CN103909121B - For the cyclic bending machine of circuit board layering - Google Patents

Abstract

The present invention relates to a kind of cyclic bending machine for circuit board layering, it comprises frame, bending mechanism, bending mechanism comprises the fixing backing plate be arranged in frame, be positioned at the pressure strip above fixing backing plate, be positioned at the upper twisted plate in pressure strip front, be positioned at the lower twisted plate below twisted plate, described pressure strip, upper twisted plate and lower twisted plate can move back and forth along above-below direction respectively, bending mechanism also comprises the compression cylinder for driving pressure strip to move back and forth, for the cam driving gear driving upper twisted plate and lower twisted plate to move back and forth, bending machine also comprises the electrical apparatus control system for controlling compression cylinder action.Circuit board delamination effectively can be arranged simple, good reliability by the present invention.

Description

Reciprocating bender for circuit board delamination

technical field

The invention relates to a reciprocating bending machine for delamination of circuit boards.

Background technique

With the advancement of science and technology and the shortening of the replacement cycle of electronic products, electronic waste is growing at an annual rate of more than 20%, becoming the fastest growing waste in the world. According to relevant data, currently the world produces more than 50 million tons of electronic waste every year, 70% of which are discarded in China through various means, while my country produced more than 2.3 million tons of electronic waste in 2007. If such a huge amount of electronic waste is not handled properly, it will cause environmental pollution comparable to natural disasters. If it is handled properly, not only will it not cause environmental pollution, but also a large amount of precious metal resources can be recovered from it, which is also very beneficial to the rapid development of electronic products.

In the recycling of electronic waste, waste circuit boards are the most difficult to deal with, mainly because the substrate of the circuit board (referred to as PCB, the same below) is made of multi-layer glass fiber cloth with copper foil sandwiched and epoxy resin bonded by high pressure. It is very difficult to separate the glass fiber cloth and copper foil of PCB. At present, there are three main methods to deal with PCB: 1) Incineration method, which is to carbonize and volatilize the glass fiber cloth at high temperature and only recover the metal. Since the waste gas emitted by the incineration method contains a large amount of dioxin, it will cause serious air pollution. It has been strictly prohibited; 2) Strong acid dissolution method, which is to use strong acid (such as sulfuric acid or aqua regia) to dissolve the metal in the PCB and discard other non-metallic substances. The waste liquid and discarded non-metallic substances discharged by this method are seriously polluted , The country has also strictly prohibited its use; 3) The pulverization method is to pulverize the PCB into powder, and then separate the metal particles from the glass fiber powder by suspension or centrifugation, and only recover metal. The metal recovery rate is 90-95%, accounting for PCB 80% of the glass fiber powder by weight has no use value anymore, landfill will pollute the land, and discarded in the open air will pollute the air.

Chinese invention patent application 201210298559.8 proposes a circuit board recycling method, which is to separate the layered structure of the circuit board, and then separate the outer layer of glass fiber cloth layer containing metal circuits, the middle copper foil layer and the inner layer of glass fiber cloth layer After peeling off, the glass fiber cloth layer containing the metal circuit is incinerated to obtain the metal, and the copper foil layer is directly reused, while the glass fiber cloth layer containing no metal is not incinerated. On the one hand, this recycling method greatly reduces the cost of incineration and reduces the pollution caused by incineration to the environment; on the other hand, the glass fiber cloth obtained by layering can be further reused for other purposes, turning waste into treasure. The key to the implementation of this recycling method is to effectively separate the layered structure of the circuit board. According to the literature report, the circuit board is first heated to above 180°C by a heating device, and then the circuit board is sequentially passed through at least four sets of rollers of the bending mechanism, so that the circuit board is bent under the force between the upper roller and the lower roller , and finally realize the separation of the layered structure under the action of internal stress. This layering method makes it difficult to peel off the PCB board layers due to the following shortcomings:

1. See Figure 1, the circuit board will not be delaminated at the inflection point (A) of the tooth tip of the roller, but will only be delaminated between the inflection point and the inflection point, so it needs to be rolled many times, and each time The folding points of rolling can not overlap, so that the PCB board can be delaminated in a large area;

2. See Figure 1, no matter how many times of rolling, the mouth (B) of the PCB cannot be delaminated;

3. See Figure 2. There are usually hundreds or even thousands of sockets (C) on a PCB. These sockets are similar to rivets to secure the PCB, and the circuit boards around the sockets cannot be layered.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a reciprocating bending machine which can conveniently and effectively separate the layers of the circuit board.

