JP3493720B2 - Prepreg heating method and heating apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a prepreg heating method and a heating apparatus.

[0002]

2. Description of the Related Art A laminated board such as a printed circuit board is manufactured by impregnating and drying a thermosetting resin varnish on a base material such as kraft paper, linter paper, glass paper cloth, glass non-woven fabric, and the like. Is cut into a predetermined size by a cutting device, a required number of the laminated pieces are laminated, copper foil is added to one side or both sides according to the application, and heat and pressure molding is performed.

When the prepreg is cut by a cutting device in the process of manufacturing the laminated plate, cutting powder remains on the cut surface, and the cutting powder scatters in the air and adheres to the surface of the laminated plate constituent material. In this case, fine unevenness or scratches that are scratches may occur on the surface of the laminated plate after molding (mainly the surface of the copper foil).

Therefore, until the long cut prepreg is conveyed at a predetermined temperature and immediately before being cut by the cutting device, the base material is impregnated with the thermosetting resin by using a heating body such as an infrared heater at the planned cutting position. There is known an apparatus in which chips are not heated during cutting so that the chips are heated to a temperature above the melting point and below the curing temperature.

[0005]

However, while the long prepreg is being conveyed at a predetermined temperature, just before the cutting is performed by the cutting apparatus, the heating target such as an infrared heater is used to heat the base material at the planned cutting point. An apparatus in which a curable resin is heated to a range not lower than its melting point and not higher than its curing temperature so as not to generate cutting chips at the time of cutting has the following problems. (1) In order to efficiently heat only the prepreg to be cut, the heating element is moved in synchronism with the carrying and feeding of the prepreg. However, the part other than the prepreg to be cut is slightly heated. No, I can disconnect. For this reason, the elastic coefficient of the prepreg is lowered, and eventually the strain of the prepreg is weakened, which may hinder the conveyance of the prepreg. In this case, interrupt the cutting work of the prepreg,
Since the work is restarted, the prepreg staying in the prepreg drying device, which is a pre-process of the cutting process, is treated as a defective product, and the yield of the prepreg is reduced.

(2) Since the heating element is always kept at a predetermined temperature, it causes an increase in the temperature of the prepreg cutting device, affects the feed rotation of the feed roll as the prepreg conveying means, and causes the prepreg to have a wrinkle defect. Occurrence or deterioration of roll bearing.

The present invention has been made in view of the above circumstances, and an object thereof is to locally heat only a portion to be cut of the prepreg without lowering the strength of the prepreg strain. Another object of the present invention is to provide a heating device for cutting a prepreg that can continue the cutting work while smoothly conveying the prepreg.

[0008]

According to the present invention, a long prepreg is impregnated with a thermosetting resin, and a dried prepreg is run, while a heating member that moves in synchronization with the prepreg is used to immediately cut a planned cutting position. In the device for heating to a temperature not lower than the softening point of the thermosetting resin and not higher than the curing temperature, when the heating body faces the planned cutting position of the prepreg, a current having a predetermined value is applied to the heating body. Then, the prepreg is heated by heating the prepreg.

Further, according to the present invention, a long base material is impregnated with a thermosetting resin, and a dried prepreg is run, while a heating body that moves in synchronization with the prepreg moves the thermosetting resin to a predetermined cutting position immediately before cutting. In the device that heats the resin to a temperature above its softening point and below its curing temperature, the start point position is detected to detect the position at which the heating element will wait until the scheduled cutting point of the prepreg runs directly under the heating element. And a detector for the end point position so that the heating element is energized for the heating time required to heat the prepreg to be cut to a predetermined temperature. When running directly under the body, in synchronization with this, along with the output of a signal to start the reciprocating movement of the heating body in a predetermined range, when a current of a predetermined value is supplied and the heating body moves to the movement limit position, A heating device prepreg and outputs a signal for controlling the energization of the thermal member.

