JP2004243688A - Method for producing resin substrate and method for producing substrate with film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To produce resin substrates of various sizes and shapes and to produce a substrate having a film, for example the film of a wiring pattern, on its one surface in a high thickness precision. <P>SOLUTION: The resin substrate 12 is produced to be molded in a constant thickness determined by the height of a spacer 82 by restricting the molding surfaces of a pair of molds 52 and 52 to be the minimum space by the spacer 82 arranged on the circumferential side of them and curing it while it is crushed between the molds 52 and 52. Since the discharge of a resin 44 with its fluidity raised by heating is suppressed by a seal material 80 arranged along the outer peripheral edge of the mold 52, the resin 44 flows excessively from a prepreg 48 to hardly generate resin missing in the peripheral edge part etc. In this way, only by determining the height of the spacer 82 appropriately, the resin substrates of various thicknesses can be obtained easily in a high thickness precision. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a resin substrate and a film-coated substrate having a film such as a conductor wiring fixed on a surface thereof.
[0002]
[Prior art]
For example, there is known a wiring board in which one or a plurality of layers of conductive wiring is provided inside or on one side or both sides of a synthetic resin substrate. For example, on one or both sides of an injection-molded synthetic resin sheet or a fiber-reinforced resin sheet obtained by impregnating and curing a synthetic resin in a cloth (especially a woven cloth), copper plating, copper paste application, copper foil etching, etc. One example is a single-sided or double-sided wiring board provided with conductor wiring, a multilayer wiring board in which a plurality of double-sided wiring boards are laminated via an insulating layer provided with a through conductor, and the like. Such a wiring board is used, for example, for a printed wiring board or a semiconductor package of an electronic device (for example, see Patent Documents 1 and 2).
[0003]
The cloth is, for example, a woven or nonwoven fabric made of inorganic fibers such as glass fibers or organic fibers such as aramid fibers, and is formed of, for example, a warp made of twisted single fibers (monofilaments). And the weft are woven in a plain weave, for example. As the synthetic resin, a thermosetting resin such as an epoxy resin, a polyimide resin, a phenol resin, a polyester resin, a silicone resin, and a polyurethane resin is generally used. For example, a substrate using glass woven fabric and epoxy resin is called a glass epoxy substrate.
[0004]
[Patent Document 1]
JP-A-6-209151
[Patent Document 2]
JP-A-11-186698
[0005]
[Problems to be solved by the invention]
However, in the conventional method of manufacturing a substrate as described above, in the case of injection molding, a substrate having high dimensional accuracy can be manufactured, but a molding die must be prepared for each size and shape of the substrate. However, there is a disadvantage that the cost of manufacturing the substrate is increased because the molding die is expensive. On the other hand, when the cloth is impregnated with a resin, the prepreg in a semi-cured state (ie, the B stage) is heated while being pressurized to shift to a cured state (ie, the C stage), so that the resin substrate having various sizes and shapes is formed. Can be manufactured relatively inexpensively, but it is difficult to control the thickness dimension after pressure molding. The pressure molding of the prepreg is performed singly or by laminating a plurality of the prepregs according to the thickness of the substrate to be manufactured. Is unstable because it can fluctuate due to various factors such as the liquidity of the product.
[0006]
The present invention has been made in view of the above circumstances, and an object thereof is to provide a resin substrate having various dimensions and shapes and a film-coated substrate having a film such as a wiring pattern on one surface thereof having a high thickness. An object of the present invention is to provide a method capable of manufacturing with dimensional accuracy.
[0007]
[First means for solving the problem]
In order to achieve such an object, the gist of the first invention is a method of manufacturing a resin substrate having a predetermined thickness, wherein (a) one sheet or one sheet is formed between molding surfaces of a pair of molds. Disposing a semi-cured resin substrate material composed of a plurality of sheets superposed on each other; and (b) forming a first spacer for limiting a minimum value of a mutual interval between the molding surfaces to the predetermined thickness dimension. A first spacer arranging step of arranging the molding surface at a predetermined position on the outer peripheral side of the resin substrate material; and (c) setting the molding surface at a predetermined position on the inner peripheral side of the first spacer in the periphery of the resin substrate material. A second spacer arranging step of arranging a second spacer which is elastically compressed in the process of being brought close to each other, and (d) applying pressure while heating between the pair of molds under vacuum. The material is of the predetermined thickness A heating and pressing step of molding and curing the law is to include.
[0008]
[Effect of the first invention]
In this case, since the minimum spacing between the molding surfaces of the pair of molds is limited by the first spacer, the resin substrate material that is cured while being crushed between the molds has a high height of the first spacer. It is formed into a resin substrate having a constant thickness dimension determined by the thickness dimension. At this time, the resin substrate material is heated to increase the fluidity of the resin, and is compressed in the thickness direction by being pressed, so that the resin tends to flow to the outer peripheral side. Since there is a second spacer elastically compressed around the resin substrate material, the outflow thereof is suppressed by the second spacer, that is, the resin outflow restricting member. Therefore, since the resin does not flow too much from the resin substrate material, even if the first spacer is restricted from approaching the molding dies, it is unlikely that defects due to the insufficient amount of resin in the peripheral portion and the like are likely to occur. The thickness of the first spacer can be easily determined by appropriately setting the height of the first spacer without causing defects such as resin defects, in combination with the suppression of the generation of bubbles by being heated and pressurized. Is obtained. Since the second spacer is compressed by being pressed, it does not prevent the mold from approaching the mutual space defined by the first spacer at all, and furthermore, both upper and lower surfaces of the second spacer are in contact with the pressing surface. Due to the close contact, resin outflow is suitably suppressed. Therefore, resin substrates of various sizes and shapes can be manufactured with high thickness dimensional accuracy.
