JPH05110255A - Manufacture of curved-surface multilayer wiring board - Google Patents

Abstract

(57) [Abstract] [Purpose] A curved multilayer wiring board with high positional accuracy of lands and patterns on each curved surface of all layers, and with not only one-direction bending but also a partial sphere, a paraboloid of revolution, etc. To get [Structure] In a base forming step 7a, a curved surface laminated substrate to be a base is manufactured by a heat press 6, and then an inner layer pattern is formed on the curved surface by laser exposure (5-axis NC) 9 to heat a single-sided copper clad laminated plate 13. A stacking process 14 in which the process of stacking with the press 6 is repeated at least once.
The curved surface is multilayered by a, and then each layer connecting step 18 for forming a through hole is performed, and subsequently, an outer layer pattern is formed by laser exposure (5-axis NC) 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a curved multilayer wiring board used for a conformal array antenna and mobile communication.

[0002]

2. Description of the Related Art FIG. 13 is a diagram showing a conventional process for manufacturing a curved multilayer wiring board, FIG. 14 is a sectional side view showing curved surface laminating by heat pressing, and FIG. 15 is a sectional side view showing outer layer pattern formation. In the figure, 1 is a copper clad laminate for inner layer,
Reference numeral 2 is a reference hole machining step, 3 is a copper clad laminate for outer layer, 4 is a prepreg, 18 is each layer connecting step, 19 is an outer layer pattern forming step performed after each layer connecting step 18, and 20e and 2e.
0f is the heat press 6 and the above-mentioned respective layer connecting step 18
Curved surface laminated substrate obtained by
And 23 are reference pins and reference pin receiving holes formed on the forming jig 21, respectively, 24 are heaters embedded in the forming jig 21, 25 is a release film, 26 is copper foil, 27
Is an inner layer pattern, 28 is a resist film formed on the curved surface laminated substrate 20f, 29 is a laser beam applied to the resist film 28, 30 is a resist pattern, 31 is a through hole for connecting the inner layer pattern 27 between layers, 32 is an outer layer pattern, 33d is the outer layer pattern forming step 19
The curved multilayer wiring board to be completed later, 45 is a laminating step, and 46 is a plane inner layer substrate obtained by performing inner layer pattern formation 44 and reference hole processing 2 on the inner layer copper clad laminate 1.

Next, a conventional method for manufacturing a curved multilayer wiring board will be described. The inner layer pattern 27 is formed in a planar state on the inner layer copper clad laminate 1 of thermosetting resin such as epoxy using a film or the like (step 44 in FIG. 13) to obtain a planar inner layer substrate 46. Next, a reference hole for positioning is made in the flat inner layer substrate 46, the copper clad laminate 3 for outer layer and the prepreg 4 (step 2 in FIG. 13), and the reference pin 22 together with the release film 25.
Lay-up 5 to the pair of molding jigs 21 of the upper die and the lower die with the reference pin receiving hole 23 as a reference, and use not only the heater of the press machine but also the heater 24 embedded in the molding jig 21 for heating. A curved surface laminated substrate 20e is obtained by pressing 6 to obtain a curved surface laminated substrate 20 (FIG. 13, step 45 and FIG. 14).

After the above laminating step 45, the hole wall is cleaned after the holes are drilled in the desired direction by the five-axis NC (steps 15 and 16 in FIG. 13), and then the inner layer pattern 27 is connected between layers. Through-hole plating 17 is applied to (Fig. 1
3 step 18).

Next, after each layer connecting step 18, a resist film 28 is formed on the copper foil 26 by electrodeposition resist, spraying or the like (step 8 in FIG. 13), and a laser beam 29 is irradiated using a 5-axis NC. A resist pattern 30 is formed by direct patterning on the curved surface (step 9 in FIG. 13 and FIG. 15A), and finally, development 10 and etching 11 are performed.
Then, the outer layer pattern 32 is formed by the resist stripping 12 and the curved multilayer wiring board 33d is completed (FIG. 13, step 1).
9, FIG. 14 (b) and FIG. 14 (c)).

