JP3514656B2 - Surface smooth wiring board and its manufacturing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface smooth wiring board in which the surface of a conductor circuit and the surface of an insulating layer are arranged at the same height to form a smooth surface, and a method for manufacturing the same.

[0002]

2. Description of the Related Art There is known a surface smooth wiring board in which the surface of a conductor circuit and the surface of an insulating resin layer are leveled to form a smooth surface. These are also referred to as smooth printed wiring boards, flash printed wiring boards, or flash circuit boards.

In such a surface smooth wiring board, the surface of the conductor circuit is embedded so as to form the same plane as the surface of the insulating layer, so that the surface of the wiring board has a smooth flat surface or is flexible. In some cases, it forms a curved surface, and is suitable as a wiring board for a sliding surface on which parts such as a rotary switch, a tuner, and a commutator come into contact.

As a conventional method of manufacturing a surface smooth substrate,
After laminating and adhering copper foil on a prepreg of glass epoxy resin (laminating press step), forming a circuit, further sandwiching it with a mirror-finished stainless steel plate and applying pressure (smooth press step) to manufacture, or before the smooth press step A method of controlling the degree of crosslinking of an epoxy resin by heat treatment after forming a circuit to improve mass productivity and reliability (Japanese Patent Publication No. 10-242621) is known, but in the former manufacturing method, the degree of crosslinking is controlled. It is apt to become non-uniform, a step is likely to remain between the conductor portion and the insulating portion on the surface of the printed wiring, and a substrate having sufficient smoothness cannot be manufactured. In addition, the latter manufacturing method requires a heat treatment step, which is inferior in productivity and makes it very difficult to control the degree of crosslinking of the epoxy resin.

Further, as a method for producing a surface smooth substrate using a thermoplastic resin, Japanese Patent Laid-Open Nos. 3-35588, 4-299892 and 5-182 are known.
Japanese Patent Laid-Open No. 805 and Japanese Patent Laid-Open No. 7-45159 describe that a highly viscous and thermoplastic saturated polyester resin is used as an insulating material. These manufacturing methods have some process differences depending on the wiring board to be manufactured.
As described in Japanese Patent No. 5588, an adhesive sheet of an amorphous insulating substrate is temporarily bonded under heat and pressure conditions of 50 ° C., 10 kg / cm ² , and 20 minutes, and this is bonded to a copper foil at 70 ° C. for 10 minutes. After laminating by hot roll pressing under the conditions, a pattern is formed by etching, and then by hot pressing at 180 ° C and a pressure of 30 kg / cm ² , the copper foil is pressed into the resin to smooth the substrate. This is a method of improving the heat resistance and the like at the same time by promoting the crystallization of the thermoplastic saturated polyester resin.

[0006]

However, JP-A-10-
As described in Japanese Patent No. 321992, a relatively elastic thermoplastic insulating material such as a thermoplastic saturated polyester resin is used to form a smooth substrate by pressing the conductive pattern to form a smooth substrate. There is a problem that the insulating substrate is deformed in the periphery by the thickness of the adhesive or the conductor pattern, and a force (residual stress) to restore the deformation is generated. In extreme cases, local strain is generated. As a result, the substrate undergoes a deformation called “waviness”.

Further, as described above, in the case of the conventional smooth surface substrate using the glass epoxy resin, it is difficult to control the degree of cross-linking of the epoxy resin before the smooth pressing process, and the reliability and mass productivity are satisfactory. It wasn't possible. Also,
Since the glass cloth is used, the flexibility of the base material is lacking, so that its use is limited.

When a thermoplastic resin such as polyester resin is used as an insulating material for a substrate to produce a surface smooth substrate as described above, it is advantageous in terms of resin quality control as compared with glass epoxy resin. However, there is a problem that residual stress is generated after smooth pressing and the substrate is easily distorted, and in reality, there is no surface smooth substrate using a thermoplastic resin.

Therefore, an object of the present invention is to solve the above-mentioned problems, and for a surface smooth substrate using a thermoplastic resin having a high heat resistance, a residual stress in a state where a conductor foil after smooth press is embedded is reduced. It is to provide a product that does not occur and the substrate is not distorted.

