Multilayer circuit board vacuum press and control method

Abstract

The application discloses a kind of multilayer circuit board vacuum pressing machine and control method thereof, it is related to multilayer circuit board vacuum pressing technical field, wherein, multilayer circuit board vacuum pressing machine includes base, upper die, lower die, piston, main oil cylinder, auxiliary oil cylinder, main pressing oil pump, auxiliary pressing oil pump, pressure oil pump and the like components.Press cavity is equipped in base inside, and front side has pressing plate entrance for multilayer circuit board to enter.Upper die can be lifted, and there is piston cavity inside, and piston cavity is driven piston to the center pressure compensation of multilayer circuit board by pressure oil pump, and main oil cylinder drives upper die to carry out prepressing, and auxiliary oil cylinder corner auxiliary pressure compensation, ensure that pressing is uniform.The application is in the case where guaranteeing that each position of multilayer circuit board is pressed evenly better, piston and auxiliary oil cylinder are directly contacted with multilayer circuit board respectively, are not restrained, and it is relatively smooth to move, and it will not lead to jam, so it is more practical.

Description

Technical Field

[0001] This invention relates to the field of vacuum lamination technology for multilayer circuit boards, and particularly to a vacuum lamination machine and control method for multilayer circuit boards. Background Technology

[0002] Multilayer circuit boards are typically laminated using a laminating machine. A conventional laminating machine uses two molds, one above the other, and a hydraulic cylinder drives the upper mold downwards to directly press the multilayer circuit board. The piston of the hydraulic cylinder is connected to the center of the upper mold, mainly applying pressure to the center of the upper mold. Uneven force distribution at the four corners of the upper mold results in poor lamination uniformity. This leads to excessive resin flow in areas with high pressure, resulting in a thinner finished board with insufficient resin, while insufficient resin flow in areas with low pressure results in a thicker board, poor filling, and even air bubbles. This directly causes the thickness tolerance of the finished board to exceed the standard.

[0003] In related technologies, a pressure-compensating component is set up to ensure uniform force on the upper die. The pressure-compensating component is used to compensate for the pressure on the upper die. The pressure-compensating component includes a base and multiple pistons. The bottom of the base has multiple hydraulic holes, and the multiple pistons are installed in the multiple hydraulic holes one by one. The bottom of the multiple pistons is connected to the upper die at the same time. By injecting oil into the multiple hydraulic holes at the same time, the multiple pistons are pushed to apply pressure to the upper die. However, after actual testing, it was found that due to the different movement resistance of each piston, some pistons will always move first, making it difficult for multiple pistons to move downward at the same time. In addition, the fact that multiple pistons are connected to the upper die at the same time can cause the piston movement to jam, and the upper die cannot move downward. Furthermore, because there are many pistons, a single oil pump needs to output a very large oil pressure to make multiple pistons extend downward at the same time. Therefore, this arrangement is not practical. Summary of the Invention

[0004] This invention aims to solve the technical problems existing in the prior art. To this end, this invention proposes a multilayer circuit board vacuum pressing machine and control method. While ensuring good uniformity of pressing at all positions of the multilayer circuit board, the piston and auxiliary oil cylinder directly contact the multilayer circuit board without constraint, resulting in smoother movement and preventing jamming, thus making it more practical.

[0005] A multilayer circuit board vacuum laminator according to a first aspect of the present invention includes:

[0006] A base having a pressing cavity, wherein the front side of the base is provided with a pressure plate inlet communicating with the pressing cavity;

[0007] The upper die is vertically mounted in the pressing cavity. A piston cavity is provided at the center of the upper die. The opening of the piston cavity is located at the bottom of the upper die. The upper die is provided with an oil inlet channel and an oil return channel communicating with the piston cavity. The upper die is also provided with a clearance hole that runs through the upper die in the vertical direction. The clearance hole is located at the corner of the upper die.

[0008] A piston is disposed in the piston chamber and can extend out of the opening of the piston chamber to abut against the multilayer circuit board below;

[0009] The main hydraulic cylinder has its output rod fixedly connected to the upper pressure mold. There are two main hydraulic cylinders, and the piston is located between the two main hydraulic cylinders.

[0010] An auxiliary hydraulic cylinder is installed on the top of the upper mold and corresponds to the position of the clearance hole. The output rod of the auxiliary hydraulic cylinder can extend out of the bottom of the upper mold through the clearance hole to abut against the multi-layer circuit board below.

[0011] The main hydraulic pump is used to provide hydraulic power to the main hydraulic cylinder;

[0012] An auxiliary pressure oil pump is used to provide hydraulic power to the auxiliary oil cylinder;

[0013] A pressure-replenishing oil pump is connected to the oil inlet channel to provide hydraulic power to the piston;

[0014] The lower pressure mold is fixedly installed inside the pressing cavity and located below the upper pressure mold;

[0015] A vacuum pumping device is used to evacuate the pressing chamber.

