JPH0818403B2 - Laminates and green composite films for laminates - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to, for example, a non-sintered composite film laminates contact and laminate, such as a low dielectric constant laminate used as a high-frequency printed wiring board.

[0002]

2. Description of the Related Art Conventionally, as a method for manufacturing a laminated plate, there are various manufacturing methods as described below. The first manufacturing method is
A base material is impregnated with a PTFE resin (polytetrafluoroethylene, tetrafluoride resin), and this is dried and fired to form a prepreg (pre-preg), and a PFA resin (4 Fluorinated ethylene / perfluoroalkyl vinyl ether copolymer resin film or FE
This is a method for producing a laminated plate by interposing a P resin (perfluoroethylene propylene resin) film, and interposing the film also between the metal foil and the prepreg arranged in the outermost layer, and carrying out lamination molding. .

According to this first manufacturing method, by interposing the film, the adhesive strength between the metal foil and the prepreg is maintained, and the adhesive force between the prepreg layers is maintained,
On the other hand, there is an advantage that the resin content ratio in the laminated plate can be adjusted. On the other hand, the above-mentioned film is generally melt-kneaded with a screw extruder and injection-molded through a T-type die.
During the manufacturing process of this film, a considerable amount of metal particles and metal powder are mixed in the film, and since the metal particles and metal powder have conductivity, they cause a short circuit of the printed wiring board, a disconnection, etc. There was a problem that it was difficult to use.

In the second manufacturing method, the base material is impregnated with the first fluororesin, dried and fired, then impregnated with PFA or FEP as the second fluororesin, dried and fired. In this method, a metal foil is placed on the outermost layer of the formed prepreg and then laminated forming is performed to produce a laminated plate.

According to this second manufacturing method, the first fluororesin impregnated in the base material is dried and then baked at a temperature above the melting point of the resin. Thus, when the fluororesin is baked above the melting point, Since the surface energy is low and the wettability is extremely deteriorated, even if an attempt is made to hold PFA or FEP on the fluororesin, the PFA or FEP is removed during the drying and baking steps, and a uniform and highly accurate film is formed. It is difficult to obtain a laminated board with stable performance because the adhesive strength between the prepreg and the metal foil, the mutual adhesive strength between the prepregs, and the resin content are partially different and the characteristic values vary. was there.

The third manufacturing method is to form a fluororesin layer on the surface of a cloth-like substrate, form a prepreg in the vicinity of the surface of the fluororesin layer which is unsintered, and apply a metal foil to the surface of the prepreg. After arranging, it is a method of manufacturing a laminated board by heating and pressurizing and adhering the above metal foil to the prepreg.

According to the third manufacturing method, the fluororesin layer impregnated in the cloth-like base material is unsintered only in the vicinity of the surface thereof, and the core portion of the base material and the vicinity of the base material are sintered. According to this third manufacturing method, there is an advantage that the adhesive strength between the prepreg and the metal foil can be secured to some extent, but on the other hand, in a large-sized laminated plate, it is difficult to obtain a uniform adhesive force over the entire surface, In the case of a laminate with a large variation and a low resin content, the chemical solution penetrates from the resin surface after the metal foil is removed by etching during circuit formation, and the solder heat resistance is poor and the metal foil swells. There is a problem that the defect of occurs. In addition, since a sintered layer and a non-sintered layer are mixed in the prepreg, there is a problem that defects such as warp and twist are likely to occur when the laminated plate is thin.

A fourth manufacturing method is to impregnate a cloth base material with PFA or FEP, dry and fire the prepreg to form a prepreg, place a metal foil on the prepreg, and form a laminate to laminate the laminate. Is a method of manufacturing.

According to the fourth manufacturing method, the adhesive strength between the prepreg and the metal foil, the mutual adhesive strength between the prepregs, and the adhesive strength between the cloth base material and the fluororesin of PFA or FEP are all stable. On the other hand, since PFA or FEP has a low viscosity and a large fluidity at a temperature higher than its melting point, PFA or FEP has a high flowability during the heating and pressurizing step during lamination molding.
There is a problem that P easily flows, and as a result, the thickness accuracy of the laminated plate deteriorates, and the cost of PFA or FEP is higher than that of PTFE.

In the fifth method, the base material is impregnated with the first fluororesin, dried and sintered, and the second fluororesin having a lower melting point than the first fluororesin for the upper layer. To form a prepreg, and after placing a metal foil on the prepreg, laminate molding is performed under a temperature condition that is lower than the melting point of the first fluororesin and higher than the melting point of the second fluororesin. This is a method for producing a laminated board.

According to the fifth manufacturing method, since the above-mentioned first fluororesin exhibits cushioning property due to the shape memory property peculiar to the resin at the time of laminating and pressurizing the laminated plate, the characteristics of the laminating plate may vary. In addition to being stable, since the first fluororesin is fired at a temperature equal to or higher than the melting point of the first fluororesin during firing, the surface energy is low and the wettability is deteriorated. Even if the second fluororesin is held, there is a problem that it becomes difficult to form a uniform film with high accuracy because it falls off during the drying and baking steps.