[0006]

Since the conventional curved multilayer wiring board is manufactured by the above-described manufacturing method, the curved surface is not curved in only one direction, such as a cylindrical shape, but a partial sphere or the like. In the case of a curved surface with a narrowed surface, the position of the land and pattern of the inner layer of the curved multilayer wiring board cannot be accurately simulated on the flat inner layer substrate before the curved surface is formed, and the flat surface There is a problem that the land or pattern on the inner layer substrate is displaced from the theoretical position on the curved surface as a result of heat pressing.

The present invention has been made to solve the above problems, and realizes a curved multilayer wiring board having a diaphragm such as a partial sphere or a paraboloid of revolution, and improves reliability and accuracy. Has a purpose. Further, it is also an object to stack and form all layers one by one with a single molding jig regardless of the number of layers of a molding jig used for a curved surface lamination molding press.
It also aims to realize a curved multilayer wiring board having not only through-holes but also blind via holes and inner via holes. Furthermore, it is also intended to realize a curved multilayer wiring board without springback due to residual stress.

[0008]

According to a method of manufacturing a curved multilayer wiring board according to the present invention, a double-sided copper-clad laminated board, or a prepreg and two single-sided copper-clad laminated boards, an upper mold, a lower mold, and a pair of molding cures. After laying up on a tool, heat-pressed to produce a curved laminated substrate, and then forming a resist film, laser exposure is performed to form an inner layer pattern, and then a single-sided copper-clad laminated plate is formed on the upper and lower molds through a prepreg. The process of laying up on a tool and stacking with a heat press is repeated at least once, and after forming a through hole, a resist film is formed and an outer layer pattern is formed by laser exposure.

Also, in the step of laying up the pair of molding jigs for the upper mold lower die and heat-pressing, a molding jig for an autoclave is used in place of the pair of molding jigs for the upper mold lower die, and a double-sided copper clad laminate is used for this. A plate or prepreg and a single-sided copper-clad laminate are laid up, further vacuum packed, and then vacuum pressed.

A double-sided copper-clad laminate, or a prepreg and two single-sided copper-clad laminates are laid up on a pair of molding jigs for the upper and lower dies or molding jigs for autoclave and pressed to form a curved surface laminate serving as a base. After the base molding process for manufacturing a substrate, a blind via hole forming process for performing hole processing, hole wall cleaning treatment and through hole plating is performed, and then the next process, a stacking process, is performed.

Further, a step of forming via holes such as blind via holes and inner via holes by laser processing or drilling is added to the stacking step after the base forming step.

Further, instead of the double-sided copper-clad laminate or the single-sided copper-clad laminate, copper foil is simply used and laid up on a molding jig together with the prepreg and pressed.

[0013]

According to the method of manufacturing a curved multilayer wiring board of the present invention, a curved laminated board to be a base is manufactured by heat pressing in a base molding step, and then a curved pattern is formed by laser exposure to form a single-sided copper clad laminated board. Since the multilayering is performed by repeating the process of stacking by pressing at least once, it is necessary to accurately form the land and pattern of the inner layer of the curved multilayer wiring board at the theoretical position on the curved surface regardless of the drawing of the curved surface. As a result, it is possible to manufacture a highly reliable curved multilayer wiring board having no land breakage in the inner layer with respect to the through hole and no break in the inner layer pattern.

Further, in the curved surface layer forming in the base forming step or the stacking step, the number of layers of the curved multilayer wiring board is increased by laying up the substrate material on the forming jig for the autoclave, vacuum packing and vacuum pressing. Even if only one molding jig is used for curved surface lamination molding, it is possible to reduce the manufacturing cost of the curved multilayer wiring board and the design jig manufacturing time significantly.

Furthermore, after the base forming step, by performing hole processing, hole wall cleaning processing and through hole plating and then the stacking step, it is possible to form blind via holes on the curved multilayer wiring board. Become.

In the stacking step after the base molding step, a step of stacking the single-sided copper-clad laminate by pressing after forming a via hole by laser processing or drilling and performing curved surface patterning by laser exposure is performed at least once. By repeating the stacking process, blind via holes and inner via holes can be formed in any layer, improving the freedom of pattern design and improving the pattern density of curved multilayered wiring boards. Become.

