JP2004111702A - Wiring board and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wiring board for achieving high wiring density and a high flexibility in design, short manufacturing lead time, and ensuring stiffness, and to provide a method for manufacturing the wiring board. <P>SOLUTION: In the wiring board, an insulating support substrate 1 and resin substrates 2, 3 are laminated. The insulating support substrate 1 ensures stiffness. In the resin substrates 2, 3, a wiring circuit is formed. The resin substrates 2, 3 are made of thermoplastic resin. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a wiring board and a method of manufacturing the same, and more particularly, to a wiring board having rigidity, high wiring density and a high degree of design freedom, and a short manufacturing lead time, and a method of manufacturing the same.
[0002]
[Prior art]
As a wiring board having a high wiring density and a high degree of design freedom and a short manufacturing lead time, and a method for manufacturing the same, there is known a wiring board and a method for manufacturing the same disclosed in JP-A-2000-38464.
[0003]
According to the method of manufacturing a wiring board disclosed in Japanese Patent Application Laid-Open No. 2000-38464, first, a copper foil is attached to the surface of a resin film made of a thermoplastic resin, and a conductive pattern is formed by selective etching. . Next, a bottomed hole having a conductive pattern as a bottom surface is formed in the resin film, and the bottomed hole is filled with a conductive paste. Then, after laminating a plurality of resin films prepared as described above, pressure is applied while heating at a predetermined temperature and pressure. As a result, the adjacent resin films are fused and integrated, and the conductive paste is sintered to connect the plurality of conductor patterns.
[0004]
[Patent Document 1] Japanese Patent Application Laid-Open No. 2000-38464
[Problems to be solved by the invention]
In the method of manufacturing a wiring board disclosed in Japanese Patent Application Laid-Open No. 2000-38464, a large number of resin films are bonded together and a wiring circuit is formed at the same time. Short production lead time.
[0006]
On the other hand, the wiring board disclosed in Japanese Patent Application Laid-Open No. 2000-38464 has a structure in which the resin film is made of a thin thermoplastic resin. Cannot secure the rigidity.
[0007]
SUMMARY OF THE INVENTION An object of the present invention is to provide a wiring board and a method of manufacturing the wiring board, which have a high wiring density and a high degree of design freedom, have a short manufacturing lead time, and can secure rigidity.
[0008]
[Means for Solving the Problems]
The invention according to claim 1 is a wiring board formed by laminating an insulating support substrate for securing rigidity and a resin substrate on which a wiring circuit is formed, wherein the resin substrate is made of a thermoplastic resin. It is characterized by consisting of.
[0009]
According to this, the rigidity of the wiring board is ensured by the insulating support substrate forming the wiring board, and the wiring density and the design of the wiring circuit formed on the resin substrate made of the thermoplastic resin forming the wiring board are ensured. The degree of freedom can be increased.
[0010]
According to a second aspect of the present invention, a wiring circuit is formed on the support substrate, and the wiring circuit and the wiring circuit of the resin substrate are connected to each other by a conductive composition formed in a through hole of the resin substrate. It is characterized by.
[0011]
According to this, not only the wiring circuit formed on the resin substrate but also the wiring circuit formed on the supporting substrate can be used as the wiring circuit formed on the wiring board, and the wiring density and design flexibility of the formed wiring circuit can be utilized. Can be higher.
[0012]
The invention according to claim 3 is characterized in that a resin substrate is laminated on both surfaces of the support substrate.
[0013]
According to this, since the resin substrate is laminated on both surfaces of the support substrate, it is possible to reduce 'warpage' due to a difference in material between the support substrate and the resin substrate. Further, since both surfaces of the support substrate are used for the wiring circuit, the wiring density and the degree of freedom of design of the wiring circuit can be further increased.
[0014]
As described in claim 4, the support substrate is made of a glass fiber-containing epoxy material, a glass fiber-containing BT resin material, a glass fiber-containing polyimide material, an aramid fiber-containing epoxy material, an aramid fiber-containing BT resin material, and an aramid fiber-containing polyimide material. , A ceramic particle-containing epoxy material, a ceramic particle-containing BT resin material, a ceramic particle-containing polyimide material, a ceramic material, or a metal core material. These materials have sufficient strength as a support substrate material for supporting a thermoplastic resin substrate, and thereby, it is possible to secure sufficient strength of a wiring board composed of the resin substrate and the support substrate. .