[0009]
[Second means for solving the problem]
Further, the gist of the second invention for achieving the above object is a method of manufacturing a film-coated substrate having a predetermined thickness in which a film having a predetermined function is provided on one surface in a predetermined plane shape. (A) a semi-cured resin substrate material consisting of one or a plurality of mutually laminated molding surfaces of a pair of molding dies having a convex portion having the predetermined planar shape on one molding surface; And (b) a first spacer arranging step of arranging a first spacer for limiting the minimum value of the mutual distance between the molding surfaces to the predetermined thickness dimension at a predetermined position on the outer peripheral side of the resin substrate material. And (c) a second spacer elastically compressed in a process of bringing the molding surfaces closer to the minimum value at a predetermined position on the inner peripheral side of the first spacer in the periphery of the resin substrate material. A second spacer disposing step of disposing (D) the resin substrate material is formed into the predetermined thickness by heating and pressing between the pair of molds under vacuum, and the one surface pressed by the one forming surface at the same time as being cured. Forming a groove in the predetermined planar shape to obtain a resin substrate, and (e) forming a film by embedding a constituent material of the film in the groove of the resin substrate. And to include.
[0010]
[Effect of the second invention]
With this configuration, as described above, the first spacer and the second spacer (that is, the resin outflow restricting member) are disposed and the resin substrate material is heated while being pressed, so that the resin substrate having an arbitrary size and shape is high. It can be manufactured with thickness dimensional accuracy. At this time, since a convex portion is provided on one molding surface of the pair of molds, the surface of the resin substrate pressed by this molding surface has a predetermined planar shape in which the convex portion is inverted. A concave groove is formed. Therefore, by embedding a predetermined film constituent material in this groove, a film having a predetermined planar shape is formed.Therefore, a film-coated substrate having various dimensions and shapes and having a film on one surface in a predetermined pattern is used. It can be manufactured with high thickness dimensional accuracy. Moreover, the film is formed by being embedded in the groove, and the groove is formed by pressing the resin with the convex portion provided in the molding die, and the planar shape of the convex portion is faithfully inverted. Because of this, there is also an advantage that a film-coated substrate with high film pattern accuracy can be obtained by a simple manufacturing process. In addition, as a result of using such a film forming method, there is no waste of film constituent materials and no etching or plating compared to a film forming method of attaching a metal foil to the entire surface of the substrate and forming a pattern by etching. There is an advantage that there is no increase in environmental load due to waste liquid treatment or the like. Furthermore, since the film is buried in the groove of the substrate and does not become convex on the surface thereof, there is an advantage that mounting and multilayering of electronic components and the like are facilitated.
[0011]
[Another aspect of the second invention]
Here, in the second invention, preferably, the method for manufacturing a substrate with a film includes a step of forming a through hole penetrating in a thickness direction at a predetermined position of the resin substrate, and the film forming step includes: This is a wiring forming step of forming the conductor wiring having the predetermined planar shape by applying a conductive paste in the groove and simultaneously forming the through conductor by applying the conductive paste in the through hole. In this case, when the multilayer wiring board is manufactured by forming the conductor wiring and simultaneously connecting the wirings provided on both sides of the board, or laminating a plurality of the wiring boards and fixing them together. In this case, the through conductor for connecting the conductor wirings of the plurality of wiring boards to each other is formed, and thus there is an advantage that the manufacturing of the wiring board is facilitated.
[0012]
[Other aspects of the first and second inventions]
In the first and second inventions, preferably, the heating and pressurizing step includes laminating a plurality of laminates of the pair of molds, the resin substrate material, the first spacer, and the second spacer. At the same time, pressure is applied while heating. In this case, there is an advantage that a plurality of resin substrates can be simultaneously pressure-formed. That is, according to the present invention, since the first spacer is arranged on the outer peripheral side of the resin substrate material, the thickness dimension of the resin substrate to be molded is determined by the height dimension of the first spacer. Therefore, even if a plurality of sets are superimposed and pressed from above and below, variations in the thickness of the resin substrate material and differences in the fluidity of the resin cannot affect the thickness of the resin substrate. It is possible to manufacture a resin substrate as a material of the attached substrate with high thickness dimensional accuracy. Further, according to the present invention, since the molding surface shape of the molding die is flat or substantially flat with only the low protrusion having the thickness dimension of the wiring provided, the molding die is particularly thick. No need to do. Therefore, when such a thin mold is used, the thickness dimension can be kept relatively small even when a plurality of sets are overlapped, so that there is an advantage that more resin substrates can be molded at the same time and mass productivity is excellent.