Further, in the press of the base forming step and the stacking step, only the copper foil is simply used instead of the double-sided copper-clad laminate and the single-sided copper-clad laminate, and this and the prepreg are laid up on a forming jig and pressed. Thereby, the residual stress of the multilayered curved multilayer wiring board can be reduced, and a curved multilayer wiring board without springback or the like can be realized.

[0018]

EXAMPLES Example 1. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional side view showing a manufacturing process of a curved multilayer wiring board, FIG. 2 is a cross-sectional side view showing a stacking step of curved-surface lamination molding and inner layer pattern formation, and FIG. 3 is a cross-sectional side view showing outer layer pattern formation. Nos. 12, 15 to 33 are exactly the same as the conventional method for manufacturing a curved multilayer wiring board.

In the figure, reference numeral 7a denotes a copper clad laminate for inner layer 1, a copper clad laminate for outer layer 3 and a prepreg 4 which are subjected to reference hole machining 2 and then laid up on a pair of molding jigs 21 of an upper die and a lower die. The base molding step of heat pressing 6, 13 is a single-sided copper-clad laminate, 14a is an inner layer pattern 27 formed by laser exposure (5-axis NC) 9, and the prepreg 4 is sandwiched on the inner-layer pattern 27. Is a stacking process in which stacking is repeated.

Next, the manufacturing method of the embodiment will be described. A reference hole for positioning is formed in the copper clad laminate for inner layer 1, the copper clad laminate for outer layer 3 and the prepreg 4 made of a thermosetting resin such as epoxy (step 2 in FIG. 1), and the reference pin 22 together with the release film 25. Lay-up 5 to the pair of molding jigs 21 of the upper die and the lower die with the reference pin receiving hole 23 as a reference, and use not only the heater of the press machine but also the heater 24 embedded in the molding jig 21 for heating. Press 6 (step 7a in FIG. 1).

Next, a resist film 28 is formed on the copper foil 26 by electrodeposition resist, spraying or the like (step 8 in FIG. 1), and direct curved surface patterning is performed by irradiating the curved surface with a laser beam 29 using a 5-axis NC. By resist pattern 30
After forming (step 9 in FIG. 1), developing 10, etching 1
The inner layer pattern 27 is formed by 1 and the resist peeling 12 to obtain the curved surface laminated substrate 20a. After that, reference holes for positioning are formed in the single-sided copper-clad laminate 13 and the prepreg 4 (step 2 in FIG. 1), and these are provided on the curved laminate board 20a together with the release film 25, the reference pins 22 and the reference pin receiving holes. The curved-surface laminated substrate 20
get b. By forming the inner layer pattern 27 and stacking the single-sided copper-clad laminate 13 at least once, a stacking step 14a is repeated to form a curved surface multilayer.

Then, after the stacking step 14a, the hole wall is cleaned by punching holes in a desired direction by the 5-axis NC (steps 15 and 16 in FIG. 1), and then the inner layer pattern 27 is formed.
Through-hole plating 17 is performed to connect the layers to each other to obtain a curved surface laminated substrate 20c (step 18 in FIG. 1).

The above base forming step 7a and stacking step 1
After 4a and each layer connecting step 18, a resist film 28 is formed on the copper foil 26 by electrodeposition resist, spraying or the like (step 8 in FIG. 1), and a laser beam 29 is irradiated on the curved surface using the 5-axis NC. After forming the resist pattern 30 by direct curved surface patterning (step 9 in FIG. 1), development 10
The curved multilayer wiring board 33a is completed by forming the outer layer pattern 32 by etching 11 and resist stripping 12 (step 19 in FIG. 1).

Example 2. In the first embodiment, the curved surface layer forming in the base forming step 7a and the stacking step 14a is performed using the pair of upper and lower forming jigs 21. However, as shown in FIGS. Ingredient 3
5 and the curved surface lamination molding using the vacuum packing 36 (see FIG. 5).
The case of performing step 34) will be described.