Another problem is that it is possible to embed a conductor foil in an insulating layer at a heating temperature as low as possible, which is lower than 300 ° C., to make the surface smooth, and to obtain solder heat resistance, chemical resistance, and electrical characteristics. It is to manufacture a surface smooth wiring board having the dual function.

[0011]

In order to solve the above problems, in the present invention, the surface of the insulating layer and the surface of the conductor circuit embedded and fixed in the insulating layer are arranged at the same height. In the surface smooth wiring board, a thermoplastic resin in which the insulating layer contains 65 to 35% by weight of a polyarylketone resin having a crystal melting peak temperature of 260 ° C. or more and 35 to 65% by weight of an amorphous polyetherimide resin. The thermoplastic resin composition has a glass transition temperature of 150 when measured by differential scanning calorimetry.
-230 ° C., surface smooth wiring board characterized in that the relationship between the heat of crystal fusion ΔHm and the heat of crystallization ΔHc generated by crystallization during heating satisfies the relationship shown by the following formula (A): It was.

Formula (A): [(ΔHm−ΔHc) / ΔHm] ≧ 0.7 Further, 65 to 35% by weight of the polyarylketone resin having a crystal melting peak temperature of 260 ° C. or higher and the amorphous polyetherimide resin 35 to 35 are used. The glass transition temperature measured by differential scanning calorimetry is 150 to 2
A film-like insulator made of a thermoplastic resin composition at 30 ° C. is provided, a conductor foil is laid on the film-like insulator, and the thermoplastic resin composition is heated to a heat of crystal melting ΔHm represented by the following formula (I). Amount of heat of crystallization generated by crystallization in warm temperature Δ
Heat fusion so as to satisfy the relationship with Hc (lamination press),
Then, the heat-bonded conductor foil is etched to form a conductor circuit, and then the thermoplastic resin composition has the following formula (II):
Is heated and pressed (smooth press) so that the surface of the conductor circuit and the surface of the film-like insulator are leveled to the same height. This is the method for manufacturing a surface smooth wiring board consisting of

Formula (I): [(ΔHm-ΔHc) / ΔHm] ≦ 0.5 Formula (II): [(ΔHm-ΔHc) / ΔHm] ≧ 0.7 The surface of the present invention configured as described above The smooth wiring board has an insulating layer composed of a film-shaped insulator in which a crystalline polyarylketone resin and an amorphous polyetherimide resin are blended in a predetermined amount, and the insulating layer has excellent properties of both resins. It has a heat-sealing property for surely bonding and fixing a conductor circuit made of copper foil, and has excellent chemical resistance, mechanical strength and electrical insulation properties peculiar to a polyimide resin.

Further, since the thermoplastic resin composition forming the insulating layer satisfies the above formula (A), this insulating layer has solder heat resistance to withstand heating at 260 ° C. during soldering. .

In the invention relating to the method for producing a surface-smoothed wiring board, the conductor foil which is heat-sealed on one or both sides of the film-like insulator is firmly adhered by the heat-sealing property of the thermoplastic resin composition. , This conductor foil is firmly adhered even when it is etched to form a precise conductor circuit.
The peel strength of the conductor circuit is high. A surface-roughened copper foil, which is usually used as a material for a conductor foil, is preferable because it has a large adhesive strength between a conductor circuit and an insulating layer.

The insulating layer after heat-sealing the conductor foil is a heat-insulating material in which the relationship between the heat of fusion of crystal ΔHm and the quantity of heat of crystallization ΔHc generated by crystallization during temperature rise satisfies the relationship represented by the above formula (I). The progress state of crystallization of the polyarylketone resin, which is a component of the insulating layer and made of a plastic resin composition, is adjusted to an appropriate degree.

Next, when a smooth plate made of a stainless steel plate or other flat plate having a smooth surface is applied to the surface of the wiring board on which the conductor circuit is formed as described above and heating and pressurization are performed, the temperature is less than 250 ° C. Normally, a low temperature condition of around 230 ° C is adopted. Even under such a relatively low temperature heating condition, the thermoplastic resin satisfying the relationship represented by the above formula (I) is in a state of exceeding the glass transition point (Tg), and the precisely formed conductor circuit is evenly distributed in the insulating layer. A wiring board having a smooth surface can be formed by embedding at a depth.

The surface-smoothed wiring board produced in this way has a thermoplastic resin composition of the insulating layer in a state of advanced crystallinity represented by the above formula (II) and has a soldering heat resistance to withstand 260 ° C. To have.

