JP4206545B2 - Manufacturing method of multilayer printed wiring board - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a multilayer printed wiring board widely used in electronic devices such as mobile communication devices and portable information terminals.
[0002]
[Prior art]
2. Description of the Related Art In recent years, as electronic devices have become lighter, thinner, multifunctional, and surface mounted electronic components mounted on a printed wiring board, a multilayer printed wiring board is also required to have a higher circuit configuration. Conventionally, multi-layer printed wiring boards have been made by the through-through hole method in which through holes are provided by NC control processing using a carbide drill and the hole wall surface is plated with copper. As the density circuit configuration is required, an inner via hole is provided so that an interlayer connection can be made only to an arbitrary layer that requires an interlayer connection, and the hole wall surface is plated with copper, or a conductive paste is applied to the inner via hole. Interlayer connection is achieved by the inner via hole method that fills up, thereby realizing high density circuit configuration.
[0003]
A method for manufacturing a four-layer printed wiring board using a conductive paste for conventional interlayer connection will be described below.
[0004]
FIG. 5A is a sectional view showing an inner layer substrate of a conventional multilayer printed wiring board, FIG. 5B is a sectional view showing a conventional four-layer multilayer printed wiring board, and FIG. It is a figure which shows the inner via hole for X-ray recognition.
[0005]
5 and 6, 60 is a prepreg, 60a and 60c are interlayer insulating adhesive sheets, 60b is an inner substrate, 61 and 68 are inner via holes filled with conductive paste, and 62 and 63 are alignment patterns for pattern formation. X-ray recognition inner via hole, 64 is copper foil, 65 and 70 are alignment holes, 66 is an inner layer conductor circuit, 67 is a positioning pattern, 69 is a positioning hole, 71 is an outer layer conductor circuit, and 52b to 52e are conductive Is an inner via hole for X-ray recognition filled with a conductive paste, and 52a is an alignment hole.
[0006]
The procedure of the manufacturing method of the multilayer printed wiring board using the conductive paste for the interlayer connection configured as described above will be described below.
[0007]
(1) First, an inner via hole 61 filled with a conductive paste and an X-ray are formed in a prepreg 60 having a predetermined size impregnated with a resin by drilling holes at a required position by a method such as carbide drilling or laser processing. Three adhesive sheets 60a for interlayer insulation in which the inner via holes 62, 63 for recognition (two layers, four layers) are formed are formed.
[0008]
(2) One of them is set with copper foil 64 on both sides of an interlayer insulating adhesive sheet 60a having an inner via hole 61 filled with a conductive paste as shown in FIG. Pressure and heating are applied to bond the copper foil and prepreg to form a double-sided copper-clad laminate.
[0009]
(3) The alignment hole 65 (FIG. 652a) is processed with an X-ray hole processing machine in a range wider than the formation region of the X-ray recognition inner via hole 62 (FIGS. 52B to 52E) of the double-sided copper-clad laminate.
[0010]
Thereafter, a photosensitive etching resist is formed on the double-sided copper-clad laminate, the exposure mask film is positioned with reference to the alignment hole 65, the etching resist is formed by exposure and development, cupric chloride, etc. Etching is performed using the above chemical solution to prepare one inner layer substrate 60b on which the inner layer conductor circuit 66 and the positioning pattern 67 are formed.
[0011]
(4) A positioning hole 69 is formed at a predetermined position of the remaining two ends of the interlayer insulating adhesive sheet 60a formed in (1) by a method such as a carbide drill, laser light, etc. Two adhesive sheets 60c are prepared.
[0012]
(5) Using the positioning pattern 69 of the inner layer substrate 60b and the positioning hole 69 of the interlayer insulating adhesive sheet 60c as a reference mark, positioning is performed by an alignment method of recognition and alignment of a CCD camera or the like, and interlayer insulation is provided on both sides of the outer layer of the inner layer substrate 60b. An adhesive sheet 60c is disposed.
[0013]
(6) Further, the copper foil is temporarily fixed on both outer sides by caulking, and after temporarily pressing by a method such as thermocompression bonding, the copper foil and the interlayer insulating adhesive sheet 60c are pressed and heated by a heat press machine, And the inner layer board | substrate 60b is laminated | stacked and the 4 layer copper clad laminated board which has the inner layer conductor circuit 66 is formed.
[0014]
(7) An alignment hole 70 as shown in FIG. 5 (b) is formed in the interlayer insulating adhesive sheet 60c by an X-ray drilling machine at the position of the X-ray recognition inner via hole 63 formed in the step (1). To do.
