JP2003086949A - Method for manufacturing printed substrate and printed substrate formed thereby - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a printed substrate easy to position contained electric elements and to provide the printed substrate formed by the method. SOLUTION: The method for manufacturing the printed substrate comprises the steps of forming a through hole 35 having substantially the same dimension as that of a profile of each of the electric elements 41 corresponding to positions to contain the elements 41 of one-side conductor pattern films 21, 31, laminating the films 21, 31, disposing the elements 41 in the hole 35 (Fig. (e)), and hot pressing the laminate from both sides to obtain the printed substrate 100 (Fig. (f)). Then, the electrodes 42 of the elements 41 are respectively electrically connected to conductor patterns 22, and a resin film 23 made of a thermoplastic resin of the base of each of the films 21, 31 is plastically deformed while being fusion-bonded to each other to seal the elements 41.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a printed board in which an electric element is incorporated in an insulating base material and a printed board formed by the method.

[0002]

2. Description of the Related Art Conventionally, there has been known a printed circuit board in which an electric element is built in an insulating base material in response to high density mounting of the electric element.

For example, there is a technique disclosed in Japanese Patent Laid-Open No. 11-31868. In this technique, after forming a plurality of insulating layers (resin film serving as an insulating base material) containing a thermosetting resin in a B stage state in which vias and conductor patterns are formed, for example, resin sealing is performed between these insulating layers. The resin films on which the electric elements are mounted are sandwiched and laminated, and pressure is applied to integrate them. After that, the laminated body is heated to cure the insulating layer to manufacture a printed circuit board containing an electric element.

[0004]

However, in the above-mentioned conventional technique, since the resin film having the electric element mounted thereon is sandwiched and laminated between the insulating layers, it is difficult to position the electric element with respect to the insulating base material. is there. When the displacement of the electric element occurs in the insulating base material, there may be a problem that the electric element and the via are not properly connected.

The present invention has been made in view of the above points,
It is an object of the present invention to provide a printed circuit board manufacturing method in which an electric element can be easily positioned with respect to an insulating base material, and a printed circuit board formed by the manufacturing method.

[0006]

In order to achieve the above object, in the method for producing a printed circuit board according to the present invention as set forth in claim 1, a laminating step of laminating a resin film (23) to be an insulating base material (39) is provided. , A disposing step of disposing the electric element (41) between the resin films (23), and a laminating step and after the disposing step, by heating the laminated body of the laminated resin film (23) while applying pressure from both sides, In a method for manufacturing a printed circuit board having a built-in electric element (41), which comprises a step of adhering the resin films (23) to each other, corresponding to the position where the electric element (41) is arranged before performing the laminating step. And a hole forming step of forming a through hole (35) having substantially the same size as the outer shape of the electric element (41) in the resin film (23).
Is inserted into the through hole (35).

According to this, the electric element (41) is positioned and held by the through hole (35) formed in the resin film (23) and having substantially the same size as the outer shape of the electric element (41). Therefore, the electric element (4
Positioning in 1) is easy.

In the method for manufacturing a printed circuit board according to the second aspect of the present invention, when the electric element (41) is thicker than the resin film (23), the through hole ( 35) Electric element (41) inserted in
The through holes (35) are formed at the same positions of the plurality of resin films (23) according to the thickness of the through holes (35).

According to this, one resin film (2
Even an electric element (41) thicker than the thickness of 3) can be easily positioned.

Further, in the method of manufacturing a printed circuit board according to the third aspect of the present invention, the total thickness of the resin film (23) forming the through holes (35) at the same position is the through holes (3).
5) It is characterized in that the thickness is substantially equal to or less than the thickness of the electric element (41) inserted inside.

According to this, at the interface (41a) with the insulating base material (39) in the vertical direction (the laminating direction of resin films, etc.) of the electric element (41) built in the printed circuit board (100), the electric element (41). It is difficult for the insulating base material (39) to be peeled off.

Further, in the method of manufacturing a printed circuit board according to the present invention, the electrode (42) is formed on the electric element (41) in the laminating direction of the resin film (23), and the resin film (23) is formed. The electrode (42) of the electric element (41) inserted into the through hole (35) before performing the stacking step.
Corresponding to the position of, the connecting material (50) is filled and the bottomed via hole (24) having the conductor pattern (22) at the bottom is formed, and the connecting material ( It is characterized by electrically connecting the electrode (42) of the electric element (41) and the conductor pattern (22) via 50).

According to this, when the resin film (23) serving as the insulating base material (39) is adhered to each other by heating while applying pressure in the adhering step to form the substrate (100), the electricity contained therein is formed. The element (41) and the conductor pattern (22) can be electrically connected. Therefore, the built-in electric element (41) and the conductor pattern (2
Since it is not necessary to make electrical connection with 2) before the bonding step, the manufacturing process can be simplified.

In the method of manufacturing a printed circuit board according to the fifth aspect of the present invention, the conductor pattern (22) is formed on the resin film (23) before the laminating step and before the arranging step. The electrically conductive pattern (22) and the electrode (42) of the electric element (41) are electrically connected.

According to this, the conductor pattern (22) and the electrode (42) of the electric element (41) are subjected to the arrangement step.
A resin film (23) electrically connected to and can be obtained. Therefore, by using the conductor pattern (22) connected to the electrode (42) of the electric element (41), the electric element (4)
The inspection of 1) can be easily performed.