[0016] The multilayer circuit board vacuum laminator according to embodiments of the present invention has at least the following beneficial effects:

[0017] First, two main hydraulic cylinders are used to pre-press the multi-layer circuit board. The two main hydraulic cylinders drive the multi-layer circuit board to move downwards smoothly. Then, a piston is used to apply additional pressure to the center of the multi-layer circuit board, and an auxiliary hydraulic cylinder is used to apply additional pressure to the corners of the multi-layer circuit board. This ensures that the pressing of the multi-layer circuit board is uniform and good at all positions. The piston and the auxiliary hydraulic cylinder directly contact the multi-layer circuit board without restraint, so the movement is smooth and will not cause jamming, making it more practical.

[0018] In some embodiments, the upper die includes a left half die and a right half die. The left half die forms a left half piston cavity, and the right half die forms a right half piston cavity. The left half piston cavity and the right half piston cavity together form the piston cavity. The left half die or the right half die is provided with the oil inlet channel and the oil return channel. The inner wall of the left half piston cavity is provided with a first semi-circular annular flange, and the first semi-circular annular flange is provided with a first semi-circular annular groove. The inner wall of the right half piston cavity is provided with a second semi-circular annular flange, and the second semi-circular annular flange is provided with a second semi-circular annular groove. The first semi-circular annular groove and the second semi-circular annular groove are combined to form an annular groove. A first sealing ring is provided in the annular groove. The piston includes a first cylinder and a second cylinder. The outer diameter of the second cylinder is smaller than the outer diameter of the first cylinder. The second cylinder is located below the first cylinder. The outer peripheral wall of the first cylinder is provided with a second sealing ring. The second sealing ring abuts against the inner wall of the piston cavity, and the outer peripheral wall of the second cylinder abuts against the first sealing ring.

[0019] In some embodiments, the oil inlet channel extends vertically and forms an oil inlet on the upper side of the upper mold, the oil return channel extends horizontally and forms an oil return outlet on the side of the upper mold, and the oil return channel is located at the lower part of the upper mold.

[0020] In some embodiments, the multilayer circuit board vacuum laminator further includes a vertically arranged guide roller located within the lamination cavity. The upper die has lugs on its left and right sides, each lug having a guide hole extending through the upper die in a vertical direction. The guide hole is slidably engaged with the guide roller.

[0021] In some embodiments, the top of the upper die has a groove, the position of the groove corresponds to the position of the clearance hole, the groove communicates with the clearance hole, and the auxiliary cylinder is installed in the groove.

[0022] In some embodiments, the top of the pressing mold is provided with a plurality of suction holes, which are used to adsorb circuit boards, and the vacuuming device is connected to the suction holes.

[0023] In some embodiments, the multilayer circuit board vacuum pressing machine further includes an electromagnetic induction coil, the machine base is provided with a mounting cavity located below the lower pressing mold, the electromagnetic induction coil is located inside the mounting cavity, and the electromagnetic induction coil is used to heat the lower pressing mold.

[0024] In some embodiments, the upper die has a square structure, and the number of auxiliary cylinders is four, with the four auxiliary cylinders located at the four corners of the upper die.

[0025] According to a second aspect of the present invention, a control method is applied to control a multilayer circuit board vacuum laminator according to a first aspect embodiment. The control method includes the following steps:

[0026] S1. Control the vacuum pumping device to evacuate the pressing chamber;

[0027] S2. Control the main pressure oil pump to drive the two main oil cylinders to drive the upper pressure mold to move downwards, so as to pre-press the multilayer circuit board;

[0028] S3. Control the pressure-replenishing oil pump to supply oil to the oil inlet channel, so as to drive the piston to replenish pressure at the center position of the multilayer circuit board;

[0029] S4. Control the auxiliary pressure oil pump to drive the output rod of the auxiliary oil cylinder to extend, so as to apply auxiliary pressure to the corner positions of the multilayer circuit board.

[0030] The control method according to embodiments of the present invention has at least the following beneficial effects:

[0031] First, two main hydraulic cylinders are used to pre-press the multi-layer circuit board. The two main hydraulic cylinders drive the multi-layer circuit board to move downwards smoothly. Then, a piston is used to apply additional pressure to the center of the multi-layer circuit board, and an auxiliary hydraulic cylinder is used to apply additional pressure to the corners of the multi-layer circuit board. This ensures that the pressing of the multi-layer circuit board is uniform and good at all positions. The piston and the auxiliary hydraulic cylinder directly contact the multi-layer circuit board without restraint, so the movement is smooth and will not cause jamming, making it more practical.