[0013]
Preferably, in the second spacer disposing step, the second spacer is disposed on a portion of the periphery of the resin substrate material except for a predetermined range of a corner thereof. In this case, the excess resin due to being crushed by the mold easily flows out from the corner to the outer peripheral side. Therefore, since the flow of the resin is appropriately allowed, the uniformity of the resin thickness is further improved on the inner peripheral side of the second spacer, so that a resin substrate or a film-coated substrate having higher thickness dimensional accuracy can be obtained.
[0014]
The predetermined range is, for example, a range from a corner of the resin substrate material to a length of about 10 (mm) along a side thereof.
[0015]
Preferably, the resin substrate material is obtained by impregnating a cloth with a resin. In other words, since the cloth is impregnated with the resin, the flow of the resin is hindered by the cloth, so that the thickness of the fiber-reinforced resin substrate tends to vary or the resin is deficient. The present invention is suitably applied to a substrate with a film such as a wiring substrate provided with a film. More preferably, the fabric is a woven fabric, more preferably, woven with inorganic fibers such as glass fibers. Since such a resin substrate material has a particularly low fluidity of the resin, the effect of applying the present invention is more remarkably obtained.
[0016]
Preferably, the second spacer is made of a rubber material such as silicone rubber or fluorine rubber. Since these rubber materials have appropriate elasticity, they can be pressed and shrunk appropriately following the deformation of the resin substrate material at the time of heat and pressure molding, and have sufficient heat resistance which does not change at the heating temperature at the time of molding the resin substrate. Therefore, there is an advantage that the quality is not affected even if it is arranged in contact with the resin substrate material. The heating temperature during molding is, for example, generally 170 to 200 (° C.), and at most 220 (° C.) or less.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
[0018]
FIG. 1 is a perspective view showing an entire wiring board 10 manufactured by applying the method of manufacturing a film-embedded substrate of the present invention. In the figure, a wiring board 10 is a thin resin board 12 having a rectangular shape of, for example, about 300 × 500 (mm) and a thickness of about 100 (μm) to 1 (mm), and a surface 14 thereof. And a plurality of wirings 20 and a plurality of resistors 22 provided on the back surface 16. The wiring board 10 is used, for example, as a circuit board for electronic equipment or a semiconductor package such as an IC by mounting electronic components such as a semiconductor, a resistor, a capacitor and a coil on the front surface 14 and the rear surface 16 thereof. Can be In the present embodiment, the above-mentioned wiring corresponds to the “film having a predetermined function” in the claims.
[0019]
As described later, the resin substrate 12 includes a woven fabric 42 that is provided in a layered shape and forms a skeleton thereof, and a synthetic resin 44 that covers the surface and enters the texture. The thickness dimension is substantially uniform over the entire surface. The woven fabric is made of, for example, E glass (Na ₂ O, K ₂ This is a glass woven fabric in which glass fibers made of alkali-free glass having an alkali content of less than 0.8 (%) such as O) are woven. The synthetic resin is obtained by curing a thermosetting resin such as an epoxy resin. The resin substrate 12 has no internal or surface air bubbles based on a manufacturing method described later.
[0020]
The wiring 20 is made of, for example, silver (Ag) or copper (Cu), and has a width of, for example, about 25 (μm) to about 4 (mm), for example, about 25 (μm). And adjacent ones are provided at an interval of, for example, about 25 (μm) to about 4 (mm), for example, about 25 (μm). FIG. 2 is a diagram for explaining an arrangement state of the wiring 20 in a cross section of the wiring board 10. On the front surface 14 and the rear surface 16 of the resin substrate 12, a planar groove 24 of the wiring 20 is provided in a range of 5 to 60 (μm), for example, with a depth of about 30 (μm). Are formed of a conductor such as silver filled in the groove 24. The surface of the embedded wiring 20 is located on substantially the same plane as the front surface 14 and the back surface 16 of the resin substrate 12. That is, the thickness dimension of the wiring 20 is, for example, about 30 (μm), and the wiring substrate 10 has no unevenness caused by the wiring 20 at all. In addition, the portion of the surface of the resin substrate 12 where the wiring 20 is not provided has no undulation or the like, and has a substantially flat surface. In FIG. 2, the glass woven fabric provided in the resin substrate 12 is omitted.
[0021]
Further, as shown in FIG. 1, a circular or rectangular land 26 and through holes 28 are provided at a plurality of positions at each end of the wiring 20 and at an intermediate portion in the longitudinal direction. The land 26 is for fixing a terminal or the like of the electronic component or connecting the resistor 22 to the wiring 20. As shown in FIG. 2, the through hole 28 penetrates the resin substrate 12 in its thickness direction, and the through conductor 30 is provided inside the through hole 28 so that the through hole 28 is formed on the front surface 14 and the back surface 16 respectively. This is for connecting the provided wirings 20 to each other. The through conductor 30 is made of, for example, the same conductive material as the wiring 20, for example, silver or copper. The opening diameter of the through hole 28 is, for example, in the range of 30 to 700 (μm), for example, about 100 (μm).
[0022]
The resistor 22 is made of, for example, carbon or the like, and is provided with an appropriate thickness, width, and length so as to obtain a desired characteristic value. The resistor 22 is also filled and formed in a recess having a depth of, for example, about 30 (μm) provided in the resin substrate 12 similarly to the wiring 20 described above.