[0015]
As described in claim 5, the thermoplastic resin is preferably any of a liquid crystal polymer, polyether ether ketone, a polyether ether ketone / polyetherimide mixture, and polyphenylene sulfide. These materials have sufficient insulation performance and manufacturing easiness as a thermoplastic resin substrate material capable of forming a high-density wiring circuit.
[0016]
The invention according to claims 6 to 8 relates to a method for manufacturing the above-mentioned wiring board.
[0017]
According to a sixth aspect of the present invention, there is provided a method for manufacturing a wiring board, comprising: an insulating support substrate for securing rigidity; and a thermoplastic resin substrate on which a wiring circuit is formed. Forming a conductor pattern of the wiring circuit on the resin film, forming a bottomed hole having the conductor pattern as a bottom surface in the resin film, and filling a conductive paste in the bottomed hole with a resin substrate preparing step; A laminating step of laminating and disposing the support substrate and the resin substrate, and by applying pressure while heating the laminated and arranged support substrate and the resin substrate, while adhering to each other and sintering the conductive paste, And a heating and pressurizing step for forming a wiring circuit.
[0018]
According to this, in the method for manufacturing a wiring board composed of the support substrate and the resin substrate, the bonding of the support substrate and the resin substrate and the formation of a wiring circuit by sintering the conductive paste can be performed simultaneously, Manufacturing lead time can be reduced.
[0019]
The invention according to claim 7, wherein a plurality of the resin substrates are prepared, and in the laminating step, an opening of a bottomed hole in one of the plurality of resin substrates is connected to a conductor in the other resin substrate. It is characterized in that the patterns are stacked and arranged facing predetermined positions of the pattern.
[0020]
According to this, a plurality of resin substrates are laminated to form a multilayer, and the laminated plurality of resin substrates are bonded together by heating and pressing, and the conductive paste is sintered to form a conductive pattern of each resin substrate. Can be connected. This makes it possible to easily manufacture a wiring board having a high wiring density composed of a multilayer resin substrate.
[0021]
In the invention according to claim 8, a conductor pattern is formed on the surface of the support substrate, and in the laminating step, the opening of the bottomed hole in the resin substrate faces a predetermined position of the conductor pattern on the support substrate. It is characterized by being stacked.
[0022]
According to this, the support substrate on which the conductor pattern is formed is laminated with the resin substrate to form a multilayer, the support substrate and the resin substrate are bonded by heating and pressing, and the conductor pattern of the support substrate and the conductor pattern of the resin substrate are combined. The connection can be made by sintering the conductive paste. This makes it possible to easily manufacture a wiring board having a high wiring density using the conductor pattern of the support substrate as a wiring circuit.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a wiring board and a method of manufacturing the same according to the present invention will be described with reference to the drawings.
[0024]
(1st Embodiment)
FIG. 1 is a schematic cross-sectional view of a wiring board 101 according to the first embodiment.
[0025]
A wiring board 101 shown in FIG. 1 is a wiring board in which resin substrates 2 and 3 are laminated on both surfaces of an insulating support substrate 1.
[0026]
The insulating support substrate 1 is made of a glass fiber-containing polyimide material in which glass fiber is impregnated with a polyimide resin, and has conductor patterns 8 and 9 on both surfaces. Through holes 5 are provided in the support substrate 1, and conductor patterns 8 and 9 are electrically connected by connection conductors 7 formed on the side wall surfaces of the through holes 5. A filling resin 6 is embedded in the through hole 5. The support substrate 1 has sufficient strength and rigidity, and is used alone as a printed circuit board.
[0027]
The insulating material of the resin substrates 2 and 3 laminated on both sides of the support substrate 1 is a polyetheretherketone / polyetherimide mixture which is a thermoplastic resin, with 65 to 35% by weight of polyetheretherketone and 35 to 35% of polyetherimide. It has a composition ratio of 65% by weight. The thickness of the resin substrates 2 and 3 is 50 to 150 μm. Conductive patterns (21, 31) are formed on the inner and outer surfaces of the resin substrates (2, 3), and the conductive compositions (22, 32) filled in the via holes (24, 34) are used to form conductors on the inner and outer surfaces of the resin substrates (2, 3). Patterns 21 and 31 are connected to each other.