On the other hand, for example, in order to obtain a low dielectric constant substrate having a relative dielectric constant of εr = 2.4 or less, it is necessary to form a prepreg having a high resin content, for example, 80 vol% or more. It was difficult to form a prepreg with a high resin content. That is, when the glass cloth base material is impregnated with the resin, and then dried and sintered repeatedly, the resin shrinks in the resin sintering step described above, so that it becomes possible to thickly coat the resin on the glass cloth base material. However, by repeating the above operation, the base material cannot withstand the shrinkage force and is deformed into a wavy shape, so that unevenness in thickness is generated in the formed prepreg, and the thickness accuracy is deteriorated.

Therefore, conventionally, as seen in the above-described first manufacturing method, there is a method of increasing the resin content by interposing a PFA film or FEP film between each layer and between the prepreg and the metal foil. However, according to such a conventional method, as described above, a metal short piece or a metal powder is mixed into the PFA film or the FEP film, which causes a trouble such as a short circuit or a disconnection of a circuit. Further, when the PFA film and the FEP film are frequently used, it is easy to reduce the dielectric constant of the laminated plate, but on the other hand, the bending elastic modulus is lowered and the thermal expansion coefficient is increased, so that the laminated plate itself is weakened.

[0014]

The invention according to claim 1 of the present invention is such that after impregnation of the PTFE resin dispersion into the substrate, it is dried under a low temperature condition not exceeding the melting point of the PTFE resin, and this unsintered In this state, impregnation and drying are repeated to form an unsintered prepreg having a required resin retention amount, and the resin amount is adjusted with the unsintered prepreg, and an unsintered composite film having an ultrathin two-layer structure is used. By forming a laminated plate, the thickness accuracy is high, the linear expansion coefficient in the thickness direction is small, the solder heat resistance is excellent, the inclusion of foreign matter is small, and the adhesive strength can be improved. and an object thereof is to provide a dielectric constant of the laminate.

According to a second aspect of the present invention, there is provided a PTFE resin formed by a casting method and the PTFE resin.
By using a non-sintered composite film having a two-layer structure of a fluororesin having a low melting point with respect to the resin, an ultrathin structure of 10 μm or less can be obtained without mixing of metal powder or carbonized fine powder. An object is to provide a non-sintered composite film for a laminated plate.

[0016] The invention of claim 3, wherein the present invention, in conjunction with the object of the invention of the second aspect, only a two-layer structure of Shoshu
By selecting the sintered composite film, and an object thereof is to provide a non-sintered composite film laminates which can be standardized manufacturing process of the prepreg.

In the invention according to claim 4 of the present invention, even when the secondary molding is performed when the laminated plate is made into a multilayer, there is no gap between layers or the flow of the circuit part, that is, a so-called swimming phenomenon, and the circuit part and the unsintered part are not sintered. An object of the present invention is to provide a laminated plate which is excellent in solder heat resistance, thermal shock resistance and dimensional stability and which can be formed into a multilayer without forming voids between the composite film and the composite film.

According to the invention of claim 5 of the present invention, in addition to the object of the invention of claim 4, an unsintered prepreg is provided between the unsintered composite films to thereby obtain an interlayer thickness of a circuit. It is an object of the present invention to provide a laminated plate that can be set arbitrarily.

In the sixth aspect of the present invention, in addition to the object of the fourth aspect of the invention, a sintered prepreg is interposed between the unsintered composite films to reduce the interlayer thickness of the circuit. An object is to provide a laminated plate that can be set arbitrarily.

In the invention according to claim 7 of the present invention, even when secondary molding is carried out when the laminated plate is made into multiple layers, there is no gap between layers or flow of the circuit part, so-called swimming phenomenon, and the circuit part and unsintered. without the gap is formed between the composite film, solder heat resistance, thermal shock resistance, excellent dimensional stability, together with that which can be multilayered, thermosetting prepreg between unsintered composite film The inter-layer thickness of the circuit can be set arbitrarily by interposing the interposition of the thermosetting prepreg with the interposition of the thermosetting prepreg to improve the rigidity of the entire laminated plate, and the compressive and restoring forces are repeatedly applied. It is an object of the present invention to provide a laminated board which can be improved in durability even when applied to a test board, and which can be attached to a chassis or the like after mounting components.

[0021] The invention of claim 8, wherein the present invention, in conjunction with the object of the invention of the seventh aspect, only a two-layer structure of Shoshu
By selecting the sintered composite film, and an object thereof is to provide a laminated board using the unsintered composite film laminates which can be standardized manufacturing process of the prepreg.

[0022]

According to a first aspect of the present invention, a base material is impregnated with a PTFE resin dispersion and dried at a low temperature relative to the melting point of the PTFE resin,
A two-layer structure in which the above-mentioned impregnation and drying are repeated to form an unsintered prepreg having a required resin holding amount, while one layer is made of PTFE resin and the other layer is made of fluorine resin having a low melting point with respect to the PTFE resin. After forming a non-sintered composite film for a laminated plate, and arranging a metal foil on the outer surface of at least one side of the above-mentioned non-sintered prepreg via the above-mentioned non-sintered composite film, it is heated at a high temperature with respect to the melting point of the PTFE resin. the product of the pressure
It is a layered board .

The invention according to claim 2 of the present invention is the PTF.
E resin dispersion is deposited on the plate to form a thin layer and then dried, and a fluororesin dispersion having a low melting point for PTFE resin is deposited on the thin layer surface and then dried.
It is a non-sintered composite film for laminated plate, which is formed by peeling a dried two-layer structure film from the plate.