[0015]
(8) A photosensitive etching resist is formed on the four-layer copper-clad laminate, the exposure mask film is positioned with reference to the alignment hole 70, and the etching resist is formed by exposure and development. Etching is performed using a chemical solution such as copper to form the outer conductor circuit 71, and a four-layer multilayer printed wiring board as shown in FIG. 5A is formed.
[0016]
(9) Finish the multilayer printed wiring board by applying solder resist, component layout and outline processing.
[0017]
[Problems to be solved by the invention]
However, in the above conventional method, in the alignment accuracy between the inner via hole of the interlayer insulating adhesive sheet 60c and the conductor circuit of the inner layer substrate 60b, the alignment method using the positioning hole 69 and the positioning pattern 67 is used for heating when forming the inner layer substrate 60b. The effect of distortion during stacking cannot be corrected and absorbed, and since it is not possible to confirm the drilling accuracy of the positioning hole 69 of the interlayer insulating adhesive sheet 60c and the alignment hole 65 of the inner layer substrate 60b, the amount of deviation and positional accuracy variation increase. Has a problem.
[0018]
The present invention has been made to solve the above problems, and realizes a multilayer printed wiring board capable of reducing the amount of positional deviation between an inner via hole filled with a conductive paste and an inner layer conductor circuit and an outer layer conductor circuit. It aims at providing the manufacturing method of the multilayer printed wiring board which improves the yield of the manufacturing process of a printed wiring board.
[0019]
[Means for Solving the Problems]
In order to solve this problem, the method of manufacturing a multilayer printed wiring board according to the present invention provides a peripheral portion of an insulating plate on which inner via holes and conductive patterns are formed on a circumference having a diameter equal to or larger than an alignment hole to be formed later. A multilayer printed wiring board is manufactured using a method of laminating a plurality of inner layer substrates and outer layer substrates provided with a plurality of inner via holes for X-ray recognition, and according to this, an inner layer formed of a conductive paste is used. A multilayer printed wiring board can be manufactured with very little misalignment between the via hole and the inner and outer layer conductor circuits.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
According to the first aspect of the present invention, an inner via hole in which a semi-cured insulating resin layer is filled with a conductive paste and a conductive paste is filled on one circumference of a peripheral portion of the insulating resin layer. Forming a plurality of inner via holes for X-ray recognition, forming a double-sided copper-clad laminate for the inner layer by superimposing copper foil on both outer sides of the insulating resin layer and pressurizing and heating, Forming an alignment hole in the inner-layer double-sided copper-clad laminate with an X-ray hole processing machine on the basis of the inner via hole for X-ray recognition on the one circumference, and using the alignment hole as a reference, A plurality of X-ray recognitions, comprising: forming an etching resist on a double-sided copper clad laminate for an inner layer; and etching the copper foil to form an inner layer material having a conductor circuit and an alignment mark. For inner A diameter of the circumference formed by a via hole is a manufacturing method of a multilayer printed wiring board characterized by being larger than a diameter of the alignment hole. Inner via hole filled with conductive paste formed on the interlayer insulating adhesive sheet by averaging the positional accuracy variation of the plurality of X-ray recognition inner via holes in the part and processing the alignment hole based on this, and inner layer It has the effect | action that the position shift of a conductor circuit and an outer layer conductor circuit can be suppressed.
[0021]
In addition, this method makes it possible to correct the position of the circuit formation, and to suppress the positional deviation between the inner via hole filled with the conductive paste formed on the interlayer insulating adhesive sheet, the inner layer conductor circuit, and the outer layer conductor circuit, and the alignment hole and the X-ray. The amount of deviation from the recognized inner via hole can be confirmed.
[0022]
According to the second aspect of the invention, after the step of forming the inner layer material, the inner via hole filled with the conductive paste and the plurality of X-ray recognitions filled with the conductive paste on one circumference of the peripheral portion Preparing an interlayer insulating adhesive sheet having an inner via hole, positioning and overlapping the interlayer insulating adhesive sheet on the upper and lower surfaces of the inner layer material, and overlaying copper foil on both outer sides thereof Forming a double-sided copper-clad laminate for multilayer by pressurizing and heating, and forming a single alignment hole on the circumference of the plurality of X-ray recognition inner via holes as a reference A step of forming an X-ray hole on the plate, a step of forming an etching resist on the double-sided copper-clad laminate for the multilayer on the basis of the alignment hole, and etching the copper to form a conductor circuit. And the diameter of the circumference formed by a plurality of inner via holes for X-ray recognition of the adhesive sheet for interlayer insulation is the diameter of the alignment hole formed in the double-sided copper-clad laminate for multilayers The multilayer printed wiring board manufacturing method according to claim 1, wherein the inner layer conductor circuit is based on the alignment hole provided in the inner layer material, and the alignment hole provided in the outer layer material is used as a reference. Since the outer layer conductor circuit is formed, the influence of the deviation at the time of lamination is small, and the positional deviation of the conductor circuit with respect to the inner via hole can be suppressed.
