WO1987001651A1

WO1987001651A1 - Press-autoclave, for example for laminating printed circuits

Info

Publication number: WO1987001651A1
Application number: PCT/FR1986/000311
Authority: WO
Inventors: Marcel Collin
Original assignee: Darragon S.A.
Priority date: 1985-09-19
Filing date: 1986-09-15
Publication date: 1987-03-26
Also published as: FR2587273B1; EP0236399A1; FR2587273A1

Abstract

A gap between platens (3) of a press-autoclave is subdivided by an envelope comprised of a rigid frame (18) and deformable bladders (15a, 15b) into an internal sealed chamber (22) connected to a vacuum pump and into at least one external pressure chamber (23). The bladders (15a, 15b) are applied against products to be treated (9) optionally mounted on toolings (14), thereby providing for their compression. The heating and cooling may be effected by the platens (3) or by the pressurization fluid of the external chamber or chambers (23). Application to the plastification and lamination of multilayer printed circuits.

Description

The present invention relates to the technical field of laminating flexible, rigid, or flexo-rigid multilayer printed circuits, that is to say each comprising at least one flexible part and at least one rigid part, as well as the technical field of the plasticization of flat elements, such as documents or cards, in particular of credit or of payment, with memory and / or with microprocessor, between two plastic films.

The invention relates more precisely to a method of laminating such printed circuits and of plasticizing such flat elements, as well as to an autoclave press for implementing this method.

The installations currently used for laminating multilayer printed circuits include laminate presses which are generally used in the following manner: the circuits to be laminated are stacked between tools made up of thick metal plates, and then transferred these tools loaded in the compartments of a press with mutipated trays that can be moved towards and away from each other using a jack, the tools are put in compression by. bringing the plates closer to one another while ensuring the heating of the tools using a heating circuit incorporated at least partially in the plates and comprising for example electrical resistances embedded in the plates of the pressa where a network of channels extending in the trays is traversed by a heat transfer fluid, such as superheated steam, then a cooling phase is provided, natural or forced, for example by circulation of a refrigerant fluid in channels provided in the trays and which can possibly be the same channels as those of the heating circuit, the cooling phase continuing while the platens are kept under pressure, and finally the tools carrying the multilayered stratified circuits are removed from the press. essentially intervenes two phases of tooling treatment, and therefore of the laminate circuits which they contain, at know a compression-heating phase and a compression-cooling phase. These two phases can be carried out in the same station, and we then have to do with a mixed press, or they can be carried out separately, and we then have to do with a press with separate stations. It should be noted that such a press with separate stations makes it possible to obtain, in specific applications, a better production rate, especially when it is equipped with an automatic installation for loading and unloading of tools. an example of installation of this type is the subject of the French patent application filed on August 7, 1981 under No. 81 15 420 for "automatic installation for loading and unloading of tools for a multi-stage press, in particular a press for laminating multilayer printed circuits "in the name of the applicant. It should also be noted that certain mixed laminating presses are also equipped with an automatic loading and unloading installation.

The various laminating presses for multilayer printed circuits which are currently used have the drawbacks that despite the care that can be taken in the manufacture of their components, and in particular the plates, as well as in their assembly, which leads to high manufacturing costs, the inevitable flatness and parallelism defects of the plates are transmitted, via the tools, to the multilayer printed circuit, which affects the quality of the latter. In addition, for the stratification of flexible printed circuits, a high number of layers of a felted material, similar to blotting paper, are consumed which are stacked above and below the flexible multilayer printed circuits to be laminated, in order to constitute a compression mattress to match the reliefs of printed circuits. In addition, known presses allow only one single multilayer printed circuit to be laminated in the interval between two press plates, because compression is directly ensured by bringing the plates together. Finally, these are bulky items and heavy, machined in the mass, and made of expensive materials (generally stainless steel) and their heating is expensive. In general, the efficiency of the heating and cooling installation is low. By the invention, it is proposed to remedy these drawbacks, and the object of the invention is a method and a laminating press making it possible to increase the productivity of the operation by the simultaneous treatment, in a single interval between two plates. , of several multilayer printed circuits, some of which may be rigid, and previously arranged in tools, while others may be flexible and installed without tools.

Another object of the invention is to propose a method and a laminating press making it possible to overcome the flatness and parallelism defects of the plates, and to ensure the compression of the circuits to be laminated by the application of pressure uniform on them.

Yet another object of the invention is to propose a method and a laminating press making it possible to economize on compression mattresses and other "blotters" for the stratification of flexible multilayer printed circuits.

The invention further aims to provide a method and a laminating press for the use of lighter trays, less complex, and therefore more economical.

Another object of the invention is to propose a method and a laminating press using heating means more efficient than those of the laminating presses of the prior art, and making it possible to obtain better homogeneity of the temperature during the heating and cooling cycle.

Yet another object of the invention is to provide a method and a laminating press for laminating flexible circuits in several stages in a single interval between two plates, in order to provide excellent productivity. Another object of the invention is to provide a method and a press for laminating multilayer printed circuits which can also be used as a method and press for laminating documents or flat elements such as memory cards and / or microprocessor. A final object finally of the invention is to propose a device made up of a set of components making it possible to transform or modify a laminating press of the state of the art into an autoclave press providing the advantages mentioned above, such a transformation being particularly advantageous if the press that is transformed is a press with one or two stations with automatic loading and unloading.