According to a third aspect of the present invention, in addition to the constitution of the second aspect, the low melting point fluororesin dispersion is PFA, FEP and ETF.
One of E is a non-sintered composite film for a laminated plate which is a fluororesin dispersion.

According to a fourth aspect of the present invention, the base material is impregnated with the fluororesin dispersion and then dried to form an unsintered prepreg, and a metal foil is disposed on at least one surface of the unsintered prepreg. Then, a plurality of circuit layers for inner layer and outer layer having a circuit portion heated and pressed at a temperature higher than the melting point of the fluororesin is formed, and between the plurality of circuit layers,
An unsintered composite film having a two-layer structure in which one layer is a PTFE resin and the other layer is a fluororesin having a low melting point with respect to the PTFE resin is interposed, and one layer side of the unsintered composite film is an anti-circuit. On the part side, while facing the other layer side to the circuit part side,
Between the one side of the unsintered composite film and the facing member, PFA
Alternatively, it is a laminated plate which is provided with an FEP interposing film and is heated and pressed at a temperature higher than the melting point of PTFE.

The invention of claim 5, wherein the present invention, the above claim 4 in conjunction with the configuration of the invention described, together with a plurality interposed the unsintered composite film to the plurality of circuit layers, a plurality of unsintered The laminated composite film is characterized in that it is a laminated plate in which a base material is impregnated with a fluororesin and then a dried unsintered prepreg is interposed.

The invention of claim 6, wherein the present invention, the above claim 4 in conjunction with the configuration of the invention described, together with a plurality interposed the unsintered composite film to the plurality of circuit layers, a plurality of unsintered The laminated composite film is characterized in that it is a laminated plate in which a sintered prepreg obtained by impregnating a base material with a fluororesin and then drying and sintering is interposed between the bonded composite films.

According to a seventh aspect of the present invention, the substrate is impregnated with the fluororesin dispersion and then dried to form an unsintered prepreg, and a metal foil is disposed on at least one surface of the unsintered prepreg. Then, a plurality of circuit layers for inner layer and outer layer having a circuit portion heated and pressed at a temperature higher than the melting point of the fluororesin is formed, and between the plurality of circuit layers,
An unsintered composite film having a two-layer structure in which one layer is a PTFE resin and the other layer is a fluororesin having a low melting point with respect to the PTFE resin is interposed, and one layer side of the unsintered composite film is an anti-circuit. On the part side, the other layer side is opposed to the circuit part side to be heat-sealed, and the surface opposite to the circuit side is surface-modified to a contact angle of 70 degrees or less. interposed thermosetting prepreg firing solidify at low temperatures to fluorine resin, laminated heated pressure at a low temperature for the two-layer unsintered composite film from PTFE constituting the low melting point of the fluororesin melting point of structure It is characterized by being a plate .

In the invention according to claim 8 of the present invention, in addition to the constitution of the invention according to claim 7, the low melting point fluororesin is one of PFA, FEP and ETFE. It is characterized by being a plate .

[0030]

According to the invention described in claim 1 of the present invention, since the unsintered prepreg having the required resin holding amount is formed by repeating the impregnation and the drying, the resin amount can be adjusted in this unsintered prepreg. It can be done, and it is very thin 2
Since manufacturing a laminated board using unsintered composite film of the layer structure, the unsintered composite film can be used for bonding without using the resin amount adjustment, high thickness accuracy, the thickness direction In addition to having a small coefficient of linear expansion and excellent heat resistance to solder, it is possible to obtain a low-dielectric-constant laminate with a large amount of resin retained, with a small amount of foreign matter mixed in, and improved adhesive strength. .

According to the second aspect of the present invention,
The unsintered composite film for a laminated plate formed by the casting method can be a film having a two-layer structure of a PTFE resin and a fluororesin having a low melting point with respect to the PTFE resin, and contains metal powder or carbonized fine powder. There is no effect, and the electric insulation is excellent, and an extremely thin structure of 10 μm or less can be obtained.

According to the invention of claim 3 of the present invention,
In conjunction with the effects of the invention described in claim 2, wherein, PTFE resin (melting point 327 which constitutes one layer of the unsintered multilayer <br/> coupling film
Fluorine resin forming the other layer with respect to (° C) is PFA (tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer having a melting point of 310 ° C), FEP (melting point of 275).
Since it is possible to select from various low melting point fluororesins such as tetrafluoroethylene hexafluoropropylene copolymer of ℃) and ETFE (tetrafluoroethylene / ethylene copolymer of melting point 270 ° C. ), various types of two-layer structure poles can be selected. A thin composite film can be obtained, which has the effect of standardizing the manufacturing process of the unsintered prepreg.

According to the invention of claim 4 of the present invention,
A non-sintered composite film is interposed between a plurality of circuit layers having a circuit portion, and one layer side of the PTFE resin of the non-sintered composite film is an anti-circuit side and a fluororesin having a low melting point with respect to the PTFE resin. Since the other layer side is arranged on the circuit side for manufacturing, even if secondary molding is performed when making a laminated board into a multilayer, the gap between the circuit part of the circuit layer and the unsintered composite film has a low melting point of fluorine. It can be filled with the melt flow of the resin, and the gap between the layers and the flow of the circuit portion, so-called swimming phenomenon can be prevented by the PTFE resin on the one side of the unsintered composite film.