[0023]
(Embodiment 1)
The manufacturing method of the multilayer printed wiring board which is one embodiment of this invention is demonstrated below.
[0024]
1 and 2 are sectional views showing a method of manufacturing a multilayer printed wiring board according to an embodiment of the present invention, FIG. 3 is a projected view of a four-layer copper-clad laminate according to an embodiment of the present invention, and FIG. It is a figure which shows the positional relationship of the inner via hole for X-ray recognition and alignment hole in embodiment of invention.
[0025]
1 to 4, FIG. 1 (a) shows a cross section of an inner layer material, 10 is an insulating resin layer, 10a is an inner layer material, 11 is an inner via hole filled with conductive paste, and 12 and 13 are during pattern formation. X-ray recognition inner via holes 14 and 15 for copper alignment, and FIG. 1B shows alignment holes 16 and 13 based on the X-ray recognition inner via holes 12 and 13 provided in the insulating resin layer. FIG. 1C is a cross-sectional view when the inner layer conductor circuits 18 and 21 and the alignment marks 19 and 20 formed by etching the copper foils 14 and 15 are formed. d) and (e) are sectional views of the interlayer adhesive sheet, 22 and 28 are interlayer insulating adhesive sheets for overlapping the upper and lower surfaces of the insulating resin layer 10, and 27 and 33 are filled with conductive paste. Inner Via holes 25, 26, 31, and 32 are X-ray recognition inner via holes for alignment during pattern formation, and 23, 24, 29, and 30 are alignment marks formed by the inner via holes. f) shows a cross section in which the insulating resin layer 10, the interlayer insulating adhesive sheets 22 and 28, and the copper foils 34 and 35 as conductive foils are overlapped, and FIG. 2 (g) is provided on the interlayer insulating adhesive sheets 22 and 28. FIG. 2 (h) is a cross-sectional view when the alignment holes 36, 37, 38, 39 are processed with reference to the inner via holes 25, 26, 31, 32 for X-ray recognition. FIG. Sectional drawing when forming the outer-layer conductor circuits 40 and 41 which were made is shown.
[0026]
FIG. 3 is a projection view of a four-layer copper-clad laminate, where 50a is a four-layer copper-clad laminate, and 50b to 50m are positions in an inner via hole for X-ray recognition when processing an alignment hole.
[0027]
FIG. 4 is a detailed view of each position shown in FIG. 3, 51b to 51e are X-ray recognition inner via holes filled with conductive paste, and 51a is an alignment hole.
[0028]
The process of the process is demonstrated below about the manufacturing method of the multilayer printed wiring board comprised as mentioned above.
[0029]
(1) First, an insulating resin layer 10 formed by impregnating and semi-curing an epoxy resin into an aramid non-woven fabric is subjected to drilling by any method such as carbide drill, laser light, punching, etc., and conductive paste is put in the hole And the inner via hole 11 filled with the conductive paste and the inner via hole 12 for X-ray recognition (50e, 50k in FIG. 3) and 13 (50b, 50h in FIG. 3) for alignment during pattern formation are insulated resins. Formed in the peripheral part of the layer. At this time, as shown in FIG. 4, the diameter of the circumference forming the X-ray recognition inner via holes 51b to 51e is made larger than the alignment hole diameter 51a to be processed later.
[0030]
Next, copper foils 14 and 15 having substantially the same size as the insulating resin layer 10 are overlapped on both outer sides of the insulating resin layer 10 and temporarily fixed by any method such as caulking or thermocompression bonding, and then pressed by a hot press. Then, the insulating resin layer 10 and the copper foil are bonded by heating to form a double-sided copper clad laminate for the inner layer.
[0031]
(2) Next, in order to perform alignment exposure on this double-sided copper clad laminate for inner layer, X-ray recognition inner via holes 12 (50e, 50k in FIG. 3), 13 (FIG. 3) provided in the inner layer material 10 50b, 50h) is used as a reference to process the alignment holes 16, 17 with an X-ray hole processing machine. At this time, the distance between the inner via hole for X-ray recognition provided on the outside and the alignment hole is measured with a length measuring device or the like, and if there is a deviation during drilling, the drilling machine is corrected to perform drilling with high accuracy.