To this end, the subject of the invention is a method for laminating multilayer printed circuits and / or for laminating documents, comprising the steps which consist of:

- to have at least one product to be treated, such as a multilayer printed circuit to be laminated or a document to be laminated between two plastic films, in an interval delimited between two plates substantially parallel to each other and mounted mobile , in a direction substantially perpendicular to their planes, on a press stand,

- to move the plates towards one another and to lock them in a position of approach,

- I subject each product to be treated to hot compression,

- to cool and decompress each product to be treated, then - to spread the trays to evacuate each treated product, and it is characterized in that it consists:

- sealingly enclosing each product to be treated in an envelope arranged in the meantime and the parts of which are located on either side of the product or products to be treated are flexible and deformable,

- to block a rigid lateral part of the envelope eg in position between the two trays locked in the approaching position, so as to delimit outside the envelope and inside the gap at least one sealed chamber extending on either side of each product to be treated, - connecting the sealed chamber delimited inside the envelope to a source of vacuum by 'at least' one passage passing through the envelope, and

- to connect each sealed outer chamber to the envelope to a source of pressurized fluid, in order to apply deformable parts of the envelope against each product to be treated with a uniform pressure ensuring the necessary compression, then

- relieve the pressure in each external chamber and return the internal chamber to ambient pressure, in order to decompress each product to be treated. It is thus obtained that the combined effects of the evacuation of the internal chamber to the envelope and the pressurization of the chamber or chambers external to the envelope force the flexible and deformable parts of the latter to closely match the external shape of the flexible circuits and flexible parts of flexo-rigid circuits or tools loaded with rigid circuits or rigid parts of flexo-rigid circuits, which gives the certainty of a good application of a uniform pressure on the circuits to be compressed.

By analogy with the state of the art presses! and in order to be able to transform the latter at the lowest cost, the heating of the products to be treated can be provided by conduction from the heating of the trays, but, preferably, according to a characteristic specific to the invention, the process consists in heating and / or to cool the pressurization fluid in at least one of the chambers external to the envelope, and to ensure by conduction the heating of the product or products to be treated. This allows significant savings in heating and possibly the use of insulating and / or cell trays. Advantageously, in order to maintain good temperature uniformity, the method further consists in maintaining a mixing of the hot and then cold fluid in the corresponding external chamber or chambers, during the pressurization cycle of this or these chambers. In order to facilitate the implementation of the process, a neutral gas such as nitrogen is advantageously used as the pressurization fluid.

Advantageously, the method according to the invention consists in controlling the pressurization of each chamber outside the envelope only after a certain time interval following the start of the depressurization of the chamber inside the envelope, and preferably , also after the start of heating of the product (s) to be treated. In this way, the evacuation of the internal chamber purges the stack of the various layers of the printed circuit of air bubbles, water vapor and other impurities which are thus extracted. Likewise, the layers of fabrics of mineral or organic fibers, for example glass, which are pre-impregnated with a heat-polymerizable resin, and which are stacked with conductive layers and insulating layers, are thus purified to form a circuit. multilayer print to laminate.

To laminate documents or flat elements, the method consists in having at least one product to be treated in an interval between two plates only after having mounted it in tools, by placing each product to be treated between two non-stick coatings, by placing the sub-assembly thus obtained between two metal sheets, and by centering the different layers of the stack thus produced before enclosing the latter in the envelope. The non-stick coatings thus used make it possible to ensure protection against the creep of the resin of the prepreg layers of the multilayer circuits, so that this resin does not adhere to the tools. By analogy with the stratification process currently used, for the stratification of rigid circuits which can have up to twenty superimposed layers, the assembly of at least one product to be treated in tooling also consists in placing the stack of the product (s) to be treated, two non-stick coatings and two metal sheets metal to be treated, between two thick metal plates and also to center the latter with the other layers of the stack thus produced before enclosing the latter in the envelope. In the latter case, the method advantageously further consists in protecting the flexible and deformable parts of the envelope from the metal plates of the tools by sticking pieces of adhesive tape on the corners of said metal plates. In addition, it easily ensures the centering of the tools and the products to be treated which they contain relative to the casing sive of compressing the product or products to be treated and mounted in the tools, these are placed on support blocks and for centering the tools in the envelope.

The subject of the invention is also a pressure autoclave for implementing the method according to the invention and comprising:

- a column frame,

- at least two plates substantially parallel to each other and mounted to slide on the frame in a direction substantially perpendicular to their planes,

- at least one member for operating the plates, controlling their approach and spacing as well as the locking of the plates in position in approach,

- At least one heating circuit for at least one product to be treated, such as a multilayer printed circuit to be laminated or a document or flat element to be laminated between two plastic films, which is arranged in a delimited interval between two neighboring trays and possibly - at least one cooling circuit for each product to be treated, and the autoclave press according to the invention is characterized in that it further comprises, for at least one interval between two trays, but preferably for each interval, - at least one rigid frame pierced with at least one suction channel and intended to be placed between the two plates or between a plate and a rigid auxiliary frame, pierced with at least one pressurization channel and arranged in the interval, or even between two auxiliary frames, and around at least one product to be treated,

- At least one pair of waterproof, flexible and deformable bladders, the two bladders of which are intended to be disposed each between one face of a frame and the opposite face of a plate or an auxiliary frame, so as to be extended one above and the other below at least one product to be treated and surrounded by this frame, and - bladder protection members, comprising, for each frame, at least two layers of a non-stick coating, intended to be deposited each between one of the two bladders, corresponding to this frame and the product or products to be treated in this frame, and in that each of the two plates is pierced with at least one channel pressurization which opens in the meantime and inside the adjacent frame, so that after locking the plates in the approaching position, each bladder is tightly sealed between a corresponding frame and a corresponding plate or auxiliary frame, and each frame and the two corresponding bladders define around the product or products to be treated in this context, a vacuum chamber intended to be connected by each suction channel to a source of vacuum, while each of the two corresponding bladders delimits, with the face opposite of a plate contiguous to the corresponding frame and inside the latter or with another bladder clamped against an auxiliary frame contiguous to the corresponding frame, a pressurization chamber intended to be connected, by each pressurization channel of this plate or of this adjoining auxiliary frame, to a source of pressurized fluid, in order to compress the product or products to be treated between portions of the two corresponding bladders. Advantageously, each suction channel of the frame (s) is connected to a vacuum pump by sealed pipes on which is mounted at least one valve controlling the isolation or the venting with possibly the adjustment of the vacuum in the room or rooms of depres if we. In addition, each pressurization channel of the plates and, where appropriate, of the auxiliary frame or frames is connected to an accumulator of a pressurized neutral gas, such as nitrogen, by leaktight pipes on which is mounted at least one valve. controlling the supply and possibly the supply speed of the pressurization chambers, as well as their decompression.