As a result, even when the laminated plate is formed into multiple layers, there is no gap between the layers or flow of the circuit portion (swimming phenomenon), and no void is formed between the circuit portion and the unsintered composite film. Also, by producing the circuit layer from the above-mentioned unsintered prepreg, there is an effect that it is excellent in solder heat resistance, thermal shock resistance and dimensional stability, and can be formed into multiple layers.

According to the invention of claim 5 of the present invention,
In addition to the effect of the invention described in claim 4, since the unsintered prepreg is interposed between the plurality of unsintered composite films, the unsintered prepreg allows an arbitrary interlayer thickness of the circuit. There is an effect that can be set.

According to the invention of claim 6 of the present invention,
In addition to the effect of the invention described in claim 4, since the sintered prepreg is provided between the plurality of unsintered composite films, the interlayer thickness of the circuit is arbitrarily set by the sintered prepreg. There is an effect that can be.

According to the invention of claim 7 of the present invention,
A non-sintered composite film is interposed between a plurality of circuit layers having a circuit portion, and one layer side of the PTFE resin of the non-sintered composite film is an anti-circuit side and a fluororesin having a low melting point with respect to the PTFE resin. Since the other layer side is arranged on the circuit side for manufacturing, even if secondary molding is performed when making a laminated board into a multilayer, the gap between the circuit part of the circuit layer and the unsintered composite film has a low melting point of fluorine. It can fill the molten resin flow, the flow-called swimming behavior of the deviation and the circuit portion of the interlayer along with preventing the unsintered composite film one layer side of the PTFE resin, the heat between the plurality of unsintered composite film Since the curable prepreg is interposed, the thermosetting prepreg can be used to set the interlayer thickness of the circuit as desired, and the thermosetting prepreg can be used to improve the rigidity of the entire laminate. Therefore, even if it is applied to a test board to which compression and restoring forces are repeatedly applied, it is possible to improve the durability sufficiently, and to mount the laminated plate on the chassis etc. after mounting the components, Since the thermosetting prepreg can be used as the mounting seat, there is an effect that the laminated plate can be screwed and fixed.

[0038] Additionally in contact thermosetting prepreg and pairs unsintered
Since surface modified the surface facing forming the composite film below the contact angle of 70 degrees, the effect capable of improving the bonding of these two (thermosetting prepreg and unsintered multi <br/> coupling film) is there.

According to the invention of claim 8 of the present invention,
In conjunction with the effects of the invention described in claim 7, wherein, PTFE resin (melting point 327 which constitutes one layer of the unsintered multilayer <br/> coupling film
Fluorine resin that composes the other layer is PFA, F
Since it is possible to select from various kinds of low melting point fluororesin such as EP and ETF E, it is possible to obtain various kinds of ultra-thin composite films having a two-layer structure. Therefore, lamination using thermosetting prepreg or unsintered prepreg is possible. There is an effect that the plate manufacturing process can be standardized.

[0040]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. The drawings illustrate unsintered composite film laminates contact and laminates, first PTFE resin 2 on the glass cloth base 1 having a basis weight of 48 g / m ² as shown in FIG. 1, in particular impregnating the PTFE resin dispersion Then, the PTFE resin 2 is dried under the condition of a low temperature of 305 ° C. with respect to the melting point of 327 ° C. of the PTFE resin 2 to hold the unsintered resin on the glass cloth substrate 1. By repeating such impregnation and drying treatment under low temperature conditions, the resin retention amount is within the range of 80 to 96 vol%, for example, 90 vol.
Multiple layers of l% green prepreg 3 are formed.

On the other hand, as shown in FIG. 3, one layer of the PTFE resin 4 and the other layer of the PTFE resin 4 have a low melting point by the casting method using the apparatus for producing a non-sintered composite film for laminated plates shown in FIG. An unsintered composite film 6 having an ultrathin and two-layer structure formed of the fluororesin 5 is formed.

That is, the PTFE resin dispersion
8 is a stainless steel thin plate (specifically, SUS foil)
After being deposited on the rear 7 to form a thin layer, it is dried to
On the surface of the layer, PFA resin with a low melting point for PTFE resin 4
After attaching the dispersion 10, it is dried and then
The composite film 6 having the two-layer structure described above is peeled from the carrier 7.
Thus, an ultrathin unsintered composite film 6 is formed.

Here, as the above-mentioned low melting point fluororesin 5, PFA, FEP, ETFE, ECTFE and PC are used.
Select one of the TFEs, eg PFA.

The above-described manufacturing apparatus shown in FIG. 2 stores a carrier 7 made of a stainless thin plate (specifically, SUS foil) which moves between a feeding position A and a winding position B, and a PTFE resin dispersion 8. The first container 9, the second container 11 storing the PFA resin dispersion 10, the first heaters 12 and 12 for heating, and the second heaters 13 and 13
And guide rollers 14 to 22 arranged at necessary positions.

Then, the carrier 7 made of SUS foil is conveyed into the PTFE resin dispersion 8 of the first container 9, the PTFE resin dispersion 8 is adhered (coated) on both surfaces of the carrier 7, and then the above-mentioned carrier 7 is formed. Is dried between the first heaters 12 and 12 at, for example, 370 ° C., and then the carrier 7 coated with the PTFE resin 4 on both sides is conveyed into the PFA resin dispersion 10 of the next second container 11 to remove the PTFE resin 4 PF on the surface of
A resin dispersion 10 is adhered (coated), then the above-mentioned carrier 7 is dried between the second heaters 13 and 13, and then the above-mentioned two-layer composite film 6 is removed from the carrier 7 at the peeling position C. When peeled off, an extremely thin composite film 6 having an isotropic property of 10 μm or less can be manufactured.