Further, as in the method for manufacturing a printed circuit board according to the sixth aspect of the present invention, the electrode (42) is formed on the electric element (41) in the laminating direction of the resin film (23),
The electrode (4) of the electric element (41) inserted into the through hole (35) is formed on the resin film (23) before the laminating step.
Corresponding to the position of 2), the connecting material (50) is filled and the bottomed via hole (24) having the conductor pattern (22) at the bottom is formed, and the connecting material (50) is formed before the arranging step. Through the electrode (42) of the electric element (41)
And the conductor pattern (22) can be electrically connected.

Further, as in the method for manufacturing a printed circuit board according to the seventh aspect of the present invention, the electrode (42a) is formed in the electric element (41a) in the laminating direction of the resin film (23), and the resin film ( 23), the conductor pattern (2) corresponding to the position of the electrode (42a) of the electric element (41a) inserted into the through hole (35) before the lamination step.
2) is formed as a land portion (22a), and the electrode (42a) of the electric element (41a) and the land portion (22a) of the conductor pattern (22) can be electrically connected before performing the arrangement step. it can.

Further, as in the printed circuit board manufacturing method of the invention described in claim 8, the electrode (42a) is formed on the electric element (41a) in the laminating direction of the resin film (23), and the resin film ( In (23), the conductor pattern (22) is formed as a land portion (22a) before performing the laminating step, and the electrode (42a) of the electric element (41a) and the conductor pattern (22) are formed before performing the arranging step. Land part (2
2a) can be electrically connected by wire bond.

In the method of manufacturing a printed circuit board according to the ninth aspect of the invention, the resin film (23) to be laminated is used.
Is characterized by being made of a thermoplastic resin.

According to this, when heating while applying pressure in the bonding step, the resin film (23) is plastically deformed in the direction of the through hole (35) in which the electric element (41) is inserted, and the electric element (41). Can be easily sealed.

In the method for manufacturing a printed circuit board according to the tenth aspect of the invention, the resin film (23) to be laminated is used.
Are made of the same material.

According to this, the resin films (23) are easily bonded to each other. Therefore, it is possible to obtain a printed board provided with an insulating base material in which the resin films (23) are securely bonded to each other.

Further, in the method for manufacturing a printed circuit board according to the invention as set forth in claim 11, the resin film (23) has a modulus of elasticity of 1 to 1000 MPa at a heating temperature in the bonding step.

According to this, in the bonding step, the resin films (23) can be reliably bonded to each other by applying pressure while the elastic modulus of the resin films (23) is sufficiently reduced to 1 to 1000 MPa. . Further, the resin film (23) is easily plastically deformed in the direction of the through hole (35) in which the electric element (41) is inserted, and the electric element (4
1) can be reliably sealed.

Further, in the method of manufacturing a printed circuit board according to the invention of claim 12, the laminated resin film (23) is used.
In the above, the resin film (2
It is characterized by including a base member forming step of forming a metal base member (46) on the outer side surface of 3).

According to this, it is possible to obtain the printed circuit board (100) having the metal base member (46) on the outermost surface. For example, when it is necessary to provide a metal base member on the surface of the printed circuit board for the purpose of heat dissipation from the printed circuit board, the electric element cannot be mounted on the surface where the metal base member is provided. Possible area is reduced. Therefore, the printed circuit board having the electric element (41) built-in for high-density mounting and the metal base member (46) on the outermost surface can be effectively obtained.

In the method for manufacturing a printed circuit board according to the thirteenth aspect of the present invention, the resin film (23) and the metal base member (4) are formed after the laminating step and the base member forming step.
The resin film (23) and the metal base member (4) are heated by pressurizing the laminate with 6) from both sides.
6) The feature is that they are adhered to each other.

According to this, each resin film (23) and the metal base member (46) can be bonded together. Therefore, even in the printed circuit board (100) including the metal base member (46), the manufacturing process can be simplified.

Further, according to the method for manufacturing a printed circuit board according to any one of claims 1 to 4, claim 1 to claim 4, and claim 10, the same method as in the invention according to claim 14 is obtained. After the resin film (23) made of a thermoplastic resin is laminated, the insulating base material (39) adhered to each other by heating while applying pressure, and the through hole (3) in the resin film (23).
5) is arranged in the space (36) formed in the insulating base material (39) by providing 5), and the electrode (42) formed in the laminating direction of the resin film (23) has vias (24, 51). And an electric element (41) connected to the conductor pattern (22) via the electric element (41).
Is sealed by the resin film (23) extruded toward the space (36) by being heated while being pressurized, and the electric element (41) is incorporated in the insulating base material (39). A characteristic printed circuit board (100) can be formed.

This is because the built-in electric element (41)
The resin films (23) are positioned with respect to the insulating base material (39) formed by surely adhering to each other, and are surely electrically connected to the conductor pattern (22), and also securely in the insulating base material (39). Printed circuit board sealed in (100)
Is.

Further, claims 1 to 3, claim 5, claim 1
~ Claims 3 to 5 and claim 1
The printed circuit board manufacturing method according to claim 1,
As in the invention described in 5, the resin film (23) made of the same thermoplastic resin is laminated and then heated under pressure while being adhered to each other, and the resin film (23).
By providing a through hole (35) in the insulating substrate (3
9) an electric element (41) which is arranged in a space (36) formed in the electrode and has an electrode (42) connected to the conductor pattern (22), the electric element (41) being pressurized. A print characterized in that it is sealed by a resin film (23) extruded in the direction of the space (36) by being heated while being enclosed, and an electric element (41) is built in an insulating base material (39). A substrate can be formed.

This is because the built-in electric element (41)
The resin films (23) are positioned with respect to the insulating base material (39) formed by surely adhering to each other, and are surely electrically connected to the conductor pattern (22), and also securely in the insulating base material (39). Printed circuit board sealed in (100)
Is.

