JP2019134045A - Collective circuit board and manufacturing method of the same - Google Patents

Abstract

To provide a collective circuit board capable of minimizing a decrease in positional accuracy of individual circuit boards due to expansion and contraction of a circuit board constituting a unit product part in a block part by blasting.SOLUTION: The collective circuit board includes: a block part 1m, having an insulating base material 10, through holes 10a and 10a', a first copper layer 11, and a second copper layer 12, in which circuit boards, in which a predetermined wiring pattern made of the first and second copper layers is formed, constituting a unit product part 1n having a predetermined product shape and via hole formed by a through hole are arranged in a matrix; and a frame part 1k that surrounds the outer periphery of the same, and is configured so that an insulating base material has a thickness of 25 μm or more and 65 μm or less, side surfaces have blasted surfaces 10a-1 and 10a'-1 formed by blasting in a state where a first copper layer formed on both surfaces of the insulating base material has a thickness of 11 μm or more and 15 μm or less, and the first copper layer on which the second copper layer is formed has a thickness of 4 μm or more and 10 μm or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an aggregate circuit board having a product shape formed by blasting and a method for manufacturing the same.

Each electronic component is becoming smaller and thinner mainly for portable devices, and the circuit board (printed substrate) on which the electronic component is mounted is also required to be smaller and thinner.
The collective circuit board has a block portion in which circuit boards constituting unit product parts are arranged in a matrix. Each circuit board is formed in an outer shape necessary to be assembled as an electronic component.
A part of the outer shape of each circuit board is usually of a type in which a connecting portion is formed for connection with an adjacent circuit board. The collective circuit board has a frame portion surrounding the outer periphery of the block portion.
Conventionally, for example, drilling or laser processing described in Patent Documents 1 and 2 is used to form the outer shape of each circuit board and the formation of a through-hole serving as a via hole with respect to the circuit board material.

JP 2006-167578 A JP 2012-235176 A

In drilling and laser processing, it is necessary to form through holes one by one in order to form the external shape and via hole of each circuit board, and to connect the formed through holes. There is a need to drill holes.
For this reason, when drilling or laser processing is used for manufacturing the collective circuit board, the productivity is very poor and the cost is high.
In addition, when forming a through hole with a very small diameter such as a via hole, it is difficult to perform a desmear process on the carbonized surface by laser processing, and in drilling, it is necessary to use a drill with a reduced diameter, which may be broken or damaged. Have the problem of getting higher.

  Other processing methods for providing openings and via holes in circuit board materials include pressing, but precision molds used for pressing are expensive, and openings for forming the outline of circuit boards that form unit product parts A separate precision mold corresponding to the shape and the size and position of the via hole inside the circuit board constituting the unit product portion is required. For this reason, if press working is used for manufacturing the collective circuit board, a huge manufacturing cost is required.

Therefore, the present inventors have considered and studied the production of an aggregate circuit board using blasting.
Blasting has better processing accuracy, no deterioration in quality, and can be formed with low production cost and high production efficiency compared to drilling, laser processing, press processing, and the like.
However, when the through hole is formed by blasting, the abrasive is physically collided with the circuit board material at a high speed, so that the circuit board material is compressed in the Z direction and stretched in the XY direction. For this reason, the positional accuracy of the circuit board forming each unit product portion of the block portion is lowered.
Further, in the manufacture of a circuit board, a through hole is formed using a circuit board material having an insulating base and a first copper layer to be a wiring circuit on both sides of the insulating base, and the through hole formed The second copper layer is plated on the wall surface to establish electrical continuity with the first copper layer that should be the front and back wiring circuit, and then the first copper layer and the second copper layer are laminated on the part. On the other hand, the wiring circuit is formed by etching, but when the second copper layer is formed by plating on the wall surface of the through hole, the second copper layer is formed on the first copper layer to be the front and back wiring circuits. By laminating, the thickness of the copper layer of the laminated portion increases. On the other hand, the thickness of the insulating base material constituting the circuit board and the thickness of the copper layer serving as the wiring circuit are specified by customer specifications and cannot be freely changed. For this reason, the circuit board material used for the production of the circuit board includes the thickness of the second copper layer that is laminated for the conduction of the front and back wiring circuits with respect to the first copper layer on both sides of the insulating base. It is necessary to use one with reduced minutes.
However, blasting is applied to the circuit board material having the thin first and second copper layers, in which the thickness of the second copper layer laminated by plating for the conduction of the front and back wiring circuits is reduced. If it does, the expansion | extension to the XY direction produced by compressing a circuit board material to a Z direction by blasting will become large, and the fall of the positional accuracy of each unit product of a block part will become large.

  The present invention has been made in view of the above problems, and it is possible to suppress a decrease in position accuracy of each circuit board due to expansion and contraction of the circuit board forming the unit product part in the block part by blasting, and processing accuracy Therefore, an object of the present invention is to provide a collective circuit board that can be formed with good production efficiency without cost deterioration and with reduced cost, and a method for manufacturing the same.

  In order to achieve the above object, an assembled circuit board according to the present invention includes an insulating base, a through hole penetrating the insulating base, a first copper layer formed on both surfaces of the insulating base, and the first A circuit having a predetermined wiring pattern having a second copper layer formed on the surface of the copper layer of 1 and the wall surface of the through hole is formed of the first copper layer and the second copper layer. A circuit board having a block portion in which a circuit board forming a unit product portion in which a predetermined product shape and a via hole are formed by the through hole is arranged in a matrix, and a frame portion surrounding an outer periphery of the block portion. The insulating base material has a thickness of 25 μm or more and 65 μm or less, and side surfaces of the insulating base material at a portion where the predetermined product shape is formed are formed on both surfaces of the insulating base material. The thickness of the first copper layer is 11 μm or more and 15 μm or less The first copper layer in the state where the second copper layer is formed has a thickness of 4 μm or more and 10 μm or less. It is characterized by.