Further, since the film-like insulator and the conductor foil are bonded by heat fusion without an adhesive such as an epoxy resin being interposed between layers, various characteristics such as heat resistance, chemical resistance, and electrical characteristics are determined by the adhesive. That is, the excellent characteristics of the insulating layer can be fully utilized and the surface smooth wiring board can be efficiently manufactured.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a surface smoothed wiring board of the present invention will be described below together with an embodiment of a manufacturing method thereof with reference to the accompanying drawings.

As shown in FIG. 1 (f), the surface smoothing wiring board A of the embodiment of the present invention has a crystal melting peak temperature 260.
Composed of 65 to 35% by weight of a polyarylketone resin at 35 ° C or higher and 35 to 65% by weight of an amorphous polyetherimide resin, and has a glass transition temperature of 150 to 230 ° C measured when the temperature is raised by differential scanning calorimetry. The surface of the insulating layer 1 ′ made of the thermoplastic resin composition and the surface of the conductor circuit 2 ′ made of the conductor foil 2 (see FIG. 1 (d)) embedded and fixed in the insulating layer 1 ′ have the same height. Is a surface smooth wiring board A which is arranged on the surface of the substrate and forms a smooth surface.

In the process of manufacturing such a surface smooth wiring board A, as shown in FIG. 1A, first, a thermoplastic resin in which a polyarylketone resin and an amorphous polyetherimide resin are blended in a predetermined ratio is used. A film-shaped insulator 1 made of the composition is prepared.

Then, as shown in FIG. 1 (b), inner layer blind holes (IVH) are formed at the essential points of the film-shaped insulator 1.
The holes 3 for forming are formed by a laser or a drill, the conductive paste 4 is filled in the holes 3 (FIG. 1 (c)), and after drying, the copper foils 2 are stacked on both sides and a vacuum heat press is used. Heat and pressure are applied to produce a double-sided copper clad laminate 5. The holes 3 are formed as needed, and the double-sided copper-clad laminate 5 may be similarly produced by using the film-shaped insulator 1 having no holes 3.

In the heating and pressing step, the glass transition point of the thermoplastic resin composition is exceeded, but the crystal melting peak temperature of the polyetherimide resin is not exceeded, that is, the amorphousness of the thermoplastic resin composition is maintained. As described above, the copper foil 2 is heat-fused on both sides of the film-like insulator 1 by heating, and at this time, the thermoplastic resin composition satisfies the relationship represented by the following formula (I). To make.

Formula (I): [(ΔHm−ΔHc) / ΔHm] ≦ 0.5 Next, the conductor circuit 2 is formed by the subtractive method to obtain the printed wiring board 6 shown in FIG.

Then, in the final step, a hard smooth plate 7 made of a stainless steel plate or the like is pressed onto both sides of the printed wiring board 6 by using a heating / pressing machine which is usually used, and heated from both sides to form an insulating layer 1 '. So that the thermoplastic resin composition forming the film satisfies the relationship represented by the following formula (II): near the crystallization temperature (Tc) (for example, 220 to 250 ° C.), a heat and pressure press (for example, 230 ° C., 50 kgf) / cm ² , for 10 minutes) to promote crystallization to manufacture a surface smooth wiring board A having solder heat resistance.

Formula (II): [(ΔHm−ΔHc) / ΔHm] ≧ 0.7 Formula (I) which is an important control factor in the invention of the present application or
The thermal characteristics of the thermoplastic resin composition represented by (II) are a relationship between the heat of crystal fusion ΔHm and the heat of crystallization ΔHc generated by crystallization during temperature increase.

This thermal characteristic is based on JIS K 7121, J
Measured values of two transition heats appearing in the DSC curve when the temperature is raised by the differential scanning calorimetry according to IS K7122, the heat of fusion of crystal ΔHm (J / g) and the heat of crystallization ΔHc (J /
It is calculated from the value of g) by the above formula (I) or (II).

Although the values of these formulas depend on the kind and molecular weight of the raw material polymer and the compounding ratio of the composition, they greatly influence the molding and processing conditions of the film-shaped insulator. That is, when forming a film, the value of the above formula can be reduced by melting the raw material polymer and then rapidly cooling it. Further, these numerical values can be controlled by adjusting the thermal history applied in each step. The thermal history as used herein refers to the temperature of the film-shaped insulator and the time during which the temperature is maintained, and the higher the temperature, the larger this numerical value tends to be.