Further, in the printed circuit board according to the sixteenth aspect of the present invention, the resin film (23) has an elastic modulus of 1 to 1000 M at a heating temperature when heated under pressure.
It is characterized by being Pa.

According to this, when the resin film (23) is heated while being pressurized, the elastic modulus of the resin film (23) is 1 to 1000 MP.
Insulating substrate (3) in which each resin film (23) is surely adhered to each other by applying pressure in a state sufficiently reduced with a.
9). Further, the resin film (23) is easily plastically deformed in the direction of the space portion (36) in which the electric element (41) is arranged, and the extruded resin film (23) surely seals the electric element (41). To be done.

The printed circuit board according to the seventeenth aspect of the present invention is characterized in that the metal base member (46) is adhered to the surface of the insulating base material (39).

For example, when it is necessary to provide a metal base member on the surface of the printed circuit board for the purpose of heat dissipation from the printed circuit board, an electric element can be mounted on the surface where the metal base member is provided. Therefore, the mountable area is reduced. Therefore, as in the present invention, in addition to incorporating the electric element (41) to cope with high-density mounting,
The effect of providing the metal base member (46) on the surface is great.

The reference numerals in parentheses attached to the above-mentioned means indicate the correspondence with the specific means described in the embodiments to be described later.

[0038]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIGS. 1A to 1C are cross-sectional views showing the steps of manufacturing a printed circuit board according to this embodiment.

In FIG. 1A, reference numeral 21 denotes a conductor pattern 22 formed by etching a conductor foil (a copper foil having a thickness of 18 μm in this example) attached to one surface of a resin film 23 which is an insulating base material. It is a single-sided conductor pattern film having. In this example, the resin film 23 has a thickness of 75 [mu] m composed of 65 to 35% by weight of polyetheretherketone resin and 35 to 65% by weight of polyetherimide resin.
m thermoplastic resin film is used.

As shown in FIG. 1A, the conductor pattern 2
When the formation of 2 is completed, next, as shown in FIG. 1B, a carbon dioxide laser is irradiated from the resin film 23 side to form a via hole 24 which is a bottomed via hole having the conductor pattern 22 as a bottom surface. The via holes are formed by adjusting the output of the carbon dioxide gas laser, the irradiation time, and the like so that holes are not formed in the conductor pattern 22.

In order to form the via hole 24, an excimer laser or the like can be used in addition to the carbon dioxide gas laser. A via hole forming method such as drilling other than laser is also possible, but drilling with a laser beam is preferable because the hole can be formed with a fine diameter and the conductor pattern 22 is less damaged.

As shown in FIG. 1B, the via hole 24
When the formation of is completed, next, as shown in FIG.
The via hole 24 is filled with a conductive paste 50 which is an electrical connection material. The conductive paste 50 has an average particle size of 5μ.
m, 300 g of tin particles having a specific surface area of 0.5 m ² / g, and 300 g of silver particles having an average particle diameter of 1 μm and a specific surface area of 1.2 m ² / g.
In addition, a solution prepared by dissolving 6 g of ethyl cellulose resin in 60 g of terpineol, which is an organic solvent, was added and kneaded with a mixer to form a paste.

Here, the ethyl cellulose resin is added to the conductive paste 50 in order to impart shape retention,
An acrylic resin or the like can be used as the shape-retaining agent.

The conductive paste 50 is printed and filled in the via holes 24 of the one-sided conductor pattern film 21 by a screen printing machine using a metal mask, and then 140 to
Dry the terpineol at 160 ° C. for about 30 minutes. The conductive paste 50 is filled in the via holes 24 by using a screen printing machine in this example, but other methods using a dispenser or the like are also possible as long as the filling can be surely performed.

Although it is possible to use other than terpineol as the organic solvent added for forming the paste, it is preferable to use an organic solvent having a boiling point of 150 to 300 ° C. An organic solvent having a boiling point of lower than 150 ° C. is likely to cause a problem that the viscosity of the conductive paste 50 changes greatly with time. On the other hand, an organic solvent having a boiling point of higher than 300 ° C. is not preferable because it takes a long time to dry.

In this example, the metal particles forming the conductive paste 50 have an average particle size of 5 μm and a specific surface area of 0.5.
m ² / g tin particles, average particle size 1 μm, specific surface area 1.2
m ² / g of silver particles were used.
It is preferable that the average particle size is 0.5 to 20 μm and the specific surface area is 0.1 to 1.5 m ² / g.

When the average particle size of the metal particles is less than 0.5 μm or the specific surface area exceeds 1.5 m ² / g,
A large amount of organic solvent is required to form a paste having a viscosity suitable for filling via holes. A conductive paste containing a large amount of an organic solvent requires a long time to dry, and if the drying is insufficient, a large amount of gas is generated by heating during interlayer connection, so that voids are easily generated in the via hole 24, and Reduce connection reliability.

On the other hand, when the average particle diameter of the metal particles exceeds 20 μm or the specific surface area is less than 0.1 m ² / g, it becomes difficult to fill the via holes 24 and the metal particles are apt to be unevenly distributed. There is a problem that it is difficult to form a conductive composition 51, which will be described later, made of a uniform alloy even when heated, and it is difficult to secure interlayer connection reliability, which is not preferable.

Further, the conductive paste 5 is placed in the via hole 24.
Before filling 0 with the via hole 24 of the conductor pattern 22.
The part facing the surface may be thinly etched or reduced. According to this, the via connection described later is more favorably performed.