[0032] In some embodiments, the top of the lower mold is provided with a plurality of suction holes for adsorbing circuit boards, the vacuum device is connected to the suction holes, and the control method further includes the following steps:

[0033] S5. Control the vacuum device to evacuate the suction hole so that the suction hole can adsorb and fix the multilayer circuit board.

[0034] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0035] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0036] Figure 1 This is a schematic diagram of the structure of a multilayer circuit board vacuum laminator according to some embodiments of the present invention;

[0037] Figure 2 This is an exploded view of a multilayer circuit board vacuum laminator according to some embodiments of the present invention;

[0038] Figure 3 This is an exploded view of a multilayer circuit board vacuum laminator according to some embodiments of the present invention;

[0039] Figure 4 This is a cross-sectional view of a multilayer circuit board vacuum laminator according to some embodiments of the present invention;

[0040] Figure 5 This is a cross-sectional view from another direction of the multilayer circuit board vacuum laminator according to some embodiments of the present invention;

[0041] Figure 6 The exploded view shows the upper die, piston, main cylinder, and auxiliary cylinder of the multilayer circuit board vacuum laminator according to some embodiments of the present invention.

[0042] Figure 7 The exploded view shows the upper die, piston, main cylinder, and auxiliary cylinder of the multilayer circuit board vacuum laminator according to some embodiments of the present invention.

[0043] Figure 8 This is a cross-sectional view (exposing the oil inlet channel) of the upper die, piston, main cylinder and auxiliary cylinder of the multilayer circuit board vacuum laminator according to some embodiments of the present invention.

[0044] Figure 9 This is a cross-sectional view (exposing the oil return channel) of the upper die, piston, main cylinder and auxiliary cylinder of the multilayer circuit board vacuum laminator according to some embodiments of the present invention.

[0045] Figure 10 This is a schematic diagram of the left half mold of a multilayer circuit board vacuum laminator according to some embodiments of the present invention;

[0046] Figure 11 This is a cross-sectional view (exposing the oil inlet channel) of the left half mold of a multilayer circuit board vacuum laminator according to some embodiments of the present invention.

[0047] Figure 12 This is a cross-sectional view (exposing the oil return channel) of the left half mold of a multilayer circuit board vacuum laminator according to some embodiments of the present invention.

[0048] Figure label:

[0049] 1000 multilayer circuit board vacuum laminator;

[0050] Machine base 100, pressing chamber 101, pressure plate inlet 102, mounting cavity 103, mounting cover 104, guide roller 105, and support feeding roller 106;

[0051] Upper mold 200, piston cavity 201, oil inlet channel 202, oil return channel 203, clearance hole 204, groove 205, left half mold 206, right half mold 207, left half piston cavity 208, right half piston cavity 209, first semi-circular ring flange 210, second semi-circular ring flange 211, first semi-circular ring groove 212, second semi-circular ring groove 213, first sealing ring 214, lug 215, guide hole 216;

[0052] Piston 300, first cylinder 301, second cylinder 302, second sealing ring 303;

[0053] Main hydraulic cylinder 400;

[0054] Auxiliary hydraulic cylinder 500;

[0055] Lowering mold 600, suction hole 601;

[0056] Electromagnetic induction coil 700;

[0057] Fan 800;

[0058] Air guide plate 900, heating resistance wire 901. Detailed Implementation

[0059] Reference Figure 1 As shown, an embodiment of the present invention provides a multilayer circuit board vacuum laminator 1000, including a base 100, an upper pressure mold 200, a lower pressure mold 600, a piston 300, a main oil cylinder 400, an auxiliary oil cylinder 500, a main pressure oil pump (not shown in the figure), an auxiliary pressure oil pump (not shown in the figure), a supplementary pressure oil pump (not shown in the figure), a vacuum pumping device (not shown in the figure), and a heating component. It is used to laminate stacked multilayer circuit board structures, the layer structure of which is generally copper foil-PP sheet-inner core board.

[0060] Among them, reference Figure 4As shown, the machine base 100 has a pressing cavity 101 inside. A pressure plate inlet 102 communicating with the pressing cavity 101 is provided on the front side of the machine base 100. Multilayer circuit boards are fed into the pressing cavity 101 through the pressure plate inlet 102 for pressing. An upper pressing mold 200 is vertically detachable within the pressing cavity 101, and a lower pressing mold 600 is fixedly installed within the pressing cavity 101, located below the upper pressing mold 200. The upper pressing mold 200 has a piston cavity 201, the opening of which is located at the bottom of the upper pressing mold 200. The upper pressing mold 200 has an oil inlet channel 202 and an oil return channel 203 communicating with the piston cavity 201. The pressure boosting pump is connected to the oil inlet channel 202, and the oil return channel 203 is connected to the oil tank. An electromagnetic reversing valve is installed between the pressure boosting pump and the oil inlet channel 202. The electromagnetic reversing valve is also located between the oil return channel 203 and the oil tank. Through the reversing function of the electromagnetic reversing valve, the pressure boosting pump can supply oil to the oil inlet channel 202 or the oil return channel 203, thereby driving the piston 300 to move back and forth.