When the value represented by the above formula (I) exceeds 0.5 before the heating and pressurization, the thermoplastic resin composition is already in a high crystallinity state, so that the smooth press ( For example, it becomes difficult to completely embed the conductor circuit 2'on the surface of the insulating layer 2 under a pressurizing condition (230 ° C., 50 kgf / cm ² , 10 minutes), and it is possible to efficiently form a complete smooth surface in a short time. Can not. Further, if it is necessary to heat and pressurize at a high temperature exceeding the crystal melting temperature of the thermoplastic resin composition, the circuit pattern will flow and the position will be displaced, resulting in a decrease in manufacturing efficiency.

The thermal characteristics of the film-like insulator must satisfy the relationship of the above formula (II) after heating and pressurizing for surface smoothing.

This is because if the value of the formula (II) is as low as less than 0.7, the crystallization of the insulating layer is insufficient and the solder heat resistance (usually 260 ° C.) cannot be maintained.

As a method for producing the film-like insulator 1 used for producing the surface smooth wiring board A, a well-known film-forming method such as an extrusion casting method using a T die or a calendering method may be adopted, and particularly, It is not necessary to use a limited manufacturing method. From the viewpoint of film forming property and stable productivity, it is preferable to adopt the extrusion casting method using a T die. The molding temperature of the extrusion casting method is appropriately adjusted depending on the flow characteristics and film forming characteristics of the composition, but is generally not less than the melting point of the composition and 430
It is below ℃.

The polyarylketone resin, which is the first component of the film-like insulator (or insulating layer) used in the present invention, is a thermoplastic resin having a structural unit containing an aromatic nucleus bond, an ether bond and a ketone bond, That is, it is a heat-resistant crystalline polymer having a combination structure of phenyl ketone and phenyl ether.

Representative examples of the polyarylketone resin include polyetherketone, polyetheretherketone, polyetherketoneketone, etc. In the present invention, the polyetheretherketone represented by the following chemical formula 1 is suitable. Can be used.

[0036]

[Chemical 1]

The amorphous polyetherimide resin which is the second component constituting the film-like insulator is an amorphous thermoplastic resin containing an aromatic nucleus bond, an ether bond and an imide bond in its structural unit. In the invention, the polyetherimide resin represented by the following chemical formula 2 can be applied.

[0038]

[Chemical 2]

The film-like insulator (or insulating layer) used in the present invention is composed of a thermoplastic resin composition prepared by blending the above-mentioned two kinds of heat-resistant resins in the above-mentioned predetermined proportions, and is measured by differential scanning calorimetry. The glass transition temperature measured when heated is 150 to 230 ° C.

The reason for limiting the blending ratio of the thermoplastic resin composition is that the polyarylketone resin is blended in a large amount exceeding 65% by weight, or the polyetherimide resin is blended in a small amount of less than 35% by weight. This is because the crystallization rate of the composition is increased and the heat fusion property with the conductor foil is reduced in proportion, so that the content of the crystalline polyallyl ether ketone resin is less than 35% by weight or the amorphous polyetherimide resin is used. When it exceeds 65% by weight, the crystallinity of the composition becomes low,
This is because even if the crystal melting peak temperature is 260 ° C. or higher, the solder heat resistance is lowered, which is not preferable.

The resin composition constituting the film-like insulator used in the present invention may be blended with other resins and other additives to such an extent that the effects of the present invention are not impaired. Examples include heat stabilizers, ultraviolet absorbers, light stabilizers, colorants, lubricants, flame retardants, and inorganic fillers.
Further, the surface of the film-shaped insulator may be subjected to embossing or corona treatment for improving the handling property.

Examples of the conductor foil used in the present invention include metal foils having a thickness of about 8 to 70 μm, such as copper, gold, silver, aluminum, nickel and tin. Among these, a copper foil whose surface is subjected to chemical conversion treatment such as black oxidation treatment is particularly preferable.