On the other hand, in FIG. 1 (d), 31 is similar to the one-sided conductor pattern film 21 shown in FIGS.
A single-sided conductor pattern film in which the conductor pattern 22 is formed, the via holes 24 are formed, and the conductive paste 50 is filled in the resin film 23 which is the insulating base material by the process shown in (c).

When the via hole 24 shown in FIG. 1B is formed in the single-sided conductor pattern film 31, the electric element 41 is laser-processed at a position corresponding to the arrangement position of the electric element 41 to be incorporated, which will be described later. A through hole 35 having substantially the same size as the outer shape is formed. The size of the through hole 35 is such that when the electric element 41 is inserted into the through hole 35, the clearance between the electric element 41 and the resin film 23 is 20 μm or more over the entire circumference of the electric element 41 and the resin film 2
It is preferable that the thickness is 3 (75 μm in this example) or less.

The through hole 35 is formed by laser processing when forming the via hole 24, but it may be formed by punching or router processing separately from the formation of the via hole 24.

Here, as the resin film 23 of the one-sided conductor pattern film 31, in this example, in the same manner as the resin film 23 of the one-sided conductor pattern film 21, the polyether ether ketone resin 65 to 35 wt% and the polyether imide resin 35 are used. A thermoplastic resin film having a thickness of 75 wt.

When the formation of the through holes 35 in the single-sided conductor pattern film 31, the filling of the conductive paste 50 in the via holes 24 of the single-sided conductor pattern films 21, 31 and the drying are completed, as shown in FIG. 1 (e). A plurality of single-sided conductor pattern films 21 and 31 (five in this example) are laminated.

At this time, the single-sided conductor pattern film 2
1 and 31 are laminated with the side on which the conductor pattern 22 is provided as the upper side. That is, the single-sided conductor pattern film 2
The layers 1 and 31 are laminated so that the surface on which the conductor pattern 22 is formed faces the surface on which the conductor pattern 22 is not formed.

Here, the single-sided conductor pattern in which the through hole 35 is provided at the same position so that the thickness of the space portion 36 formed by the through hole 35 is substantially equal to or less than the thickness of the electric element 41 described later. Multiple sheets of film 31 (two sheets in this example)
Adjacent and stacked. In this example, since the thickness of the electric element 41 is 160 μm, the dimension in the thickness direction is 75 μm so that the thickness of the space 36 is substantially equal to or less than this.
So that the two through holes 35 are adjacent to each other (that is, the space 3
The single-sided conductor pattern film 31 was laminated so that 6 had a thickness of 150 μm).

Further, the single-sided conductor pattern films 21, 3
When laminating the 1's, an electric element 41 such as a resistor, a capacitor, a filter or an IC is inserted in the space 36 formed by the through hole 35. Electric element 41
The electrodes 42 are formed on both ends of the single-sided conductor pattern films 21, 31 including the surfaces in the stacking direction.

Then, in the single-sided conductor pattern film 21 laminated on the upper side of the space 36 in which the electric element 41 is inserted, the conductive paste 50 is provided at a position where the conductor pattern 22 and the electrode 42 can be electrically connected. A via hole 24 filled with is arranged.

Further, a heat sink 46 made of aluminum is laminated on the lower side of the laminated single-sided conductor pattern films 21, 31. Heat sink 4
6 is a metal base member in the present embodiment. By the way, the lowermost resin film 2 that contacts the heat sink 46
The via hole 24 is not formed in No. 3.

After laminating the single-sided conductor pattern films 21 and 31 and the heat sink 46 as shown in FIG. 1 (e), pressure is applied from above and below on both sides by heating with a vacuum heating press. In this example, it was heated to a temperature of 250 to 350 ° C. and pressurized at a pressure of 1 to 10 MPa for 10 to 20 minutes.

As a result, as shown in FIG. 1F, the single-sided conductor film patterns 21, 31 and the heat sink 46 are adhered to each other. Since the resin films 23 are all made of the same thermoplastic resin material, the insulating film 39 can be easily heat-sealed and integrated.

Further, the conductive paste 50 in the via hole 24 is sintered and integrated with the conductive composition 51 to connect the adjacent conductor patterns 22 to each other, and the electrodes 42 of the electric element 41 and the conductor pattern 22 are connected to each other. Are connected, and a multilayer printed circuit board 100 having the electric element 41 built therein is obtained. Here, the conductive composition 51 is an electrical connection material, and the via hole 24 and the conductive composition 51 form the via of the present embodiment.

Here, the mechanism of interlayer connection of the conductor pattern 22 will be briefly described. The conductive paste 50 filled in the via holes 24 and dried is in a state in which tin particles and silver particles are mixed. And this paste 50 is 2
When heated to 50 to 350 ° C, the melting point of tin particles is 232.
Since the melting point of the silver particles is 961 ° C., the tin particles melt and adhere to cover the outer circumference of the silver particles.

When heating is continued in this state, the molten tin begins to diffuse from the surface of the silver particles and forms an alloy of tin and silver (melting point 480 ° C.). At this time, the conductive paste 50
Since a pressure of 1 to 10 MPa is applied to, the conductive composition 51 made of an alloy integrated by sintering is formed in the via hole 24 with the formation of the alloy of tin and silver.

When the conductive composition 51 is formed in the via hole 24, since the conductive composition 51 is pressurized, it is pressed against the surface of the conductor pattern 22 constituting the bottom portion of the via hole 24. It Thereby, the tin component in the conductive composition 51 and the copper component of the copper foil forming the conductor pattern 22 are solid-phase diffused with each other, and the conductive composition 51 is formed.
A solid phase diffusion layer is formed at the interface between the conductor pattern 22 and the conductor pattern 22 to electrically connect them.

