JP5175694B2 - Multilayer board manufacturing method and multilayer printed wiring board manufacturing method - Google Patents

Description

  The present invention relates to a method for producing a multilayer board and a method for producing a multilayer printed wiring board.

  Conventionally, a multilayer board for manufacturing a multilayer printed wiring board is obtained by superposing a plurality of inner layer materials on which a circuit is formed through a prepreg and heating a metal foil such as a copper foil on the outermost layer. Manufactured by pressing and molding.

  When a plurality of inner layer materials are laminated and molded in this way, each inner layer material needs to be laminated and integrated in a state where the circuits are aligned. In recent years when high accuracy is required for the production of multilayer printed wiring boards, it is necessary to suppress the positional deviation between the inner layer materials to, for example, 100 μm or less.

Therefore, in the prior art, prior to molding the multilayer board, in advance, a plurality of inner layer materials are aligned with each other through a prepreg to form a laminated body, and in a plurality of locations near the peripheral edge of the inner layer material in the laminated body, By heating and pressurizing the surface of the part for a certain time, the resin of the B stage of the prepreg is partially melted and cured at the part. A plurality of inner layer materials in a laminate are welded and fixed with the melted and cured prepreg resin, and a multilayer board is molded using the welded and fixed laminate (see Patent Document 1).
JP 2001-121565 A

  However, in this conventional fixing method by welding, wrinkles or welding members are formed on the outer layer metal foil surface of the multilayer plate due to the prepreg resin rising in the welding part or excessive resin flow occurring during welding. There was a problem that defects such as dents occurred.

  The present invention has been made in view of the circumstances as described above, and can suppress defects in the outer layer metal foil surface due to the rise of the resin in the welded portion and the resin flow at the time of welding. It is an object of the present invention to provide a method for manufacturing a multilayer board and a method for manufacturing a multilayer printed wiring board that can suppress misalignment therebetween.

  The present invention is characterized by the following in order to solve the above problems.

1st: The process of providing a through-hole in each of 2 sheets of inner-layer materials in which the circuit was formed, and the process of stacking two sheets of the inner-layer material with the positions of the respective through-holes sandwiched between the prepregs. And pressurizing and pressing the periphery of the through hole of the inner layer material in the laminate so as to be 1.0 to 1.5 times the thickness of the periphery of the through hole of the laminate after the multilayer board is molded. Heating the through-hole portion in the state to melt the resin of the prepreg, filling and welding the prepreg resin to the through-hole of the inner layer material, thereby fixing the two inner layer materials and the prepreg to each other; The manufacturing method of the multilayer board characterized by including.
Second: a step of providing a through hole in each of the two inner layer materials on which the circuit is formed, and a step of stacking the two inner layer materials with the positions of the respective through holes being overlapped with a prepreg sandwiched therebetween And the inner layer material by melting the resin of the prepreg by heating the portion of the through hole while pressing and pressing the periphery of the through hole spaced 1 to 30 mm from the through hole of the inner layer material in the laminate A method of manufacturing a multilayer board, comprising: filling a through-hole with a resin of a prepreg and welding, thereby fixing the two inner layer materials and the prepreg together.
Third: Pressurize and press around the through hole of the inner layer material in the laminate so as to be 1.0 to 1.5 times the thickness of the periphery of the through hole of the laminate after the multilayer board is molded. The method for producing the second multilayer board, wherein the portion of the through hole is heated in a heated state.

Fourth : The method for producing a multilayer board according to any one of the first to third aspects, wherein the through hole portion of the inner layer material in the laminate is heated at 250 to 350 ° C. for 10 to 90 seconds.

Fifth : The method for producing a multilayer board according to any one of the first to fourth aspects, wherein the through hole portion of the inner layer material in the laminate is heated by a metal bar member, laser irradiation, or ultrasonic waves.

6: A method for producing a multilayer printed wiring board, wherein a multilayer printed wiring board is obtained using at least one multilayer board produced by any one of the first to fifth methods.