In order to solve the above technical problems, the present invention takes the following technical solutions:

A reciprocating bending machine for circuit board delamination, which includes a frame, a bending mechanism arranged on the frame, the bending mechanism includes a fixed backing plate arranged on the frame, a pressing machine located above the fixed backing plate plate, an upper curved plate located in front of the pressing plate, and a lower curved plate located below the upper curved plate, the pressing plate, the upper curved plate and the lower curved plate can reciprocate along the up and down direction respectively, and the bending mechanism also includes A compression cylinder for driving the compression plate to reciprocate, a cam drive device for driving the upper bending plate and the lower bending plate to reciprocate; the bending machine also includes an electrical control device for controlling the action of the compression cylinder system.

Further, the horizontal distance L3 between the upper curved plate and the fixed backing plate, and the horizontal distance L4 between the lower curved plate and the fixed backing plate are both less than or equal to 3 times the thickness of the circuit board and greater than or equal to the thickness of the circuit board. The front edge of the fixed backing plate close to the upper curved plate and the front edge of the pressure plate close to the lower curved plate are all rounded, and the radius of the rounded corners is less than or equal to twice the thickness of the circuit board.

Preferably, the reciprocating bending machine further includes a feed mechanism for conveying the circuit board through the bending mechanism, the feed mechanism is controlled by the electrical control system, and the circuit board is conveyed forward by a set distance Then stop. Further, the feeding mechanism includes a pair of feeding rollers and a driving motor for driving the feeding rollers, and the driving motor is a stepping motor or a servo motor.

Preferably, the above-mentioned cam driving device includes a cam, a motor for driving the cam to rotate, an upper curved plate roller connected to the upper curved plate, and a lower curved plate roller connected to the lower curved plate, and the cam has The upper curved plate track and the lower curved plate track in contact with the lower curved plate roller.

Further, the track of the upper curved plate and the track of the lower curved plate both extend along the circumferential direction of the cam and are respectively located on two opposite sides of the cam.

Preferably, the reciprocating bending machine completes a reciprocating bending cycle every time the cam rotates one circle, and the reciprocating bending cycle includes the following five actions: a, conveying the circuit board forward for a certain distance; b, pressing the pressing cylinder to drive the pressing plate to press Tighten the circuit board; c. The cam drives the upper bending plate to bend the circuit board downward and quickly retreats; d. The cam drives the lower bending plate to bend the circuit board upward and quickly returns; e. The compression cylinder drives the compression plate to release the circuit board, so The order of the above five actions is a→b→c→d→e or a→b→d→c→e.

Further, the bending mechanism also includes a cam angle positioning device that collects the cam rotation angle information and transmits the collected information to the electrical control system, and the electrical control system controls the feed mechanism and the compression cylinder according to the collected cam angle information action. The cam angle positioning device can be, for example, an induction switch or a travel switch.

According to the present invention, the cam may be a radial cam or an axial cam.

Preferably, the bending mechanism further includes a limiting device for limiting the pressing plate, the upper bending plate and the lower bending plate so that they can only reciprocate up and down.

Preferably, at least one heating device capable of heating the temperature to 120° C. to 300° C. is provided in the fixed backing plate, the pressing plate, the upper curved plate and the lower curved plate respectively.

Preferably, the reciprocating bending machine further includes an insulating layer arranged on the outer periphery of the bending mechanism for insulating the working environment of the circuit board.