Further, the electrode 42 of the electric element 41 is formed by forming a tin plating layer or the like on the surface of a metal member such as copper or nickel, and by the mechanism similar to the above-mentioned interlayer connection of the conductor pattern 22, a via hole is formed. A conductive composition 51 formed in the conductive layer 24 and a solid phase diffusion layer formed at the interface between the conductive composition 51 and the conductor pattern 22 and at the interface between the conductive composition 51 and the electrode 42; Pattern 22
To be electrically connected to.

The elastic modulus of the resin film 23 is about 5 to 40 when being heated while being pressurized by a vacuum heating press.
It has fallen to MPa. Therefore, the resin film 23 around the through hole 35 tends to be deformed so as to be pushed into the through hole 35. Further, the resin film 23 located in the film stacking direction of the through holes 35 also tries to be deformed so as to be pushed into the through holes 35. That is, the resin film 23 around the space 36 is extruded toward the space 36.

As a result, the electric element 41 is sealed by the insulating base material 39 which is integrated while the resin film 23 is deformed. The elastic modulus of the resin film 23 during hot pressing is preferably 1 to 1000 MPa. When the elastic modulus is greater than 1000 MPa, it is difficult for the resin films 23 to be heat-sealed together and the resin film 23 is not easily deformed. Further, when the elastic modulus is less than 1 MPa, the resin film easily flows under pressure, and it is difficult to form the printed board 100.

Further, as described above, the resin film 23
The size of the through hole 35 formed in the above is such that the clearance between the electric element 41 and the resin film 23 is 20 μm or more over the entire circumference of the electric element 41 and the thickness of the resin film 23 (75 μm in this example) or less. did. This is because it is difficult to insert the electric element 41 into the through hole 35 when the clearance is less than 20 μm, and when the clearance is larger than the thickness of the resin film 23, the electric element 41 is completely sealed even if the resin film 23 is deformed by heating press. This is because it is difficult to stop.

Further, as described above, when the single-sided conductor pattern films 21 and 31 are laminated, the thickness of the space portion 36 (that is, the total thickness of the resin film 23 in which the through holes 35 are formed) is the thickness of the electric element 41. The single-sided conductor pattern film 3 having the through holes 35 so as to be substantially equal to or less than
The number of laminated sheets of 1 was determined.

This is because the thickness of the space 36 is equal to that of the electric element 41.
If the thickness of the electric element 41 is greater than
2A, the upper and lower surfaces of the portion of the printed circuit board 100 in which the electric elements 41 are embedded have a concave shape. Printed circuit board 100 in this state
However, when placed in, for example, a high temperature environment, the insulating base material 39 located in the upper and lower surface directions of the electric element 41 (the laminating direction of the resin films 23) tends to return to a flat shape.

As a result, stress in the peeling direction is generated at the interface 41a with the insulating base material 39 in the vertical direction of the electric element 41,
The inconvenience of lowering the reliability of insulation and sealing of the electric element 41 is likely to occur.

When the thickness of the space portion 36 is equal to or less than the thickness of the electric element 41, the upper and lower surfaces of the portion containing the electric element 41 are flat or convex as shown in FIG. 2 (b). Become. When the printed circuit board 100 is placed in, for example, a high temperature environment and the insulating base material 39 tries to return to a flat shape when it has a convex shape, the insulating base material 39 in the vertical direction of the electric element 41 is formed.
At the interface 41a with and, pressure is generated and stress in the peeling direction is unlikely to occur.

The thickness of the space 36 is preferably equal to or less than the thickness of the electric element 41. However, if the stress in the peeling direction is small enough to cause no problem, the thickness of the space 36 is smaller than that of the electric element 41. It may be slightly larger than the thickness. If the thickness of the space 36 is much smaller than the thickness of the electric element 41, the convex portion on the surface of the printed circuit board 100 becomes large, and the electric element is connected when this portion becomes the surface mounting portion of the electric element. Inconveniences such as difficulty in performing may occur.

In the manufacturing process described above,
The step of forming the through hole 35 shown in (d) is the hole forming step in the present embodiment, and the step shown in FIG. 1 (e) is the laminating step, the arranging step and the base member forming step in the present embodiment. The step of forming the printed board 100 shown in FIG. 1 (f) by hot pressing the laminated body shown in FIG. 1 (e) is the bonding step in this embodiment.

According to the above-described manufacturing method and the structure obtained by the manufacturing method, the built-in electric element 41 has the insulating base material 39 in which the resin films 23 are securely bonded to each other.
A printed circuit board 100 that is positioned relative to the conductive pattern 22 and is surely electrically connected to the conductor pattern 22 and that is surely sealed in the insulating base material 39 is obtained.

The printed circuit board 100 is a substrate having a heat sink 46 on the lower surface. As shown in FIG. 1F, the electric element 61 is surface-mounted on the upper surface of the printed circuit board 100 and the electric element 41 is built in. By doing so, it is possible to cope with high-density mounting while having good heat dissipation.

Further, the single-sided conductor pattern films 21, 3
1 and the heat sink 46 are integrally laminated, the interlayer connection between the conductor patterns 22 and the connection between the electric element 41 and the conductor pattern 22 can be simultaneously performed by heating while applying pressure. Therefore, the number of processing steps of the printed circuit board 100 can be reduced, and the manufacturing cost can be reduced.

(Second Embodiment) Next, a second embodiment will be described with reference to the drawings.