In the base molding step 7b, the inner layer copper-clad laminate 1 and the outer layer copper-clad laminate 3 and the prepreg 4 are formed on the autoclave molding jig 35, and in the stacking step 14b, the autoclave molding jig 35 is curved. Laminated substrate 20
d and the single-sided copper clad laminate 13 and the prepreg 4 are laid up 5, packed with the vacuum packing 36, and then vacuum-pressed (step 34 in FIG. 5) to perform curved-surface laminate molding. There is an effect that the number of forming jigs to be used for is only one regardless of the number of layers, and the manufacturing cost of the curved multilayer wiring board can be considerably reduced.

Example 3. Next, as shown in FIG. 7, after finishing the base forming step 7, hole processing (step 15 in FIG. 7) is performed using the 5-axis NC, and then hole wall cleaning processing 16 is performed and then through-hole plating. The case of performing the blind via hole forming step 37 of 17 will be described.

After the base forming step 7 is completed, hole forming (5
Axis NC) 15, hole wall cleaning treatment 16 and through hole plating 17 blind via hole forming step 37
Since the stacking step 14, which is the next step, is performed after the above step, the curved multilayer wiring board 33b having the blind via hole 38 in addition to the through hole 31 can be manufactured as shown in FIG. There is an effect that you can.

Example 4. Next, FIG. 9, FIG. 10 and FIG.
As shown in FIG. 5, after the base molding step 7, a blind via hole 38 and an inner via hole 43 are formed if necessary, and an inner layer pattern 27 is formed by laser exposure (5-axis NC) 9. A case where the step of stacking the stretched laminated plates 13 with the press 40 is repeated at least once will be described.

In this case, the first embodiment and the second embodiment
In the stacking step 14 of the above, the copper foil 26 is formed on the curved laminated substrate 20 in the order of resist film formation 8, laser exposure (5-axis NC) 9, development 10, etching 11, and resist stripping 12 in this order. After removing and making a hole in the portion by laser processing (step 41 in FIG. 10), hole hole cleaning treatment 16
And a via hole forming step 39 for applying the via hole plating 42 is inserted before the resist film forming 8 for forming the inner layer pattern 27, and the via hole forming step 3
Since 9 is a manufacturing process that is performed as necessary, there is an effect that not only the through-holes 31 penetrating through but also the inner via holes 43 can be formed in addition to the blind via holes 38.

In the above-mentioned Examples 1, 2, 3 and 4, in the base molding step 7, the inner layer copper-clad laminate 1 and the outer layer copper-clad laminate 3 are prepreg 4 formed. The curved surface laminated substrate 20 obtained by pressing with sandwiching is sandwiched in the next step, but the same effect can be obtained by directly pressing the double-sided copper clad laminated plate to form the curved surface laminated plate 20.

In the fourth embodiment, in the via hole forming step 39, the copper foil 26 is removed by laser exposure (5-axis NC) 9 and a hole is formed in the portion by laser processing (step 41 in FIG. 10). However, the same effect can be obtained even if the hole wall cleaning treatment 16 and the via hole plating 42 are performed by drilling a hole without removing the copper foil 26.

Example 5. Next, as shown in FIG. 12, in the layup 5 of the base forming step 7 and the stacking step 14, the inner layer copper-clad laminate 1, the outer layer copper-clad laminate 3 and the single-sided copper-clad laminate 13 are stacked. The case of laying up 5 with only the copper foil 26 together with the prepreg 4 will be described.

In this case, the semi-cured prepreg 4 is the only insulator that is curvedly laminated and molded by the press 40.
The residual stress of the curved surface multilayer wiring board 33 after the curved surface lamination molding can be reduced, and the curved surface multilayer wiring board 33 without springback or the like can be realized.

It should be noted that although the substrate material of thermosetting resin is used in the above-mentioned first embodiment, the second embodiment, the third embodiment, the fourth embodiment and the fifth embodiment, the thermoplastic resin-based substrate material is used. Similar effects can be obtained by using a substrate material.

[0035]

The present invention has the above-described manufacturing process, and therefore has the following effects.

