull the mandrel (321) upwards. At the same time, the annular glue injection assembly continuously injects resin into the through hole (401) and seals the exhaust channel (322) so that the injected resin synchronously fills the space left after the mandrel (321) is pulled out. Step 4: Stop applying glue after the mandrel (321) is completely pulled out, and complete the plugging process of the through hole (401).

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