JP2001094236A - Method of manufacturing circuit board for high voltage and large current - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost land for mounting components on a circuit board in a high-voltage / high-current circuit board configured by embedding a conductive circuit pattern in an insulating resin member. Aim. SOLUTION: In a method for forming a circuit board using a simple mold, an insulating resin member and a conductive circuit pattern, a cream solder 8 is filled into a land forming portion, and an integral of the insulating resin members 4 and 5 and the conductive circuit pattern 2 is provided. A land is formed by melting the cream solder 8 simultaneously with the formation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit component mounting board which constitutes a circuit in an electronic apparatus, and more particularly to a high current / high voltage board for a power supply unit of home electric appliances such as a television, a rice cooker and an air conditioner.

[0002]

2. Description of the Related Art In recent years, the power consumption of electronic devices has been increasing due to the increase in functions such as high-speed processing and the increase in the number of circuits due to the commercialization of composite products, in the direction of miniaturization, lightness, and lightness.

In response to this trend, power supply circuits for electronic devices and electric products are also required to be reduced in size and weight, while other circuits such as signal circuits are used for safety measures against circuit boards and cost reduction accompanying the increase in power consumption. Development is behind the department.

In particular, large televisions, plasma displays, etc. weigh more than 100 kg and are several times thinner than conventional ones, but have high current of 13 [A] due to high resolution processing, high sound quality processing, high speed processing, etc. Use of a high voltage of 1.6 [KV] is required.

[0005] As a conventional technique, a circuit board is a wiring material for mounting components, and it has been a major problem how to perform wiring at low cost. In addition, they have been individually configured by changing the material for protecting the conductive circuit, such as a phenol resin, an epoxy resin, or a liquid crystal polymer, depending on the purpose of use.

Hereinafter, an example of a conventional circuit board will be described with reference to the drawings.

FIG. 7 shows a cross section of a conventional circuit board, and shows an insulating resin 1, a conductive circuit pattern 2 forming an electric circuit, an insulating resin 1 for insulating and protecting the conductive circuit pattern 2, and a part of the conductive circuit pattern 2. Is a land 3 provided for electrical connection with the outside.

Although the circuit board having such a configuration may be used for various applications, it is particularly effective for a high-current / high-voltage circuit board in consideration of safety due to insulation.

A method of manufacturing the circuit board configured as described above will be described.

First, based on a predetermined electric circuit, a conductive circuit pattern 2 is formed from a conductive metal plate by etching or sheet metal pressing. Generally, a copper plate is often used in consideration of solderability and conductivity.

Next, the formed conductive circuit pattern 2 is placed in a molding die for forming a circuit board having a predetermined shape, and an insulating resin 1 having predetermined characteristics is injected into the molding die to form the conductive circuit pattern 2. The periphery is covered with the insulating resin 1 except for the portion where the land 3 is formed.

The formation of the land 3 is performed by making the land forming portion of the molding die convex so as to come into contact with the surface of the conductive circuit pattern 2 to prevent the insulating resin 1 from entering. If the contact between the convex portion of the molding die and the conductive circuit pattern 2 is weak, the insulating resin 1 enters, so that the conductive circuit pattern 2 may be supported from the surface opposite to the convex portion of the molding die.

[0013]

However, in the above-described structure, since a molding die is manufactured every time a circuit is changed, the cost increases, and at the same time, a lot of time and cost are required to cope with the circuit change. In particular, circuit changes occur frequently in product development, and creating a mold every time causes a great loss of productivity, which also affects product development.

The present invention has been made in view of the above problems, and provides a method of manufacturing a circuit board (for large current) which can be efficiently and inexpensively formed.

[0015]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention comprises a structure in which a circuit board is formed using a conductive circuit pattern, an insulating resin member sandwiching them from both sides, and a simple mold. It is.

[0016]

According to a first aspect of the present invention, in a circuit board formed of an insulating resin member and a conductive circuit pattern, a first insulating resin member having land holes and a second insulating resin member having conductive holes are electrically conductive. Provided on both sides of the circuit pattern, filling the land holes with a conductive material such as cream solder, and then integrating them by heating and pressing to form a land. Having a function of forming a land by melting the conductive member and joining it to the conductive circuit pattern at a temperature at which heating and pressing are performed to integrate the insulating resin member and the conductive circuit pattern after filling the conductive member. It is. Here, the conductive member may be cream solder or conductive paste. It is also better to temporarily join the conductive circuit pattern and the insulating resin member in advance, and then to simultaneously melt the conductive member and join the conductive circuit pattern and the insulating resin member at the same time.