[0010]

According to the present invention, the heating by the heating element is limited only to the planned cutting point of the prepreg, so that the weakening of the prepreg strain is suppressed to the utmost, the conveyance of the prepreg is not hindered, and the cutting operation is not interrupted. It can be done efficiently.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a cutting device equipped with a prepreg heating device according to the present invention. As shown in the figure, the long prepreg 1 travels in the arrow direction at a predetermined speed on the upper surface of the flow plate 3 which is a support base. As seen in the running direction of the prepreg 1, a pair of upper and lower feed rolls 2 and 2 that are opposed to each other, which are prepreg conveying means, are provided on the upstream side of the flow plate 3, and the prepreg 1 is cut on the downstream side of the flow plate 3. A rotating upper blade 5 and a lower blade 4, which are cutting means for cutting a predetermined portion, are provided. Therefore, the prepreg 1 travels by being pushed toward the upper surface of the flow plate 3 by the pair of feed rolls 2 and 2, and when passing through the downstream side of the flow plate 3, the planned cutting position is the rotary upper blade 5 and It is cut by the lower blade 4.

On the upstream side of the rotating upper blade 5 and the lower blade 4 which are cutting means and above the flow plate 3, for example, an infrared heater 6 is provided as a heating body for heating the planned cutting portion of the prepreg 1. It is arranged so as to be able to reciprocate in parallel with the flow plate 3. The infrared heater 6 is rod-shaped and is provided with its length direction facing both ends of the prepreg 1. The length of the infrared heater 6 is at least longer than the width dimension of the prepreg 1, and is preferably 1.1 times to 1.2 times the prepreg width dimension.
It is better to use double one. Both ends of the infrared heater 6 are connected to belts 9 and 9 which reciprocate by a heater driving motor 8 and a traveling guide 10 and
It is supported by 10.

A heater starting position detector 12 for detecting the position where the prepreg 1 runs near the feed rolls 2 and 2 of the prepreg 1 and waits until the planned cutting position is directly below the infrared heater 6. Is provided. Correspondingly to this, the position where the infrared heater 6 is energized for a predetermined heating time required to heat the thermosetting resin of the prepreg 1 to a temperature above the softening point and below the curing temperature. The movement limit position is set, and the detector 13 for the heater end point position is provided at this movement limit position. Therefore, the installation position of this detector 13 is the prepreg 1
Is determined by the relative relationship between the traveling speed of No. 2 and the heating time of the infrared heater 6 required to heat the planned cutting point to a predetermined temperature.

A rotary encoder 7 is provided so as to be connected to the feed roll 2 of the prepreg 1. The rotary encoder 7 detects the position of the prepreg 1 and cuts the prepreg 1 into a predetermined length. A signal is output, the rotation of the rotary upper blade 5 is controlled by this output signal, and the infrared heater 6 is capable of heating while facing the planned cutting point of the prepreg 1.

With such a configuration, the infrared heater 6
Detects the planned cutting point of the prepreg 1 by the pulse signal of the rotary encoder 7, starts the operation of the motor 8, moves the infrared heater 6 at the same speed as the traveling speed of the prepreg 1, and energizes the infrared heater 6. Then, the planned cutting point of the prepreg 1 is heated.

When the planned cutting point is heated to a predetermined temperature,
The infrared heater 6 passes through the heater end position detecting device 13, and an output signal from the detecting device 13 causes the motor 8 to move.
Rotates in the reverse direction, the infrared heater 6 moves in the opposite direction, returns to the detector 12 for the heater start position, and waits until the next cut point of the prepreg 1 comes directly below the infrared heater 6. .

When the infrared heater 6 passes the detection device 13 for the heater end position, the infrared heater 6 passes the rotary encoder 7
Is detected, the power supply to the infrared heater 6 is controlled, and the applied voltage is reduced to zero or a value close to zero.

Further, when the planned cutting point of the prepreg 1 heated by the infrared heater 6 passes through the rotating upper blade 5 and the lower blade 4, the rotary encoder 7 detects this and
The rotating upper blade 5 is rotated by the signal to cut the planned cutting point.

Prepreg 1 cut in this way
Is conveyed to the next step by the conveyor belt 11, and this operation is sequentially repeated, so that the cutting of the prepreg 1 at the planned cutting position is repeated.

This cutting device applies the voltage necessary for heating the planned cutting point to the infrared heater 6 only when the infrared heater 6 is moving forward, and the voltage is applied except when the infrared heater 6 is moving forward in synchronization with the prepreg 1. The voltage is set to zero or a minimum voltage.