Here, the above-mentioned composite film 6 has a PF having a thickness of the PTFE resin 4 shown in FIG.
Since the thickness of the low melting point fluororesin 5 such as A can be adjusted in the range of 3 to 20 μm, the composite film 6 having a minimum thickness of 7 μm can be obtained.

In the manufacturing apparatus of FIG. 2, the container and the heater have a front and rear two-stage structure. However, in the manufacturing apparatus having only one side and one step, the PTFE resin 4 is coated on the SUS foil and the PTFE resin after peeling is coated. 4 may be coated with a PFA resin.

Further, since the PTFE resin 4 is first coated on the carrier 7 made of SUS foil, the releasability at the peeling position C is good and the surface of the PTFE resin 4 is coated with the PFA resin. The adhesiveness to the PTFE resin 4 becomes good.

A plurality of layers of the green prepreg 3 are formed,
For example, four layers are superposed, and C having a thickness of about 35 μm as a metal foil is formed on the upper and lower outer layers with the above-mentioned composite films 6 and 6 interposed therebetween.
For the one in which u foils 23, 23 are arranged, the above PTFE
As a result of lamination molding under the conditions of the temperature of 380 ° C., which is higher than the melting point 327 ° C. of the resins 2 and 4, and the surface pressure of 3.4 MPa and the pressurizing time of about 60 minutes, the thickness is as shown in FIG. A double-sided copper foil-clad laminate 24 (Example product in the following Table 1) having a thickness of 0.8 mm and a relative permittivity εr = 2.32 could be manufactured.

On the other hand, as a comparative example, a glass cloth substrate having a basis weight of 48 g / m ² was impregnated with PTFE resin dispersion, dried, and then sintered at 380 ° C. The impregnation, drying and sintering were repeated to maintain a resin retention amount of 75 vol. % Sintered prepreg is formed, and the conventional PFA film (thickness of about 25 μm is provided between the two sets of two layers of the sintered prepreg and between the two sets of one set of the sintered prepreg and the Cu foil having a thickness of about 35 μm, respectively. ) Is placed under the conditions of a high temperature of 380 ° C., a surface pressure of 3.4 MPa, and a pressing time of about 60 minutes to perform laminate molding, and the overall thickness is 0.8 mm and the relative permittivity εr = A double-sided copper foil-clad laminate of 2.6 (Comparative Product 1 in Table 1 below) was produced.

Similarly, as a comparative example, a glass cloth substrate having a basis weight of 48 g / m ² was impregnated with PTFE resin dispersion, dried, and then sintered at 380 ° C. This impregnation, drying and sintering were repeated to maintain the resin retention amount. A total of three layers of 80 vol% sintered prepregs were formed, and the conventional PFA film (thickness: 50 μm) was interposed between each of these sintered prepregs and between the sintered prepreg and a Cu foil having a thickness of about 35 μm. Then, under high temperature conditions of 380 ° C., lamination molding was performed under surface pressure of 3.4 MPa and pressurization time of about 60 minutes, and the total thickness was 0.6 mm and the relative permittivity εr = 2.33. A double-sided copper foil-clad laminate (Comparative Product 2 in Table 1 below) was produced.

The following Table 1 shows the results of various measurements and tests performed on the above-described example product, comparative product 1 and comparative product 2.

[0053]

[Table 1]

As is clear from Table 1 above, in the case of the example product, the variation R in plate thickness (where R is the value obtained by subtracting the minimum dimension from the maximum dimension) is as small as 0.012 mm, and the solder heat resistance is also good. The linear expansion coefficient was 180 × 10 ⁻⁶ / k, which was a good value. Note that x in Table 1 above indicates the plate thickness.

In summary, according to the laminated plate of this embodiment (corresponding to claim 1), the impregnation and the drying are repeated to form the unsintered prepreg 3 having the required resin holding amount (for example, 90 vol%). The amount of resin can be adjusted in this unsintered prepreg 3, and since the laminated plate 24 is manufactured using the composite film 6 having an ultrathin two-layer structure, the composite film 6 can be used for adjusting the amount of resin. Instead, it can be used for bonding. As a result, the thickness accuracy is high, the linear expansion coefficient in the thickness direction is small, the solder heat resistance is excellent, the inclusion of foreign matter is small, and the adhesive strength can be improved. There is an effect that the laminated plate 24 having a dielectric constant can be manufactured.

Further, the unsintered composite film 6 for laminates formed by the casting method of the above-mentioned embodiment (corresponding to claims 2 and 3) is a PTFE resin 4 and a fluororesin having a low melting point with respect to the PTFE resin 4. It is possible to make a two-layer film with No. 5, and since there is no mixing of metal powder or carbonized fine powder,
It is excellent in electrical insulation and has an effect that an extremely thin structure of 10 μm or less can be formed.