[0061] Reference Figure 6 As shown, the piston 300 has a cylindrical structure and is located in the piston chamber 201. It is supplied with oil by a pressure-replenishing oil pump and can extend out of the opening of the piston chamber 201. The piston 300 is used to abut against the multi-layer circuit board below the upper mold 200, thereby applying pressure to its center position.

[0062] Reference Figure 4 As shown, the output rod of the main oil cylinder 400 is fixedly connected to the upper pressure mold 200. There are two main oil cylinders 400. The piston 300 is located between the two main oil cylinders 400. The piston 300 and the two main oil cylinders 400 are arranged in a straight line so that they are evenly distributed above the multilayer circuit board.

[0063] Reference Figure 7 As shown, the upper mold 200 is also provided with a clearance hole 204 extending through the upper mold 200 in the vertical direction. The clearance hole 204 is located at the corner of the upper mold 200. The auxiliary cylinder 500 is installed on the top of the upper mold 200 and corresponds to the position of the clearance hole 204. The output rod of the auxiliary cylinder 500 can extend out of the bottom of the upper mold 200 through the clearance hole 204 to abut against the multilayer circuit board below. In some embodiments, the upper mold 200 has a square structure, and there are four auxiliary cylinders 500. The four auxiliary cylinders 500 are respectively located at the four corners of the upper mold 200, thereby providing auxiliary pressure at the four corners. The four auxiliary cylinders 500 are driven by four auxiliary pressure oil pumps.

[0064] During operation, the stacked multilayer circuit boards are first fed into the pressing chamber 101. The vacuum device evacuates the pressing chamber 101, and the heating component heats the upper pressing mold 200 or the lower pressing mold 600. Then, the multilayer circuit boards are pre-pressed by the main hydraulic cylinders 400. There are two main hydraulic cylinders 400, which drive the multilayer circuit boards to move downwards smoothly. Then, the piston 300 is used to apply additional pressure to the center of the multilayer circuit boards, and the auxiliary hydraulic cylinders 500 are used to apply additional pressure to the corners of the multilayer circuit boards, thereby ensuring that the pressing of the multilayer circuit boards is uniform and good. The piston 300 and the auxiliary hydraulic cylinder 500 directly contact the multilayer circuit boards without restraint, and move smoothly without jamming, making them more practical.

[0065] This combined pressure application method of "main pressure + center supplementary pressure + four corner auxiliary pressure" is the core of this invention in solving the problem of uneven pressure distribution in existing technologies. Traditional pressing machines rely solely on hydraulic cylinders to drive the entire pressing plate for pressure application. Due to the deformation of the pressing plate itself and the differences in fluidity of the multi-layer circuit board materials after heating and melting, it is very easy to cause insufficient pressure in the central area of ​​the board, while the pressure in the area where the hydraulic cylinders are located is too high. Insufficient central pressure will cause incomplete filling of PP resin, forming voids or poor bonding; excessive edge pressure will cause excessive extrusion of resin, resulting in defects such as thin boards and exposed fiberglass yarn. This invention achieves refined and regional control of the pressure field by setting an independent supplementary pressure piston 300 in the center and independent auxiliary pressure cylinders at the four corners. These three pressure systems (main pressure, supplementary pressure, and auxiliary pressure) can be driven by independent oil pumps and control valve circuits, meaning that their pressure values ​​and pressure application sequence can be independently programmed and controlled according to product process requirements, forming a dynamic and customizable pressure distribution. This greatly improves the lamination quality and yield, especially for complex circuit boards with large size, high layer count, and high density, where the advantages are even more significant.

[0066] It should also be noted that, since the piston 300 needs to be installed inside the upper mold 200, the structure of the upper mold 200 has requirements. The technical problem that also needs to be considered is how to easily manufacture the upper mold 200 and easily install the piston 300 inside the upper mold 200.