Moreover, the manufacturing method of the collective circuit board according to the present invention includes an insulating base, a through hole penetrating the insulating base, a first copper layer formed on both surfaces of the insulating base, and the first A second copper layer formed on the surface of the copper layer and the wall surface of the through hole, and a circuit of a predetermined wiring pattern comprising the first copper layer and the second copper layer is formed; A collective circuit board having a block portion in which a circuit board forming a unit product portion in which a predetermined product shape and a via hole are formed by the plurality of through holes is arranged in a matrix, and a frame portion surrounding an outer periphery of the block portion It is a manufacturing method, Comprising: The process of the order of following (a)-(j) is included, It is characterized by the above-mentioned.
(A) A step of preparing a substrate material having a first copper layer having a thickness of 11 μm or more and 15 μm or less formed on both surfaces of an insulating base material having a thickness of 25 μm or more and 65 μm or less.
(B) forming a first resist layer on both surfaces of the substrate material and forming a first resist mask for forming the through hole;
(C) The process of removing the said 1st copper layer exposed from the opening part of a said 1st resist mask by an etching process, and exposing the said insulating base material.
(D) forming a recess in which the thickness of the insulating base material is approximately half the thickness by blasting from one side of the insulating base material exposed in the opening of the first resist mask; And a step of forming the through hole through the bottom surface of the recess by blasting from the other surface side.
(E) removing the first resist mask.
(F) A step of thinning the first copper layer to a thickness of 4 μm to 10 μm by etching.
(G) A step of forming, by plating, a second copper layer having a predetermined thickness on the surface of the thinned first copper layer and the wall surface of the through hole.
(H) forming a second resist layer on both surfaces of the substrate material on which the second copper layer is formed, and forming a second resist mask for forming the circuit;
(I) A step of forming the circuit by etching a copper layer composed of the first copper layer and the second copper layer exposed from the opening of the second resist mask.
(J) A step of removing the second resist mask.

  According to the present invention, it is possible to suppress the elongation of the substrate material due to blast processing, and to maintain the position accuracy of the unit product in the block portion within the design value ± 20 μm, the processing accuracy is good, the quality is not deteriorated, and the cost is reduced. An aggregate circuit board that can be formed with low production efficiency and a manufacturing method thereof can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram showing a schematic configuration of an aggregate circuit board according to an embodiment of the present invention, in which (a) is a plan view conceptually showing an arrangement of circuit boards constituting unit product parts in the aggregate circuit board, and (b) is a unit. It is sectional drawing which shows the lamination | stacking state of the copper layer on the insulating base material in one circuit board which makes a product part, and the processing state of the side surface of an insulating base material. It is explanatory drawing which shows the manufacturing process of the collective circuit board concerning one Embodiment of this invention, and the change of the thickness of the 1st copper layer in a manufacturing process. It is a graph which shows the position accuracy of each collective circuit board manufactured with the manufacturing method of the collective circuit board concerning the Example and comparative example of this invention.

Prior to the description of the embodiments, the process of deriving the collective circuit board and the method for manufacturing the same according to the present invention and the operation and effects thereof will be described.
As described above, there are drilling, laser processing, and press processing as methods for processing a through hole for forming a product shape or a via hole in a circuit board material.
The present inventors first considered and examined whether or not it is possible to process a through hole for forming a product shape and a via hole in a circuit board material by drilling that is generally used conventionally.
However, in drilling, it is necessary to form through holes one by one in order to form product shapes and via holes of individual circuit boards, and the formed through holes must be joined together. This led to the conclusion that the productivity was very poor and the cost was high.

Accordingly, the inventors of the present invention next considered and examined whether or not it is possible to process a through hole for forming a product shape and a via hole in a circuit board material by laser processing and press processing.
However, in the laser processing method, the processing end face may be carbonized, and the carbonized portion may have conductivity.
In the past, the present inventors conducted a test to remove the carbonized resin by performing a desmear treatment, but the carbonized resin could not be completely removed by the desmear treatment.
Further, it is difficult to remove the carbonized portion from the circuit board in a state where the carbonized portion has conductivity and is short-circuited when the electronic component is mounted.
Moreover, the laser processing takes a long processing time, the productivity is deteriorated, and the equipment cost for the laser processing is increased.

  Moreover, the press work requires a separate precision die corresponding to each product shape of the unit product portion and the size and position of the via hole. For this reason, a collective circuit having a block portion in which a circuit board forming a unit product portion in which a predetermined product shape and a via hole are formed is arranged in a matrix using press working, and a frame portion surrounding the outer periphery of the block portion If it is going to form a board | substrate, a huge manufacturing cost will start.

Accordingly, the present inventors have conceived, studied and studied the idea of forming a product shape and the possibility of processing a through hole for forming a via hole in a circuit board material by blasting.
Blasting is a processing method in which only a processing target portion in a circuit board material is covered with a resist mask so that the substrate is exposed at high speed with compressed air to remove the substrate at the processing target portion.
Also, unlike drilling, blasting requires manual setting on a blasting machine after resist mask formation, and cannot be manufactured on a continuous line conveyed in one direction. For this reason, it is a processing method that is difficult to use for manufacturing an electronic component mounting board on a continuous line.
The inventors of the present invention have compared and compared with other processing methods. Unlike drilling, the blast processing can accurately process a predetermined product shape on the circuit board forming the unit product portion. It is possible to simultaneously form a predetermined product shape and via hole on the circuit board to be formed. Furthermore, unlike laser processing, there is no carbonization of the processed surface, and unlike press processing, the design freedom is wide and the manufacturing cost can be reduced. found.
Further, the present inventors have further studied and found that the use of blasting for processing a product shape and a through hole for forming a via hole in a circuit board material has the following problems. did.