As in the prior art laminating presses, the heating circuit and / or the cooling circuit can be embedded in the plates, but, according to a characteristic specific to the invention, the heating circuit and / or the cooling circuit includes the pressurization chambers and channels as well as sealed pipes connecting to a group for heating and / or cooling the pressurizing fluid, which is heated and / or cooled in the passage in this group before entering in pressurization chambers. Advantageously, moreover, the heating and / or cooling circuit comprises a circulation pump, mounted on a sealed pipe loop which is closed on the pressurization chambers and which passes through the heating and / or cooling groups.

In addition, the layers of the non-stick bladder protection coating advantageously consist of sheets of glass fiber fabrics agglomerated by a material with a low coefficient of friction such as a poly-tetrafluoroethylene. This avoids ripples of flexible printed circuits which could be caused by bladders under pressure, since these coatings have an excellent coefficient of slip. In addition, these coatings also protect the bladders against possible leakage of the resin from the prepreg layers of the printed circuits.

For laminating, the press comprises tools, in the form of at least one pair of metal sheets, between which are intended to be arranged two non-stick coatings to be spread on either side of at least one product to be treated, the facing faces of the two sheets of each pair having a mirror polished surface, the pro (s) duits to be treated, the two coatings and the two metal sheets being intended to be assembled in a stack centered by means of at least two centering pins passing through the stack which is intended to be placed in the interval between the two layers of the protective non-stick coating of two bladders.

For the stratification of a rigid circuit, or rigid parts of flexo-rigid circuits, the tools further comprise, for each pair of sheets, a pair of metal plates intended to be centered against the sheets and outside of those -this in a pinned stack containing at least one product to be treated.

Preferably, the two non-stick coatings of the tools are sheets of aramid fiber fabrics, for example from Tedlar (registered trademark).

A subject of the invention is finally a device for converting into an autoclave press for laminating multilayer printed circuits and / or for laminating documents, a laminating press which comprises: a column frame,

at least one member for operating the plates, controlling their spacing, their bringing together and their locking in the close position, and

a heating circuit and / or a cooling circuit which are at least partially integrated in the plates, the device according to the invention being characterized in that it comprises:

at least one rigid frame pierced with at least one suction channel and intended to be placed between two plates and around at least one product to be treated, and for each frame,

- at least one pair of bladders, waterproof, flexible and deformable, the two bladders of which are intended for each be tightly sealed against one face of the corresponding frame, on either side of the product or products to be treated and surrounded by the frame and

- At least two sheets of a non-stick coating, each intended to be deposited between a bladder and the product or products to be treated in this context.

Preferably, this transformation device also comprises a vacuum pump, at least one pipe for connecting the vacuum pump to the suction channels of the frame or frames, and at least one control valve. Preferably, there is also provided at least one pipe for connecting an accumulator of a neutral pressurized fluid to at least one pressurization channel which is to be drilled in each of the press plates, as well as at least one control to be mounted on this connection pipe.

Advantageously, if one wishes to push the transformation to the heating and / or cooling circuit, the transformation device also comprises a heating and / or cooling group and a pump for circulation of the neutral fluid under pressure, which are intended to be mounted on at least one pipe for transporting the neutral fluid under pressure. In this case, the transformation device can also comprise at least two insulating plates, each pierced with at least one pressurization channel, and substitutable for the plates with a partially integrated heating and / or cooling circuit of the press to be transformed.

Of course, this transformation device can also include tools as presented above for the stratification of circuits or parts of rigid circuits and for the plasticization of flat elements.

Finally, to allow the stratification of flexible printed circuits in several stages in a single interval between two press plates, the transformation device advantageously comprises at least one rigid auxiliary frame, pierced with at least one pressurization channel, and intended to be , on the one hand, clamped between two frames arranged in the same interval, with interposition of bladders, and, on the other hand, connected to a source of pressurized fluid.

Other advantages and characteristics of the invention will emerge from the description given below, without implied limitation, with reference to the appended drawings in which:

- Figure 1 shows schematically, partly in section and partly in side elevation, an autoclave press to laminate at two intervals or stages in the layering configuration of rigid multilayer printed circuits, _ Figure 2 schematically shows in section the stacking centered on a rigid multilayer printed circuit in tools and which is prepared before installation in an interval of the autoclave press of Figure 1, - Figures 3 and 4 schematically show in section a single interval or stage of the press autoclave of FIG. 1, respectively before and after the locking of the two plates, for the stratification of one or more rigid multilayer printed circuits mounted in tools, as shown in FIG. 2,

FIG. 5 schematically represents, in section, the stratification of a flexible multilayer printed circuit in a single interval of an autoclave press,

FIG. 6 represents in a similar manner the stratification in stages of several flexible multilayer printed circuits in a single interval of the autoclave press; and

- Figure 7 schematically shows the stratification of a rigid multilayer printed circuit in a single interval of an autoclave press equipped with a vacuum circuit whose pipes are represented by a single solid line and a circuit pressurization whose pipelines are represented by a double continuous line.