The second embodiment differs from the first embodiment in the step of connecting the electric element 41 and the conductive pattern 22. The same parts as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

Similar to the first embodiment shown in FIGS. 1A to 1C, when the formation of the conductor pattern 22, the formation of the via holes 24, and the filling of the conductive paste 50 are completed, as shown in FIG. After the electric element 41 is arranged on the surface of the single-sided conductor pattern film 21 laminated on the upper side of the space portion 36 in the process, on which the conductor pattern 22 is not formed, pressure is applied from both sides while heating.

The single-sided conductor pattern film 21 includes
Via hole 2 which is a bottomed via hole filled with conductive paste 50 corresponding to the position of electrode 42 of electric element 41.
4 are formed. Then, the conductive paste 50 in the via hole 24 is sintered by the above-mentioned heat pressing to form an integrated conductive composition 51, and as shown in FIG. 3, the electrode 42 of the electric element 41 and the conductor pattern 22 are electrically connected. Connected to.

On the other hand, similar to the first embodiment shown in FIG. 1D, the single-sided conductor pattern film 31 having the through holes 35 is formed. Formation of through-hole 35 in single-sided conductor pattern film 31, single-sided conductor pattern films 21, 31
Filling and drying the conductive paste 50 in the via holes 24 of the electric element 41 on the single-sided conductor pattern film 21.
When the connection is completed, in the second embodiment, as shown in FIG. 4, the single-sided conductor pattern films 21 and 31 are laminated together with a plurality of (five in this example) heat sinks 46.

The steps shown in FIG. 4 are the stacking step, the arranging step and the base member forming step in this embodiment. In these steps, the present embodiment is different from the first embodiment in that the electrode 42 of the electric element 41 is already electrically connected to the conductor pattern 22 of the single-sided conductor pattern film 21. This is that the conductive paste in the via holes 24 of the connected single-sided conductor pattern film 21 is the conductive composition 51.

The dimensional relationship of the through-hole 35 formed in the single-sided conductor pattern film 31 and the space 36 formed by the through-hole 35 with respect to the electric element 41 is the same as in the first embodiment. is there.

As shown in FIG. 4, when the single-sided conductor pattern films 21, 31 and the heat sink 46 are laminated,
As in the first embodiment, pressure is applied while heating, and as shown in FIG.
A multilayer printed circuit board 100 including the electric element 41 as shown in (f) is obtained. Even if the conductive composition 51 is already formed in the via hole 24 of the single-sided conductor pattern film 21 before hot pressing, the tin component in the conductive composition 51 and the conductive pattern 22 are formed at the time of hot pressing. The copper components of the copper foil to be solid-phase diffused with each other, forming a solid-phase diffusion layer at the interface between the conductive composition 51 and the conductor pattern 22 to electrically connect.

According to the above-described manufacturing method and the structure obtained by the manufacturing method, as in the first embodiment, the built-in electric element 41 has the insulating base material in which the resin films 23 are securely bonded to each other. It is possible to obtain the printed circuit board 100 that is positioned with respect to 39, is surely electrically connected to the conductor pattern 22, and is surely sealed in the insulating base material 39.

The printed board 100 is a board having a heat sink 46 on the lower surface. As shown in FIG. 1F, the electric element 61 is surface-mounted on the upper surface of the printed board 100 and the electric element 41 is built in. By doing so, it is possible to cope with high-density mounting while having good heat dissipation.

Further, the single-sided conductor pattern films 21, 3
1 and the heat sink 46 can be integrated at the same time and the interlayer connection between the conductor patterns 22 can be simultaneously performed by heating while applying pressure.

Further, in this embodiment, the electric element 41 is connected to the conductor pattern 22 of the single-sided conductor pattern film 21 before laminating the respective one-sided conductor pattern films 21 and the like. Therefore, before incorporating the electric element 41, the electric element 41 can be easily inspected by utilizing the conductor pattern 22 of the single-sided conductor pattern film 21 to which the electric element 41 is connected.

This is because when the electric element 41 is inspected by itself, it is necessary to establish electrical connection with the electrode 42 of the electric element 41. Therefore, especially when the electric element 41 is extremely small, the effect of utilizing the conductor pattern 22 is great. Further, since the inspection can be performed before the electric element 41 is built in, it is possible to prevent the printed circuit board 100 from being a defective product even if the electric element 41 has a defect.

(Other Embodiments) In each of the above embodiments, the single-sided conductor pattern films 21 and 31 are laminated as shown in FIG. 1 (e) or FIG. 4 at the time of manufacturing a printed circuit board, but the laminated pattern is not limited thereto. Not something.
A double-sided conductor pattern film, a single-sided conductor pattern film, and a resin film on which no conductor pattern is formed may be appropriately combined and laminated. However, by laminating only the single-sided conductor pattern film as in the above embodiment, the manufacturing process can be simplified.

As a combination of the single-sided conductor pattern films 21 and 31 and the resin film 23 on which the conductor pattern is not formed and laminated, there are, for example, laminated patterns shown in FIGS. Among these, especially in FIGS.
As shown in FIG. 6, when the through hole 35 for inserting the electric element 41 is provided only in the resin film 23 in which the conductor pattern is not formed, there is an advantage that the degree of freedom in circuit design in the substrate is improved.

In addition, in the second embodiment, as shown in FIG.
As shown in FIG. 5, the conductor pattern 22 of the single-sided conductor pattern film 21 and the electrode 42 of the electric element 41 were connected by the conductive composition 51 obtained by sintering the conductive paste 50 filled in the via hole 24. The connection may be made without the conductive composition 51.