  As described above, blasting is a processing method in which fine abrasive grains are sprayed at high speed with compressed air on a circuit board material in which a resist mask is formed in a part other than the processing target, and the circuit board material in the processing target part is removed. is there. When the through hole is formed by blasting, the abrasive is physically collided with the circuit board material at a high speed, so that the circuit board material is compressed in the Z direction and stretched in the XY direction. Therefore, the position accuracy of each unit product in the block portion is lowered.

In the blast processing, as a measure for relaxing the compression of the substrate material in the portion covered with the resist mask and suppressing the expansion in the XY direction, a film of a resist film used for a resist mask formed in a portion other than the processing target It is conceivable to increase the thickness.
However, when the thickness of the resist film is increased, the processing accuracy of the mask shape formed on the resist film through exposure and development decreases, and as a result, the processing accuracy of the product shape formed by blast processing decreases. In addition, when the resist film is thickened, the material cost is increased and the production cost is increased accordingly.

Further, in the manufacture of a circuit board, a through hole is formed using a circuit board material having an insulating base and a first copper layer to be a wiring circuit on both sides of the insulating base, and the through hole formed The second copper layer is plated on the wall surface to establish electrical continuity with the first copper layer that should be the front and back wiring circuit, and then the first copper layer and the second copper layer are laminated on the part. On the other hand, the wiring circuit is formed by etching, but when the second copper layer is formed by plating on the wall surface of the through hole, the second copper layer is formed on the first copper layer to be the front and back wiring circuits. By laminating, the thickness of the copper layer of the laminated portion increases. On the other hand, the thickness of the insulating base material constituting the circuit board and the thickness of the copper layer serving as the wiring circuit are specified by customer specifications and cannot be freely changed. For this reason, the circuit board material used for the production of the circuit board includes the thickness of the second copper layer that is laminated for the conduction of the front and back wiring circuits with respect to the first copper layer on both sides of the insulating base. It is necessary to use one with reduced minutes.
However, blasting is applied to the circuit board material having the thin first and second copper layers, in which the thickness of the second copper layer laminated by plating for the conduction of the front and back wiring circuits is reduced. If it does, the expansion | extension to the XY direction produced by compressing a circuit board material to a Z direction by blasting will become large, and the fall of the positional accuracy of each unit product of a block part will become large.

  However, the present inventors verified the problem in this blasting method, and in the process of repeating trial and error, without changing the thickness of the customer specification for the copper layer that becomes the wiring circuit in the final product, by blasting The inventors have conceived a policy that can suppress the elongation of the circuit board material in the XY direction, and have led to the present invention.

  The collective circuit board of the present invention includes an insulating base material, a through hole penetrating the insulating base material, a first copper layer formed on both surfaces of the insulating base material, a surface of the first copper layer, and a through hole. A second copper layer formed on the wall surface, a circuit having a predetermined wiring pattern composed of the first copper layer and the second copper layer is formed, and a predetermined product shape and a via hole are formed by the through hole The assembly circuit board has a block part in which circuit boards constituting the unit product parts are arranged in a matrix and a frame part surrounding the outer periphery of the block part, and the insulating base has a thickness of 25 μm or more and 65 μm or less And the side surface of the insulating base material at the portion where the predetermined product shape is formed is blasted in a state where the first copper layer formed on both surfaces of the insulating base material has a thickness of 11 μm or more and 15 μm or less Blasted surface formed by A first copper layer in a state in which the second copper layer is formed has a thickness of 10μm or more 4 [mu] m.

  As in the collective circuit board of the present invention, the insulating base material has a thickness of 25 μm or more and 65 μm or less, and the side surfaces of the insulating base material at the part where the predetermined product shape is formed are formed on both surfaces of the insulating base material. If the first copper layer has a blasted surface formed by blasting in a state having a thickness of 11 μm to 15 μm, when the blasted surface is formed by blasting, The first copper layer having a thickness of 11 μm or more and 15 μm or less formed on both surfaces of an insulating base material having a thickness of 25 μm or more and 65 μm or less in the circuit board material causes the pressure of the abrasive grains that collide with the circuit board material at high speed. The effect of mitigating and suppressing elongation in the XY direction is enhanced. As a result, the positional accuracy of the circuit board forming the unit product portion in the block portion formed by blasting can be kept within the design value ± 20 μm.

  On the other hand, the first copper formed on both surfaces of the insulating substrate having a thickness of 25 μm or more and 65 μm or less, wherein the blasted surface formed on the side surface of the insulating substrate in the portion where the predetermined product shape is formed When the blasted surface is formed by blasting when the layer has a thickness of less than 11 μm, the thickness of the circuit board material is 25 μm or more and 65 μm or less. The first copper layer having a thickness of less than 11 μm formed on both surfaces of the insulating base material has an effect of suppressing the elongation in the XY direction because the pressure of the abrasive grains colliding with the circuit board material at high speed cannot be alleviated. I can't. As a result, the positional accuracy of the circuit board constituting the unit product portion in the block portion formed by blasting cannot be kept within the design value ± 20 μm, and the degradation of the positional accuracy becomes large.