Due to the implementation of the above technical solutions, the present invention has the following advantages compared with the prior art:

The reciprocating bending machine of the present invention can not only effectively separate the adjacent two layers of the circuit board, but also the glass fiber cloth and the rivet are easy to separate, therefore, the circuit board can be effectively peeled off in layers; in addition, the present invention has good reliability and simple structure , Easy to set up.

Description of drawings

Below in conjunction with accompanying drawing and specific embodiment the present invention is described in further detail:

Figure 1 is a schematic diagram of circuit board bending using the roller bending method provided by 2012102985598;

Fig. 2 is a schematic diagram of the socket structure of the circuit board;

Fig. 3 is a schematic front view of a reciprocating bending machine according to the present invention;

Fig. 4 is a schematic sectional view of A-A direction in Fig. 3;

Fig. 5 is an area distribution diagram when the upper curved plate roller and the lower curved plate roller are designed in the same radial direction;

Fig. 6 is a schematic sectional view of the cam;

Fig. 7 is a schematic diagram of the right side of Fig. 6, which shows the trajectory of the lower curved plate;

Fig. 8 is a schematic view on the left side of Fig. 6, which shows the trajectory of the upper curved plate;

Fig. 9 is a schematic diagram when the circuit board is in a state to be bent;

Fig. 10 is a schematic diagram of the circuit board being bent downward;

Among them: 1. Circuit board; 3. Reciprocating bending machine; 30a, feed roller; 30b, heating insulation board; 31, fixed backing plate; 32, pressing plate; 33, upper bending plate; 34, lower bending plate; 350 , cam; 351, pressing cylinder; 352, upper bending plate roller; 353, lower bending plate roller; 354, cam angle positioning device; 36, bending plate slide bar; 37, pressing plate slide bar; 38, frame; 39. Insulation layer; J1, track of upper bending plate; J2, track of lower bending plate; Q1, feeding area; Q2, pressing area; Q3, upper bending area; Q4, lower bending area.

Detailed ways

Example 1

As shown in Figures 3 to 8, the reciprocating bending machine 3 of the present invention is mainly composed of a feed mechanism, a fixed backing plate 31, a pressing plate 32, an upper bending plate 33, a lower bending plate 34, a driving device, and a bending plate slide bar 36. , Compression plate slide bar 37, frame 38, insulation layer 39 and corresponding induction switch or travel switch, electric control system etc. are formed. The driving device comprises a cam driving device and a compression cylinder 351 . The fixed backing plate 31 is fixed on the frame 38 . The pressing plate 32 can move along the pressing plate slide bar 37 . The upper curved plate 33 and the lower curved plate 34 can move along the curved plate slide bar 36 . The action information of the feed mechanism and each cylinder is collected by the corresponding induction switch or travel switch, and their action coordination is completed by the electrical control system. The pressing plate 32 is driven by the pressing cylinder 351 to reciprocate up and down, and the upper curved plate 33 and the lower curved plate 34 are both driven by the cam driving device to reciprocate up and down.

The horizontal distance L3 between the upper curved plate 33 and the fixed backing plate 31 and the horizontal distance L4 between the lower curved plate 34 and the fixed backing plate 31 are less than or equal to three times the thickness of the circuit board 1 . The front edge R1 of the fixed backing plate 31 close to the upper curved plate 33 and the front edge R2 of the pressing plate 32 close to the lower curved plate 34 are all rounded, and the radius of the rounded corners is less than or equal to twice the thickness of the circuit board 1 .

In this example, the cam driving device includes a motor, a reducer, a cam 350 driven by the motor, an upper bending plate roller 352 , and a lower bending plate roller 353 . Cam 350 is a combination cam. On two opposite side surfaces of the cam 350, an upper curved plate track J1 and a lower curved plate track J2 extending along its circumferential direction are respectively provided. The upper curved plate roller 352 and the lower curved plate roller 353 are in contact with the upper curved plate track J1 and the lower curved plate track J2 respectively. The reciprocating bending machine also includes a cam angle positioning device 354 . The cam angle positioning device 354 collects the information of the rotation angle of the cam 350 and transmits the information to the electrical control system, and the electrical control system controls the feed mechanism and the compression cylinder to perform corresponding actions.