[0023]
Meanwhile, the wiring board 10 configured as described above is manufactured, for example, according to the process illustrated in FIG. Hereinafter, a method of manufacturing the wiring board 10 will be described with reference to FIGS. 4 and 5 for describing an implementation state in each step, according to the step diagrams.
[0024]
First, in the resin impregnation step 40, a glass woven cloth 42 having a uniform width and a uniform width and wound on a roll or the like, for example, is pulled out from one end and passed through a resin varnish, so that the glass The cloth 42 is impregnated with a resin. Next, in a drying step 46, this is subjected to a drying treatment at a predetermined drying temperature predetermined for each type of resin. As a result, the resin is changed to the B stage, and a prepreg 48 is obtained in which the glass woven cloth 42 is covered with the resin 44 and the texture is impregnated with the resin 44 as shown in FIG. . The obtained prepreg 48 is stored, for example, in a state of a rectangular thin plate which is cut into a predetermined length so as to be easily used in a post-process, or is stored without being cut off by a winding roll. You. In this embodiment, the prepreg 48 corresponds to a resin substrate material.
[0025]
The glass woven fabric 42 is formed by, for example, weaving a plurality of parallel warps and a plurality of wefts orthogonal to and parallel to each other in a plain weave, and the warp and the weft are, for example, About 100 to 500 single fibers having a diameter of about 5 to 10 (μm) are twisted. The thickness dimension of the glass woven fabric 42 is, for example, about 44 (μm), and the amount of the resin 44 adhered to the surface of the glass woven cloth 42 is, for example, about 7 to 8 (μm) after drying. Therefore, the thickness dimension of one prepreg 48 is, for example, about 60 (μm). The resin varnish is obtained by, for example, diluting an epoxy resin with an organic solvent so as to have a constant viscosity.
[0026]
On the other hand, in the mold inner surface resin coating step 50, a pair of molding dies 52 (that is, an upper mold 52a and a lower mold 52b) for forming the groove 24 in the prepreg 48 are prepared and positioned on the prepreg 48 side. A resin is applied to the entire inner surface 54 (see FIG. 4B). This resin is, for example, a resin obtained by diluting the same resin as the resin 44 with a solvent. Next, in a drying step 56, by heating at a predetermined temperature determined according to the type of the resin, the solvent is volatilized, and the resin is converted to the B-stage, whereby a resin film 58 is formed. The inner surface 54 of the mold is provided with a projection 60 having a planar shape that matches the planar shape of the wiring 20. The height from the bottom surface of the inner surface 54 to the upper surface of the protrusion 60 is, for example, about 30 (μm), that is, equal to the depth of the groove 24.
[0027]
Further, the molding die 52 is provided with a frame portion 62 having a height dimension of about 30 to 1 (mm) in accordance with the thickness of the sheet to be molded from the inner surface 54, for example, higher than the projection 60 along the outer peripheral edge thereof. I have. The frame portion 62 is provided to form a sufficiently thick resin film 58 without flowing out when the liquid resin is applied as described above. In this embodiment, the liquid resin is applied. Thereafter, by scraping off with a doctor blade or the like, the resin film 58 is formed so that the surface is positioned at the same height as the upper surface of the frame portion 62. The molding die 52 is made of, for example, stainless steel such as SUS304, and is a thin plate having a thickness from the bottom surface to the back surface of the inner surface 54 of about 0.4 (mm).
[0028]
Returning to FIG. 3, in the heating / pressing step 64, the pair of forming dies 52a and 52b and the prepreg 48 are arranged at predetermined positions of, for example, a vacuum hot press apparatus, and the prepreg 48 is heated in a vacuum to form the prepreg 48. Pressure is applied between the molds 52a and 52b. FIG. 4B is a cross-sectional view schematically showing an implementation state of this step. In the figure, the upper mold 52a and the lower mold 52b are arranged such that their respective inner surfaces 54 face the prepreg 48, and are pressed in directions approaching each other as shown by arrows P and P in the figure. The molding die 52 is placed on the support plate 74 of the press device. The support plate 74 is placed in contact with the outer peripheral edge of the molding die 52 or the outer peripheral edge of the prepreg 48 or slightly therefrom. A seal member 80 is placed so as to be spaced apart from it, and a spacer 82 is further placed on the outer peripheral side thereof. In the present embodiment, the spacer 82 corresponds to a first spacer, and the sealing material 80 corresponds to a second spacer.
[0029]
The sealing material 80 is made of, for example, a rubber material such as silicone, and has, for example, a length dimension of about 300 to 500 (mm) in a direction perpendicular to the paper surface and a width dimension of 2 (in the left-right direction of the paper surface). mm), and is a substantially rectangular parallelepiped elastic body having a dimension of about 2 (mm) in the vertical direction of the paper surface, that is, the thickness direction of the prepreg 48. As shown in FIG. 5, four seal members 80 are arranged along four sides of the molding die 52 having a rectangular shape in plan view. The length is determined so that both ends of each side of the molding die 52 are located at positions receding along the side from the four corners by about L = 5 to 10 (mm). . For this reason, the outer periphery of the molding die 52 is substantially surrounded by the seal material 80 except for the four corners.