Moreover, the 1st copper layer formed in the both sides of the insulation base material in which the blasting surface formed in the side surface of the insulation base material in the site | part in which the predetermined | prescribed product shape was formed has a thickness of 25 micrometers or more and 65 micrometers or less is provided. Insulation having a thickness of 25 μm or more and 65 μm or less in the circuit board material when the blasted surface is formed by blasting if it is formed by blasting in a state having a thickness exceeding 15 μm The first copper layer having a thickness of more than 15 μm formed on both surfaces of the substrate relaxes the pressure of the abrasive grains that collide with the circuit board material at a high speed, and the effect of suppressing elongation in the XY direction is enhanced. However, the first copper layer having a thickness exceeding 15 μm weakens the pressure of the abrasive grains that collide with the exposed part of the insulating base material through which the through hole is to be formed, and forms a predetermined product shape. It takes a long time to form a through-hole for this purpose. When the abrasive spray time is long, the circuit board material covered with the resist mask is exposed and scraped off by the collision of the abrasive grains, resulting in poor product quality as a circuit board. There is a fear.
In the blasting process, as a measure for forming the opening and the outer edge in the unit product part without exposing the part covered with the resist mask, the resist film used for the resist mask to be formed in a part other than the processing target is used. It is conceivable to increase the film thickness.
However, increasing the thickness of the resist film decreases the processing accuracy of the mask shape formed on the resist film through exposure and development, and as a result, the processing accuracy of the predetermined product shape and via hole formed by blast processing is reduced. descend. In addition, when the resist film is thickened, the material cost is increased and the production cost is increased accordingly.
In addition, if the insulating base material is thinned, the blasting time is shortened accordingly, and it becomes easier to improve the positional accuracy of the circuit board forming the unit product portion in the block portion. However, the thickness of the insulating base material is thinner than 25 μm. In such a case, there is a risk that the rigidity is lowered and poor conveyance or the like occurs. On the other hand, when the thickness of the insulating base material is larger than 65 μm, the blasting time becomes too long, and the position accuracy of the circuit board forming the unit product portion in the block portion may be lowered.

  In addition, as a result of trial and error, the inventors of the present invention have a thickness of 25 μm or more and 65 μm or less, and the side surface of the insulating substrate at a site where a predetermined product shape is formed is formed on both surfaces of the insulating substrate. The unit in the block portion formed by blasting is formed by having a blasted surface formed by blasting in a state where the first copper layer formed in the thickness of 11 μm to 15 μm. It has been found that a via hole having a very small diameter of φ30 μm to φ50 μm can be formed while maintaining the positional accuracy of the circuit board constituting the product part within the design value ± 20 μm.

Such a collective circuit board of the present invention can be manufactured by including the following steps (a) to (i).
(A) A step of preparing a substrate material having a first copper layer having a thickness of 11 μm or more and 15 μm or less formed on both surfaces of an insulating base material having a thickness of 25 μm or more and 65 μm or less.
(B) A step of forming a first resist layer on both surfaces of the substrate material and forming a first resist mask for forming a through hole.
(C) The process of removing the 1st copper layer exposed from the opening part of a 1st resist mask by an etching process, and exposing an insulating base material.
(D) Forming a recess in which the thickness of the insulating base is approximately half by blasting from one side of the insulating base exposed in the opening of the first resist mask, and then the other side A process of forming a through hole through the bottom surface of the recess by blasting from the side.
(E) A step of removing the first resist mask.
(F) A step of thinning the first copper layer to a thickness of 4 μm or more and 10 μm or less by etching.
(G) A step of forming a second copper layer having a predetermined thickness on the surface of the thinned first copper layer and the wall surface of the through hole by plating.
(H) A step of forming a second resist mask for forming a circuit by forming a second resist layer on both surfaces of the substrate material on which the second copper layer is formed.
(I) A step of forming a circuit by etching a copper layer composed of the first copper layer and the second copper layer exposed from the opening of the second resist mask.
(J) A step of removing the second resist mask.

The thinning of the first copper layer in the step (f) is performed by plating the second copper layer on the first copper layer by plating for conducting the circuits on both sides in the subsequent step (g). This is performed so that the laminated copper layer has a wiring thickness necessary for the product.
Thus, in the present invention, instead of preparing a substrate material having a thin copper layer as the first copper layer first, the first copper layer having a thickness of 11 μm or more was provided before blasting. By preparing a substrate material and forming a copper layer having a necessary thickness as a product after blasting, when the blasted surface is formed by blasting, the first copper layer having a thickness of 11 μm or more is The effect of relieving the pressure of the abrasive grains that collide with the circuit board material at a high speed and suppressing the elongation in the XY direction is enhanced. As a result, the position accuracy of the circuit board forming the unit product part in the block part formed by blasting can be suppressed to within ± 20 μm, and then a copper layer having a thickness necessary for the product is formed. This improves product quality.

  Therefore, according to the present invention, it is possible to suppress the elongation of the substrate material due to the blast processing, and to suppress the position accuracy of the unit product within the block portion within ± 20 μm, the processing accuracy is good, the quality is not deteriorated, and the cost is reduced. An aggregate circuit board that can be formed with low production efficiency and a manufacturing method thereof can be obtained.

Next, an embodiment of the present invention will be described.
FIG. 1 is an explanatory diagram showing a schematic configuration of an aggregate circuit board according to an embodiment of the present invention. FIG. 1A is a plan view conceptually showing an arrangement of circuit boards constituting unit product parts in the aggregate circuit board. ) Is a cross-sectional view showing a laminated state of a copper layer on an insulating base material and a processed state of a side surface of the insulating base material in one circuit board constituting a unit product part. FIG. 2 is an explanatory view showing a manufacturing process of the collective circuit board according to the embodiment of the present invention and a change in the thickness of the first copper layer in the manufacturing process. FIG. 3 is a graph showing the positional accuracy of each collective circuit board manufactured by the collective circuit board manufacturing method according to the example of the present invention and the comparative example.