According to a third aspect of the present invention, in a circuit board formed of an insulating resin member and a conductive circuit pattern, a land made of a solder material is provided at a portion where a land of the conductive circuit pattern is formed, and the land is protected so as to protect the land. A first insulating resin member having a hole for use and a second insulating resin member are stacked from above and below and integrated by heating and pressing, and a solder having a size and a height necessary for forming a land of a conductive circuit pattern is provided. After forming a land by plating, the first insulating resin member and the second
Heating and pressurizing the whole superposition so that the land made of solder plating is inserted into the hole of the insulating resin member, the conductive circuit pattern and the insulating resin member are integrated, and at the same time the land is formed by soldering. Have

According to a fourth aspect of the present invention, in the circuit board formed of the insulating resin member and the conductive circuit pattern, the land of the conductive circuit pattern is formed after the first insulating resin member and the conductive circuit pattern are integrated. After forming a land by electroplating of solder on the portion, a second insulating resin member provided with a hole for protecting the land is overlapped and integrated, and the conductive circuit pattern, the first insulating resin member and the second insulating resin member are integrated. After integrating the insulating resin member of No. 2, solder plating is performed, and no solder resist is required to prevent solder from attaching when solder plating. Solder adheres only to the holes for land formation, and the workability of solder plating is improved. It has the effect of measuring improvement.

According to a fifth aspect of the present invention, in a circuit board formed of an insulating resin member and a conductive circuit pattern, a solder resist, a plating resist, or an equivalent is formed at a portion where a land of the conductive circuit pattern is formed in accordance with a land shape. After printing the resin having the performance described above, the first insulating resin member and the second insulating resin member having holes for protecting the land are overlapped on both surfaces of the conductive circuit pattern and integrated by heating and pressing. The land is formed by removing the resist, the plating resist, or the resin having the same performance with the solvent, and the solder resist, the plating resist, and the like can be printed. It has excellent workability because it can be removed, has good quality because it can perform stable work, and has the effect of good mass productivity. It is.

According to a sixth aspect of the present invention, after a first insulating resin member having a land protecting hole and a second insulating resin member are overlapped on both surfaces of the conductive circuit pattern, a fitting means is fitted into the hole. After the fitting means is brought into pressure contact with a land portion formed of a solder resist, a plating resist, and an equivalent resin, the whole is heated and pressurized and integrated. At the same time, the fitting means prevents the first and second insulating resin members from entering the lands, thereby facilitating removal of the solder resist, the plating resist, and the like.
This has the effect of keeping the shape of the land clean.

According to a seventh aspect of the present invention, after the solder resist, the plating resist, or the resin having the same performance is removed, solder is attached to the conductive circuit pattern of the removed portion. This has the effect of preventing oxidation of the metal surface, improving the solderability at the time of component mounting, and improving component mounting quality.

According to an eighth aspect of the present invention, in the circuit board formed of the insulating resin member and the conductive circuit pattern, a land hole is provided after the first insulating resin member and the conductive circuit pattern are integrated. The second insulating resin member is superimposed on the conductive circuit pattern, and heated and pressed using a mold having a projection fitted into the hole to form a land. A protrusion corresponding to the shape of the land is formed, and the protrusion is fitted into a hole of the second insulating resin member serving as a land, and is heated and pressed to prevent the second insulating resin member from entering the land forming portion to thereby prevent the land. Is formed.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

The same components have the same reference characters allotted, and description thereof will not be repeated.

(Embodiment 1) FIG. 1 is a cross-sectional view of a circuit board according to an embodiment of the present invention, and a conductive circuit pattern 2 serving as a power supply or signal transmission circuit formed based on a predetermined electric circuit. Are sandwiched from above and below, a first insulating resin member 4 and a second insulating resin member 5 are formed. The first insulating resin member 4 and the second insulating resin member 5 have holes 6 for providing lands at predetermined locations of the conductive circuit pattern 2.
Are formed.

This hole is a through hole as shown in the figure, and is provided on one or both sides of the first insulating resin member 4 and the second insulating resin member 5. Some conductive circuit patterns 2 are provided with conductive holes 7. Cream solder 8 has hole 6
And the conductor holes 7 are filled to form lands.

Next, a description will be given of a method of manufacturing the circuit board according to the above-described embodiment and the formation of lands used for component mounting and connection on the circuit board.

A land forming hole 6 is formed in the first insulating resin member 4 and the second insulating resin member 5 so as to match the land forming position of the conductive circuit pattern 2, and the upper and lower portions of the conductive circuit pattern 2 formed in advance are formed. Tuck more. That is, when the conductive circuit pattern 2 formed in advance is sandwiched between the first insulating resin member 4 and the second insulating resin member 5 from above and below, holes (for forming the land) are formed on the conductive circuit pattern 2 at positions where lands are to be formed. Hole 6 is provided.