Referring to Figure 1, the autoclave press comprises a rigid frame 1 supporting vertical columns 2 along which horizontal plates 3, relatively thick and made of stainless steel, are slidably mounted. In this example, the autoclave press has three platens, which delimit two by two, between them, two intervals or stages in which are arranged the multilayer printed circuits to be laminated. The lower plate 3 rests on a piston 4 supported at the upper end of the rod 6 of an actuating and closing cylinder 5, the cylinder 7 of which is secured to the lower cross members of the frame 1. The cylinder 5 may be a cylinder of any known suitable type, for example hydraulic, mechanical, electromechanical or electric, and it is equipped with a locking device, also of any known suitable type, for example hydraulic, mechanical, electromechanical or electric, in order to be able to block the rod 6 relative to the cylinder 7 in any desired position and in particular in the closed position of the autoclave press, in a position of approaching the plates 3, in which the upper plate 3 is in abutment against upper crosspieces of the frame 1. In each plates 3 are partially integrated a heating device and a cooling device identified as a whole by the reference 8. These d devices are for example made up of a network of shielded electrical resistors which are embedded in the plates 3 alternating with pipes of an internal network in the plates 3 and which is connected to an external source of a refrigerant, the regulations of the passages respectively of the electric current in the resistors and of the coolant in the pipes making it possible to control the heating and then the cooling of the plates 3 according to desired laws as a function of time. These heating and cooling devices 8 can also include networks of pipes internal to the plates 3 and successively traversed by a heat-transfer fluid, such as a thermofluid or steam, then / in refrigerant, such as water, air, a mixture of water and air or a thermofluid.

At this point in the description, the autoclave press described above is no different from the prior art laminating presses. By analogy with the implementation of the latter for laminating rigid multilayer printed circuits or the rigid parts of printed circuits my flexo-rigid multilayers, which are laminated in two operations (one for the rigid parts and one for the flexible parts), these rigid circuits or parts of printed circuits are mounted in tools before being loaded into the press intervals -autoclave. This preliminary preparation is described with reference to FIG. 2: it consists in placing a steel plate 10a on a support, then in covering it with a stainless steel sheet 11a, one face of which has a polished surface state. mirror, is facing up. Then spread on this side of the sheet lia a non-stick coating, for example a sheet of Tedlar 12a. The stack of layers of the multilayer printed circuit or circuits to be laminated 9 is then placed on this sheet 12a which is covered with a second non-stick coating (sheet of Kevlar fabrics) 12b. On the latter, a sheet 11b is placed, identical to the sheet 11a but the mirror polished side of which is turned downwards, then a second steel plate 10b, identical to the plate 10a, is placed on the second sheet 11b. The different layers of the stack thus produced are centered by centering pins 13, which pass through holes drilled opposite one another in the different layers. The pinned and centered assembly constitutes a tool 14 loaded with one or more rigid circuits or rigid part of multilayer integrated circuits to be laminated.

Such loaded tooling 14 is then placed in an interval, between two plates 3, in the manner described below with reference to FIGS. 3 and 4.

Is deposited on the lower plate 3 of two plates spaced in the open position, a membrane or bladder 15a flexible, defective and waterproof, silicone. To make this bladder 15a, use is made, for example, of the material sold in France under the name of M OSITE by the company SCEI, 2 Avenue Kléber Paris. The property of such a bladder is to be vacuum and nitrogen tight under pressure, to have good mechanical and heat resistance, to have great flexibility and a good coefficient of elongation. A ti As an indication, in a first reference, this material has an elongation coefficient of 300% and withstands a temperature of 200 ° C and in a second reference, its elongation coefficient is only 100%, but it resists a maximum temperature of 250 ° C. Then deposited on the central part of this bladder 15a, a non-stick coating, consisting of a sheet 16a of a fabric of glass fibers impregnated with a polytetrafluoroethylene, then positioning the loaded tool 14 on the sheet 16a , after taking care to cover the corners and angles of the tool 14 with protective elements 17, produced for example by gluing pieces of adhesive tape. Then the tooling 14 is covered with a second non-stick coating, namely a second sheet 16b identical to the sheet 16a, and a rigid frame 18, made of steel or Duralumin, is positioned around the stack thus obtained. the periphery of the lower plate 3 and rests on the peripheral edge of the bladder 15a. This frame 18 is pierced laterally, on each side, with a vacuum channel 19. In order to facilitate centering of the tool 14 in the frame 18, it is possible, as shown in FIG. 4, to use shims of support and centering 20 which is then placed first on the lower plate 3, before placing the bladder 15a. After the setting up of the frame 18, there is a second bladder 15b, identical to the bladder 15a, on the upper face of the frame 18 and covering the stack surrounded by the latter, then the press is closed using the jack 5 (see FIG. 1), which causes the blocking of the frame 18 between the two plates 3, with pinching of the peripheral edges of the bladders 15a and 15b between this frame 18 and the plates 3 (see FIG. 4) . An essential characteristic of the plates 3 of the autoclave press with respect to the plates of the prior art laminating presses is that they each have at least one bent channel 21, one end of which opens out towards the plate 3, in a lateral face of the latter, and the other end of which opens towards the inside of the gap between the two plates 3, and at a sufficient distance from the edge of the plates for this channel 21 to mouth inside the frame 18. These channels 21 have been represented in FIGS. 3 and 4, but not in FIG. 1, so as not to overload the latter, but it must be understood that the plates 3 of FIG. 1 are also pierced with such channels.

By the cooperation of the bladders 15a and 15b with the frame 18, there is defined, after closing the press, an internal sealed chamber 22 which contains the tool 14 and which does not communicate with the outside of the interval defined between the two plates 3 as through the channels 19 of the frame 18. Simultaneously, the bladders 15a and 15b delimit with the parts of the opposite faces of the plates 3 which are located inside the frame 18, two sealed external chambers 23, located one at above and the other below the internal chamber 22, and which communicate with the outside of the interval only through the channels 21 of the plates 3.

