JPH02133792A - Warpage correction apparatus and method for metallic foil-clad laminated plate - Google Patents

Abstract

PURPOSE:To obtain a metallic foil-clad laminated plate having no warpage and no change in size by arraying in a zigzag pattern three or more rollers so that the rollers are positioned in a furnace at right angles therewith in the longitudinal direction of the furnace retaining a preset temperature. CONSTITUTION:A metallic foil-clad laminated plate 4 introduced into a heating furnace 1 first passes between rollers 2 for elevating a temperature, which vertically form a pair. In this process, the metallic foil-clad laminated plate 4 receives heat from an atmosphere in the heating furnace and, at the same time, also receives heat from the rollers 2 for elevating a temperature because the plate 4 is brought into contact with the rollers 2 for elevating a temperature. Further, an electric heater is inserted into the rollers 2 for elevating a temperature to warm up the whole rollers so as to promote the temperature rise of the metallic foil-clad laminated plate 4. Then, the metallic foil-clad laminated plate 4 whose temperature has been elevated to the level of a glass transition temperature or higher passes between rollers 3 for collecting the warpage of the plates, which are arranged in a zigzag pattern, whereby the metallic foil-clad laminated plate is repeatedly subjected to the bending processing so that residual strain is removed and the warpage is corrected. Further, after-cure is performed by heating in the heating furnace 1.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Applications) The present invention relates to a warpage correction device and method for metal foil-clad laminates.

(Conventional technology) Metal foil-clad laminates used for printed wiring boards are heated and
In the circuit board manufacturing process, which involves pressure pressing and repeated heating and humidification, warping and dimensional changes occur in the board, causing problems in circuit manufacturing work or component assembly work. In recent years, with the increase in the size of circuit boards and the automation of 1-7 processes, the requirements for preventing warpage and dimensional changes in circuit boards have become increasingly strict.

The cause of this warpage and dimensional change is often due to the heating and pressure pressing process. In other words, residual material remains inside the laminate due to the flow of the resin impregnated into the main phase, the uncured resin, the difference in thermal expansion coefficient between the metal foil and the laminate, and the difference in the thermal expansion coefficient with the stainless steel mold plate. strain mass,
Warping or dimensional changes occur when the product is removed from the press or subjected to heat history during the wiring board manufacturing process.

Possible methods for improving this bright spot include annealing treatment and mechanically correcting warpage. For example, JP-A No. 57-203548, JP-A No. 57-2035
As shown in Japanese Patent Publication No. 49 and Japanese Patent Application Laid-open No. 57-203554, there is a method in which the material is cooled once to below the glass transition temperature in the press molding station and then heated again to above the glass transition temperature for annealing treatment. Also, JP-A-60-2603
As shown in Japanese Patent No. 36, there is a method of forcibly deforming the material using several rolls to correct the warpage.

(Problem to be solved by the invention) However, with the dimensions of 7ii"S, the press forming time was long (and in my case, the press work was rate-limiting in laminate manufacturing1, resulting in poor production efficiency9. Also, the latter method However, laminates made of paper substrates are easily plastically deformed and can be easily corrected for warping, but laminates made of woven glass fabric can only be distorted and cannot be corrected for warpage.

Therefore, the present invention was made in view of the above-mentioned points, and it is possible to remove the residual strain accumulated in the laminate by performing annealing treatment and warp correction on the laminate without impairing production efficiency, thereby eliminating warpage and dimensional changes. The object of the present invention is to provide a method for correcting warpage of metal foil-clad laminates and a method thereof.

(Means for Solving the Problems) The configuration of the present invention for achieving the objects set forth in AiJ will be explained using FIG. 1 corresponding to an embodiment.

The warp straightening device for metal foil-clad laminates according to the first invention comprises a heating furnace in the form of a long tube, which can maintain the atmospheric temperature in the heating furnace at a set temperature, and has an inlet portion and a protruding portion; A technical means is provided consisting of a roll group consisting of a plurality of rolls arranged vertically perpendicular to the furnace in the direction, and three or more rolls in which all or part of the roll group is arranged vertically and alternately in a staggered manner. ing.

The method for straightening warpage of a metal foil-clad laminate according to the second invention is such that the atmospheric temperature in the heating furnace and the roll surface temperature are set in the glass transition temperature range -1- of the metal foil-clad laminate to be warped, and the temperature at the entrance of the heating furnace is set to -1-. A technical step has been taken in which a metal foil-clad laminate is inserted into the furnace, passed through a space between 1 and 10 meters, and then taken out from the heating furnace outlet.