[0067] Based on this, referring to the figures, in some embodiments, the upper die 200 includes a left half die 206 and a right half die 207. The left half die 206 forms a left half piston cavity 208, and the right half die 207 forms a right half piston cavity 209. The left half piston cavity 208 and the right half piston cavity 209 are half-cylindrical cavities, and the left half piston cavity 208 and the right half piston cavity 209 together form a piston cavity 201. The left half die 206 and the right half die 207 are fixed by bolts. The left half die 206 or the right half die 207 is provided with an oil inlet channel 202 and an oil return channel 203, so that only one of the structures needs to be further processed to continue processing the oil inlet channel 202 and the oil return channel 203. The inner wall of the left piston chamber 208 is provided with a first semi-circular flange 210, and the first semi-circular flange 210 is provided with a first semi-circular groove 212. The inner wall of the right piston chamber 209 is provided with a second semi-circular flange 211. The function of the first semi-circular flange 210 and the second semi-circular flange 211 is to restrict the piston 300 from disengaging from the piston chamber 201. The second semi-circular flange 211 is provided with a second semi-circular groove 213. The first semi-circular groove 212 and the second semi-circular groove 213 combine to form an annular groove, and a first sealing ring 214 is provided in the annular groove. The piston 300 includes a first cylinder 301 and a second cylinder 302. The outer diameter of the second cylinder 302 is smaller than the outer diameter of the first cylinder 301. The second cylinder 302 is located below the first cylinder 301. The outer peripheral wall of the first cylinder 301 is provided with an annular groove. A second sealing ring 303 is provided in the annular groove. The second sealing ring 303 abuts against the inner wall of the piston chamber 201. The outer peripheral wall of the second cylinder 302 abuts against the first sealing ring 214.

[0068] In this embodiment, the left half mold 206 and the right half mold 207 are similar structures. The left half mold 206 and the right half mold 207 can be manufactured by casting or die casting integral molding processes. The same set of molds can be used to realize the processing, saving manufacturing costs. The oil inlet channel 202 and the oil return channel 203 are processed on the basis of the structure of the left half mold 206 by CNC turning process in the later stage. It is more convenient to process the upper pressure mold 200 into two structures. During installation, first insert the piston 300 into the first sealing ring 214, then insert the piston 300 laterally into the left half piston cavity 208. At the same time, the first sealing ring 214 is engaged in the first semi-circular groove 212 of the left half mold 206. Then, the right half mold 207 is attached to the left half mold 206, and the piston 300 extends into the right half piston cavity 209. The first sealing ring 214 is engaged in the second semi-circular groove 213 of the right half mold 207. Finally, tighten the bolts to fix the left half mold 206 and the right half mold 207. The entire installation operation is relatively convenient.

[0069] In some embodiments, the left half mold 206 and the right half mold 207 can be positioned by the cooperation of a positioning boss and a positioning groove. A sealing gasket can also be used between the left half mold 206 and the right half mold 207 to seal the piston cavity 201. After the left half mold 206 and the right half mold 207 are fixed, the sealing gasket is clamped.

[0070] Reference Figure 8 and Figure 9 As shown, in some embodiments, the oil inlet channel 202 extends vertically and forms an oil inlet on the upper side of the upper mold 200, while the oil return channel 203 extends horizontally and forms an oil return outlet on the left side of the upper mold 200. This arrangement facilitates the manufacturing of the oil inlet channel 202 and the oil return channel 203.

[0071] Reference Figure 9 As shown, the oil return channel 203 is located at the lower part of the upper mold 200, and the distance between the oil return channel 203 and the lower end face of the upper mold 200 is 3cm to 5cm. This arrangement is to allow the temperature of the oil in the oil return channel 203 to be transferred to the bottom end face of the upper mold 200, thereby heating the upper end of the multilayer circuit board and ensuring good heating uniformity of the multilayer circuit board.

[0072] Reference Figure 4 As shown, in some embodiments, the multilayer circuit board vacuum laminator 1000 further includes a vertically arranged guide roller 105, which is fixed inside the lamination cavity 101. (Refer to...) Figure 6 As shown, the upper die 200 has lugs 215 on both its left and right sides. Each lug 215 has a guide hole 216 extending through the upper die 200 in the vertical direction. The guide hole 216 slides into the guide roller 105. This design serves as a guide, thereby improving the movement accuracy of the upper die 200. It ensures stability during lifting and lowering, preventing problems such as inaccurate pressing position or uneven pressure distribution due to offset or swaying.

[0073] Reference Figure 6 As shown, in some embodiments, the top of the upper die 200 has a groove 205, the position of which corresponds to the position of the clearance hole 204, and the groove 205 communicates with the clearance hole 204. The auxiliary cylinder 500 is fixedly installed in the groove 205. The groove 205 is provided to reduce the extension length of the auxiliary cylinder 500, allowing the auxiliary cylinder 500 to be closer to the multilayer circuit board in its initial position. This can shorten the stroke of the auxiliary cylinder 500, improve its response speed and pressing accuracy, and also help optimize the overall structural layout of the equipment.