[0028]
In the wiring board 101 shown in FIG. 1, a wiring circuit is formed on resin substrates 2 and 3 mainly made of a polyetheretherketone / polyetherimide mixture which is a thermoplastic resin. The resin substrates 2 and 3 made of a polyetheretherketone / polyetherimide mixture are excellent in insulation performance, can easily form a wiring circuit having a multilayer structure, and can reduce the wiring density and design freedom of the formed wiring circuit. Can be higher. As a material for such a resin substrate 2, in addition to the polyetheretherketone / polyetherimide mixture, any one of a liquid crystal polymer, polyetheretherketone, and polyphenylenesulfide is preferable. These thermoplastic resins have sufficient insulation performance and manufacturing easiness as a substrate material capable of forming a high-density wiring circuit.
[0029]
A wiring circuit composed of the conductor patterns 8, 9 and the connection conductors 7 is also formed on the support substrate 1 made of a glass fiber-containing polyimide material. The support substrate 1 mainly has a role of securing the rigidity of the wiring substrate 101. . As a material of such a support substrate 1, a glass fiber-containing epoxy material and a glass fiber-containing BT resin material are preferable in addition to the glass fiber-containing polyimide material. In addition, aramid fiber-containing epoxy material, aramid fiber-containing BT resin material, aramid fiber-containing polyimide material, ceramic particle-containing epoxy material using non-conductive aramid fiber or ceramic particles instead of glass fiber as a filler (reinforcing material), A ceramic particle-containing BT resin material or a ceramic particle-containing polyimide material may be used. Further, the material of the support substrate 1 may be a single ceramic material instead of the resin material containing the non-conductive filler as described above. These insulating materials are used alone as a printed circuit board, and have sufficient strength and rigidity as the material of the support substrate 1 that supports the thermoplastic resin substrate 2. Therefore, sufficient rigidity can be ensured even for the wiring substrate 101 on which the resin substrate 2 is supported by the support substrate 1.
[0030]
As shown in FIG. 1, in a wiring board 101, resin substrates 2 and 3 are laminated on both surfaces of a support substrate 1. Thereby, as compared with the case where the resin substrate 2 or 3 is laminated only on one side of the support substrate 1, it is possible to reduce the 'warpage' due to the difference in the materials of the support substrate 1 and the resin substrates 2 and 3.
[0031]
As described above, the wiring circuit is mainly formed on the resin substrates 2 and 3. However, in the wiring substrate 101 shown in FIG. 1, the wiring circuit is also formed on the support substrate 1, and the conductor patterns 8 and 9 of the support substrate 1 are formed. The conductive patterns 21 and 31 of the resin substrates 2 and 3 are connected to each other by conductive compositions 23 and 33. As described above, in the wiring board 101 shown in FIG. 1, not only the wiring circuits formed on the resin substrates 2 and 3 but also the wiring circuit formed on the support substrate 1 is used, and the wiring density and design freedom of the formed wiring circuit are increased. The degree is high. In addition, by laminating the resin substrates 2 and 3 on both surfaces of the support substrate 1, this also increases the wiring density and the degree of design freedom as compared with the case where the resin substrates 2 or 3 are laminated only on one surface. I have.
[0032]
Next, a method for manufacturing the wiring board 101 shown in FIG. 1 will be described with reference to FIGS. 2A to 2F and sectional views by steps shown in FIGS. 3A and 3B.
[0033]
First, as shown in FIG. 2A, a support substrate 1 constituting the wiring substrate 101 is prepared. The support substrate 1 is made of the above-mentioned glass fiber-containing polyimide material. The support substrate 1 may be made of various other materials having insulating properties and rigidity as described above. However, the manufacturing method is publicly known, and a detailed description thereof will be omitted. As the support substrate 1, a substrate used alone as a printed circuit board can be used, and the conductor patterns 8, 9 are formed on the surface by using a known method such as etching. Thus, a predetermined wiring circuit is formed on the support substrate 1 by the conductor patterns 8 and 9 and the connection conductor 7 of the through hole 5. Since the support substrate 1 is laminated with a resin substrate and undergoes a heating and pressurizing step as described later, it is desirable that the through hole 5 has a filling resin 6 embedded therein.