According to the first to third inventions described above, the through-holes are provided in each of the two inner-layer materials on which the circuit is formed, and the through-hole portion in the laminate of the two inner-layer materials and the prepreg is heated to The resin is melted and welded. Therefore, since the resin of the prepreg enters and is welded into the through hole of the inner layer material, the occurrence of unevenness due to the rise of the resin in the welded portion and the resin flow at the time of welding is suppressed. Therefore, it is possible to suppress defects such as wrinkles on the outer layer metal foil surface of the multilayer plate and dents on the welding member. Furthermore, by filling the through-holes of the inner layer material with the resin of the prepreg, the welding strength is improved, and the positional deviation between the inner layer materials due to molding can be suppressed.
In particular, according to the first and third aspects of the present invention, the portion of the through hole is pressed in a state where the periphery of the through hole of the inner layer material in the laminate is pressed and pressed so as to have a thickness within the specific range. Since it is heated, the melted resin of the prepreg is appropriately filled in the through-holes of the inner layer material, so that the welding strength is particularly improved, and the positional deviation between the inner layer materials due to molding can be further suppressed, and the outer layer metal foil Defects such as surface wrinkles can be further suppressed.
According to the second aspect of the invention, the portion of the through hole is heated in a state where the periphery of the through hole spaced from the through hole of the inner layer material in the laminate is pressed and pressed. Therefore, the molten resin of the prepreg is appropriately filled in the through-holes of the inner layer material, so that the welding strength is particularly improved, and the positional deviation between the inner layer materials due to molding can be further suppressed, and the outer layer metal foil surface Defects such as wrinkles can be further suppressed.

According to the fourth aspect of the present invention, by heating the through-hole portion of the inner layer material in the laminate at a temperature and time within the specific range, the resin of the prepreg is melted without causing carbonization of the resin. The through-holes in the inner layer material are appropriately filled with the prepreg resin. Therefore, in addition to the effects of the first invention, the welding strength is particularly improved, and the positional deviation between the inner layer materials due to molding can be further suppressed.

According to the fifth aspect of the invention, by heating the through-hole portion of the inner layer material in the laminated body with the metal rod member, laser irradiation, or ultrasonic wave, the resin of the prepreg is partially melted to penetrate the inner layer material. The holes are appropriately filled with the resin of the prepreg. Therefore, in addition to the effects of the first and second inventions, the welding strength is particularly improved, and the positional deviation between the inner layer materials due to molding can be further suppressed.

According to the sixth invention, a multilayer printed wiring board is obtained by using at least one multilayer board manufactured by any one of the first to fifth methods. It can be obtained with good yield.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 and 2 are cross-sectional views for explaining an embodiment of a method for producing a multilayer board according to the present invention in the order of steps, and FIG. 3 is a diagram showing a laminate in which two inner layer materials are overlapped with a prepreg sandwiched by a holding jig. FIG. 4 is a top view of the pressed state of FIG. 1B, and FIG. 4 is an enlarged view of a portion where the periphery of the through hole of the inner layer material of FIG.

  In the manufacturing method of the multilayer board in the present embodiment, as the first step, as shown in FIG. 1A, the welded portion with the prepreg 20 in each of the two inner layer materials 10a and 10b on which the circuit 11 is formed. A through hole 12 is provided.

  As the inner layer materials 10a and 10b, for example, one in which a circuit is formed on one side or both sides of a resin laminate by etching a metal foil or the like can be used.

  The through hole 12 can be provided, for example, by punching using a mold, drilling, or the like. In this embodiment, as shown in FIG. 3, the through-holes 12 are provided at the positions of the four corners of the inner layer materials 10a and 10b. The through holes 12 need to be provided at a plurality of locations of the inner layer materials 10a and 10b in order to appropriately fix the two inner layer materials 10a and 10b. The number and position of the through holes 12 are between the inner layer materials 10a and 10b by molding. It can be set appropriately in consideration of obtaining the welding strength necessary for suppressing the displacement of the position. The through holes 12 are preferably provided at positions near the peripheral edge portions of the inner layer materials 10a and 10b, that is, at corners and sides.

From the point that the area of the cross-section of the through-hole 12 suppresses the defect of the outer layer metal foil surface due to the rise of the resin in the welded portion and the resin flow at the time of welding, and the positional deviation between the inner layer materials due to molding is also suppressed. Preferably, it is 7-100 mm < ² > per location.

  The cross-sectional shape of the through hole 12 is not particularly limited, and may be, for example, a polygon such as a circle or a rectangle. Moreover, as shown in FIG. 5, it can also be set as the through-hole 12 as an aggregate | assembly of a some hole. Further, a metal foil such as a copper foil for forming the circuit 11 of the inner layer materials 10 a and 10 b may be located at the through hole 12.

  As the next step, as shown in FIG. 1B, the two inner layer materials 10a and 10b are overlapped with the positions of the respective through holes 12 and the prepreg 20 sandwiched therebetween. The laminate 30 is made of the prepreg 20.