[0030]
The spacer 82 is made of, for example, SUS304, and has a length of about 300 to 500 (mm) in a direction perpendicular to the plane of FIG. 4 and a width of about 10 (mm) in the horizontal direction of the plane of FIG. The height dimension (i.e., the thickness dimension) in the up-down direction of the paper surface is a substantially rectangular parallelepiped shape of about 1.1 to 1.8 (mm). The height dimension is determined in order to obtain a substrate thickness of about 300 (μm) to 1 (mm) as described above, and the thickness of the mold 52 is about 0.4 (mm). Therefore, the value is obtained by adding the thickness of the pair of molds 52 to the thickness of the substrate. The height dimension of the sealing material 80 described above is initially a value sufficiently larger than the height dimension of the spacer 82, and is elastically compressed until it reaches the same height dimension as the spacer 82. It is set to obtain. In FIG. 4B, the top of the sealing material 80 is drawn away from the lower surface of the support plate 74 located on the upper side, but when the sealing material 80 is arranged as shown in FIG. There is no problem even if the support plate 74 is on (that is, in contact with). The length of the spacer 82 is set to a value sufficiently larger than the length of one side of the molding die 52 along the length direction of the spacer 82 as shown in FIG. 5, for example. Note that the dimensional ratio of each part is not always accurate in each drawing. For example, in this drawing and FIG. 6 described below, for the sake of illustration, the height of the sealing material 80 and the spacer 82 is exaggerated as compared to the width. ing.
[0031]
The heating / pressing step 64 is performed in a state where the molding die 52, the spacer 82, and the like are arranged as described above, and the molding condition is such that the temperature is in the range of 160 to 220 (° C.), for example, 180 (° C.). And the pressure is 0.98 to 3.92 (MPa), that is, 10 to 40 (kgf / cm ² ), For example, about 2 (MPa). In FIG. 4B, three prepregs 48 are shown separated from each other for convenience of explanation, but the number of stacked prepregs is determined according to a desired substrate thickness. Actually, they are arranged between the molding dies 52 in a state of being in close contact with each other. As a result of heating and pressurization in this manner, the resin 44 and the resin film 58 of the prepreg 48 are both softened and integrated in the process of moving to the C stage. That is, the resin substrate 12 having a thickness of, for example, about 300 (μm) is obtained. As described above, since the thickness of one prepreg 48 is only about 60 (μm), a plurality of prepregs 48 are stacked for obtaining a required substrate thickness. FIG. 4C shows a stage at which the pressurization and the heating are completed. In the drawing, a dashed line indicates a boundary position between the prepreg 48 and the resin film 58 before being integrated.
[0032]
In this heating and pressurizing process, the molds 52a and 52b are brought close to each other until the support plate 74 is pressed against the spacer 82, so that the distance between them at the time of closest approach is determined by the height dimension of the spacer 82. Is limited to a value determined according to. That is, the distance between the bottom surfaces of the inner surfaces 54 is made close to each other until the distance between the bottom surfaces coincides with the substrate thickness, so that a uniform substrate thickness can be obtained. At this time, the excess resin 44 (and resin film 58) between the molding dies 52, 52 has sufficient fluidity by being softened, and therefore, from the space between the molding dies 52, 52 to the outer peripheral side. Try to flow out. However, since the sealing material 80 is disposed almost in close proximity around the molding die 52, the resin 44 is prevented from flowing out through the middle portion of each side of the molding die 52, so that the resin 44 is sealed. The material 80 flows out only from the corners of the mold 52 where the material 80 is not arranged. Moreover, since the seal member 80 is elastically pressed against the support plate 74 from the initial stage of pressurization, the seal member 80 adheres to the support plate 74 in a range where the seal member 80 is provided except for the corners. Since the sealing is performed by being performed, a more reliable sealing effect can be obtained.
[0033]
As a result, excessive outflow of the resin 44 during the pressurization process is suppressed, so that even if the molds 52 and 52 are restricted from approaching each other by the spacer 82, the resin 44 may be insufficient in the mold 52 and extend. Defects are preferably suppressed. Since the sealing material 80 is made of a rubber material and is easily compressed by being pressed, it does not hinder the molds 52 and 52 from approaching each other at all. Height dimensions.
[0034]
In addition, when the molding dies 52, 52 are brought close to each other, the occurrence of the inclination is suppressed by the sealing material 80. Therefore, the upper mold 52a is made to approach the lower mold 52b while keeping substantially horizontal. Therefore, the entire surface of the prepreg 48 is pressed substantially uniformly. For this reason, thickness variations, resin defects, and the like due to the local pressing in the pressing process are suitably suppressed. As described above, in this embodiment, the outflow of the resin is restricted by the sealing material 80 described above.
[0035]
Although FIG. 4B shows only a pair of molding dies 52, 52, the vacuum heat press device has a device configuration capable of, for example, stacking the molding dies 52 in multiple stages. FIG. 6 schematically shows the configuration of the multi-stack. In the figure, a plurality of pairs of molds 52, for example, about 10 to 20 pairs, are stacked via a plurality of support plates 74. The support plate 74 is made of, for example, SUS430 or the like, and is, for example, a flat thin plate having a thickness of about 1 (mm). The molding die 52 is in close contact with the support plate 74 via a release film, for example, so that the resin substrate 12 can be easily taken out together with the molding dies 52 after molding. Further, the above-described 10- to 20-stage molding dies 52 and support plates 74 are sandwiched between hot plates 76 from above and below. The hot plate 76 is connected to a heating source (not shown) of the press device. In the press apparatus of the present embodiment, such a structure sandwiched between the hot plates 76, 76 is stacked, for example, about 10 steps. Therefore, when performing the heating and pressurizing treatment, heat is transmitted to each of the molding dies 52 via the hot plate 76 and the support plate 74, and the prepreg 48 is heated and molded by the pressing force and heating given from the molding dies 52. Is Therefore, in this embodiment, about 100 to 200 resin substrates 12 are molded in one molding step.