Further, the low melting point fluororesin 5 constituting another layer in addition to the PTFE resin 4 constituting one layer of the composite film 6 is made of PFA, FEP, ETFE, ECTF.
Since it is possible to select from various kinds of low melting point fluororesins such as E and PCTFE, it is possible to obtain various kinds of ultra-thin composite films 6 having a two-layer structure, and thus standardize the manufacturing process of the above-mentioned unsintered prepreg 3. There is an effect that can be.

FIG. 4 shows another embodiment of the laminated plate (corresponding to claim 4). The glass cloth substrate 25 is impregnated with a fluororesin dispersion, for example, a dispersion of PTFE resin 26, and then dried to obtain a resin. The unsintered prepreg 27 having a holding amount of 60 to 70 vol% is formed, and the Cu foils 28, 28 are arranged on both surfaces of at least one unsintered prepreg 27,
As shown in FIG. 4, a plurality of circuit layers G, G for outer layers, which are heated and pressed at a temperature higher than the melting point of the PTFE resin 26 (for example, 380 ° C.), are formed, and the Cu foils 28, 28 on one side of the circuit layers G, G are formed as shown in FIG. The circuit portions 29, 29, so-called circuit patterns are formed by etching.

Next, between the above-mentioned plurality of circuit layers G, G, one layer is made of the PTFE resin 4, and the other layer is made of the fluororesin 5 having a low melting point with respect to the PTFE resin 4. The same composite films 6 and 6 as described above are provided, and the PTFE resin 4 side of these composite films 6 and 6 faces the non-circuit part side and the low melting point fluororesin 5 side faces the circuit part 29 side, and An intervening film 30 of PFA or FEP (film used as a fluidized bed) is interposed between the composite films 6 and 6, and heated and pressed at a temperature higher than the melting point of PTFE (for example, 380 ° C.) to manufacture a multilayer printed wiring board 31. .

In this way, the composite film 6 is interposed between the plurality of circuit layers G having the circuit portion 29, and the one side of the composite film 6 made of the PTFE resin 4 is the opposite circuit side, and P is the opposite side.
Since the other layer side made of the fluororesin 5 having a low melting point with respect to the TFE resin 4 is disposed on the side of the circuit portion 29 for manufacturing, even if the secondary molding is performed at the time of manufacturing the multilayer board, the structure shown in FIG. As shown in (partial cross-sectional view after completion), the gap between the circuit portion 29 of the circuit layer G and the composite film 6 can be filled with the melt flow of the low melting point fluororesin 5, resulting in a gap between layers and a circuit portion. Two
The flow phenomenon of 9 (so-called swimming phenomenon) can be prevented by the PTFE resin 4 on one side of the composite film 6.

As a result, even when the laminated plates are made into multiple layers, there is no gap between the layers or flow of the circuit portion 29 (swimming phenomenon), and no void is formed between the circuit portion 29 and the composite film 6. In addition, the production from the unsintered prepreg 27 has the effects of excellent solder heat resistance, thermal shock resistance, and dimensional stability, and also capable of forming multiple layers.

As a comparative example of this example, when only the PTFE film was used instead of the composite film 6 as shown in FIG. 6, the melt viscosity was 10 ¹⁰ to 10 ¹⁰ at 380 ° C.
Because of the high poise of ¹¹ poise, the PTFE resin does not flow into the corners of the circuit portion 29, and the void 32 (including the case where it is formed by the contraction when the PTFE resin solidifies) remains between the circuit portion 29 and the PTFE film. The adhesive strength was weak, and it was inferior to both solder heat resistance and thermal shock resistance.

Further, as a comparative example of the above-mentioned examples, when only the PFA film was used in place of the composite film 6, the melt viscosity was 10 ⁴ to 10 ⁵ poise under the condition of 380 ° C., and the melt fluidity was Since it is large, a gap between layers and a flow of the circuit portion 29 occur.

FIG. 7 shows another embodiment (corresponding to claim 4) of a laminated plate, in which a glass cloth substrate 25 is impregnated with a fluororesin dispersion, for example, a dispersion of PTFE resin 26, and then dried to obtain a resin. The unsintered prepreg 27 having a holding amount of 60 to 70 vol% is formed, and the Cu foils 28, 28 are arranged on both surfaces of at least one unsintered prepreg 27,
Higher than the melting point of PTFE resin 26 (eg 380 ° C)
A circuit layer N for the inner layer is formed by heating and pressurizing in step C, and the Cu foils 28, 28 on both sides of the circuit layer N are etched as shown in FIG. 7 to form circuit portions 29, 29.

Circuit layers G and G for outer layers formed on the upper and lower surfaces of the circuit layer N for inner layers through the composite films 6 and 6 and the interposing films 30 and 30 by the same manufacturing method as in the embodiment of FIG. And was heated and pressed at 380 ° C., which is higher than the melting point of PTFE, to manufacture a multilayer printed wiring board 33.

Even with such a configuration, the same operation and effect as those of the embodiment of FIG. 4 can be obtained. Therefore, in FIG. 7, the same parts as those of FIG. Is omitted.

FIG. 8 shows still another embodiment of the laminated plate (corresponding to claim 4). The composite films 6 and 6, the interposing films 30 and 30, and the composite film 6 are formed on the upper and lower surfaces of the circuit layer N for the inner layer. , 6 and the circuit layer G for the outer layer are disposed and heated and pressed at 380 ° C., which is higher than the melting point of PTFE, to manufacture the multilayer printed wiring board 34.