As shown in FIG. 1A, a collective circuit board 1 according to an embodiment of the present invention includes a block part 1m in which unit product parts 1n as circuit boards constituting unit product parts are arranged in a matrix, and a block part. And a frame portion 1k surrounding the outer periphery of 1 m.
As shown in FIG. 1B, the unit product portion 1n includes the insulating base 10, the through holes 10a and 10a ′ penetrating the insulating base 10, and the first formed on both surfaces of the insulating base 10. It has the copper layer 11, and the 2nd copper layer 12 formed in the surface of the 1st copper layer 11, and the wall surface of through-hole 10a, 10a '. A circuit having a predetermined wiring pattern made of the first copper layer 11 and the second copper layer 12 is formed, and a predetermined product shape and a via hole are formed by the through holes 10a and 10a ′.
The insulating base material 10 has a thickness of 25 μm or more and 65 μm or less. Moreover, the side surface of the insulating base material 10 in the site | part in which the predetermined product shape was formed has the blasting surface 10a-1.
The blasted surfaces 10a-1, 10a′-1 are formed by blasting in a state where the first copper layer 11 formed on both surfaces of the insulating base material 10 has a thickness of 11 μm or more and 15 μm or less. Yes.
In addition, as a material of the insulating base material 1a, it is possible to use an epoxy resin, a phenol resin, a polyimide resin, a fluorine-containing resin, a polyester resin, a polyphenylene oxide resin, or the like, or a mixture of a plurality of resins. Moreover, what further mix | blended various additives and softening agents, and what used organic fibers, such as inorganic fibers, such as glass, a polyester resin, a polyimide resin, and various natural fibers, can also be used as a reinforcing material.
The first copper layer 11 in a state where the second copper layer 12 is formed has a thickness of 4 μm or more and 10 μm or less.
The through hole 10a ′ for forming the via hole is formed with a diameter of 30 μm to 50 μm.
The blasted surfaces 10a-1 and 10a'-1 of the through holes 10a and 10a 'forming the product shape and the via hole have an opening diameter at a predetermined depth position at the surface position of the collective circuit board 1. It is formed narrower than. Here, for convenience, a narrowly formed portion is not shown.
And the site | part with the narrowest opening diameter in the blasting surface 10a-1, 10a'-1 of the through holes 10a and 10a which form a product shape and a via hole is formed in the substantially intermediate | middle depth position.

  The collective circuit board 1 of the present embodiment configured as described above can be manufactured, for example, as follows (see FIG. 2). Note that description of pre-processing and post-processing including chemical solution cleaning and water cleaning performed in each manufacturing process is omitted for the sake of convenience.

  First, a substrate material 1 ′ having a first copper layer 11 having a thickness of 11 μm to 15 μm formed on both surfaces of an insulating base material 10 having a thickness of 25 μm to 65 μm is prepared (see FIG. 2A). ). In FIG. 2, for convenience, the insulating base material 10 and the first copper layer 11 are shown with relative thicknesses different from actual ones.

Next, a first dry film resist having a predetermined thickness is laminated on both surfaces of the substrate material 1 ′ as a first resist layer. The thickness of the first dry film resist is determined by the thickness of the insulating base material 10 to be processed and the minimum opening diameter.
Although the kind of 1st dry film resist is not specifically limited, Usually, the negative type which a photosensitive part hardens | cures is used. In addition, a positive type dry film resist may be used. Alternatively, a liquid photoresist may be applied. In FIG. 2, for the sake of convenience, the first dry film resist is shown with a relative thickness different from the actual thickness.

  Next, a pattern for forming the through holes 10a and 10a 'is exposed at predetermined portions of the first dry film resist.

  Next, development is performed to form a first resist mask 30 in which through holes 10a and 10a 'having respective shapes are formed on both surfaces of the substrate material 1' (see FIG. 2B).

  Next, the first copper layer 11 exposed from the openings of the first resist masks 30 on both sides is etched to remove the first copper layer 11, and the insulating base material 10 is exposed at the removed portion. (See FIG. 2 (c)).

Next, the slit nozzle is appropriately moved at a predetermined pressure and a predetermined injection amount by using blasting abrasive grains having a predetermined abrasive grain size determined by the thickness of the insulating base material 10 to be processed and the minimum opening diameter. The blasting abrasive grains are sprayed while blasting from one surface side (for example, the upper surface side of the insulating base material 10 shown in FIG. 2) to the insulating base material 10 exposed from the opening of the first resist mask 30. Processing is performed, and the insulating base material 10 is dug into a substantially half thickness to form a recessed portion (not shown) having a predetermined opening shape and a recessed portion (not shown) having a circular opening shape.
Next, from the other surface side (for example, the lower surface side of the insulating base material 10 shown in FIG. 2) with respect to the insulating base material 10 exposed from the opening of the first resist mask 30, similarly to the one surface side. Blasting is performed, and the insulating base material 10 is dug, and an opening shape is penetrated through a bottom surface of a concave portion (not shown) having a predetermined product shape and a bottom surface of a concave portion (not shown) having a circular opening shape. Thereby, the through holes 10a and 10a ′ are formed (see FIG. 2D).