  As the prepreg 20, a base material such as a glass cloth impregnated with a thermosetting resin such as an epoxy resin and dried, and the thermosetting resin semi-cured on a B stage can be used. The prepreg 20 may be a stack of a plurality of prepregs.

  Then, as shown in FIGS. 1B, 3, and 4, the periphery of the through hole 12 of the inner layer material 10 a, 10 b in the laminated body 30 is pressed and pressed with a pressing jig 50.

  As the pressing jig 50, a ring plate-shaped member having a hole in the center can be used, and a material made of a rigid material such as a stainless steel plate can be used. The opening shape of the holding jig 50 may be a circular shape as shown in FIG. 6 in addition to the rectangular shape as shown in FIG.

  The holding jigs 50 are respectively arranged around the through hole 12 of the inner layer material 10 a and around the through hole 12 of the inner layer material 10 b on the opposite side. Press and hold.

At this time, as shown in FIG. 1 (b), the periphery of the through holes 12 of the inner layer materials 10a and 10b in the laminated body 30 is passed through the through holes of the laminated body 30 after the multilayer board 42 shown in FIG. 2 (b) is molded. It is preferable to press and hold so that the thickness t ₁ is 1.0 to 1.5 times the thickness t ₂ around 12. If the thickness t ₁ is too smaller than the thickness t _2, misalignment between the inner layer materials due to molding may occur, or defects such as wrinkles on the outer layer metal foil surface may occur. If the thickness t ₁ is too larger than the thickness t ₂ , fixing by welding may not be possible.

  Further, as shown in FIG. 4, the penetration in the next step is performed while pressing and pressing the periphery of the through-hole 12 at a distance d of 1 to 30 mm from the through-hole 12 of the inner layer material 10 a, 10 b in the laminate 30. It is preferable to heat the portion of the hole 12. If the distance d is too narrow, defects such as wrinkles on the outer metal foil surface may occur, or the resin 21 of the prepreg 20 may adhere to the holding jig 50 during welding, making it impossible to manufacture the multilayer plate 42. . If the distance d is too wide, misalignment between the inner layer materials due to molding may occur, or defects such as wrinkles on the outer layer metal foil surface may occur.

  As a next step, in a state where the periphery of the through hole 12 is pressed and pressed by the holding jig 50, as shown in FIG. The resin 21 of the prepreg 20 is melted and cured by heating. As a result, the resin 21 of the prepreg 20 is filled and welded in the through holes 12 of the inner layer materials 10a and 10b, whereby the two inner layer materials 10a and 10b and the prepreg 20 are fixed to each other.

  At this time, it is preferable to heat the portions of the through holes 12 of the inner layer materials 10a and 10b in the laminate 30 at 250 to 350 ° C. for 10 to 90 seconds. If the heating temperature is too low or the heating time is too short, the resin 21 of the prepreg 20 may not be sufficiently melted and cannot be fixed by welding. If the heating temperature is too high or the heating time is too long, the resin 21 of the prepreg 20 may be carbonized and the multilayer plate 42 may not be manufactured.

  The portions of the through holes 12 of the inner layer materials 10a and 10b in the laminated body 30 are preferably heated by a metal bar member, laser irradiation, or ultrasonic waves. By heating with these, the resin 21 of the prepreg 20 is partially melted, and the resin 21 of the prepreg 20 is appropriately filled in the through-holes 12 of the inner layer materials 10a and 10b. The positional deviation between the inner layer materials 10a and 10b can be further suppressed.

  After fixing the two inner layer materials 10a and 10b and the prepreg 20 through the above steps, as shown in FIG. 2 (a), the outer layer prepreg 40 and the outer layer metal such as copper foil are formed on both sides of the laminate 30. The multilayer board 42 is manufactured as shown in FIG. 2B by stacking and arranging the foils 41 and molding them. The molding can be performed, for example, by heating and pressing in accordance with conditions generally applied in the production of multilayer boards.

  A printed wiring board can be manufactured by forming a circuit on the outer layer metal foil 41 of the multilayer board 42 by etching or the like. Alternatively, the outer layer metal foil 41 of the multilayer board 42 can be formed by etching or the like, and this can be used as a new inner layer material to produce a printed wiring board according to the procedure described above.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples at all.
<Example 1>
A multilayer board with the following specifications was manufactured. A through-hole is provided in each welded portion of two inner layer materials formed on a copper foil of double-sided copper-clad laminate (R1766, manufactured by Panasonic Electric Works Co., Ltd., resin thickness 0.1 mm, copper foil thickness 35 μm / 35 μm) It was. That is, φ5 through-holes were drilled at a total of six locations, including the four corners of each of the two inner layer materials and the central portion of the two opposing sides.