The channels 19 are then placed in communication with an external vacuum source, for example a vacuum pump, the start of the heating cycle of the plates 3 is controlled, then, after a certain time interval, the channels 21 are put in communication with an external source of a neutral pressurized fluid, for example a pressurized nitrogen accumulator. This evacuation of the internal chamber 22 containing the loaded tool 14 makes it possible to purify the prepreg layers of resin not yet polymerized from the rigid printed circuits or rigid parts of flexorigid printed circuits 9 and to purge the stack of air bubbles , water vapor and other impurities it may contain. The heating of the plates 3 is carried out according to a law making it possible to reach a maximum temperature of 250 ° C. at the level of the circuits 9, and the pressurization of the external chambers 23 is also carried out according to a progressive law until a maximum pressure of 2 MPa approximately. The combined effects of the evacuation of the chamber 22 (arrow V) and the pressurization of the chambers 23 (arrow P) cause deformation of the bladders 15a and 15b, which closely match the external shape of the tool 14 and exert on the latter a compression, with uniform application of pressure. This results in good compression of the rigid circuits or rigid parts of printed circuits 9. The elements 17 for protecting the corners and angles of the tool 14 and the sheets 16a and 16b of a non-stick coating prevent damage to the bladders 15a and 15b during their deformation. In addition, the sheets 16a and 16b prevent wrinkling or the formation of undulations on the printed circuits 9 which could be caused by the deformation under pressure of the bladders, due to the excellent sliding coefficient of these sheets 16a and 16b, which , in addition, protect the bladders 15a and 15b against possible flow of resin out of the printed circuits, just as, in the loaded tool 14, the sheets 11a and 11b and the plates 10a, 10b are protected against creep of the resin by the sheets 12a and 12b of Kevlar fabric.

In FIG. 1, the autoclave press comprises three plates 3, therefore two intervals or stages, in each of which a tool loaded 14 has been mounted in the manner described with reference to FIGS. 2 to 4. In addition, there are shown by double continuous lines the pipes 24 supplying the chambers 23 with nitrogen under pressure, these pipes 24 being connected to the channels 21 drilled in the plates 3. If the plates 3 lower and upper can be satisfied with the channels 21 opening respectively in their upper faces and lower, the intermediate plate 3 has channels 21 opening into its upper face and into its lower face. In fact, all the trays can have channels 21 opening into their upper and lower faces, but these channels can be selectively connected to the pressurized nitrogen accumulator, according to the needs and the position of each tray. After the heating phase of the plates 3, their cooling phase is controlled, while maintaining, the evacuation of the internal chambers 22 and the pressurization of the external chambers 23. Then, at the end of the cooling phase, control the depressurization of the chambers 23, and finally the gradual bringing to room pressure of the chambers 22. The pressautoclave is then opened by spreading the plates 3 using the jack 5, the tools 14 are discharged and the circuits are removed from the latter laminate prints.

In Figure 5, there is shown a presseautoclave stage similar to that of Figure 5, so that the same components have been identified by the same references. However, this autoclave press stage is used in this case for the stratification of a flexible multilayer printed circuit 9 '. This flexible circuit 9 'is not mounted in a tool, but simply placed between the two sheets 16a and 16b of glass fiber fabric impregnated with polytetraf luoroethylene (PTFE), and the bladders I5a and 15b directly compress these sheets 16a and 16b as well as circuit 9 ', when the internal chamber

22 is evacuated by connecting the channels 19 of the frame 18 to the vacuum pump, and when the external chambers

23 are pressurized by connecting the channels 21 of the plates 3 to a pressurized neutral gas accumulator.

In this example, the sheets 16a and 16b not only protect the bladders 15a and 15b against the flow of resin from the flexible printed circuit 9 'to be laminated, but they prevent undulations which could form on this flexible circuit 9' come from the deformation under pressure of the bladders 15a and 15b, this advantageous result being obtained due to the good sliding coefficient of the glass fabric impregnated with PTFE.

In FIG. 6, there is shown an assembly allowing, in a single interval between two plates 3, to laminate several flexible multilayer printed circuits 9 ′ in several stages. In this arrangement, the constituent elements similar to those of the preceding figures have been identified by the same references. This assembly comprises three identical frames 18, each pierced with these suction channels 19, and arranged vertically one above the other, being separated in pairs by a rigid auxiliary frame 25, also made of steel or duralumin , also pierced with lateral channels 26 on each side, and which differs from a frame 18 only in its height, which is lower than that of the latter. This assembly therefore comprises two auxiliary frames 25 separated from each other and each of the closest plate 3 by a frame 18. With each frame 18 is associated, as before, a pair of bladders 15a and 15b. Between the two bladders of each pair is disposed a multilayer printed circuit 9 'sandwiched between two sheets of glass fabric impregnated with PTF E 16a and 16b. The assembly is mounted so that when the autoclave press is closed, by bringing the plates 3 closer together, the lower bladder 15a of the lower frame 18 is pinched between the latter and the lower plate 3, and the upper bladder 15b of this frame lower is pinched between the latter and the lower auxiliary frame 25. The lower bladders 15a and upper 15b of the middle frame 18 are pinched between this frame 18 and the auxiliary lower and upper frames 25 respectively, and the lower bladders 15a and upper 15b of the upper frame 18 are pinched between this frame and the auxiliary frame respectively 25 upper and tray 3 superior. Three internal chambers 22 are thus formed, each delimited between a frame 18 and the two corresponding bladders 15a and 15b. Between the lower plate 3 and the lower bladder 15a of the lower frame 18, and between the upper plate 3 and the upper bladder 15b of the upper frame 18, two external chambers 23 are defined. Finally, between the upper bladder 15b of the lower frame 18 and the lower bladder 15a of the middle frame 18, on the one hand, and, on the other hand, between the upper bladder 15b of the middle frame 18 and the lower bladder 15a of the upper frame 18, two auxiliary sealed chambers 23 'are formed , each of which communicates with the outside only through the channels 26 of the auxiliary frames 25. By connecting all the channels 19 of the frames 18 to a vacuum pump, the three chambers 22 are placed under vacuum, then, by connecting the channels 21 of the two plates 3 and all the channels 26 of the auxiliary frames 25 to a pressurized neutral gas accumulator, the two chambers 23 and the two chambers 23 ′ are pressurized, as shown in FIG. 6. Thus, the deformation of all the bladders 15a and 15b, and therefore the compression of the three flexible printed circuits 9 '. In this example, the heating, pressurization, cooling, depressurization and venting vacuum cycle is carried out as in the previous example, the plates 3 also being in this case heating plates and coolers.