A curved surface pattern is formed by laser exposure on a curved surface laminated substrate of a base obtained by forming a curved surface of the copper clad laminated plate with a pair of upper mold lower molds or a curved laminated molding, and then a single-sided copper is formed on it. Curved multilayer wiring boards are manufactured by stacking the stretched laminated board further by a pair of upper and lower molds, then forming curved surface patterns, and then stacking further. Position accuracy can be obtained, and since curved patterning is performed by laser exposure on all layers, not only curved multilayer wiring boards bent in one direction such as cylindrical shape but also apertures such as partial spherical surfaces are included. There is an effect that a curved surface multilayer wiring board having an arbitrary curved surface shape can be obtained.

Further, as a molding jig for a press for stacking a curved surface laminated substrate as a base or a single-sided copper clad laminated plate on this, a molding jig for an autoclave is used instead of a pair of molding jigs for an upper die and a lower die. Using a curved surface laminated board or a single-sided copper clad laminated board or prepreg and packing for vacuum and then vacuum pressing, curved surface multilayering can be performed with only one type of molding jig regardless of the number of layers. The effect is obtained.

Further, since the curved laminated substrate obtained in the base forming step is subjected to through hole plating using the 5-axis NC and through hole plating is performed before the next stacking step, the curved multilayer board having blind via holes is formed. There is an effect that a wiring board can be obtained.

In addition, not only through-holes but also through-holes can be formed by adding a via-hole forming step of forming a via hole by performing laser processing or drilling as required in the stacking step which is the next step of the base forming step. It is possible to obtain a curved multilayer wiring board having blind via holes and inner via holes, and it is possible to improve the pattern density.

Further, the copper clad laminate used in the base forming step and the stacking step is made of only copper foil, and this and the prepreg are laid up on a forming jig and pressed to form a curved multilayer wiring board. Residual stress can be reduced,
There is an effect that it is possible to obtain a curved multilayer wiring board having a curved surface that conforms to the theoretical curved surface without springback or the like.

[Brief description of drawings]

FIG. 1 is a manufacturing process diagram of a curved multilayer wiring board showing Example 1 of the present invention.

FIG. 2 is a sectional side view of a stacking step showing curved surface layer forming and inner layer pattern formation in Example 1 of the present invention.

FIG. 3 is a sectional side view showing formation of an outer layer pattern according to the first embodiment of the present invention.

FIG. 4 is a perspective view of a curved multilayer wiring board obtained according to Example 1 of the present invention.

FIG. 5 is a manufacturing process diagram of a curved multilayer wiring board showing Embodiment 2 of the present invention.

FIG. 6 is a sectional side view showing a vacuum press after vacuum packing according to a second embodiment of the present invention.

FIG. 7 is a manufacturing process drawing of a curved multilayer wiring board showing Embodiment 3 of the present invention.

FIG. 8 is a cross-sectional view of a curved multilayer wiring board obtained according to Example 3 of the present invention.

FIG. 9 is a manufacturing process drawing of a curved multilayer wiring board showing Embodiment 4 of the present invention.

FIG. 10 is a manufacturing process diagram showing a via hole forming process in Embodiment 4 of the present invention.

FIG. 11 is a sectional view of a curved multilayer wiring board obtained according to Example 4 of the present invention.

FIG. 12 is a process drawing of curved surface lamination molding using a copper foil and a prepreg in Example 5 of the present invention.

FIG. 13 is a manufacturing process diagram showing a manufacturing process of a conventional curved multilayer wiring board.

FIG. 14 is a cross-sectional view showing curved surface layer forming in a conventional manufacturing process of a curved surface multilayer wiring board.

FIG. 15 is a cross-sectional side view showing formation of an outer layer pattern in a conventional process for manufacturing a curved multilayer wiring board.