[0074] Reference Figure 3 As shown, in some embodiments, the top of the lower mold 600 is provided with a plurality of suction holes 601. The suction holes 601 are used to adsorb multilayer circuit boards. A vacuum device is connected to the suction holes 601. The vacuum device can suction the suction holes 601 to adsorb and fix the multilayer circuit boards, thereby preventing the multilayer circuit boards from shifting during the pressing process.

[0075] It should be noted that currently, resistance wires are usually placed at the position of the upper die 200 or the lower die 600 to heat them. After the upper die 200 or the lower die 600 heats up, the heat is then transferred to the multilayer circuit board. This heating method is relatively inefficient, and the resistance wire heats up slowly.

[0076] Based on this, refer to Figure 2 As shown, in some embodiments, the lower pressing mold 600 is made of ferromagnetic material. The multilayer circuit board vacuum pressing machine 1000 also includes an electromagnetic induction coil 700. The base 100 has a mounting cavity 103 located below the lower pressing mold 600. The electromagnetic induction coil 700 is located inside the mounting cavity 103 and is wound into a disc-shaped spiral. The electromagnetic induction coil 700 is used to heat the lower pressing mold 600 and the bottom of the multilayer circuit board. The electromagnetic induction coil 700 can be a copper coil. The electromagnetic induction coil 700 is connected to a high-frequency inverter circuit. The high-frequency inverter circuit inputs high-frequency alternating current to the electromagnetic induction coil 700, thereby causing the electromagnetic induction coil 700 to generate a high-frequency alternating magnetic field whose direction and intensity change rapidly. Its magnetic field lines pass perpendicularly through the lower pressing mold 600. The changing magnetic field induces eddy currents inside the lower pressing mold 600, causing the lower pressing mold 600 to heat up rapidly. This heating method is more efficient and has a faster heating speed. In addition, some of the magnetic field will also pass through the copper foil at the bottom of the multilayer circuit board, and can directly heat the copper foil at the bottom, allowing the multilayer circuit board to heat up directly inside, resulting in a more uniform heating effect.

[0077] It should be noted that uneven heating can lead to inconsistent resin curing. Areas with lower temperatures may not cure completely, resulting in poor adhesion; while areas with higher temperatures may over-cure, causing the resin to become brittle. Ultimately, this can lead to board warping, increased risk of delamination, and inconsistent dielectric properties of the material.

[0078] The electromagnetic induction heating technology employed in this invention not only boasts a heating rate several times faster than traditional resistance wire heating, significantly shortening the production cycle, but more importantly, it features "volume heating" and "targeted heating" characteristics. The eddy current effect of the lower pressure mold 600 ensures uniform heating throughout, avoiding "hot spots" or "cold spots" caused by poor local contact or aging in resistance wire heating. Simultaneously, the magnetic field lines directly penetrate the PP sheet and core board, directly heating the underlying copper foil, achieving heat transfer from the inside out. Compared to traditional outside-to-inside heat conduction, this more effectively promotes the melting and flow of resin within the PP sheet, reducing stress caused by large temperature differences between the inside and outside. Furthermore, the power of the high-frequency inverter circuit can be precisely and rapidly adjusted, allowing the system to strictly adhere to a preset heating curve (e.g., multi-stage heating, constant temperature holding), thereby achieving precise control over the resin curing process.

[0079] To complement the efficient heating system, embodiments of the present invention can also integrate a cooling system (not shown in the accompanying drawings). For example, cooling channels are pre-set inside the upper mold 200 and / or the lower mold 600. After the pressing and holding stage, a cooling medium (such as cooling water or heat transfer oil) can be switched in to force-cool the mold of the pressed circuit board, thereby achieving a rapid cooling effect. Rapid and uniform cooling is also a key factor in preventing board warping and ensuring dimensional stability. The combination of electromagnetic induction heating and internal channel cooling constitutes a complete thermal management cycle of "rapid heating - precise temperature control - rapid cooling," further improving production efficiency and product quality.

[0080] In some embodiments, refer to Figure 2 As shown, a rotatable support feeding roller 106 is also provided at the pressure plate inlet 102. The support feeding roller 106 is horizontally set and can roll to support the multi-layer circuit board, so as to assist the multi-layer circuit board with larger weight to move laterally into the pressing cavity 101.