Even if configured in this manner, the same actions and effects as in the respective embodiments of FIGS. 4 and 7 can be obtained. Therefore, in FIG. 8, the same parts as those in the previous figure are designated by the same reference numerals and symbols. , Its detailed description is omitted.

FIG. 9 shows still another embodiment of the laminated plate (corresponding to claim 5), in which a plurality of composite films 6 and 6 are provided between a plurality of outer circuit layers G, G, and a plurality of outer layers are provided. Between the composite films 6 and 6, a glass cloth base material 35, such as PTF, is used.
After impregnating the dispersion of the E resin 36, a dry unsintered prepreg 37 (used as an electric insulating layer) is provided, and the interposing films 30, 30 are provided on both upper and lower surfaces of the unsintered prepreg 37. The multilayer printed wiring board 38 is manufactured by the same manufacturing method as described above.

With such a structure, there is an effect that the green thickness of the circuit can be arbitrarily set by the above-mentioned green prepreg 37. In addition, in other respects, the same operation and effect as those of the respective embodiments described above are obtained, and therefore, FIG.
In the figure, the same parts as those in the previous figure are designated by the same reference numerals and their detailed description will be omitted.

FIG. 10 shows still another embodiment of the laminated plate (corresponding to claim 5), in which the composite film 6, the interposing film 30, the unsintered prepreg 3 are formed on the upper and lower surfaces of the circuit layer N for the inner layer.
7, the interposer film 30, the composite film 6, and the circuit layer G for the outer layer are respectively arranged in this order, and heated and pressed at 380 ° C., which is higher than the melting point of PTFE, to manufacture the multilayer printed wiring board 39.

Even with this structure, the same operation and effect as in the embodiment of FIG. 9 can be obtained. Therefore, in FIG. 10, the same parts as those in the previous figure are designated by the same reference numerals and symbols, and detailed description thereof will be given. Is omitted.

FIG. 11 shows still another embodiment of the laminated plate (corresponding to claim 6), in which a plurality of composite films 6 and 6 are provided between a plurality of outer circuit layers G, G and a plurality of outer films. Between the composite films 6 and 6, a glass cloth substrate 40, for example, PT
A sintered prepreg 42 (used as an electric insulating layer) that has been dried and sintered after being impregnated with the dispersion of the FE resin 41 is provided, and the interposing films 30, 30 are provided on both upper and lower surfaces of the sintered prepreg 42. Then, the multilayer printed wiring board 43 is manufactured by the same manufacturing method as described above.

In the case of such a structure, there is an effect that the above-mentioned sintered prepreg 42 can arbitrarily set the interlayer thickness of the circuit. In addition, in other respects, the same operation and effect as those of the above-described respective embodiments are achieved, and therefore, FIG.
In the figure, the same parts as those in the previous figure are designated by the same reference numerals and their detailed description will be omitted.

FIG. 12 shows still another embodiment of the laminated plate (corresponding to claim 7), in which a plurality of composite films 6 and 6 are provided between a plurality of circuit layers G for outer layers and heat fusion is performed. Along with
Between the composite films 6 and 6, a thermosetting prepreg 46 (also serving as an electrical insulating layer) that is fired and solidified at a low temperature with respect to an epoxy-based or polyimide-based fluororesin on the glass cloth base material 44 is provided. The multilayer printed wiring board 47 is manufactured by heating and pressing at a temperature lower than the melting point of the fluororesin having a melting point lower than that of PTFE constituting the composite films 6 and 6.

Here, the surfaces 4a, 4a of the composite films 6, 6 facing the thermosetting prepreg 46 are brought into contact with water (H ₂ 0) by a plasma treatment method, a corona discharge treatment method, a chemical treatment method or the like. Surface is preliminarily modified to an angle of 70 ° or less.

In the case of such a constitution, the thermosetting prepreg 46 interposed between the plurality of composite films 6 and 6 is provided.
By using the thermosetting prepreg 46, it is possible to improve the rigidity of the entire multilayer printed wiring board 47 by using the thermosetting prepreg 46. Even if it is applied to a biased test board, the durability can be sufficiently improved, and in order to mount the multilayer printed wiring board 47 on the chassis after mounting the components, for example, each upper element G in FIG. , 6, 30 can be provided with holes for disposing screw heads, and the above-mentioned thermosetting prepreg 46 can be used as a mounting seat, so that the multilayer printed wiring board 47 can be screwed and fixed. .

In addition, since the opposing surfaces 4a, 4a of the composite film 6 which are in contact with the above-mentioned thermosetting prepreg 46 are surface-modified so that the contact angle with H ₂ O is 70 degrees or less,
There is an effect that a sufficient bondability of these both 46 and 6 can be secured.

Further, the low melting point fluororesin 5 constituting another layer in addition to the PTFE resin 4 constituting one layer of the composite film 6 is made of PFA, FEP, ETFE or ECTF.
Since it is possible to select from various kinds of low melting point fluororesins such as E and PCTFE, it is possible to obtain various kinds of ultra-thin composite films 6 having a two-layer structure. There is an effect that the manufacturing process of the used laminated plate can be standardized.

In the correspondence between the constitution of the present invention and the above-mentioned embodiments, the base material of the present invention corresponds to the glass cloth base materials 1, 25, 35, 40 of the embodiments, and the same applies to the metal foil hereinafter. , Cu foils 23 and 28, the present invention is not limited to the configurations of the above-described embodiments.