[0034]
Next, using the steps shown in FIGS. 2B to 2E, preparation for manufacturing the resin substrates 2 and 3 constituting the wiring board 101 of FIG. 1 is prepared.
[0035]
First, as shown in FIG. 2B, a resin substrate 4 is prepared in which a conductive foil 41 made of copper is adhered to one surface of a thermoplastic resin film 40. The resin film 40 is a mixture of polyetheretherketone / polyetherimide having a composition ratio of 65 to 35% by weight of polyetheretherketone, 35 to 65% by weight of polyetherimide, and a thickness of 25 to 75 μm. As the material of the resin film 40, various thermoplastic resins as described in the description of the resin substrates 2 and 3 in FIG. 1 can be used. The same can be applied. The conductor foil 41 may use other metal foil such as aluminum in addition to the copper foil. The conductor foil 41 preferably has a thickness of 10 to 40 μm.
[0036]
Next, as shown in FIG. 2C, the conductor foil 41 of FIG. 2B is selectively etched to be processed into a conductor pattern 41.
[0037]
Next, as shown in FIG. 2D, a bottomed hole 44 having the conductor pattern 41 as a bottom surface is formed. The formation of the bottomed hole 44 is performed by inverting the resin substrate 4 of FIG. 2C and irradiating the resin film 40 with a carbon dioxide laser from above. In forming the bottomed hole 44, the output of the carbon dioxide gas laser and the irradiation time are adjusted so that a hole is not formed in the conductor pattern 41. For forming the bottomed hole 44, an excimer laser or the like can be used other than the carbon dioxide gas laser. The diameter of the bottomed hole 44 is about 100 μm. The diameter of the bottomed hole 44 is preferably 20 to 200 μm.
[0038]
Next, as shown in FIG. 2E, the conductive paste 42 is filled in the bottomed hole 44. The conductive paste 42 is obtained by kneading terpineol, which is an organic solvent, and ethylcellulose resin with a mixer using a metal particle of silver and tin as a conductive filler, and forming the paste. As the conductive filler, metal particles such as copper, gold, platinum, palladium, and nickel can be used in addition to silver and tin. The viscosity of the conductive paste 42 is set such that the conductive paste 42 does not fall even if the direction of the resin substrate 4 is changed arbitrarily. The filling of the conductive paste 42 is performed by inverting the resin substrate 4 of FIG. The filling of the conductive paste 42 into the bottomed hole 44 may be performed using a screen printing machine or the like. After the conductive paste 42 is filled into the bottomed holes 44, the terpineol in the conductive paste 42 is evaporated by heating at 100 to 150 ° C. for about 10 minutes, and the conductive paste 42 is dried.
[0039]
Thus, the preparation of the resin substrate 4 in which the conductive pattern 41 is formed on the thermoplastic resin film 40 and the conductive paste 42 is filled in the bottomed hole 44 having the conductive pattern 41 as the bottom surface is completed.
[0040]
Next, as shown in FIG. 2F, on both sides of the support substrate 1 prepared in the step of FIG. 2A, the resin substrates 45 and 46 prepared in the steps of FIGS. The substrates 47 and 48 are stacked and arranged. In this lamination, for example, the conductive paste 42 of the resin substrate 45 shown in FIG. 2F is set so as to face a predetermined position of the conductor pattern 41 of the resin substrate 46. Similarly, for example, the conductive paste 42 of the resin substrate 47 shown in FIG. 2F is set so as to face a predetermined position of the conductive pattern 8 of the support substrate 1.