(Function) The reason why the temperature of the atmosphere inside the heating furnace and the surface temperature of the rolls are set to be higher than the glass transition temperature of the laminate to be warped is as follows. One is that when the temperature exceeds the glass temperature, the elastic modulus of the laminate decreases, resulting in plastic deformation, softening, and straightening.
This makes it easier to remove residual strain (anil treatment). This is particularly effective for laminates using glass woven fabric as the reinforcing phase. Another is that uncured resin can be completely cured (after-cure treatment). This after-cure treatment can save time for heating in the process of the warp straightening device of the present invention, so it also has the advantage of shortening the press forming time.

Warp correction is possible with at least three rolls. However, it is preferable to arrange a large number of rolls in a staggered arrangement. This is because the distribution of residual strain locally accumulated within the laminate is divided into smaller sections depending on whether the laminate is subjected to repeated bending or not.

In addition, near the inlet of the heating furnace, several sets of two silk rolls placed directly above and below each other are arranged horizontally, and when the laminate passes between them, the upper and lower surfaces of the laminate and the roll surface are It is preferable to use a force such that the two contact each other. By doing this, the laminate is heated to 17. It passes through a group of rye wheels arranged in a staggered manner and undergoes warpage correction. In order to increase the temperature increase rate,
A heating device such as an electric heater or steam piping may be embedded in the roll to heat the roll itself from within.

(Example) An example of the present invention will be described below using FIGS. 1 to 3.

FIG. 1 shows a schematic perspective view of the warpage correction device 7. As shown in FIG. The metal foil cladding ff1ii&4 released from the press is conveyed to a warpage correction device 7 by a belt conveyor 5. The heating furnace 1 is set to a predetermined temperature in advance. The entire area foil-covered laminated sheet &4 entering the heating furnace 1 passes between the temperature raising rolls 2 which are rolled in the upper and lower blade directions. During this process, the metal foil-clad laminate 4 receives heat from the atmosphere in the heating furnace and also receives heat from the temperature raising roll 2 since it is in contact with the temperature raising roll 2. An electric heater is inserted into the temperature raising roll 2 to warm the entire roll and help raise the temperature of the metal foil clad laminate 4. Next, the metal foil-clad laminate 4 whose temperature has risen to above the glass transition temperature is passed between the warp correction rolls 3 arranged in a staggered manner to remove residual strain and correct warpage. . Also,
After-cure is achieved by heating in the heating furnace 1.

Figure 2 schematically represents another embodiment of the warpage correction device!
11 is shown. No temperature raising rolls 2 were provided, and only eight warp correction rolls 3 were arranged. A gas heater is embedded inside the roll.

FIG. 3 shows a schematic cross-sectional view of another embodiment of the warpage correction device. Three warpage correction rolls 3 were arranged in a staggered manner. An electric heater is embedded inside the roll. Further, a direction corrector 6 is attached so that the metal foil-clad laminate 4 can pass smoothly between the rolls.

(Effects of the Invention) As described above, according to the present invention, it is possible to remove residual strain accumulated in a laminate, correct warpage, and after-cure uncured resin without reducing production efficiency. We were able to provide foil-clad laminates.

[Brief explanation of the drawing]

FIG. 1 is a cutaway perspective view showing an embodiment of the present invention, FIG.
FIG. 3 is a schematic sectional view showing another embodiment of the present invention. Explanation of symbols 1...Heating furnace 2...Temperature raising roll 3...
...Warp correction roll 4...Metal foil cladding & laminate 5.
... Belt conveyor 6 ... Direction correction tool 7 ...
orthodontic device

Claims (5)

[Claims] 1. Rolls consisting of an oblong cylindrical heating furnace that can maintain the atmospheric temperature inside the heating furnace at a set temperature and has an inlet and an outlet, and a plurality of rolls arranged vertically in the longitudinal direction of the furnace and perpendicular to the furnace. 1. A warpage correction device for a metal foil-clad laminate, comprising a roll group and three or more rolls in which all or part of the roll group is arranged in a staggered manner alternating up and down. 2. The warp straightening device for metal foil-clad laminates according to claim 1, comprising a group of rolls arranged vertically symmetrically near the heating furnace inlet, and a roll group arranged vertically alternately in a staggered manner near the heating furnace exit. A warpage correction device for a metal foil-clad laminate, comprising: 3. 3. The apparatus for straightening warpage of a metal foil-clad laminate according to claim 1 or 2, wherein the roll is provided with a heating device inside. 4. The temperature of the atmosphere inside the heating furnace and the surface temperature of the rolls are set to be higher than the glass transition temperature of the metal foil-clad laminate to be warped, and the metal foil-clad laminate is inserted from the entrance of the heating furnace and passed between the upper and lower rolls. A method for straightening warpage of a metal foil-clad laminate, characterized in that it is taken out from an outlet. 5. 5. The method for straightening warpage of a metal foil-clad laminate according to claim 4, wherein the reinforcing material for the metal foil-clad laminate is a glass woven fabric.