[0036]
Further, in the multi-stack configuration as described above, the seal material 80 and the spacer 82 are provided for each of the pair of molds 52, 52. Therefore, even when the stacking is performed in multiple stages, the mutual interval at the end of pressurization of the molding dies 52 in each molding stage has a constant value determined by the height dimension of the spacer 82. In addition, resin outflow from between each pair of molding dies 52, 52 is also controlled by the sealing material 80 provided for each stage as described above. Therefore, even if the resin is stacked in multiple stages, there is no resin deficiency caused by the excessive outflow of the resin as in the case of the single stage. As described above, in this embodiment, since the approaching behavior of the molding dies 52, 52 and the resin outflow are controlled for each molding step, the thickness dimension is obtained by stacking in multiple stages and collectively pressing. There is an advantage that the resin substrate 12 having high accuracy and no resin deficiency can be formed with extremely high efficiency. The arrangement positions of the seal members 80 and the spacers 82 in each stage are set so as to be substantially the same in the surface direction, for example, between the heat plates 76.
[0037]
After the heating / pressing step 64 is completed and the resin substrate 12 is removed from the mold 52, in a punching step 66, a through hole is passed through a predetermined position of the resin substrate 12 using a laser drilling device, an NC machine board, or the like. A hole 28 is provided. FIG. 4D shows a stage where the through hole 28 is provided. As is apparent from the drawing, the surface of the resin substrate 12 is formed in a shape following the inner surface 54 of the molding die, and the front surface 14 and the rear surface 16 of the resin substrate 12 are formed with grooves 24 following the protrusions 60. Other than that, no undulations or irregularities are generated.
[0038]
Next, in a conductor application step 68, a conductor paste 84 such as a silver paste is applied to the front surface 14 and the back surface 16 of the resin substrate 12 where the grooves 24 are formed, and an excess portion protruding from the grooves 24 is squeezed or the like. Remove by scraping. FIG. 4E shows a state in which the conductor paste 84 is applied using, for example, a screen printing method. In this step, the conductor paste 84 may be simultaneously applied to the inside of the through hole 28 and the groove 24. However, if the conductor paste 84 having high fluidity is not used, the filling in the through hole 28 becomes insufficient. In such a case, different solvents may be applied separately. If necessary, as shown in the figure, the paste can be easily sucked into the through-hole 28 by sucking from the back surface side of the resin substrate 12. Then, in the drying step 70, heating is performed at a predetermined temperature at which all the solvent in the conductive paste is volatilized, for example, a temperature in the range of 100 to 180 (° C.). As a result, the conductor is cured in the groove 24, and the wiring 20 is formed. That is, the wiring board 10 is obtained.
[0039]
In short, according to the present embodiment, since the minimum distance between the molding surfaces 54 of the pair of molding dies 52, 52 is limited by the spacers 82 arranged on the outer peripheral sides thereof, the pressing surfaces between the molding dies 52, 52 are pressed. The resin substrate 12 obtained by being cured while being crushed is formed into a fixed thickness dimension determined by the height dimension of the spacer 82. At this time, the prepreg 48 is heated to increase the fluidity of the resin 44 and is compressed in the thickness direction by being pressed, so that the resin 44 tends to flow to the outer peripheral side. Is suppressed by the seal material 80 arranged along the outer peripheral edge of the molding die 52. Therefore, since the resin 44 does not flow too much from the prepreg 48, even if the approach of the molding dies 52, 52 is restricted by the spacer 80, the loss due to the insufficient amount of the resin in the peripheral portion or the like hardly occurs. The thickness of the spacer 82 is easily determined by appropriately setting the height of the spacer 82 without causing defects such as resin defects, in combination with the suppression of the generation of bubbles by being heated and pressurized below. Is obtained. Further, since the sealing material 80 is compressed by being pressed, it does not hinder the molds 52, 52 from approaching each other up to the mutual interval determined by the spacer 82. Therefore, according to the present embodiment, it is possible to manufacture the resin substrates 12 having various dimensions and shapes with high thickness dimensional accuracy.
[0040]
Moreover, according to the present embodiment, since the convex portion 60 is provided on the molding surface 54 of the molding die 52, the convex portion 60 is provided on the surface of the resin substrate 12 pressed by the molding surface 54. Are formed, and a concave groove 24 having a planar shape inverted from the above is formed. Therefore, a desired wiring pattern is formed by embedding and curing the conductive paste 84 in the groove 24, so that the wiring board 10 having various dimensions and shapes and having the wiring 20 in a predetermined pattern on one surface is provided. Can be manufactured with high thickness dimensional accuracy. Moreover, the groove 24 into which the conductive paste 84 is embedded is formed by pressing the prepreg 48 with the convex portion 60 provided in the molding die 52, and the planar shape of the convex portion 60 is faithfully inverted. Therefore, there is also an advantage that the wiring substrate 10 with high pattern accuracy of the wiring 20 can be obtained by a simple manufacturing process.