For example, as shown in FIG.
When the electrode 42a is formed in the film laminating direction of 1a and the gold bump is formed on the surface of the electrode 42a, after the nickel gold plating layer 22b is formed on the surface of the land portion 22a of the conductor pattern 22, the electrode 42a is formed. 42a and the land portion 22a may be joined by pressure bonding processing, ultrasonic processing, or the like.

Further, for example, as shown in FIG. 11, when the electrode 42a made of aluminum is formed in the film laminating direction of the electric element 41a, the conductor pattern 2 is formed.
After the gold bump 22c is formed on the nickel gold plating layer 22b formed on the surface of the second land portion 22a, the electrode 42
The a and the land portion 22a may be joined by pressure bonding processing, ultrasonic processing, or the like.

Further, for example, as shown in FIG. 12, when the electrode 42a made of aluminum is formed in the film laminating direction of the electric element 41a, the conductor pattern 2 is formed.
No. 2 land portion 22a has a nickel gold plating layer 22b on the surface.
After forming, the electrode 42a and the land portion 22a may be wire-bonded and connected.

In each of the above examples, the electrode of the electric element is
Although it is formed in the film laminating direction of the electric element, the electrode may be formed in a direction other than the film laminating direction as long as it can be electrically connected to the conductor pattern.

In each of the above embodiments, the resin film 23 is made of polyetheretherketone resin 65 to 65.
35 wt% and polyetherimide resin 35-65 wt%
Although a resin film made of is used, the film is not limited to this, and may be a film in which a non-conductive filler is filled in a polyetheretherketone resin and a polyetherimide resin, or a polyetheretherketone (PEEK) or a polyetheretherketone. It is also possible to use ether imide (PEI) alone.

Furthermore, polyphenylene sulfide (P
A thermoplastic resin such as PS), a thermoplastic polyimide, or a so-called liquid crystal polymer may be used. A resin film having an elastic modulus of 1 to 1000 MPa at the heating temperature at the time of hot pressing and having heat resistance necessary for a soldering step which is a post-step can be preferably used.

In each of the above embodiments, the through hole 3
Although the surface of the electric element 41 inserted in the member 5 is not subjected to any treatment, it may be subjected to a surface treatment for improving the adhesion with the resin film 23, an adhesive coating, or the like. .

Further, in each of the above embodiments, the heat sink 46 is provided on the entire surface of one side of the printed circuit board 100, but it may be provided on a part of one side or on both sides. Good. Further, it is needless to say that a printed circuit board without the heat sink 46 may be used if there is no demand for improvement of heat dissipation.

When the heat sink 46 is provided, the adhesive surface of the heat sink 46 to the insulating substrate 39 contains, for example, a polyetherimide sheet or a heat conductive filler for the purpose of improving the adhesiveness and the thermal conductivity. A so-called bonding sheet such as a thermosetting resin sheet or a thermoplastic resin sheet containing a thermally conductive filler may be formed.

In each of the above embodiments, the printed circuit board 100 is a five-layer board, but it goes without saying that the number of layers is not limited.

[Brief description of drawings]

FIG. 1 is a cross-sectional view for each process showing a schematic manufacturing process of a printed circuit board according to a first embodiment of the present invention.

2A and 2B are explanatory views showing a state where the surface of the printed circuit board has an uneven shape, where FIG. 2A is a concave shape regardless of the present embodiment, and FIG. 2B is a convex shape according to the present embodiment. The shape is shown.

FIG. 3 is a cross-sectional view showing a part of a schematic manufacturing process for a printed circuit board according to a second embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a part of a schematic manufacturing process of a printed circuit board according to a second embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a part of a schematic manufacturing process of a printed circuit board according to another embodiment of the present invention.

FIG. 6 is a cross-sectional view showing a part of a schematic manufacturing process of a printed circuit board according to another embodiment of the present invention.

FIG. 7 is a cross-sectional view showing a part of a schematic manufacturing process of a printed circuit board according to another embodiment of the present invention.

FIG. 8 is a cross-sectional view showing a part of a schematic manufacturing process of a printed circuit board according to another embodiment of the present invention.

FIG. 9 is a cross-sectional view showing a part of a schematic manufacturing process of a printed circuit board according to another embodiment of the present invention.

FIG. 10 is a cross-sectional view showing a part of a schematic manufacturing process of a printed circuit board according to another embodiment of the present invention.

FIG. 11 is a cross-sectional view showing a part of a schematic manufacturing process of a printed circuit board according to another embodiment of the present invention.

FIG. 12 is a cross-sectional view showing a part of a schematic manufacturing process of a printed circuit board according to another embodiment of the present invention.

[Explanation of symbols]

21, 31 Single-sided conductor pattern film 22 Conductor pattern 22a Land part 23 Resin film 24 Via holes (bottomed via holes, part of vias) 35 through hole 36 Space Department 39 Insulating material 41 Electric element 41a Interface 42 electrodes 46 Heat sink (metal base member) 50 Conductive paste (connection material) 51 Conductive composition (connecting material, part of via) 100 printed circuit board

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Toshihiro Miyake             1-1, Showa-cho, Kariya city, Aichi stock market             Inside the company DENSO (72) Inventor Satoshi Takeuchi             1-1, Showa-cho, Kariya city, Aichi stock market             Inside the company DENSO F term (reference) 5E346 AA05 AA12 AA15 AA22 AA32                       AA43 AA51 BB16 CC02 CC08                       DD02 DD12 DD32 EE09 EE13                       EE15 FF01 FF18 FF45 GG15                       GG19 GG22 GG28 HH17 HH31

Claims (17)