In Figure 7, there is shown the assembly of a laminating installation comprising a single autoclave press stage which is identical to that of Figure 4, for the stratification of one or more rigid multilayer printed circuits or rigid parts of flexo-rigid printed circuits 9 mounted in tools 14. The constituent elements of this autoclave press stage are therefore identified by the same references as in FIG. 4, and they are not described again. In this installation, the channels 19 of the frame

18 are connected by lines 27 which meet, to a vacuum pump 29 of a motor-pump unit 28, the motor of which electric 30 drives the vacuum pump 29. From upstream to downstream on the pipe connecting to the pump 29, and from the junction point of the two pipes 27, a control manometer 31, of an electro- blocking valve 32 and a filter 33 are mounted on this connecting pipe. On this is also connected, in bypass, between the junction of the two pipes 27 and the blocking electro-valve 32, a vent pipe 34, on which are mounted, from upstream to the 'downstream, an electro-valve for venting 35 and a vacuum adjustment valve 36. The channels 21 of the two plates 3 are connected to a pressurized nitrogen bottle 37 by lines 38 which meet and are connected to a regulator and pressure gauge assembly 39 mounted at the outlet of the bottle 37. A nitrogen supply solenoid valve 40, a feed speed adjustment valve 41 and a control manometer 42 are mounted on the common part of the pipes 38, from upstream to downstream. Between the valve 41 and the pressure gauge 42, a decompression pipe 43 is connected in bypass and an electro-decompression valve 44 is mounted on this pipe 43. In addition, a loop pipe 45 connects the two branches of the pipes 38 which supply the channels 21 located on the two opposite sides of the plates 3, in order to constitute a closed loop on the two chambers 23, and a motor-pump group 46 with circulation pump 47 driven by an electric motor 48, is mounted on this looping pipe 45, in order to ensure, after pressurization of the chambers 23, a continuous circulation of the nitrogen, and therefore a stirring favoring the homogeneity of the stratification temperature. In this example, heating and cooling can be provided, as in the previous examples, by conduction from the heating and cooling plates 3. However, preferably, a heating and cooling group 49 is mounted on the supply lines 38 and on the loop line 45 in order to be able to successively heat and cool the nitrogen which is used as pressurizing agent for the chambers. 23. The use of nitrogen or another neutral, gaseous or liquid fluid, simultaneously as a pressurizing fluid and as a heating and cooling fluid makes it possible to achieve significant savings. It is also possible to use trays 3 devoid of heating and cooling devices, these trays then being able to be thinner and, for example, honeycombed, and even thermally insulating.

The control of the operation of the valves 36 and 41 and of the electro-valves 32, 35, 40 and 44, the control of the supply of the motors 30 and 48 to drive the pumps 29 and 47, as well as the control of the operation of the group of heating and cooling 49 are ensured according to a programming by microprocessor setpoint generator, so that the heating, cooling, depressurization and pressurization are carried out according to predetermined laws.

To laminate documents or flat objects, using the examples of autoclave press described above, using tools limited for example to two sheets of stainless steel or chrome-plated brass, with a polished face mirror and a thickness of approximately 1 mm, such as the two sheets 11a and 11b of FIG. 2, and there is between them the document or documents or flat objects to be laminated and previously sandwiched between the two sheets 12a and 12b of fabric Kevlar for the rest, the procedure is the same.

Note that in the autoclave presses described above, it is possible to have between two bladders several multilayer printed circuits, some of which are housed in tools and others of which are not.

Finally, by using a set of components comprising frames and auxiliary frames, bladders, non-stick coatings and tools as described above, as well as a vacuum pump, an accumulator of '' a pressurized neutral ffuide and corresponding regulating valves and valves, a state-of-the-art laminating press can be transformed into a car press clave according to the invention. If, in addition, it is desired not to use the heating and cooling devices which are fitted with the plates of the transformer press, one can also provide, in the transformation device, a heating and cooling group and a pump unit. continuous circulation of pressurizing fluid.

Claims

CLAIMS 1. Method for laminating multilayer printed circuits and / or laminating documents and flat elements, comprising the steps consisting in: - providing at least one product to be treated (9), such as a multilayer printed circuit to be laminated or a document to be laminated between two plastic films, in / interval delimited between two plates (3) substantially parallel to each other and mounted movable, in a direction substantially perpendicular to their plane, on a press frame ( 1),

- moving the plates (3) relative to each other and locking them in a position of approximation, - subjecting each product to be treated (9) to hot compression,

- to cool and decompress each product to be treated (9), then

- spreading the trays (3) to evacuate each treated product (9), characterized in that it consists:

- sealingly enclosing each product to be treated (9) in an envelope (15a, 15b, 18) arranged in the meantime and the parts (15a, 15b) of which are located on either side of the product or products process (9) are flexible and deformable,

- to block a rigid lateral part (18) of the envelope in position between the two plates (3) locked in the approaching position, so as to delimit outside the envelope and inside the gap at least one sealed chamber (23) extending on either side of each product to be treated (9),

- connecting the sealed chamber (22) delimited inside the envelope to a vacuum source (29) by at least one passage (19) passing through the envelope, and

- to connect each sealed chamber (23) outside the envelope to a source of pressurized fluid (37), so applying deformable parts (15a, 15b) of the envelope against each product to be treated (9) with a uniform pressure ensuring the necessary compression, then

- Releasing the pressure in each outer chamber (23) and bringing the inner chamber (22) to ambient pressure, in order to decompress each product to be treated.