Next, the first resist mask 30 is removed (see FIG. 2E).
Next, the first copper layer 11 is etched to reduce the thickness to 4 μm or more and 10 μm or less (see FIG. 2 (f)).
Next, the second copper layer 12 having a predetermined thickness is formed by plating on the surface of the thinned first copper layer 11 and the wall surfaces of the through holes 10a and 10a '(see FIG. 2 (g)). .

Next, a second dry film resist is laminated as a second resist layer on both surfaces of the substrate material 1 ′ on which the second copper layer 12 is formed, and a formation method similar to that for the first resist mask 30 is performed. Then, a second resist mask 31 for forming a circuit with a copper layer in which the first copper layer 11 and the second copper layer 12 are laminated is formed (see FIG. 2 (h)).
Next, the copper layer composed of the first copper layer 11 and the second copper layer 12 exposed from the opening of the second resist mask 31 is etched to form a circuit (FIG. 2 ( i)).
Thereafter, the second resist mask 31 is removed (see FIG. 2 (j)).
Thereby, the collective circuit board 1 is obtained.

  According to the collective circuit board 1 of the present embodiment, the insulating base material 10 has a thickness of 25 μm or more and 65 μm or less, and the side surface of the insulating base material 10 at the part where the predetermined product shape is formed is the insulating base material 10. Since the first copper layer 11 formed on both sides of the metal plate 11 has a blasted surface 10a-1, 10a′-1 formed by blasting in a state having a thickness of 11 μm or more and 15 μm or less. When the blasted surface is formed by blasting, the first having a thickness of 11 μm or more and 15 μm or less formed on both surfaces of the insulating substrate 10 having a thickness of 25 μm or more and 65 μm or less in the circuit board material 1 ′. The copper layer 11 relaxes the pressure of the abrasive grains that collide with the circuit board material 1 ′ at a high speed, and the effect of suppressing elongation in the XY direction is enhanced. As a result, the position accuracy of the circuit board forming the unit product portion 1n in the block portion 1m formed by blasting can be kept within the design value ± 20 μm.

Further, according to the collective circuit board 1 of the present embodiment, the diameter is as large as φ30 μm to φ50 μm while maintaining the positional accuracy of the circuit board constituting the unit product part in the block part formed by blasting within the design value ± 20 μm. A very small diameter via hole can be formed.
Further, the narrowest part of the opening diameter in the blasted surfaces 10a-1 and 10a′-1 of the through holes 10a and 10a forming the product shape and the via hole is formed at a substantially intermediate depth position. For this reason, when the via fill plating is performed on the via hole in the unit product portion 1n of the collective circuit board 1, it is easy to stay on the inner wall surface at a substantially intermediate depth position in the via hole, and it is easy to fill the plating.

  Further, according to the method of manufacturing the collective circuit board 1 of the present embodiment, the narrowest portion of the opening diameter is formed at a substantially intermediate depth position on each of the blasted surfaces 10a-1, 10a′-1. As a result, the blasting time from both sides of the collective circuit board 1 can be substantially halved. For this reason, the film thickness of the resist film can be made the same on both sides of the substrate material 1 ′, and only one type of resist film is used for blasting. By making the blast processing time substantially the same, the processing time can be shortened to the minimum, so that the production efficiency is improved.

In the manufacturing process of FIG. 2, in the process of forming the through holes 10 a and 10 a ′ for forming the product shape and the via hole, the blasting is performed from one surface side of the substrate material 1 ′, and then the substrate material 1 ′ is formed. The through holes 10a and 10a ′ are formed by blasting from the other side. However, in the method of manufacturing the collective circuit board according to the embodiment of the present invention, blasting is simultaneously performed from both sides of the substrate material 1 ′. Accordingly, the through holes 10a and 10a ′ for forming the product shape and the via hole may be formed.
In this way, the blasting time can be greatly shortened.

  Moreover, according to the manufacturing method of the collective circuit board 1 of the present embodiment, since the blasting is used to form the product shape and the through holes 10a and 10a ′ for forming the via holes, the unit product is different from the drilling process. The predetermined product shape on the circuit board forming the part 1n can be processed with high accuracy, and the predetermined product shape and the via hole on the circuit board forming the unit product part 1n can be simultaneously formed. There is no carbonization, and, unlike press processing, the degree of freedom in design is wide and the manufacturing cost can be reduced.

  Therefore, according to the present embodiment, the elongation of the substrate material due to blasting can be suppressed, the position accuracy of the unit product in the block portion can be kept within the design value ± 20 μm, the processing accuracy is good, and the quality is not deteriorated. Thus, a collective circuit board that can be formed with low production cost and high production efficiency and a method for manufacturing the same are obtained.