[0081] Reference Figure 1 As shown, in some embodiments, the multilayer circuit board vacuum laminator 1000 further includes a fan 800 located within the lamination chamber 101. The fan 800 is used to blow air toward the multilayer circuit board. During the heating process, the fan 800 can circulate the hot air in the lamination chamber 101 to the multilayer circuit board, thereby uniformly heating the multilayer circuit board. (Refer to...) Figure 5 As shown, in some embodiments, two air guide plates 900 are preferably arranged inside the pressing cavity 101. The air guide plates 900 are L-shaped and extend vertically. There are four fans 800 arranged in a straight line. The two air guide plates 900 are located on the left and right sides of the four fans 800 respectively. The two air guide plates 900 are symmetrically arranged, and the air guide plates 900 and the fans 800 form a U-shaped structure to surround the multilayer circuit board. An air guide channel is formed between the air guide plates 900 and the inner wall of the pressing cavity 101. The air guide channel extends from the front to the rear to guide the airflow to circulate from front to back. The direction of airflow can be referenced. Figure 5 As shown by the dashed arrow, the inner wall of the air guide plate 900 is provided with a heating resistance wire 901. The heating resistance wire 901 faces the multilayer circuit board. The fan 800 can transfer the heat of the heating resistance wire 901 to the multilayer circuit board. In this embodiment, by setting the air guide plate 900, the hot air flow can be guided, which is conducive to the circulation of hot air flow. The flow rate is large and can evenly heat the multilayer circuit board.

[0082] When the fan 800 is running, it not only transfers the heat from the heating resistance wire 901 to the multilayer circuit board, but also guides the hot air flow with the help of the air guide plate 900, making it circulate and flow at a high speed, thereby achieving uniform heating of the multilayer circuit board. This hot air circulation system design, combined with electromagnetic induction heating, further ensures the temperature uniformity of the multilayer circuit board during the lamination process, providing a strong guarantee for improving the lamination quality.

[0083] The present invention also provides a control method for controlling the multilayer circuit board vacuum laminator of the above embodiments. The control method includes the following steps:

[0084] S1. Control the vacuum pumping device to evacuate the pressing chamber;

[0085] S2. Control the main pressure oil pump to drive the two main oil cylinders to drive the upper pressure mold to move downwards, so as to pre-press the multi-layer circuit board;

[0086] S3. Control the pressure-replenishing oil pump to supply oil to the oil inlet channel to drive the piston to replenish pressure at the center position of the multilayer circuit board;

[0087] S4. Control the auxiliary pressure oil pump to drive the output rod of the auxiliary oil cylinder to extend, so as to apply auxiliary pressure to the corners of the multilayer circuit board.

[0088] In some other embodiments, the control method further includes the following steps:

[0089] S5. Control the vacuum device to evacuate the suction hole so that the suction hole can adsorb and fix the multilayer circuit board.

[0090] Furthermore, this control method can be executed by a central controller (such as a PLC or industrial computer) that integrates comprehensive management of the pressure system, vacuum system, heating system, cooling system, and fan system. The optimized control flow can be further refined as follows:

[0091] S6. Process parameter setting: Operators can input or call up pre-stored process formulas through the human-machine interface to set parameters including target vacuum degree, temperature of each stage (heating rate, constant temperature point, holding time, cooling rate), pressure value of each pressure system (main pressure, supplementary pressure, auxiliary pressure), pressurization sequence and holding time.

[0092] S7.1 Multi-stage vacuuming: In S1, the vacuuming process can be carried out in stages. For example, a low vacuum pre-vacuum is first performed to slowly remove most of the air and volatiles and prevent resin splashing. When the temperature rises to near the resin melting point, a high vacuum is then performed to thoroughly remove residual gas and moisture and ensure the quality of pressing.

[0093] S7.2 Coordinated Temperature and Pressure Control: During the pressure application processes in S2, S3, and S4, the pressure is synchronized and coordinated with the heating system. For example, a lower pre-pressure (contact pressure) is applied at the low temperature stage to facilitate heat transfer; as the temperature rises and the resin begins to flow, the main pressure is gradually increased; after the resin has fully flowed, the center pressure supplement and the four corner auxiliary pressure are activated for refined pressure compensation, ensuring that the pressure and temperature curves are perfectly matched throughout the curing process to achieve the best pressing effect.

[0094] S8. Post-pressing treatment: After the pressure holding period, the controller will first activate the cooling system to lower the temperature. Once the circuit board temperature drops below a safe level, the pressure will be released and the vacuum will be broken. Finally, the upper pressure mold will be lifted to complete the entire pressing cycle. This precise timing control can effectively avoid product defects caused by high-temperature pressure release.

[0095] Examples of the embodiments described above are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described above with reference to the accompanying drawings are exemplary and are only used to explain the invention, and should not be construed as limiting the invention.