[Brief description of drawings]

[1] cross-sectional view of the laminate of the present invention.

FIG. 2 is an explanatory view of a manufacturing apparatus used for manufacturing a non-sintered composite film for a laminated plate of the present invention.

FIG. 3 is a cross-sectional view of an unsintered composite film for laminated plates of the present invention.

FIG. 4 is an exploded sectional view showing another embodiment of the laminated plate .

FIG. 5 is a partial cross-sectional view after completion of secondary molding.

FIG. 6 is a partial cross-sectional view showing a comparative example.

FIG. 7 is an exploded sectional view showing still another embodiment of the laminated plate .

FIG. 8 is an exploded sectional view showing still another embodiment of the laminated plate .

FIG. 9 is an exploded sectional view showing still another embodiment of the laminated plate .

FIG. 10 is an exploded sectional view showing still another embodiment of the laminated plate .

FIG. 11 is an exploded sectional view showing still another embodiment of the laminated plate .

FIG. 12 is an exploded sectional view showing still another embodiment of the laminated plate .

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Glass cloth base material 2 ... PTFE resin 3 ... Unsintered prepreg 4 ... PTFE resin 4a ... Opposing surface 5 ... Low melting point fluororesin 6 ... Composite film 23 ... Cu foil 25, 35, 40 ... Glass cloth base material 27 ... Unsintered prepreg 28 ... Cu foil 29 ... Circuit part G, N ... Circuit layer 30 ... Insertion film 37 ... Unsintered prepreg 42 ... Sintered prepreg 46 ... Thermosetting prepreg

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-63-173638 (JP, A) JP-A-3-79343 (JP, A) JP-A-60-257592 (JP, A) JP-A-60- 257596 (JP, A) JP 63-199636 (JP, A) JP 63-47136 (JP, A)

Claims (8)

[Claims] 1. A base material is impregnated with a PTFE resin dispersion, which is dried at a low temperature with respect to the melting point of the PTFE resin, and the impregnation and drying are repeated to form a green prepreg having a required resin retention amount. to one, more is a PTFE resin, non-laminates having a two-layer structure other layer is formed of a low melting point of the fluorine resin with respect to the PTFE resin
Forming a sintered composite film, the green on at least one side outer surface of said green prepreg
Via imaging composite film after placing the metal foil, laminate was heated and pressurized at a high temperature with respect to the PTFE resin melting point
Board. 2. A PTFE resin dispersion is adhered onto a plate to form a thin layer and then dried, and a fluororesin dispersion having a low melting point for PTFE resin is adhered to the surface of the thin layer and then dried. A non-sintered composite film for a laminated plate, which is formed by peeling the two-layer structure film from the plate. 3. The laminated board according to claim 2, wherein the low melting point fluororesin dispersion is one of PFA, FEP and ETFE .
Unsintered composite film. 4. A base material impregnated with a fluororesin dispersion and then dried to form an unsintered prepreg, and a metal foil is disposed on at least one surface of the unsintered prepreg, and the temperature is higher than the melting point of the fluororesin. A plurality of circuit layers for the inner layer and the outer layer having a circuit portion heated and pressed by are formed, and between the plurality of circuit layers, one layer is a PTFE resin and the other layer is a fluororesin having a low melting point with respect to the PTFE resin. in interposed unsintered composite film formed two-layer structure, the counter circuit section side one layer side of the unsintered composite film, along with to face the other layer side to the circuit side, unsintered composite PFA between the one side of the film and the facing member
Or interposed the interposed film of FEP, the laminated plate heated pressure at a temperature above the melting point of PTFE. 5. with a plurality interposed the unsintered composite film to the plurality of circuit layers, between a plurality of unsintered composite film, after impregnation the fluororesin to the base material, dry green prepreg Claim 4 with the interposition
The laminate described . 6. A sintered body obtained by interposing a plurality of the unsintered composite films between the plurality of circuit layers and impregnating a base material with a fluororesin between the plurality of unsintered composite films, followed by drying and sintering. The laminated board according to claim 4, wherein a binding prepreg is provided . 7. A substrate is impregnated with a fluororesin dispersion and then dried to form an unsintered prepreg, and a metal foil is disposed on at least one surface of the unsintered prepreg, and the temperature is higher than the melting point of the fluororesin. A plurality of circuit layers for the inner layer and the outer layer having a circuit portion heated and pressed by are formed, and between the plurality of circuit layers, one layer is made of PTFE resin and the other layer is made of fluorine having a low melting point with respect to the PTFE resin. A non-sintered composite film having a two-layer structure formed of resin is interposed, and one layer side of the non-sintered composite film is opposed to the circuit side and the other layer side is opposed to the circuit side for heat fusion. At the same time, the surface opposite to the circuit side is surface-modified to a contact angle of 70 degrees or less, and a thermosetting prepreg that is baked and solidified at a low temperature with respect to an epoxy-based or polyimide-based fluororesin is interposed between the plurality of circuit layers. unsintered composite off a two-layer structure <br/> laminate was heated under pressure at a lower temperature with respect than the low melting point of the fluororesin melting PTFE constituting the Lum. 8. The low melting point fluororesin is PFA or FE.
The laminated plate according to claim 7, wherein one of P and ETFE is a fluororesin .