In this example, the cam 350 is designed so that the reciprocating bending machine completes one reciprocating bending cycle when the cam 350 rotates once. The reciprocating bending cycle includes the following five actions in sequence: a, the feed mechanism transports the circuit board 1 forward for a certain distance; b, the compression cylinder 351 drives the compression plate 32 to compress the circuit board 1; c, the cam 350 Drive the upper bending plate 33 to bend the circuit board 1 downward and quickly retreat; d, the cam 350 drives the lower bending plate 34 to bend the circuit board 1 upward and quickly retreat; e, the compression cylinder 351 drives the compression plate 32 to release the circuit board 1. As shown in FIG. 5 , in the 360-degree rotation of the cam 350, there are designed a feeding zone Q1, a pressing zone Q2, an upper bending zone Q3, and a lower bending zone Q4. When the cam 350 rotates within the angle range corresponding to each zone, corresponding actions can be performed. For example, when the cam 350 rotates within the angular range of the feeding zone Q1, the feeding mechanism can transport the circuit board 1 forward for a certain distance; when the cam 350 rotates within the angular range of the pressing zone Q2, the compression cylinder 351 Drive the pressing plate 32 to compress the circuit board 1, and outside the pressing area Q2, the pressing plate 32 loosens the circuit board 1; when the cam 350 rotates within the angle range of the upper bending area Q3, the cam 350 drives the upper The pressing plate 33 bends downward, and when the cam 350 rotates within the angle range of the lower bending area Q4, the cam 350 drives the lower pressing plate 34 to bend upward.

In this example, the feeding mechanism includes a pair of feeding rollers 30a and a driving motor for driving the feeding rollers 30a, and the driving motor is a stepping motor or a servo motor. The feeding mechanism may further include upper and lower heating and heat preservation boards 30b arranged on the frame 38, allowing the circuit board 1 to pass between the upper and lower heating and heat preservation boards 30b.

Adopt the step that the present invention carries out circuit board delamination as follows:

a. The feed mechanism sends the circuit board forward for a certain distance L1 and then stops; b. The pressing plate compresses the circuit board under the drive of the compression cylinder; c. The upper bending plate bends the circuit board downward under the drive of the cam and quickly retreat; d, the lower bending plate is driven by the cam to bend the circuit board upwards and quickly retreat; e, the compression cylinder drives the compression plate to release the circuit board. The above 5 steps are a reciprocating bending cycle, and the reciprocating bending cycle is repeated continuously until the feeding mechanism cannot effectively control the forward transport of the circuit board, and then the circuit board is turned around to continue the above reciprocating bending cycle until the entire circuit board has been reciprocated bending.

Example 2

This example provides a method for bending a circuit board by using the reciprocating bending machine in Example 1 (reciprocating bending method or bending split-layer method). Each feed rate is L (L=3mm), and the thickness of each layer in the circuit board is a (a=0.2 mm), see Figure 9, when it is compressed and bent, the phenomenon shown in Figure 10 will occur, the inner layer and the outer layer will be forced to stagger H (H=1.884), two adjacent layers It will also be staggered by h (h=0.314), h=(a×Π)÷2, we divide the stagger amount h of two adjacent layers by the feed amount L and call it the stagger degree of two adjacent layers, and use d means that d=h/L, when the degree of stagger d is sufficiently greater than the elongation of the material itself, the stagger force of two adjacent layers will overcome the bonding force between them and produce a stagger. The circuit board is made of multi-layer glass fiber cloth Bonded, the elongation of glass fiber cloth at 180 degrees is less than 0.3%, and the stagger d given in Figure 10 is 10.47% (d=0.314/3), which is much greater than the elongation of glass fiber cloth. The stagger is the same as The feed rate is related, and the feed rate should not be too large. When the jack rivet moves to the bending staggered area, the rivet will be stretched and tilted at a certain angle to loosen, and the fiberglass cloth hole will also be pulled into an ellipse, making it easy to separate the glass fiber cloth from the rivet. , the fiberglass cloth and rivets are easier to separate.