[0032]
(3) Next, when exposing the copper foil on the surface of the double-sided copper clad laminate for inner layer to a predetermined etching resist pattern such as photographic method, direct drawing method, etc. If the fiducial mark is a direct drawing method, the coordinate value on the data is recognized, exposed by a method generally called alignment method, developed, and then etched using a chemical such as cupric chloride. Simultaneously with the formation of the inner layer circuits 18 and 21, the alignment marks 19 and 20 formed with the inner layer conductor circuit are formed to obtain the inner layer material 10a shown in FIG.
[0033]
(4) Next, interlayer insulating adhesive sheets 18 and 19 are formed to overlap the upper and lower surfaces of the inner layer material 10a. At this time, the interlayer insulating adhesive sheet 22 provided with the inner via holes 23 and 24 for overlaying the inner layer material and the interlayer insulating adhesive sheet 28 provided with the inner via holes 29 and 30 are respectively used for alignment during pattern formation. Inner via holes 25 for line recognition (50f, 50l in FIG. 3), 26 (50c, 50i in FIG. 3) (upper surface), 31 (50g, 50m in FIG. 3), 32 (50d, 50j in FIG. 3) (lower surface) ) At a position shifted from each layer and in the peripheral portion of the insulating resin layer. At this time, as shown in FIG. 4, the diameter of the circumference forming the inner via holes 51b to 51e for X-ray recognition is made larger than the alignment hole diameter 51a to be processed later in the same manner as the inner layer material.
[0034]
(5) The alignment marks 19 and 20 provided with the interlayer insulating adhesive sheets 22 and 28 shown in FIGS. 1D and 1E on the upper and lower surfaces of the inner layer material 10a and the interlayer insulating adhesive sheet 22 , 28 is used to recognize the position of the alignment marks 23, 24, 29, 30 and is positioned by the central portion so that the positional deviation between the inner layer material and the interlayer insulating adhesive sheets 22, 28 is minimized by a method generally called an alignment method. And superimpose.
[0035]
Thereafter, the insulating resin layer 10, the interlayer insulating adhesive sheets 22 and 28, and the copper foils 34 and 35 having substantially the same size as the copper are laminated on both outer sides as shown in FIG. The insulating resin layer 10 and the copper foils 34 and 35 are bonded by temporary fixing by an arbitrary method such as pressurization and heating with a hot press machine to form a four-layer copper-clad laminate.
[0036]
(6) In order to perform alignment exposure on this double-sided copper clad laminate for outer layer, an inner via hole 25 for X-ray recognition (50f, FIG. 3) provided on the interlayer insulating adhesive sheets 22 (upper surface) and 28 (lower surface). 50l), 26 (50c, 50i in FIG. 3) (upper surface), 31 (50g, 50m in FIG. 3), 32 (50d, 50j in FIG. 3) (lower surface), alignment holes 36, 37 (upper surface), 38 and 39 (lower surface) are processed by an X-ray hole processing machine. At this time, the distance between the inner via hole for X-ray recognition provided on the outside and the alignment hole is measured with a length measuring device or the like, and if there is a deviation during drilling, the drilling machine is corrected to perform drilling with high accuracy.
[0037]
(7) When exposing the copper foil on the surface of the double-sided copper clad laminate for inner layer to a predetermined etching resist pattern such as photographic method and direct drawing method, the alignment holes 36, 37 (upper surface), 38, 39 (lower surface) If it is a photographic method, the reference mark of the film is recognized, and if it is a direct drawing method, the coordinate value on the data is recognized and exposed by a method generally called an alignment method. Etching is performed using a chemical solution to form inner layer circuits 40 and 41.
[0038]
(8) After solder resist is formed on the parts that do not require soldering when electronic parts are mounted and the surface layer is treated with gold plating, etc., by any method such as router, mold, carbide drill, laser, etc. A four-layer multilayer printed wiring board using a conductive paste for interlayer connection is completed by processing into the required outer shape.
[0039]
In this embodiment and the conventional interlayer insulating adhesive sheet, the positional deviation between the inner via hole 11 in which the conductive paste is filled and the conductor circuits 18 and 21 is 0.15 mm at the maximum by the conventional method. The form could be within 0.05 mm.
[0040]
【The invention's effect】
As described above, the present invention forms a plurality of X-ray-recognizing inner via holes at a position shifted from each layer in the peripheral portion of the insulating substrate when processing through-holes filled with conductive paste in an interlayer adhesive sheet, An alignment hole is formed on each of the plurality of centers. As a result of confirming the amount of deviation between the alignment hole after machining and multiple inner via holes for X-ray recognition with a length measuring machine, etc., the accuracy of the alignment hole machine is improved and the amount of deviation due to hole machining is reduced, resulting in an inner via It is possible to realize an excellent method for manufacturing a multilayer wiring board capable of extremely reducing the relative positional deviation between the hole and the conductor circuit.