The thickness of the film-like insulator used in the present invention is preferably twice or more the thickness of the conductor foil used in the present invention. If it is less than 2 times, it becomes difficult to completely embed the conductor circuit 2'into the surface of the insulating layer 2 under the pressure condition of the smooth press step (for example, 230 ° C, 50 kgf / cm ² , 10 minutes), and it becomes a perfect smooth surface. Because it cannot be formed efficiently in a short time.

In order to enhance the adhesive effect, it is preferable to use, as the conductor foil, one in which the contact surface (overlapping surface) side with the film-shaped insulator is chemically or mechanically roughened in advance. Specific examples of the surface-roughened conductor foil include a roughened copper foil that has been electrochemically treated when producing an electrolytic copper foil.

[0045]

EXAMPLES AND COMPARATIVE EXAMPLES First, Production Examples 1 to 3 of film-like insulator satisfying the conditions of the film-like insulator of the present invention.
The production methods of Reference Examples 1 and 2 and the physical properties thereof will be described below.

[Production Example 1 of Film Insulator] Polyether ether ketone resin (manufactured by Victorex Co .: PEE)
K381G) (P in the following text or Tables 1 and 2
Abbreviated as EEK. ) 60% by weight, and a polyetherimide resin (manufactured by General Electric Co .: Ultem-1)
000) (in the following text or in Tables 1 and 2, PEI
Is abbreviated. ) 40 wt% was dry blended. This mixed composition was extruded to produce a film-like insulator having a thickness of 25 μm.

[Production Example 2 of Film Insulator] Production Example 1
In the above, a film-shaped insulator was manufactured in the same manner except that the mixing ratio of the mixed composition was 40% by weight of PEEK and 60% by weight of PEI.

[Production Example 3 of Film Insulator] Production Example 1
In the same manner, except that the mixing ratio of the mixed composition was 30% by weight of PEEK and 70% by weight of PEI, a film-like insulator was manufactured in the same manner.

[Reference Examples 1 and 2 of Film Insulator] In Production Example 1, the mixing ratio of the mixed composition was PEEK100.
Each film-like insulator was manufactured in the same manner except that the weight percentage (Reference Example 1) or the PEI was set to 100 wt% (Reference Example 2).

In order to investigate the physical properties of the film-like insulators obtained in the above Production Examples and Reference Examples, the following (1) and (2)
The items shown in 1 were measured, or the calculated values were calculated from the measured values. The results are summarized in Table 1.

(1) Glass transition temperature (° C.), crystallization temperature (° C.), crystal melting peak temperature (° C.) According to JIS K7121, a 10 mg sample was used and heated with DSC-7 manufactured by Perkin Elmer. Speed 1
Each of the above temperatures when the temperature was raised at 0 ° C./min was determined from the thermogram.

(2) (ΔHm-ΔHc) / ΔHm According to JIS K7122, 10 mg of a sample was used, and the heating rate was 1 using Perkin Elmer's DSC-7.
The heat of crystal fusion ΔHm (J / g) and the heat of crystallization ΔHc (J / g) were determined from the thermogram when the temperature was raised at 0 ° C./min, and the value of the above formula was calculated.

[0053]

[Table 1]

Example 1 Thickness 25 obtained in Production Example 1
A 12 μm-thick electrochemically roughened electrolytic copper foil is laminated on both sides of a film-like insulator of μm, 760 mmHg in vacuum atmosphere, press temperature 200 ° C., press pressure 30 kg / cm ² , press time Heat fusion was performed under the condition of 10 minutes to produce a double-sided copper clad laminate.

The film-like insulator of the double-sided copper-clad laminate thus prepared was subjected to the measurement test of (2) (ΔHm-ΔHc) / ΔHm by the same method as described above, and the formula values are shown in Table 2.

The adhesive strength of the double-sided copper-clad laminate obtained as described above was examined by the method (3) described later, and the results are also shown in Table 2.

A circuit pattern was formed on the double-sided copper clad laminate obtained as described above by a subtractive method, and a conductive circuit was formed by etching to manufacture a printed wiring board.

Then, as shown in FIG. 1 (e), a smooth plate 7 made of stainless steel is placed on both front and back surfaces of the printed wiring board thus obtained, and a vacuum atmosphere 760 is provided.
mmHg, press temperature 220 ℃, press pressure 30kg / c
Smooth pressing was carried out under a hot press condition of m ^{2 for} a pressing time of 20 minutes to produce a surface smooth substrate which is a thermoplastic resin composition in which the insulating layer 1 ′ satisfies the relationship represented by the above formula (II).