[Claims] 1. A laminating step of laminating a resin film (23) to be an insulating base material (39), an arranging step of arranging an electric element (41) between the resin films (23), the laminating step and After the arranging step, a bonding step of bonding the resin films (23) to each other by heating the laminated body of the resin films (23) while applying pressure from both sides, the electric element (41) In the method for manufacturing a printed circuit board having a built-in board, before the stacking step, the outer shape of the electric element (41) is substantially formed on the resin film (23) at a position where the electric element (41) is arranged. Through holes of the same size (3
5) The hole forming step of forming 5), wherein in the arranging step, the electric element (41) is inserted into the through hole (35). 2. The electric element inserted into the through hole (35) in the hole forming step when the electric element (41) is thicker than the resin film (23). The method for manufacturing a printed circuit board according to claim 1, wherein the through holes (35) are formed at the same positions of the plurality of resin films (23) according to the thickness of the (41). 3. The total thickness of the resin film (23) forming the through hole (35) at the same position is the thickness of the electric element (41) inserted in the through hole (35). 3. The method for manufacturing a printed circuit board according to claim 2, which is substantially equal to or less than the above. 4. An electrode (42) is formed on the electric element (41) in a laminating direction of the resin film (23), and the electric film (23) is formed on the resin film (23) before the laminating step. Corresponding to the position of the electrode (42) of the electric element (41) inserted into the through hole (35), the connecting material (50) is filled and the conductor pattern (22) is the bottomed bottom. A via hole (24) is formed, and by heating while applying pressure in the bonding step,
The electric element (41) through the connection material (50)
The method for producing a printed circuit board according to claim 1, wherein the electrode (42) and the conductor pattern (22) are electrically connected. 5. The conductor pattern (22) is formed on the resin film (23) before performing the laminating step, and the conductor pattern (22) and the electric element (before the arranging step are performed. The method for producing a printed circuit board according to any one of claims 1 to 3, wherein the electrode (42) of 41) is electrically connected. 6. The electric element (41) is provided with the electrode (42) in the laminating direction of the resin film (23), and the resin film (23) is provided with the electrode (42) before the laminating step. Corresponding to the position of the electrode (42) of the electric element (41) inserted into the through hole (35), the connecting material (50) is filled and the conductor pattern (2) is filled.
2) a bottomed via hole (24) is formed as a bottom portion, and the electrode (42) of the electric element (41) and the conductor pattern are connected via the connection material (50) before performing the arrangement step. 6. The method for manufacturing a printed circuit board according to claim 5, wherein (22) is electrically connected. 7. The electric element (41a) is provided with the electrode (42a) in the laminating direction of the resin film (23), and the resin film (23) is provided with the electrode (42a) before the laminating step. The conductor pattern (22) is formed as a land portion (22a) corresponding to the position of the electrode (42a) of the electric element (41a) inserted into the through hole (35). The printed circuit board according to claim 5, wherein the electrode (42a) of the electric element (41a) and the land portion (22a) of the conductor pattern (22) are electrically connected to each other before performing. Manufacturing method. 8. The electrode (42a) is formed on the electric element (41a) in the laminating direction of the resin film (23), and the resin film (23) is formed on the resin film (23) before the laminating step. The conductor pattern (22) is a land portion (22a)
Characterized in that the electrode (42a) of the electric element (41a) and the land portion (22a) of the conductor pattern (22) are electrically wire-bonded to each other before the arrangement step. The method for manufacturing a printed circuit board according to claim 5. 9. The laminated resin film (23)
9. The method for manufacturing a printed circuit board according to claim 1, wherein the thermoplastic resin is a thermoplastic resin. 10. The laminated resin film (23)
10. The method for manufacturing a printed circuit board according to claim 9, wherein is made of the same material. 11. The resin film (23) has an elastic modulus of 1 to 1000 MP at a heating temperature in the bonding step.
11. The method for manufacturing a printed circuit board according to claim 9, wherein the printed circuit board is a. 12. The laminated resin film (23)
In the above, the resin film (2
The method for manufacturing a printed circuit board according to any one of claims 1 to 11, further comprising a base member forming step of forming a metal base member (46) on the outer surface of (3). 13. After each of the laminating step and the base member forming step, each resin film (23) is heated by applying pressure to both sides of the laminated body of the resin film (23) and the metal base member (46). ) And the metal base member (46) are adhered to each other. 14. An insulating substrate (39) in which resin films (23) made of the same thermoplastic resin are laminated and then heated under pressure while being adhered to each other, and through holes (35) in the resin film (23). Is provided in the space (36) formed in the insulating base material (39) and the resin film (2
The electrode (42) formed in the stacking direction of (3) has a via (2).
4, 51) and an electric element (41) connected to the conductor pattern (22), and the electric element (41) is extruded toward the space portion (36) by being heated while being pressurized. And the electric element (41) sealed by the resin film (23)
A printed circuit board characterized in that the insulating base material (39) is incorporated therein. 15. An insulating base material (39) in which a resin film (23) made of the same thermoplastic resin is laminated and then heated under pressure while being adhered to each other, and a through hole (35) in the resin film (23). Is provided in the space portion (36) formed in the insulating base material (39) by providing an electric element (41) in which the electrode (42) is connected to the conductor pattern (22), The electric element (41) is sealed by the resin film (23) extruded toward the space (36) by being heated while being pressurized, and the electric element (41)
A printed circuit board characterized in that the insulating base material (39) is incorporated therein. 16. The resin film (23) has an elastic modulus of 1 to 1000 MPa at a heating temperature when being heated while being pressurized.
Alternatively, the printed circuit board according to claim 15. 17. The printed circuit board according to claim 14, wherein a metal base member (46) is adhered to a surface of the insulating base material (39).