[Explanation of symbols]

 1 Copper Clad Laminate for Inner Layer 2 Reference Hole Machining 3 Copper Clad Laminate for Outer Layer 4 Prepreg 5 Lay-up 6 Heat Press 7 Base Forming Process 8 Resist Film Formation 9 Laser Exposure (5-axis NC) 10 Development 11 Etching 12 Resist Stripping 13 Single-sided copper-clad laminate 14 Stacking process 15 Hole processing (5-axis NC) 16 Hole wall cleaning treatment 17 Through hole plating 18 Each layer connection process 19 Outer layer pattern forming process 20 Curved laminated substrate 21 Forming jig 22 Reference pin 23 Reference pin receiving hole 24 Heater 25 Release Film 26 Copper Foil 27 Inner Layer Pattern 28 Resist Film 29 Laser Light 30 Resist Pattern 31 Through Hole 32 Outer Layer Pattern 33 Curved Multilayer Wiring Board 34 Vacuum Packing and Vacuum Press 35 Autoclave Molding Tool 36 Vacuum Packing 37 Blind buy A hole forming process 38 Blind via hole 39 Via hole forming process 40 Press 41 Laser hole processing (5-axis NC) 42 Via hole plating 43 Inner via hole 44 Inner layer pattern formation 45 Laminating process 46 Planar inner layer substrate

Claims (6)

[Claims] 1. A base molding in which a double-sided copper-clad laminate having a reference hole processed or a prepreg and two single-sided copper-clad laminates are laid up on a pair of molding jigs for an upper die and a lower die to perform curved laminating molding by heat pressing. Step, after the above base molding step, a resist film is formed, and a curved surface board on which an inner layer pattern is formed by laser exposure and a single-sided copper clad laminate processed with reference holes are laid up on a pair of molding jigs of an upper die and a lower die via a prepreg. Then, a stacking step in which the step of performing curved surface lamination molding by heat pressing is repeated at least once, each layer connecting step of performing through hole hole processing and through hole plating on the curved surface laminated substrate obtained by the stacking step, and each layer connecting step are obtained. Of curved surface multilayer wiring board having outer layer pattern forming step of forming resist film on curved curved surface laminated substrate and performing laser exposure Law. 2. A double-sided copper-clad laminate having a reference hole formed therein or a prepreg and two single-sided copper-clad laminates are laid up on a molding jig for an autoclave, packed with vacuum packing, and then vacuum-pressed. Therefore, the base molding process for performing curved surface layered molding, the curved surface substrate on which the resist film is formed after the base molding step and the inner layer pattern is formed by laser exposure, and the single-sided copper clad laminated plate on which the reference hole is processed, through the prepreg. Stacking step in which the step of laying up on a pair of molding jigs of a mold and performing curved surface lamination molding by heat pressing is repeated at least once, and each layer connection for performing through-hole processing and through-hole plating on the curved surface laminated substrate obtained by the stacking step Step, and an outer layer for forming a resist film on the curved laminated substrate obtained by the above-mentioned each layer connecting step and performing laser exposure A method for manufacturing a curved multilayer wiring board having a pattern forming step. 3. The curved surface according to claim 1, further comprising a blind via hole forming step of performing through hole processing and through hole plating between the base forming step and the stacking step. Manufacturing method of multilayer wiring board. 4. A curved laminated board having an inner layer pattern formed by laser exposure after a stacking step, if necessary, a via hole forming step by laser processing or drilling, and a single-sided copper clad laminated board having a reference hole formed therein. The step of repeating the curved surface layer forming by pressing through a prepreg is repeated at least once.
Item 2. A method for manufacturing a curved multilayer wiring board according to item 2 or item 2. 5. A base forming step of laying up a copper foil having a reference hole and a prepreg on a forming jig and performing curved surface layer forming by pressing, a resist film is formed after the base forming step, and an inner layer pattern is formed by laser exposure. The step of laying up the curved board and the copper foil having the reference holes processed into a forming jig via a prepreg and performing the curved surface lamination molding by a press at least one or more times. A method for manufacturing a curved multilayer wiring board, comprising: each layer connecting step of performing through hole drilling and through hole plating; and an outer layer pattern forming step of forming a resist film on a curved layered substrate obtained by each of the above layer connecting steps and performing laser exposure. 6. A curved laminated substrate having an inner layer pattern formed by laser exposure and a copper foil having a reference hole processed through a prepreg through a stacking step, a via hole forming step by laser processing or drilling if necessary. 6. The method for manufacturing a curved multilayer wiring board according to claim 5, wherein the step of forming the curved surface laminate by pressing is repeated at least once.