Example 1
First, a substrate material 1 ′ having a first copper layer 11 having a thickness of 12 μm formed on both surfaces of an insulating base material 10 having a thickness of 60 μm was prepared (see FIG. 2A).
Next, guide holes serving as a positioning reference used in each step were formed by drilling in four locations of the substrate material 1 ′ (not shown).
Next, a glass in which a predetermined pattern for forming the through holes 10a and 10a ′ is drawn on both surfaces of the substrate material 1 ′ by laminating a first dry film resist having a predetermined thickness as a first resist layer. Exposure and development were performed using a mask to form a first resist mask 30 (see FIG. 2B).
Next, using the first resist mask 30 as an etching resist mask, the first copper layer 11 exposed from the openings of the first resist masks 30 on both sides is subjected to an etching process, and the first copper layer 11 is etched. The layer 11 was removed, and the insulating substrate 10 was exposed at the removed site (see FIG. 2 (c)).
Next, using the first resist mask 30 as a blasting mask, blasting is performed from one surface side, the insulating base material 10 is dug into a substantially half thickness, and the opening shape is a recess having a predetermined product shape. (Not shown) and a recess (not shown) having a circular opening shape were formed.
Next, from the other surface side of the insulating base material 10 exposed from the opening of the first resist mask 30, blasting is performed in the same manner as the one surface side, and the insulating base material 10 is dug to form an opening shape. Pass through the bottom surface of the recess (not shown) having a predetermined product shape and the bottom surface of the recess (not shown) having a circular opening shape to form an external shape of the circuit board and a via hole having an opening diameter of about φ30 to φ50 μm. Through holes 10a and 10a ′ to be formed were formed (see FIG. 2D).
Next, the first resist mask 30 was removed (see FIG. 2 (e)).
Next, etching was performed to reduce the thickness of the first copper layer 11 from 12 μm to 5 μm in the base material 1 ′ in which the through holes 10a and 10a ′ were formed by blasting (see FIG. 2 (f)). ).
Next, in order to establish conduction between the copper layers on the front and back sides, the substrate material 1 ′ is subjected to copper plating, and the surface of the thinned first copper layer 11 and the wall surfaces of the through holes 10a and 10a ′ are predetermined. A second copper layer 12 having a thickness was provided, and a copper layer formed by laminating the thinned first copper layer 11 and the second copper layer was formed to have a thickness of 12 μm (FIG. 2). (See (g)).
Next, a second dry film resist having a predetermined thickness is laminated on both surfaces of the substrate material 1 ′ as a second resist layer, and exposure and development are performed using a glass mask on which a predetermined circuit pattern is drawn. Then, a second resist mask 31 was formed (see FIG. 2 (h)).
Next, the copper layer composed of the first copper layer 11 and the second copper layer 12 exposed from the opening of the second resist mask 31 is etched to form a wiring circuit having a thickness of 12 μm. Formed (see Fig. 2 (i))
Finally, the second resist mask 31 was removed (see FIG. 2 (j)) to obtain the collective circuit board 1 of Example 1.

Example 2
A substrate material 1 ′ having a first copper layer 11 having a thickness of 12 μm formed on both surfaces of an insulating base material 10 having a thickness of 25 μm was prepared, and the same processing as in Example 1 was performed. However, in the blasting process, the through-holes were formed by adjusting the line speed to a speed at which a concave part having a depth of approximately half was formed, and by blasting the front and back surfaces.

Comparative Example 1
First, as in Example 1, a substrate material 1 ′ having a first copper layer 11 having a thickness of 12 μm formed on both surfaces of an insulating base material 10 having a thickness of 60 μm is prepared, and a guide hole for positioning is drilled. Next, etching is performed to prepare a substrate material 1 ′ of Comparative Example 1 having the first copper layer 11 having a thickness of 5 μm formed on both surfaces of the insulating base material 10 having a thickness of 60 μm. did.
Thereafter, as in Example 1, the first resist mask 30 is formed (see FIG. 2B), the insulating base material 10 is exposed by etching (see FIG. 2C), and the circuit board is blasted. The formation of the outer shape and the via hole (see FIG. 2D) and the removal of the first resist mask 30 (see FIG. 2E) were performed.
After the removal of the first resist mask 30, the etching process for thinning the first copper layer 11 was not performed.
Thereafter, as in Example 1, the formation of the second copper layer 12 (see FIG. 2G), the formation of the second resist mask 31 (see FIG. 2H), and the thickness by etching are 12 μm. The wiring circuit was formed (see FIG. 2 (i)) and the second resist mask 31 was removed (see FIG. 2 (j)) to obtain the collective circuit board 1 of Comparative Example 1.

Comparative Example 2
First, as in Example 1, a substrate material 1 ′ having a first copper layer 11 having a thickness of 12 μm formed on both surfaces of an insulating base material 10 having a thickness of 60 μm is prepared, and a guide hole for positioning is drilled. Next, etching is performed to prepare as a substrate material 1 ′ of Comparative Example 1 having the first copper layer 11 having a thickness of 8 μm formed on both surfaces of the insulating base material 10 having a thickness of 60 μm. did.
Thereafter, as in Example 1, the first resist mask 30 is formed (see FIG. 2B), the insulating base material 10 is exposed by etching (see FIG. 2C), and the circuit board is blasted. External shape and via hole formation (see FIG. 2 (d)), removal of the first resist mask 30 (see FIG. 2 (e)), formation of the second copper layer 12 (see FIG. 2 (g)), first 2 resist mask 31 (see FIG. 2 (h)), a wiring circuit having a thickness of 12 μm by etching (see FIG. 2 (i)), and removal of the second resist mask 31 (FIG. 2 (j) The collective circuit board 1 of Comparative Example 2 was obtained.

Evaluation of Positional Accuracy of Unit Products of Collective Circuit Boards of Example 1 and Comparative Examples 1 and 2 Positions of Individual Circuit Boards Forming Unit Product Part 1n in Collective Circuit Boards of Example 1 and Comparative Examples 1 and 2 The accuracy was measured and evaluated.
The position accuracy is measured by measuring the center position of each circuit board formed by blasting with respect to the design center position of each circuit board constituting the unit product part, with the center position of one block part as a reference origin. The magnitude of the difference from the design center value was expressed as position accuracy and evaluated.
FIG. 3 is a graph showing the positional accuracy of each collective circuit board manufactured by the collective circuit board manufacturing method according to Example 1 and Comparative Examples 1 and 2.
In FIG. 3, the upper part shows the positional accuracy of the collective circuit board of Comparative Example 1, the middle part shows Comparative Example 2, and the lower part shows Example 1. Further, the left graph in FIG. 3 shows the position of each block portion in the collective circuit board formed by blasting with respect to the design position of each block section in the collective circuit board shown in FIG. The center graph shows the position of each unit product portion on the collective circuit board formed by blasting. Further, the graph on the right side shows the standard deviation of the distribution of the deviation amount from the design position of each unit product part in the collective circuit board formed by blasting.