  The two inner layer materials were stacked with the positions of the respective through holes being aligned, and three stacked prepregs (R1661GG, manufactured by Panasonic Electric Works Co., Ltd., thickness 0.2 mm) were sandwiched to obtain a laminate.

  A pressing jig in which a central portion of a stainless steel plate having a thickness of 5 mm is formed in a circular shape is arranged around the through-holes of the two inner layer materials in the laminated body, and pressed by pressing from above and below, and in this state, heated φ4 The metal rod member of .5 was pressed against the through-hole portion to heat the through-hole portion.

  Thereby, the resin of the prepreg in the through hole portion of the inner layer material in the laminated body is melted, and the through hole of the inner layer material is filled and welded, thereby fixing the two inner layer materials and the prepreg to each other. .

  Next, the multilayer board was shape | molded using the laminated body after welding. An outer layer prepreg (R1661GD, manufactured by Panasonic Electric Works Co., Ltd., thickness 0.06 mm) and an outer layer copper foil having a thickness of 12 μm were superimposed on both sides of the laminate, and laminate molding was performed. The temperature was increased from normal temperature to 160 ° C. at 2.0 ° C./min from the start of pressing, and held for 50 minutes. The pressure was maintained at 1.0 MPa for 10 minutes, then increased from 1.0 MPa to 2.9 MPa in 10 minutes, and then maintained at 2.9 MPa until the end of pressing. Further, the vacuum was maintained at 13.3 kPa or less for 70 minutes from the start of pressing.

  Thus, a 510 × 510 mm multilayer board (manufactured sheets: 10 sheets / stage × 2) was obtained.

  About the obtained multilayer board, the number of wrinkles generated in the outer layer copper foil and the positional deviation between the inner layer materials were evaluated. The presence or absence of wrinkles was confirmed visually. Regarding the positional deviation between the inner layer materials, it was determined that 100 μm or less was acceptable and that more than 100 μm was unacceptable.

Table 1 shows the evaluation results of the circle diameter of the holding jig, the heating time and heating temperature at the time of welding, the thickness of the periphery of the through-hole at the time of pressurizing the laminate, and the number of wrinkles generated and the positional deviation between the inner layer materials. .
<Examples 2-8, Reference Examples 1-8>
The diameter of the pressing jig, the heating time and heating temperature during welding, and the thickness of the periphery of the through hole when the laminate is pressed are changed as shown in Table 1, and the other layers are laminated in the same manner as in Example 1. Attempts were made to weld plates and produce multilayer boards. Tables 1 and 2 show the evaluation results of the number of wrinkles generated and the positional deviation between the inner layer materials for the possibility of manufacturing the multilayer plate and those for which the multilayer plate could be manufactured.
<Comparative Example 1>
In Example 1, the inner layer material having no through-holes was used to press a heated φ6 metal rod member into a total of six locations in the same positions as the through-hole locations in Example 1, and a heating temperature of 300 A laminate composed of two inner layer materials and a prepreg was welded and fixed under the conditions of ° C., pressure 0.5 MPa, and time 20 seconds.

  Using this laminate, a multilayer board was molded in the same manner as in Example 1. About the obtained multilayer board, the generation | occurrence | production number of a wrinkle and the position shift between inner layer materials were evaluated. The results are shown in Table 2.

  In Examples 1 to 8, Reference Examples 1 to 8, and Comparative Example 1, the thickness around the through hole after molding was set to 1.035 mm.

  From Table 1, the part of the said through-hole is heated in the state which pressurized and pressed the circumference | surroundings of the through-hole which left | separated 1-30 mm from the through-hole of the inner-layer material in a laminated body, and the through-hole of the inner-layer material in a laminated body Is heated at 250 to 350 ° C. for 10 to 90 seconds, and the periphery of the through hole of the inner layer material in the laminate is 1.0 to 1. In Examples 1 to 8 where the portion of the through hole was heated while being pressed and pressed so as to be 5 times thicker, no wrinkles were generated in the outer layer copper foil, and no displacement between the inner layer materials was generated. It was.

  On the other hand, from Table 2, in Comparative Example 1, wrinkles occurred in the outer layer copper foil in many multilayer plate samples.

  Further, in Reference Example 1 in which a portion of the through hole is heated in a state where the periphery of the through hole at a distance of less than 1 mm from the through hole of the inner layer material in the laminated body is pressed and pressed, the resin adheres to the holding jig. The subsequent process could not be performed, and wrinkles of the outer layer copper foil were also observed.