Generally, the heating element is placed on top of the prepreg. It is most preferable to heat the prepreg only at the planned cutting site, and for this purpose, it is advisable to bring the prepreg close to the heating body prepreg. On the other hand, the long base material is connected to the next base material at the terminal end thereof. This connection is generally smoothed. However, when the base material is cut in the middle, it may be connected in a dango. In this case, the height of the dango knot is 40-60m
m, the heating element is 80 to 1 from the prepreg surface.
Installed at a distance of 00 mm. Then, the following problems occur. (1) In the case where the heating element is an infrared heater, the infrared rays that are extra for heating the prepreg are absorbed by the cutting device itself, causing the temperature of the device to rise. For this reason, the apparatus frame portion thermally expands, which hinders the rotation of the feed roll and other rotating bodies. As a result of the coarseness, the feed amount of the prepreg is not uniform and the feed itself becomes impossible. If the temperature rises further,
It also occurs when the temperature of the device covers causes burns to the human body. Further, since the material of the feed roll of the prepreg is rubber, it becomes a factor that causes separation of the rubber from the roll core metal. (2) When the heating element is a far-infrared heater, if the heating element and the prepreg are separated by 80 to 100 mm, the amount of heat rays reflected by the prepreg surface is large, which is extremely dazzling and may cause deterioration of the working environment. . (3) It is impractical to make the heating element movable or to attach a reflecting plate to the heating element, because the device becomes complicated and the functional deterioration due to dirt on the reflecting plate cannot be avoided. So, from the heating element, put a glass cloth in the shape of a curtain,
The heat rays from the heating body are shielded (see FIG. 2). The light-shielding glass cloth 28 is laid in a curtain shape so that only the lower surface of the infrared heater 6 is opened, and the light-shielding glass cloth is fixed by a glass cloth stopper 29 so as not to drop when the infrared heater 6 is running. The distance between the lower end of the light-shielding glass cloth 28 and the prepreg is preferably as short as possible, but considering the waving of the prepreg 7 or the like, it is suitable to be about 10 to 20 mm. The light-shielding glass cloth 28 has a thickness of 0.2 m.
It is appropriate to double the number of m, but triple or quadruple if necessary. As the glass cloth and the fitting 29, a stainless plate having a thickness of 1 to 2 mm bent in a U shape is sufficient. By putting the glass cloth in a curtain shape from the heating element, the heat rays of the heating element can be blocked, and the dumpling knot of the base material can easily pass under the heating element, and it is wasted as leakage heating light. You can save energy by 20%. Further, even if the resin powder adheres to the glass substrate, it can be easily replaced.

[0022]

As described above, according to the present invention,
In heating and cutting the planned cutting position while conveying the prepreg, it is possible to locally heat only the planned cutting position, so that it is possible to minimize the decrease in the strength of the prepreg strain, and to reduce the prepreg's strength. Enables smooth running,
This enables efficient work without interrupting the cutting work.

[Brief description of drawings]

FIG. 1 is a perspective view of a cutting device including a prepreg heating device according to the present invention.

FIG. 2 is a perspective view showing a state where a light shielding glass cloth is put on a heating body.

[Explanation of symbols]

1 prepreg 2 Feed roll 3 flow board 4 lower blade 5 rotating upper blades 6 infrared heater 7 Rotary encoder

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B26D 7/10 C08J 5/24

Claims (2)

(57) [Claims] 1. A method of heating a dried prepreg obtained by impregnating a long base material with a thermosetting resin, comprising a heating body that moves in synchronization with the prepreg, the heating body cutting the prepreg. When facing the planned position, by energizing this heating element, immediately before cutting the planned cutting position, it is heated to a temperature not lower than the softening point of the thermosetting resin and not higher than the curing temperature. Characteristic prepreg heating method. 2. A softening point of the thermosetting resin immediately before cutting at a planned cutting position by a heating body that moves in synchronization with the prepreg while running a prepreg in which a long base material is impregnated with the thermosetting resin and running. The above is a device for heating to a temperature not higher than the curing temperature, which is the cutting position of the prepreg.
A detector for the starting position for detecting a position to wait for the heating body to the location is facing the heating body, cut position of the prepreg
It is equipped with a detector for the end point position to energize the heating element for the heating time required to heat the device to a predetermined temperature.Furthermore, the position of the prepreg is detected, and the planned cutting position faces the heating element.
At the same time , in synchronization with this, a signal is output to start the reciprocating movement of the heating element within a predetermined range, and at the same time , a current is applied, and when the heating element moves to the movement limit position, a signal for controlling the energization to the heating element is output. A prepreg heating device characterized by outputting.