[Brief description of the drawings]
1A is a cross-sectional view of an inner layer material showing a method for manufacturing a multilayer printed wiring board according to an embodiment of the present invention; FIG. 1B is a cross-sectional view when an alignment hole is machined in the inner layer material; Sectional view when a circuit is formed (d) Sectional view of the same interlayer adhesive sheet (for the upper surface) (e) Sectional view of the same interlayer adhesive sheet (for the lower surface) FIG. 2 (f) (f) in the embodiment of the present invention Cross-sectional view of inner layer material, interlayer adhesive sheet and copper foil superimposed (g) Cross-sectional view when alignment hole is processed (h) Cross-sectional view when outer-layer conductor circuit is formed [FIG. 3] FIG. 4 is a projected view of a four-layer copper-clad laminate in the embodiment.
The figure which shows the positional relationship of the inner via hole for X-ray recognition and alignment hole in embodiment of this invention. [FIG. 5] (a) Section which shows the structure of the printed wiring board which used the electrically conductive paste for the conventional interlayer connection FIG. 6B is a cross-sectional view showing the structure of a conventional four-layer multilayer printed wiring board. FIG. 6 is a diagram showing the positional relationship between a conventional X-ray recognition inner via hole and an alignment hole.
DESCRIPTION OF SYMBOLS 10 Insulating resin layer 11 Inner via hole 12 and 13 filled with the conductive paste formed in the insulating resin layer X-ray recognition inner via hole 14 formed with the inner via hole filled with the conductive paste formed in the insulating resin layer, 15 Copper foil 16, 17 Inner layer conductor circuit forming alignment holes 18, 21 Inner layer conductor circuits 19, 20 Alignment marks 22 and 28 formed by inner layer conductor circuits Interlayer insulating adhesive sheets 23, 24, 29, 30 Insulating resin layer Alignment marks 25, 26, 31, 32 formed by inner via holes filled with conductive paste formed on the inner via hole for X-ray recognition formed by inner via holes filled with conductive paste formed on the insulating resin layer 27,33 Inner filled with conductive paste formed on interlayer adhesive sheet Inner via holes 34, 35 for copper X-ray recognition formed by ear holes 36, 37, 38, 39 Alignment holes 40, 41 for forming outer layer conductor circuits 50a, outer layer conductor circuits 50a, four layer copper clad laminates 50b-50m X-ray recognition inner via hole position 51a Alignment holes 51b to 51e X-ray recognition inner via hole 52a Alignment holes 52b to 52e X-ray recognition inner via hole

Claims (2)

An inner via hole filled with a conductive paste in a semi-cured insulating resin layer and a plurality of X-ray recognition inner via holes filled with a conductive paste on one circumference of the peripheral portion of the insulating resin layer Forming, and
A step of forming a double-sided copper-clad laminate for an inner layer by superimposing copper foil on both outer sides of the insulating resin layer and pressurizing and heating;
Forming an alignment hole in the double-sided copper-clad laminate for inner layer with an X-ray hole processing machine based on the inner via hole for X-ray recognition on the one circumference;
Forming an etching resist on the double-sided copper clad laminate for inner layer with reference to the alignment hole;
And a step of etching the copper foil to form an inner layer material having a conductor circuit and an alignment mark,
A method of manufacturing a multilayer printed wiring board, wherein a diameter of the circumference formed by the plurality of X-ray recognition inner via holes is larger than a diameter of the alignment hole. After the step of forming the inner layer material,
Providing an interlayer insulating adhesive sheet having an inner via hole filled with a conductive paste and a plurality of X-ray recognition inner via holes filled with a conductive paste on one circumference of a peripheral portion; ,
Positioning and overlaying the interlayer insulation adhesive sheet on the upper and lower surfaces of the inner layer material, overlaying copper foil on both outer sides and pressurizing and heating to form a multilayer double-sided copper-clad laminate,
Forming one alignment hole in the multilayer double-sided copper-clad laminate with an X-ray hole processing machine based on a plurality of X-ray recognition inner via holes on the one circumference;
A step of forming an etching resist on the double-sided copper-clad laminate for multilayers based on the alignment hole, and a step of forming a conductor circuit by etching the copper foil,
The diameter of the circumference formed by the plurality of X-ray recognition inner via holes of the interlayer insulating adhesive sheet is larger than the diameter of the alignment hole formed in the multilayer double-sided copper-clad laminate. The manufacturing method of the multilayer printed wiring board of Claim 1 characterized by the above-mentioned.

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