[0096] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0097] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0098] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0099] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A multilayer circuit board vacuum laminating machine, characterized in that, include: A base having a pressing cavity, wherein the front side of the base is provided with a pressure plate inlet communicating with the pressing cavity; The upper die is vertically mounted in the pressing cavity. A piston cavity is provided at the center of the upper die. The opening of the piston cavity is located at the bottom of the upper die. The upper die is provided with an oil inlet channel and an oil return channel communicating with the piston cavity. The upper die is also provided with a clearance hole that runs through the upper die in the vertical direction. The clearance hole is located at the corner of the upper die. A piston is disposed in the piston chamber and can extend out of the opening of the piston chamber to abut against the multilayer circuit board below; The main hydraulic cylinder has its output rod fixedly connected to the upper pressure mold. There are two main hydraulic cylinders, and the piston is located between the two main hydraulic cylinders. An auxiliary hydraulic cylinder is installed on the top of the upper mold and corresponds to the position of the clearance hole. The output rod of the auxiliary hydraulic cylinder can extend out of the bottom of the upper mold through the clearance hole to abut against the multi-layer circuit board below. The main hydraulic pump is used to provide hydraulic power to the main hydraulic cylinder; An auxiliary pressure oil pump is used to provide hydraulic power to the auxiliary oil cylinder; A pressure-replenishing oil pump is connected to the oil inlet channel to provide hydraulic power to the piston; The lower pressure mold is fixedly installed inside the pressing cavity and located below the upper pressure mold; A vacuum pumping device is used to evacuate the pressing chamber.

2. The multilayer circuit board vacuum laminator according to claim 1, characterized in that, The upper die includes a left half die and a right half die. The left half die forms a left piston cavity, and the right half die forms a right piston cavity. The left and right piston cavities together form the piston cavity. The left or right half die is provided with an oil inlet channel and an oil return channel. The inner wall of the left piston cavity is provided with a first semi-circular flange and a first semi-circular groove. The inner wall of the right piston cavity is provided with a second semi-circular flange and a second semi-circular groove. The first and second semi-circular grooves combine to form an annular groove. A first sealing ring is provided in the annular groove. The piston includes a first cylinder and a second cylinder. The outer diameter of the second cylinder is smaller than that of the first cylinder. The second cylinder is located below the first cylinder. The outer peripheral wall of the first cylinder is provided with a second sealing ring. The second sealing ring abuts against the inner wall of the piston cavity, and the outer peripheral wall of the second cylinder abuts against the first sealing ring.

3. The multilayer circuit board vacuum laminator according to claim 1, characterized in that, The oil inlet channel extends vertically and forms an oil inlet on the upper side of the upper mold. The oil return channel extends horizontally and forms an oil return outlet on the side of the upper mold. The oil return channel is located at the lower part of the upper mold.

4. The multilayer circuit board vacuum laminator according to claim 1, characterized in that, The multilayer circuit board vacuum laminator also includes a vertically arranged guide roller located inside the lamination cavity. The upper mold has lugs on its left and right sides, and the lugs have guide holes that penetrate the upper mold in the vertical direction. The guide holes are slidably engaged with the guide roller.

5. The multilayer circuit board vacuum laminator according to claim 1, characterized in that, The top of the upper die has a groove, the position of which corresponds to the position of the clearance hole, and the groove communicates with the clearance hole. The auxiliary cylinder is installed in the groove.

6. The multilayer circuit board vacuum laminator according to claim 1, characterized in that, The top of the lower mold is provided with multiple suction holes, which are used to adsorb the circuit board, and the vacuum device is connected to the suction holes.

7. The multilayer circuit board vacuum laminator according to claim 1, characterized in that, The multilayer circuit board vacuum pressing machine also includes an electromagnetic induction coil. The machine base is provided with a mounting cavity, which is located below the lower pressing mold. The electromagnetic induction coil is located inside the mounting cavity and is used to heat the lower pressing mold.

8. The multilayer circuit board vacuum laminator according to claim 1, characterized in that, The upper die has a square structure, and there are four auxiliary cylinders, which are located at the four corners of the upper die.

9. A control method, characterized in that, The control method for controlling the multilayer circuit board vacuum laminator according to any one of claims 1 to 8 includes the following steps: S1. Control the vacuum pumping device to evacuate the pressing chamber; S2. Control the main pressure oil pump to drive the two main oil cylinders to drive the upper pressure mold to move downwards, so as to pre-press the multilayer circuit board; S3. Control the pressure-replenishing oil pump to supply oil to the oil inlet channel, so as to drive the piston to replenish pressure at the center position of the multilayer circuit board; S4. Control the auxiliary pressure oil pump to drive the output rod of the auxiliary oil cylinder to extend, so as to apply auxiliary pressure to the corner positions of the multilayer circuit board.

10. The control method according to claim 9, characterized in that, The top of the lower mold is provided with multiple suction holes, which are used to adsorb the circuit board. The vacuum device is connected to the suction holes. The control method further includes the following steps: S5. Control the vacuum device to evacuate the suction hole so that the suction hole can adsorb and fix the multilayer circuit board.

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