[0041]
Next, as shown in FIG. 3A, a heater 55 is buried between the support substrate 1 and the resin substrates 45, 46, 47, 48, which are stacked and arranged, via an adhesion preventing film 51, a buffer material 52, and a metal plate 53. It is inserted between a pair of hot press plates 54 thus formed, and is heated and pressed to bond them. The adhesion preventing film 51 prevents the resin films of the resin substrates 45 and 48 from adhering to surrounding members during heating and pressurizing, and prevents the resin films and the conductor patterns of the resin substrates 45 and 48 from being damaged. For example, a thermosetting polyimide film or the like is used. The cushioning material 52 is provided for uniformly applying pressure to the support substrate 1 and the resin substrates 45, 46, 47, 48 having unevenness by the copper foil pattern, and is inserted between the adhesion preventing film 51 and the metal plate 53. As the cushioning material 52, a material obtained by cutting a metal such as stainless steel into a fibrous shape and shaping the fibrous metal into a plate shape having a thickness of about 1 mm is used. The metal plate 53 is for preventing the hot press plate 54 from being scratched. For example, a plate of stainless steel (SUS) or titanium (Ti) having a thickness of about 2 mm is used.
[0042]
After disposing the laminate of the support substrate 1 and the resin substrates 45, 46, 47, and 48 and the above-described press members, the heater 55 is first heated, and the whole is heated at 200 ° C. for 5 minutes without applying pressure. . Next, a pressure of 1 to 10 MPa is applied to the laminated body of the support substrate 1 and the resin substrates 45, 46, 47 and 48 via a hot press plate 54 by a press machine (not shown). Next, the entire temperature is set to 250 to 350 ° C., and heating and pressing are performed for 10 to 20 minutes. Heating and pressurizing may be performed in the air, but are preferably performed in a vacuum in order to suppress oxidation of the conductor pattern.
[0043]
By the above-mentioned heating and pressurization, as shown in FIG. 3B, the adjacent resin substrates 45 and 46 and the resin substrates 47 and 48 are fused and integrated, and the resin substrate 2 and the resin It becomes the substrate 3 and adheres to the support substrate 1. Further, silver particles and tin particles of the conductive paste 42 of FIG. 3A are alloyed to form sintered conductive compositions 22, 23, 32, and 33, and these are used to form the conductive patterns 21, 31. , 8, 9 are connected.
[0044]
In the above-described method of manufacturing the wiring board 101 including the support substrate 1 and the resin substrates 2 and 3, the wiring circuit is formed by bonding the support substrate 1 and the resin substrates 45, 46, 47, and 48, and sintering the conductive paste 42. Can be formed simultaneously. Therefore, the production lead time of the wiring board can be reduced.
[0045]
Since the obtained wiring board 101 has the supporting substrate 1, the rigidity is secured, and the number of laminated resin substrates 45, 46, 47, 48 can be arbitrarily set, so that the degree of freedom in design is high. Further, by increasing the number of laminated resin substrates, a wiring substrate having a high wiring density can be easily manufactured.
[0046]
(Second embodiment)
In the first embodiment, a wiring board formed by laminating a support substrate made of a resin material containing a reinforcing material or a single ceramic material and a resin substrate made of a thermoplastic resin, and a method of manufacturing the same are described. The second embodiment relates to a wiring substrate in which a resin substrate made of a thermoplastic resin is laminated on a support substrate made of a metal core material, and a method of manufacturing the same.
[0047]
FIG. 4 is a schematic cross-sectional view of the wiring board 102 of the present embodiment.
[0048]
The wiring substrate 102 shown in FIG. 4 is a wiring substrate in which resin substrates 2 and 3 are laminated on both surfaces of a support substrate 10 made of a metal core material. The same parts as those of the wiring board 101 of the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.
[0049]
In the wiring board 102 of FIG. 4, the insulating support substrate 10 is made of a metal core material in which a metal core 11 is covered with a coating layer 12 of glass or resin. Also in the supporting substrate 10 made of a metal core material, the conductor patterns 8 and 9 are formed on both surfaces, and the conductor patterns 8 and 9 are electrically connected by the connection conductor 7.
[0050]
The support substrate 10 made of a metal core material has sufficient strength and rigidity, and mainly has a role of securing the rigidity of the wiring substrate 102 shown in FIG. The effect of the wiring board 102 using the supporting substrate 10 made of the metal core material is the same as that of the first embodiment, and thus the detailed description is omitted. Also, the method of manufacturing the wiring board 102 and the effects thereof are the same as those in the first embodiment, and a description thereof will be omitted.