The present invention has been described in detail above, and its purpose is to allow those familiar with this field to understand the content of the present invention and implement it, and can not limit the scope of protection of the present invention. Effect changes or modifications should be covered within the protection scope of the present invention .

Claims (8)

1., for a cyclic bending machine for circuit board layering, it comprises frame, the bending mechanism be arranged in described frame, it is characterized in that:

Described bending mechanism comprises the fixing backing plate be arranged in described frame, be positioned at pressure strip above described fixing backing plate, be positioned at the upper twisted plate in described pressure strip front, be positioned at lower twisted plate below described upper twisted plate, the forward position of the forward position of the close described upper twisted plate of described fixing backing plate, the close described lower twisted plate of described pressure strip is fillet, and the radius of fillet is all less than or equal to 2 times of circuit board thickness;

Described pressure strip, upper twisted plate and lower twisted plate can move back and forth along above-below direction respectively, and described bending mechanism also comprises the compression cylinder for driving described pressure strip to move back and forth, the cam driving gear for driving described upper twisted plate and lower twisted plate to move back and forth;

Described bending machine also comprises the electrical apparatus control system for controlling compression cylinder action;

Level interval L3 between described upper twisted plate and described fixing backing plate, level interval L4 between described lower twisted plate and described fixing backing plate are all less than or equal to 3 times of circuit board thickness, are more than or equal to circuit board thickness.

2. the cyclic bending machine for circuit board layering according to claim 1, it is characterized in that: the lower twisted plate roller that described cam driving gear comprises cam, the motor for driving described cam to rotate, the upper twisted plate roller be connected with described upper twisted plate and is connected with described lower twisted plate, described cam have respectively with upper twisted plate track and the lower twisted plate track of described upper twisted plate roller and lower twisted plate roller contact.

3. the cyclic bending machine for circuit board layering according to claim 2, it is characterized in that: described upper twisted plate track and described lower twisted plate track all extend along the circumference of described cam, and lay respectively on the relative two side faces of described cam.

4. the cyclic bending machine for circuit board layering according to Claims 2 or 3, it is characterized in that: described cam rotates the described cyclic bending machine of a circle and completes a cyclic bending cycle, and the described cyclic bending cycle comprises following five action: a, circuit board is fed forward certain distance; B, compression cylinder drive pressure strip to compress circuit board; On c, actuated by cams, twisted plate is bent downwardly circuit board and returns fast; Under d, actuated by cams, twisted plate is bent upwards circuit board and returns fast; E, compression cylinder drive pressure strip to unclamp circuit board, and the order of described five actions is a → b → c → d → e or a → b → d → c → e.

5. the cyclic bending machine for circuit board layering according to claim 4, it is characterized in that: described cyclic bending machine also comprises for the feed mechanism of transporting circuit board by described bending mechanism, described feed mechanism is controlled by described electrical apparatus control system, namely stops after described circuit board is fed forward setpoint distance.

6. the cyclic bending machine for circuit board layering according to claim 5, it is characterized in that: described bending mechanism also comprises collects described angular displacement of the cam information and the cam angle degree positioner collected information being passed to electrical apparatus control system, and described electrical apparatus control system controls described feed mechanism and described compression cylinder action according to the cam angle degree information of collecting.

7. the cyclic bending machine for circuit board layering according to claim 1, is characterized in that: described bending mechanism also comprises makes them can only do the restraint device pumped for limiting described pressure strip, upper twisted plate and lower twisted plate.

8. the cyclic bending machine for circuit board layering according to claim 1, is characterized in that: being respectively arranged with at least one in described fixing backing plate, pressure strip, upper twisted plate and lower twisted plate can by the heater between heating temperatures to 120 DEG C ~ 300 DEG C; Described cyclic bending machine also comprises and is arranged on the heat-insulation layer of described bending mechanism periphery for being incubated the working environment of circuit board.