[0041]
Further, according to the present embodiment, when the conductive paste 84 is applied in the groove 24, the conductive paste 84 is also applied in the through hole 28 at the same time, so that the wirings 20 provided on both surfaces of the substrate 10 are connected to each other. Is formed, there is an advantage that the manufacture of the wiring board 10 is facilitated.
[0042]
Further, according to the present embodiment, since the heating and pressing step 64 is performed in a state where a plurality of pairs of forming dies 52, 52 are stacked in multiple stages, there is an advantage that a plurality of resin substrates 12 can be pressed and formed simultaneously. is there. At this time, as described above, the thickness of the resin substrate 12 in each step is controlled by the spacer 82 and the inclination of the upper mold 52a is suitably suppressed by the sealing material 80 during the pressing process. There is an advantage that the resin substrate 12 having uniform dimensions and no resin defect can be easily manufactured with high accuracy.
[0043]
Further, according to the present embodiment, since the sealing material 80 is arranged on the entire periphery except for the corners of the molding die 52, the resin is prevented from flowing out from the middle part of each side, and the resin is appropriately discharged from the corners. By doing so, the outflow of the resin from between the molds 52, 52 is suitably controlled, so that there is an advantage that the thickness dimensional accuracy is further increased and resin deficiency hardly occurs.
[0044]
Further, in this embodiment, since the sealing material 80 is made of a rubber material such as silicone, the sealing material 80 has appropriate elasticity, so that the sealing material 80 can be appropriately compressed and shrunk so as to follow the deformation of the prepreg 48 at the time of heating and pressing. In addition, there is an advantage that the quality is not affected by the quality of the resin substrate 12 because the quality is not changed at the heating temperature at the time of molding the substrate.
[0045]
As described above, the present invention has been described in detail with reference to the drawings. However, the present invention can be implemented in other embodiments.
[0046]
For example, in the embodiment, the case where the present invention is applied to the method of manufacturing the wiring board 10 has been described. However, the present invention can be applied to various kinds of substrates that form a film on the resin substrate 12. For example, the present invention can be similarly applied to a case where an optical waveguide resin is filled in the groove 24 to manufacture an optical waveguide substrate.
[0047]
Further, in the embodiment, the sealing material 80 is provided in contact with the outer peripheral edge of the molding die 52 or the like. However, the outflow of the resin is appropriately controlled without hindering the approach of the molding dies 54 during the pressure molding. As long as it is possible, it may be arranged at a position separated from the molding die 52, and conversely, it may be arranged on the outer peripheral edge of the molding inner surface 54 in contact with the prepreg 48 or at an appropriate distance. .
[0048]
In addition, the sealing material 80 is disposed at a portion of the entire circumference of the molding die 52 except for the four corners. However, the sealing material 80 may be provided on the entire outer peripheral edge as long as it does not hinder resin outflow during pressure molding. Instead of the four corners, a resin outlet may be provided at an intermediate portion of each side or the like.
[0049]
Further, in the embodiment, the thickness dimension of the spacer 82 is set to about 1.1 to 1.8 (mm). Is appropriately determined according to the substrate thickness and the like. Further, in the embodiment, since the spacer 82 is arranged on the outer peripheral side of the molding die 54, the thickness thereof is set to a value obtained by adding the thickness of the pair of molding dies 52 to the substrate thickness. It is also possible to dispose the spacer 82 on the inner surface 54 of the molding die. In this case, the thickness of the spacer is determined to be, for example, a value obtained by subtracting the height of the projection 60 of the molding die 52 from the thickness of the substrate.
[0050]
In the embodiment, the conductor wiring 20 is buried in the groove 24 formed on the surface of the resin substrate 12. The present invention is similarly applied. In such a case, a molding die having a flat pressing surface (that is, a molding surface) may be used instead of the molding die 52.
[0051]
Further, in the embodiment, the present invention is applied to the method for manufacturing the double-sided wiring board 10 in which the wirings 20 are provided on both surfaces of the resin substrate 12. The present invention can be applied to a method of manufacturing a multilayer wiring board manufactured by laminating a large number of boards, and the like. In the case where the wiring 20 is provided only on one side, for example, it is sufficient that the groove 24 is provided on only one side of the resin substrate 12. Therefore, the molding die 52 also protrudes only on one molding surface 54 corresponding to the one side. What is necessary is just to provide the part 60.
[0052]
In the embodiment, the forming die 52 is formed of a SUS thin plate having a thickness of about 0.4 (mm). However, a forming die having a large thickness such as that used in normal press forming is used. However, as long as heat resistance and pressure resistance are sufficiently provided, a molding die made of another material may be used. Since the height of the sealing material 80 and the spacer 82 is determined in accordance with the thickness of the forming die and the thickness of the substrate to be obtained as described above, the height of the forming die is large. , These height dimensions are set accordingly.
[0053]
Further, in the embodiment, the heating and pressure molding was performed by the vacuum hot press. However, inconveniences such as bubbles being mixed in the substrate after the pressure molding are unlikely to occur, or the mixing of bubbles and the like is a problem. If not, it is not always necessary to heat and pressurize under vacuum.