[0051]
(Other embodiments)
In the first embodiment, the wiring substrate is formed by laminating two resin substrates each made of a thermoplastic resin film on both sides of the support substrate, but the number of laminations is arbitrary, and three or more Or one sheet. Further, a wiring board in which a resin substrate is laminated only on one side of the support substrate, not on both sides of the support substrate, may be used.
[0052]
In the first embodiment, the wiring circuit of the wiring board includes a conductive pattern of the supporting substrate and the resin substrate, a connecting conductor of a through hole provided in the supporting substrate, and a conductive composition of a via hole provided in the resin substrate. The example shown in FIG. The wiring circuit of the wiring board is not limited to this. For example, it is also possible to provide a through-hole penetrating the support substrate and the resin substrate. On the other hand, the through-hole may not be formed in the supporting substrate. Further, the support substrate may be a multilayer substrate of three or more layers having a conductor pattern on the inside as well as the surface.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of a wiring board according to a first embodiment of the present invention.
FIGS. 2A to 2F are cross-sectional views illustrating steps in a method for manufacturing a wiring board according to the first embodiment of the present invention.
FIGS. 3A and 3B are cross-sectional views illustrating a method for manufacturing a wiring board according to the first embodiment of the present invention.
FIG. 4 is a schematic sectional view of a wiring board according to a second embodiment of the present invention.
[Explanation of symbols]
101,102 Wiring substrate 1,10 Support substrate 2,3,4,45,46,47,48 Resin substrate 8,9,21,31,41 Conductive pattern 22,23,32,33 Conductive composition

Claims (8)

An insulating support substrate for securing rigidity, a wiring substrate formed by laminating a resin substrate on which a wiring circuit is formed,
The wiring board, wherein the resin board is made of a thermoplastic resin. A wiring circuit is formed on the support substrate, and the wiring circuit and the wiring circuit of the resin substrate are connected to each other by a conductive composition formed in a through hole of the resin substrate. 2. The wiring board according to 1. The wiring substrate according to claim 1, wherein the resin substrate is laminated on both surfaces of the support substrate. The support substrate is a glass fiber-containing epoxy material, a glass fiber-containing BT resin material, a glass fiber-containing polyimide material, an aramid fiber-containing epoxy material, an aramid fiber-containing BT resin material, an aramid fiber-containing polyimide material, a ceramic particle-containing epoxy material, and ceramic. The wiring board according to any one of claims 1 to 3, wherein the wiring board is made of any one of a particle-containing BT resin material, a ceramic particle-containing polyimide material, a ceramic material, and a metal core material. The wiring according to any one of claims 1 to 4, wherein the thermoplastic resin is any one of a liquid crystal polymer, polyether ether ketone, a polyether ether ketone / polyetherimide mixture, and polyphenylene sulfide. substrate. An insulating support substrate for securing rigidity, and a method for manufacturing a wiring board formed by laminating a thermoplastic resin substrate on which a wiring circuit is formed,
Preparation of a resin substrate for forming a conductor pattern of the wiring circuit on a thermoplastic resin film, forming a bottomed hole having the conductor pattern as a bottom surface in the resin film, and filling the bottomed hole with a conductive paste. Process and
A laminating step of laminating and disposing the support substrate and the resin substrate,
A heating and pressurizing step of forming the wiring circuit by sintering the conductive paste while applying pressure while heating the support substrate and the resin substrate arranged in a stack. Method of manufacturing a wiring board. A plurality of the resin substrates are prepared, and in the laminating step, the opening of the bottomed hole in one of the plurality of resin substrates is laminated so as to face a predetermined position of the conductor pattern on the other resin substrate. The method according to claim 6, wherein the wiring board is arranged. A conductor pattern is formed on a surface of the support substrate, and in the laminating step, an opening of the bottomed hole in the resin substrate is laminated and arranged facing a predetermined position of the conductor pattern on the support substrate. Item 8. The method for manufacturing a wiring board according to item 6 or 7.

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