As shown in FIG. 3, the positional accuracy of each circuit board of the substrate material 1 ′ of Comparative Example 1 in which the first copper layer 11 is blasted with a thickness of 5 μm is −12 to +18 μm in the X direction, The Y direction was −28 to +19 μm, and the standard deviation was 5.2 μm in the X direction and 9.4 μm in the Y direction.
The positional accuracy of each circuit board of the substrate material 1 ′ of Comparative Example 2 in which the first copper layer 11 is blasted to a thickness of 8 μm is −10 to +7 μm in the X direction and −20 to +15 μm in the Y direction. The standard deviation was 3.3 μm in the X direction and 7.0 μm in the Y direction.
The positional accuracy of each circuit board of the substrate material 1 ′ of Example 1 in which the first copper layer 11 was blasted to a thickness of 12 μm is −8 to +6 μm in the X direction and −14 to +10 μm in the Y direction. The standard deviation was 2.9 μm in the X direction and 4.8 μm in the Y direction.
From this result, it was confirmed that the thicker the copper layer of the substrate material, the difference in thickness was several μm, and the elongation by blasting was suppressed.
The substrate material 1 ′ of Example 1 is a set in which the position accuracy of the circuit board forming the unit product part 1n of the block part is kept within the design value ± 20 μm by blasting a copper layer having a thickness of 11 μm or more. It was confirmed that a circuit board was obtained.
In addition, it was also confirmed that the substrate material 1 ′ of Example 1 can form via holes with a diameter of φ30 to φ50 μm while maintaining the positional accuracy of the circuit board within the design value ± 20 μm.
In the collective circuit board of Example 2, the positional accuracy of each circuit board constituting the unit product portion 1n was within a design value ± 20 μm in both the X direction and the Y direction (not shown). Note that the standard deviation in the Y direction was larger than 5.0 μm, and the variation in the distribution of the deviation amount from the design position of each unit product part was larger than that of the collective circuit board of Example 1.

  The collective circuit board and the manufacturing method thereof according to the present invention are required to form product shapes and via holes by blasting as an collective circuit board on which electronic components corresponding to the demands for miniaturization and thinning of various electronic devices are mounted. This is useful in a certain field.

DESCRIPTION OF SYMBOLS 1 Collective circuit board 1n Unit product part 1m Block part 1k Frame part 1 'Board | substrate material 10 Insulating base material 10a, 10a' Through-hole 10a-1, 10a'-1 Blasting surface 11 1st copper layer 12 2nd copper Layer 30 First resist mask 31 Second resist mask

Claims (2)

Formed on an insulating base, a through hole penetrating the insulating base, a first copper layer formed on both surfaces of the insulating base, a surface of the first copper layer, and a wall surface of the through hole A circuit having a predetermined wiring pattern including the first copper layer and the second copper layer is formed, and a predetermined product shape and a via hole are formed by the through hole. A circuit board that forms a unit product part, and a block part in which the circuit board is arranged in a matrix, and a frame part that surrounds the outer periphery of the block part,
The insulating substrate has a thickness of 25 μm or more and 65 μm or less,
Side surfaces of the insulating base material at a portion where the predetermined product shape is formed are blasted in a state where the first copper layer formed on both surfaces of the insulating base material has a thickness of 11 μm to 15 μm. Having a blasted surface formed by
The collective circuit board according to claim 1, wherein the first copper layer in a state where the second copper layer is formed has a thickness of 4 μm to 10 μm. Formed on an insulating base, a through hole penetrating the insulating base, a first copper layer formed on both surfaces of the insulating base, a surface of the first copper layer, and a wall surface of the through hole A circuit having a predetermined wiring pattern including the first copper layer and the second copper layer is formed, and a predetermined product shape and a via hole are formed by the plurality of through holes. A method of manufacturing an aggregate circuit board having a block portion in which circuit boards constituting the formed unit product portion are arranged in a matrix and a frame portion surrounding the outer periphery of the block portion, the following (a) to (j A method of manufacturing an aggregate circuit board, comprising the steps of:
(A) A step of preparing a substrate material having a first copper layer having a thickness of 11 μm or more and 15 μm or less formed on both surfaces of an insulating base material having a thickness of 25 μm or more and 65 μm or less.
(B) forming a first resist layer on both surfaces of the substrate material and forming a first resist mask for forming the through hole;
(C) The process of removing the said 1st copper layer exposed from the opening part of a said 1st resist mask by an etching process, and exposing the said insulating base material.
(D) forming a recess in which the thickness of the insulating base material is approximately half the thickness by blasting from one side of the insulating base material exposed in the opening of the first resist mask; And forming the through hole through the bottom surface of the recess by blasting from the other surface side.
(E) removing the first resist mask.
(F) A step of thinning the first copper layer to a thickness of 4 μm to 10 μm by etching.
(G) A step of forming, by plating, a second copper layer having a predetermined thickness on the surface of the thinned first copper layer and the wall surface of the through hole.
(H) forming a second resist layer on both surfaces of the substrate material on which the second copper layer is formed, and forming a second resist mask for forming the circuit;
(I) A step of forming the circuit by etching a copper layer composed of the first copper layer and the second copper layer exposed from the opening of the second resist mask.
(J) A step of removing the second resist mask.

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