[0054]
In the embodiment, the case where the present invention is applied to the method of manufacturing the wiring board 10 using the resin substrate 12 having the glass woven fabric 42 as a skeleton has been described. It may be made of a material, and may be a non-woven fabric instead of a woven fabric. The present invention is preferably applied to a resin substrate 12 having no skeleton such as the glass woven cloth 42 when a resin having low fluidity is used.
[0055]
In addition, as the resin constituting the resin substrate 12, other than the epoxy resin shown in the embodiment, any other resin such as a thermosetting resin or a thermoplastic resin may be used as appropriate according to the use of the substrate.
[0056]
Further, in the embodiment, the surface of the wiring 20 is located on the same plane as the surface of the resin substrate 12, but may be slightly concave or convex depending on the use of the wiring substrate 10.
[0057]
Further, in the embodiment, a relatively thick resin substrate 12 is manufactured by laminating a plurality of prepregs 48, but the number of laminations is determined according to the application. May be formed by heating and pressing alone.
[0058]
Further, in the embodiment, the case where a large number of resin substrates 12 are molded simultaneously by multi-stage stacking has been described, but the present invention can be applied to a case where only one resin substrate 12 is molded sequentially.
[0059]
In the embodiment, the sealing material 80 is made of a rubber material such as silicone rubber. However, the sealing material 80 is appropriately compressed elastically and hardly deteriorates at the heating temperature during molding. If so, various ones are suitably used.
[0060]
Although not specifically exemplified, the present invention can be implemented with various modifications without departing from the spirit of the invention.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an example of a wiring board manufactured by applying the method for manufacturing a conductor-embedded wiring board of the present invention.
FIG. 2 is a diagram illustrating a main part of a cross-sectional structure of the wiring board of FIG. 1;
FIG. 3 is a process diagram for describing a main part of a manufacturing process of the wiring board of FIG. 1;
4 (a) to 4 (e) are cross-sectional views for explaining an implementation state at a main part stage in FIG. 3;
FIG. 5 is a plan view schematically showing an implementation state of a pressure heating step of FIG. 3;
FIG. 6 is a cross-sectional view for explaining an example of an arrangement state of a molding die and a substrate material in the heating and pressing step of FIG.
[Explanation of symbols]
10: Wiring substrate (embedded film substrate)
12: Resin substrate
20: Wiring (film)
24: groove (recess)
42: Glass woven cloth
48: Prepreg (resin substrate material)
52: Mold
54: Inside

Claims (5)

A method of manufacturing a resin substrate having a predetermined thickness,
A step of arranging a resin substrate material in a semi-cured state composed of one or a plurality of sheets superimposed on each other between molding surfaces of a pair of molds,
A first spacer arranging step of arranging a first spacer at a predetermined position on an outer peripheral side of the resin substrate material, for limiting a minimum value of a mutual interval between the molding surfaces to the predetermined thickness dimension;
A second spacer is provided at a predetermined position on the inner peripheral side of the first spacer in the periphery of the resin substrate material, the second spacer being elastically compressed during the process of bringing the molding surfaces closer to the minimum value. Spacer placement step,
Heating and pressurizing the resin substrate material to the predetermined thickness by applying pressure while heating between the pair of molds under vacuum, and a heating and pressurizing step of curing the resin substrate material. Method. A method for manufacturing a film-coated substrate having a predetermined thickness dimension in which a film having a predetermined function is provided in a predetermined planar shape on one surface,
A step of arranging a semi-cured resin substrate material composed of one or a plurality of mutually laminated molding surfaces between the molding surfaces of a pair of molding dies having the predetermined planar shape convex portion on one molding surface; ,
A first spacer arranging step of arranging a first spacer at a predetermined position on an outer peripheral side of the resin substrate material, for limiting a minimum value of a mutual interval between the molding surfaces to the predetermined thickness dimension;
A second spacer is provided at a predetermined position on the inner peripheral side of the first spacer in the periphery of the resin substrate material, the second spacer being elastically compressed during the process of bringing the molding surfaces closer to the minimum value. Spacer placement step,
The resin substrate material is molded to the predetermined thickness by being heated and pressurized between the pair of molds under vacuum, and is cured while the predetermined surface is pressed on the one molding surface. A heating and pressurizing step of obtaining a resin substrate by forming a groove having a planar shape of
Forming a film by embedding a constituent material of the film in the groove of the resin substrate to form the film. Forming a through hole in a predetermined position of the resin substrate in the thickness direction,
The film forming step is a wiring forming step of forming a conductor conductor having a predetermined planar shape by applying a conductor paste in the groove and simultaneously forming a through conductor by applying the conductor paste in the through hole. 3. A method for manufacturing a substrate with a film according to claim 2. 2. The heating and pressurizing step, wherein a plurality of laminates of the pair of molds, the resin substrate material, the first spacer, and the second spacer are stacked and heated and pressurized while heating. 3. The method for manufacturing a resin substrate or the method for manufacturing a substrate with a film according to claim 2. 3. The method according to claim 1, wherein the step of arranging the second spacer includes arranging the second spacer in a portion of the periphery of the resin substrate material other than a predetermined range of a corner thereof. A method for manufacturing a substrate with a film.

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