2. Method according to claim 1, characterized in that it consists in heating the plates (3) and in ensuring by conduction the heating of the product or products to be treated (9).

3. Method according to claim 1, characterized in that it consists in heating and / or cooling the pressurization fluid of at least one of the external chambers (23) to the envelope and in ensuring by conduction the heating of the or products to be treated (9).

4. Method according to claim 3, characterized in that it consists in maintaining a stirring (47, 45) of the hot then cold fluid in the outer chamber (s) (23) corresponding during the pressurization cycle of this or these chamber (s).

5. Method according to one of claims 1 to 4, characterized in that it consists in using a neutral gas, such as nitrogen, as pressurization fluid.

6. Method according to one of claims 1 to 5, characterized in that it consists in controlling the pressurization of each outer chamber (23) to the envelope only after a certain interval αa time following the start of the setting in depression of the interior chamber (22) to the envelope and, preferably, also of the heating of the product or products to be treated (9).

7. Method according to one of claims 1 to 6, for the stratification of rigid circuits and rigid parts of flexo-rigid circuits, or for the plasticization of documents and flat elements, characterized in that it consists in having at least a product to be treated (9) in the interval between two plates (3) after having mounted it in the tools, by placing each product to be treated between two rev non-stick tements (12a, 12b), by placing the sub-assembly thus obtained between two metal sheets (11a, 11b), and by centering the different layers of the stack thus produced before enclosing the latter in the envelope (15a, 15b, 18).

8. Method according to claim 7, for the stratification of a rigid circuit and rigid parts of a flexo-rigid circuit, characterized in that the mounting of at least one product to be treated (9) in tools consists of more to place the stack of the product (s) to be treated, the two non-stick coatings (12a, 12b) and the two metal sheets (11a, 11b) between two metal plates (10a, 10b) and also to center the latter with the other layers of the stack thus produced in order to enclose the latter in the envelope.

9. Method according to claim 8, characterized in that it consists in protecting the flexible and deformable parts (15a, 15b) of the envelope against the metal plates (10a, 10b) of the tools by gluing pieces adhesive tape (17) on the corners of said metal plates.

10. Method according to one of claims 8 and 9, characterized in that it consists before compressing the product or products to be treated (9) and mounted in tools (14), placing the latter on support wedges and centering (20) of the tools in the envelope (15a, 15b, 18).

11. Autoclave press for laminating multilayer printed circuits and / or for laminating documents or flat elements, for implementing the method according to one of claims 1 to 10, comprising:

- a frame (1) with columns (2), - at least two plates (3) substantially parallel to each other and slidably mounted on the frame (1) in a direction substantially perpendicular to their planes,

- at least one operating member (5) of the plates (3) controlling their approach and their spacing as well as the locking of the plates in the approach position,

- at least one heating circuit (8) of at least a product to be treated (9), such as a multilayer printed circuit to be laminated or a document to be laminated between two plastic films, which is placed in an interval delimited between two neighboring plates (3), and, optionally, at least a cooling circuit (8) for each product to be treated, characterized in that it further comprises, for at least one interval between two plates (3), and preferably for each interval,

- at least one rigid frame (18) pierced with at least one suction channel (19), and intended to be disposed between the two plates (3) or between a plate (3) and a rigid auxiliary frame (25) pierced with at least one pressurization channel (26) and arranged in the interval, or even between two auxiliary frames (25) and around a product to be treated (9, 9 '), - at least one pair of bladders (15a, 15b) watertight, flexible and deformable, the two bladders of which are intended to be arranged each between one face of a frame (18) and the opposite face of a plate (3) or of an auxiliary frame (25 ), so as to be extended one above and the other below at least one product to be treated and surrounded by this frame, and

- bladder protection members (15a, 15b) comprising, for each frame (18) at least two layers of a non-stick coating (16a, 16b), intended to be deposited each between one of the two bladders ( 15a, 15b) corresponding to this frame (18) and the product or products to be treated in this frame, and in that, each of the two plates (3) is pierced with at least one pressurization channel (21) which opens into the interval and inside the adjacent frame (18), so that after the trays (3) have been locked in the approaching position, each bladder is tightly tightened between a corresponding frame and a tray or a frame corresponding auxiliary, and each frame (18) and the two corresponding bladders (15a, 15b) delimit, around the product or products to be treated in the frame (18), a vacuum chamber (22) intended to be connected by each channel d suction (19) to a source of vacuum (29), while each of the two bladders (15a, 15b) delimits, with the opposite face of a plate (3) contiguous to the corresponding frame and inside the latter or with another bladder clamped against an auxiliary frame (25) contiguous to the corresponding frame, a pressurization chamber (23, 23 ') intended to be connected, by each pressurization channel (21, 26) of this plate (3) or of this adjoining auxiliary frame (25), to a source of pressurized fluid (37) in order to compress the product or products to be treated (9, 9 ') between portions of the two corresponding bladders.

12. Autoclave press according to claim 11, characterized in that each suction channel (19) of the frame (s) (18) is connected to a vacuum pump (29) by sealed pipes (27) on which is mounted at least one valve (32, 35, 36) controlling the isolation or free airing with, optionally, the adjustment of the vacuum in the vacuum chamber (s) (22).