The surface smooth printed wiring board thus obtained was subjected to the measurement test of (2) (ΔHm-ΔHc) / ΔHm, and the adhesive strength between the copper foil circuit and the film-like insulator at room temperature was determined as follows. The test method of (3) was examined, and the solder heat resistance was examined by the following test method. The results are shown in Table 2.

(3) Adhesive Strength The peel strength of the copper foil of the copper foil of the FPC blank was measured in accordance with the normal peel strength of JIS C6481, and the average value was shown in kgf / 10 cm. .

(4) Solder heat resistance According to JIS C6481 normal solder heat resistance, 2
Floating in a solder bath at 60 ° C for 10 seconds with the copper foil side of the test piece in contact with the solder bath, taking out of the bath and allowing to cool to room temperature, and visually observing the presence or absence of swelling and peeling points of the test piece, Was evaluated.

[0062]

[Table 2]

Example 2 In Example 1, using Production Example 2 as the film-shaped insulator, the pressing temperature for producing a double-sided copper-clad laminate was 225 ° C., and the hot pressing for producing a smooth substrate. A smooth printed wiring board was prepared in the same manner as in Example 1 except that the conditions were changed to a temperature of 240 ° C. and a pressing time of 30 minutes, and the evaluations of tests (3) to (4) are also shown in Table 2.

[Comparative Example 1] A smooth printed wiring board was prepared in the same manner as in Example 1 except that the pressing temperature in preparing the double-sided copper-clad laminate was changed to 215 ° C. The evaluations of the tests (3) to (4) for the above are also shown in Table 2.

Comparative Example 2 In Example 2, the press temperature of the smooth printed wiring board was 230 ° C. and the press time was 10
A smooth printed wiring board was prepared in the same manner as in Example 2 except that the amount was changed, and the evaluations of tests (3) to (4) are also shown in Table 2.

[Comparative Example 3] Production Example 3 was used as the film-like insulator in Example 1, but the pressing temperature and the pressing time were changed to 240 ° C and 20 minutes when the double-sided copper-clad laminate was prepared. A smooth printed wiring board was prepared in the same manner as in Example 1 except for the above, and the evaluations of the tests (3) to (4) for this were also shown in Table 2.

As is clear from the results in Table 2, the double-sided copper-clad laminate of Example 1 has a good adhesive strength of 0.7 kgf / 10 cm, and the value of (ΔHm-ΔHc) / ΔHm is also It was a proper value of 0.31. Further, the smooth printed wiring board is a precise one in which the conductor circuits are embedded in a uniform depth, and the value of (ΔHm-ΔHc) / ΔHm is 0.9.
It is an appropriate value of 6, and the adhesion density is 1.5 kgf / 10 cm.
It was a good value. The results of the solder heat resistance test were good results in that no swelling or peeling was observed on the substrate.

The adhesive strength of the double-sided copper-clad laminate of Example 2 was a good value of 1.3 kgf / 10 cm, the result of the solder heat resistance test was also good, and the state of the resin wrapping around the circuit pattern was also good. It was good.

On the other hand, in the smooth printed wiring board of Comparative Example 1, the adhesion between the layers was insufficient, and the solder heat resistance was poor because swelling and peeling were observed.

The smooth printed wiring board of Comparative Example 2 is
There was adhesion between the layers, but the solder heat resistance was poor.

In Comparative Example 3, the adhesive strength between the copper foil and the film of the double-sided copper-clad laminate was as low as 0.2 kgf / 10 cm, and the circuit was peeled off in the etching process.

[0072]

As described above, the surface smooth wiring board of the present invention is heated and pressed so that a conductor circuit forms a smooth surface on an insulating layer made of a predetermined thermoplastic resin composition having excellent heat resistance. It has heat resistance, chemical resistance, and electrical insulation that can withstand the solder melting temperature, and has the advantage that residual stress does not occur when the conductor foil is embedded after smooth pressing and the board does not distort. is there.

The surface smooth wiring board manufacturing method of the present invention is a manufacturing method capable of embedding a conductor foil in an insulating layer and smoothing the surface even at a heating temperature as low as 250 ° C. Moreover, there is an advantage that a surface smooth wiring board having heat resistance (solder heat resistance), chemical resistance, and electric characteristics can be efficiently manufactured by a simple manufacturing process.