  In Reference Example 2 in which the portion of the through-hole was heated in a state where the periphery of the through-hole having a space exceeding 30 mm from the through-hole of the inner layer material in the laminate was pressed and pressed, wrinkles occurred in the outer layer copper foil, Misalignment between the inner layer materials also occurred.

  In Reference Example 3 in which the through hole portion of the inner layer material in the laminate was heated for less than 10 seconds, the laminate could not be welded and fixed.

  In Reference Example 4 in which the through-hole portion of the inner layer material in the laminate was heated for more than 90 seconds, the prepreg resin was carbonized and a multilayer board could not be produced.

  In Reference Example 5 in which the portion of the through hole of the inner layer material in the laminate was heated at less than 250 ° C., the laminate could not be welded and fixed.

  In Reference Example 6 in which the portion of the through hole of the inner layer material in the laminate was heated at a temperature exceeding 350 ° C., the resin of the prepreg was carbonized and a multilayer board could not be produced.

  The through hole in a state where the periphery of the through hole of the inner layer material in the laminated body is pressed and pressed so as to have a thickness of less than 1.0 times the thickness of the laminated body around the laminated body after the multilayer board is molded. In Reference Example 7 in which this portion was heated, wrinkles were generated in the outer layer copper foil, and misalignment between the inner layer materials also occurred.

  In the state where the periphery of the through hole of the inner layer material in the laminate is pressed and pressed so as to have a thickness exceeding 1.5 times the thickness of the periphery of the through hole of the laminate after the multilayer board is molded, In Reference Example 8 where the portion was heated, only the surface of the prepreg was melted, and the laminate could not be welded and fixed.

(A), (b), (c) is sectional drawing explaining embodiment of the manufacturing method of the multilayer board of this invention to process order. (A), (b) is sectional drawing explaining embodiment of the manufacturing method of the multilayer board of this invention to process order. It is a top view of the state of FIG.1 (b) which pressed the laminated body which laminated | stacked the inner layer material of 2 sheets on both sides of the prepreg with the pressing jig. FIG. 4 is an enlarged view of a portion where the periphery of the through hole of the inner layer material of FIG. 3 is pressed by a pressing jig. It is the figure which showed the modification of the through-hole provided in an inner layer material. It is the figure which showed the modification of the opening shape of a pressing jig.

Explanation of symbols

10a Inner layer material 10b Inner layer material 11 Circuit 12 Through hole 20 Prepreg 21 Resin 30 Laminate body 42 Multilayer plate t ₁ Thickness around the through hole t ₂ Thickness around the through hole d Interval

Claims (6)

A step of providing a through hole in each of the two inner layer materials on which the circuit is formed, a step of stacking the two inner layer materials with the positions of the respective through holes being sandwiched between the prepregs, and a laminate In a state where the periphery of the through hole of the inner layer material in the body is pressed and pressed so as to be 1.0 to 1.5 times the thickness of the periphery of the through hole of the laminated body after the multilayer board is molded. Filling the prepreg resin into the through-holes of the inner layer material and welding them by heating the through-hole portion to melt the prepreg resin, thereby fixing the two inner-layer materials and the prepreg together. A method for producing a multilayer board characterized by the above. A step of providing a through hole in each of the two inner layer materials on which the circuit is formed, a step of stacking the two inner layer materials with the positions of the respective through holes being sandwiched between the prepregs, and a laminate The through-hole of the inner layer material is melted by heating the portion of the through-hole in a state where the periphery of the through-hole spaced 1 to 30 mm away from the through-hole of the inner layer material in the body is pressed and pressed. A method of manufacturing a multilayer board comprising the steps of: filling and welding a prepreg resin to fix the two inner layer materials and the prepreg together. In a state where the periphery of the through hole of the inner layer material in the laminated body is pressed and pressed so as to be 1.0 to 1.5 times the thickness of the peripheral hole of the laminated body after the multilayer plate is molded. The method for producing a multilayer board according to claim 2, wherein a portion of the through hole is heated. The method for producing a multilayer board according to any one of claims 1 to 3, wherein the through-hole portion of the inner layer material in the laminate is heated at 250 to 350 ° C for 10 to 90 seconds. The method for producing a multilayer board according to any one of claims 1 to 4, wherein a through hole portion of the inner layer material in the laminate is heated by a metal bar member, laser irradiation, or ultrasonic waves. A method for producing a multilayer printed wiring board, wherein a multilayer printed wiring board is obtained using at least one multilayer board produced by the method according to any one of claims 1 to 5 .

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