13. Autoclave press according to one of claims 11 and 12, characterized in that each pressurization channel (21, 26) of the plates (3) and, where appropriate, of the auxiliary frame or frames (25), is connected to an accumulator of a pressurized neutral gas (37), such as nitrogen, by leaktight pipes (38) on which is mounted at least one valve (40, 41, 44) controlling the supply and, optionally , the supply speed of the pressurization chambers (23, 23 ') or their decompression.

14. Autoclave press according to one of claims 11 to 13, characterized in that the heating circuit and / or the cooling circuit (8) are embedded in the plates (3).

15. Autoclave press according to one of claims 11 to 13, characterized in that the heating circuit and / or the cooling circuit include the chambers (23, 23 ') and the pressurization channels (19, 26) as well that sealed pipes (38, 45) connecting to a heating and / or cooling group (49) of the pressurizing fluid which is heated and / or cooled in passing through said group (49).

16. Autoclave press according to claim 15, characterized in that the heating and / or cooling circuit comprises a pump (47) mounted on a sealed pipe loop (45) which is closed on the pressurization chambers (23, 23 ') and which passes through the heating and / or cooling group (49).

17. Autoclave presser according to one of claims 11 to 16, characterized in that the non-stick coating layers for protecting the bladders (15a, 15b) consist of sheets (16a, 16b) of glass fiber fabric agglomerated by a material with a low coefficient of friction such as a polytetrafluoroethylene.

18. Autoclave press according to one of claims 11 to 17, for the stratification of rigid circuits or rigid parts of flexo-rigid circuits, and for the plasticization of documents or flat elements, characterized in that it also comprises tools, in the form of at least a pair of metal sheets (11a, 11b) between which are intended to be arranged two non-stick coatings (12a, 12b) to be spread on either side of at least one product to be treated (9), the facing faces of the two sheets of each pair having a mirror polished surface state, the product or products to be treated (9), the two coatings (12a, 12b), and the two metal sheets (11a , 11b) being intended to be assembled in a centered stack using at least two centering pins (13) passing through the stack which is intended to be placed in an interval, between the two layers of the non-stick coating (16a, 16b) for protecting the bladder s (15a, 15b).

19. Autoclave press according to claim 18, for the stratification of rigid circuits or rigid parts of flexo-rigid circuits, characterized in that the tools further comprise, for each pair of sheets (11a, 11b), a pair of metal plates (10a, 10b) intended to be centered against and outside the sheets in a pinned stack (13) containing at least one product to treat (9).

20. Autoclave press according to one of claims 18 and 19, characterized in that the two non-stick coatings (12a, 12b) of the tools (14) are sheets of aramid fiber fabric.

21. Device for converting into an autoclave press for laminating multilayer printed circuits and / or for laminating documents or flat elements, a laminating press comprising: - a frame (1) with columns (2),

- at least two plates (3) substantially parallel to each other and mounted to slide on the frame (1) in a direction substantially perpendicular to their planes,

- at least one operating member (5) of the plates (3), controlling their spacing, their bringing together and their locking in the close position,

- a heating circuit (8) and a cooling circuit (8) which are at least partially integrated in the plate (3), - the device being characterized in that it comprises:

- at least one rigid frame (18) pierced with at least one suction channel (19) and intended to be disposed between two plates (3) and around at least one product to be treated (9), and for each frame (18),

- At least one pair of waterproof, flexible and deformable bladders (15a, 15b), the two bladders of which are each intended to be tightly sealed against one face of the corresponding frame (18), on either side of the products to be treated (9), and surrounded by the frame, and

- At least two sheets of a non-stick coating (16a, 16b) each intended to be deposited between a bladder (15a, 15b) and the product (s) (9, 9 ') to be treated in this context (18).

22. Transformation device according to claim 21, characterized in that it comprises a vacuum pump (29), at least one connection pipe (27) of the pump vacuum at the suction channels (19) of the middle frame (s) (18) and at least one control valve (32, 35, 36).

23. Transformation device according to one of claims 21 and 22, characterized in that it comprises at least one connection pipe (38) of a pressurized neutral fluid accumulator (37) to at least one pressurization channel (-2i) to be drilled in each of the plates (3) of the press and at least one control valve (40, 41, 44).

24. Transformation device according to claim 23, characterized in that it comprises a heating and / or cooling group (49) and a circulation pump (47) of the neutral pressurized fluid, which are intended to be mounted on at least one transport pipe (45, 38) for the neutral fluid under pressure.

25. Transformation device according to claim 24, characterized in that it includes at least two insulating plates, each pierced with at least one pressurization channel (21) and substitutable for the plates (3) with heating circuit and / or partially integrated cooling of the press.

26. Transformation device according to one of claims 21 to 25, characterized in that it comprises tools for the stratification of rigid circuits and rigid parts of; flexo-rigid circuit, and for the plasticization of documents or flat elements, said tools comprising:

- at least one pair of metal plates (10a, 10b),

- at least one pair of metal sheets (11a, 11b), one face of which has a mirror-polished surface,

- at least one pair of non-stick coating sheets (12a, 12b), and

- centering pins (13) of the plates and / or sheets, cover sheets and at least one product to be treated (9), which are intended to be assembled in a stack.

27. Transformation device according to one of the Claims 21 to 26, characterized in that it comprises, for the stratification of flexible circuits (9 ') in several stages in an interval between two press plates (3), at least one auxiliary frame (25), rigid, pierced at least one pressurization channel (26), and intended to be, on the one hand, clamped between two frames (18) arranged in this same interval, with interposition of bladders (15a, 15b), and, on the other part, connected to a source of pressurized fluid (37).