[Brief description of drawings]

FIG. 1 is a schematic view showing a manufacturing process of a surface smooth wiring board according to an embodiment.

[Explanation of symbols]

1 Film-like insulator 1'insulating layer 2 conductor foil 2'conductor circuit 3 holes 4 Conductive paste 5 Double-sided copper clad laminate 6 printed wiring board 7 Smooth plate A surface smooth wiring board

Continuation of front page (51) Int.Cl. ⁷ Identification code FI H05K 1/03 H05K 1/03 610N 3/38 3/38 B (72) Inventor Koichiro Taniguchi 5-8 Mitsuyacho, Nagahama-shi, Shiga Mitsubishi Tree Fat Co., Ltd. Nagahama Plant (72) Inventor Kaoru Nomoto 1-1, Showa-cho, Kariya city, Aichi prefecture, Denso Co., Ltd. (72) Inventor Hiroyasu Iwama 1-1-1-1, Showa-machi, Kariya city, Aichi prefecture, Denso company (56) ) References JP-A-6-21619 (JP, A) JP-A-2-269765 (JP, A) JP-A-5-310951 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB) Name) H05K 1/03 H05K 1/05 H05K 3/00 H05K 3/22 H05K 3/28 H05K 3/44 H05K 3/46 C08J 5/18 C08L 71/10 C08L 73/00 C08L 79/08

Claims (4)

(57) [Claims] 1. A surface smooth wiring board in which a surface of an insulating layer and a surface of a conductor circuit embedded and fixed in the insulating layer are arranged at the same height, wherein the insulating layer has a crystal melting peak temperature 260. ℃ and polyaryl ketone resin 65 to 35 wt% or more, and contains a 35 to 65 wt% amorphous polyetherimide resin, a glass transition temperature which is measured when the temperature was raised by differential scanning calorimetry 150 to 230 Composed of a thermoplastic resin composition at
The conductor foil is placed on the insulating layer and the crystal fusion expressed by the following formula (I) is applied.
Heat of crystallization ΔHm and heat of crystallization generated by crystallization during heating
Heat fusion to meet the relationship with the amount ΔHc,
The relationship between the heat of crystal fusion ΔHm and the heat of crystallization ΔHc generated by crystallization of the conductor circuit formed by etching the deposited conductor foil is shown by the following formula (II). Apply heat and pressure to satisfy the relationship between the surface of the insulating layer and the conductor circuit.
A surface smooth wiring board characterized in that the surfaces are arranged at the same height . Formula (I): [(ΔHm−ΔHc) / ΔHm] ≦ 0.5 Formula (II) : [(ΔHm−ΔHc) / ΔHm] ≧ 0.7 2. Containing 65 to 35% by weight of a polyarylketone resin having a crystal melting peak temperature of 260 ° C. or higher and 35 to 65% by weight of an amorphous polyetherimide resin, and measured when the temperature is raised by differential scanning calorimetry. Glass transition temperature is 1
A film-like insulator made of a thermoplastic resin composition at 50 to 230 ° C. is provided, a conductor foil is laid on the film-like insulator, and the thermoplastic resin composition has a heat of crystal fusion ΔHm represented by the following formula (I). And heat fusion so as to satisfy the crystallization heat amount ΔHc generated by crystallization during temperature rise, and then the heat-fused conductor foil is etched to form a conductor circuit, and then the thermoplastic resin composition is used. The object is heated and pressed so as to satisfy the relationship represented by the following formula (II), in which case the surface of the conductor circuit is pressed against the surface of the conductor circuit to make the surface of the conductor circuit the same as the surface of the film-like insulator. A method for producing a surface-smoothed wiring board, which comprises flattening the surface. Formula (I): [(ΔHm−ΔHc) / ΔHm] ≦ 0.5 Formula (II): [(ΔHm−ΔHc) / ΔHm] ≧ 0.7 3. The method for producing a surface-smoothed wiring board according to claim 2, wherein the conductor foil laminated on the film-shaped insulator is a conductor foil whose surface is roughened. 4. The method for producing a surface smooth wiring board according to claim 2, wherein the polyarylketone resin is a polyetheretherketone resin.