The integration of the first insulating resin member 4 and the second insulating resin member 5 via the conductive circuit pattern 2 is performed while heating using a mold (30, 31) having a heating function from above and below. It is performed by applying pressure and fusing and joining each other (Fig. 1
(See (a) and (b)). The heating and pressurizing at this time may be performed at a time to perform integration, or may be performed to a degree of temporary integration (a certain degree of integration) first, and then complete integration may be performed in a subsequent process. Temporary and complete integration may be considered in the case where a number of layers of substrates are stacked and temporarily integrated and fixed, and then integrated together.

Next, the cream solder 8 is filled into the hole 6 by a predetermined method such as screen printing or dispensing (FIG. 1).
(C)). After the filling is completed, the whole is heated and pressed from above and below as described above. The first insulating resin member 1 and the second insulating resin member 5 are integrated with the cream solder 8 by heating and pressing.
Melting at the same time, after heating and pressing for a predetermined time, cooling,
A circuit board having lands is formed (see FIG. 1D). Here, the time, temperature, and pressure of the heating and pressing are, for example, 2
Time, 180 ° C., 20-30 kgf / m ² .

The purpose of the cream solder 8 is to maintain the shape of the hole 6 formed in the insulating resin member at the time of heating and pressing. However, when the circuit board is used as it is, the soldering property is extremely high. Good land is obtained, and workability is also improved. Also, as described above, the solder may be used after removing the solder instead of using it as it is.

Next, the land at the conductor hole 7 will be described. As described above, the cream solder 8 is filled in the portion of the conductor hole 7 and heated and pressurized. However, the behavior of the cream solder 8 in the conductor hole 7 at the time of melting is different from that of the portion without the conductor hole 7.

That is, when the solder is melted, surface tension is generated and the solder tends to be rounded. This force generates a force in the portion of the conductor hole 7 that is rounded toward the outer periphery around the center of the conductor hole 7 as shown in part A of FIG. The cream solder 8 is composed of a metal component and a flux component, but when heated and melted, the flux component does not evaporate, and the solder particles have a small integrated volume.
For this reason, the volume of the metal component of the solder becomes smaller than the volume of the filling portion, and when the solder is pulled around due to surface tension, a hole is formed in the center at the center.

The size of the hole is determined by the relationship between the filling volume of the cream solder 8 formed by the conductor hole 7 and the hole 6 in the land forming portion. Therefore, when it is used to insert a lead wire or the like, it is necessary to confirm it in advance. Then, the filling volume can be adjusted for each inserted part to make a hole suitable for the part. In addition, the roundness formed at the corner of the hole has an advantageous effect in preventing catching when inserting the component.

(Embodiment 2) A second embodiment will be described with reference to FIG.

A predetermined plating solder 9 is disposed on a land forming portion of the conductive circuit pattern 2 to serve as a land, and insulating resin members (17, 18) are provided around the land to protect the plating solder 9.

The manufacturing process of such a substrate will be described.

In FIG. 2A, electroplating solder 9 is applied to the conductive circuit pattern 2 by electroplating so as to have a predetermined land size and size. FIG. 2 (b) shows that the first insulating resin member 18 on the lower side and the hole 6 of the second insulating resin member 17 on the upper side match the electroplating solder 9 so as to sandwich the conductive circuit pattern 2 therebetween. Install and heat and press from above and below them. As shown in FIG. 2C, the first insulating resin member 18, the second insulating resin member 17, and the conductive circuit pattern 2 with the electroplating solder 9 are integrated by heating and pressing, and a land made of electroplating solder is formed. A circuit board having the same can be formed. Here, the lands are protected by holes in the first and second insulating resin members.

In the substrate of such an embodiment, since lands are formed on the conductive circuit pattern, it is not necessary to consider the compression bonding conditions in the subsequent thermal compression bonding, the flux treatment, and the like, and the manufacture is easy.

(Embodiment 3) Although the substrate is basically the same as the substrate described in Embodiment 2, a manufacturing method thereof will be described here.

The conductive circuit pattern 2 is fixed to the first insulating resin member 18 (FIG. 3A). Here, the first insulating resin member 18 is provided with a hole 6 at a position corresponding to a predetermined position of the conductive circuit pattern when necessary, and a plated solder serving as a land is formed in the hole 6. Next, electroplating solder 9
A predetermined shape on the land forming portion of the conductive circuit pattern 2,
It is formed in a size (FIG. 3B). A second insulating resin member 17 separately prepared so that the hole 6 matches the electroplating solder 9 is overlaid and heated and pressed from above and below. By heating and pressing, the first insulating resin member 18, the second insulating resin member 17, and the conductive circuit pattern 2 with the electroplating solder 9 are integrated to form a circuit board (FIG. 3C). Here, the lands are protected by holes in the first and second insulating resin members.

(Embodiment 4) A fourth embodiment will be described with reference to FIG.

First, a solder resist 10 that can be dissolved and removed with a solvent is printed on the land forming portion of the conductive circuit pattern 2 according to the land shape (FIG. 4A). Next, the first insulating resin member 20 and the second insulating resin member 19 separately prepared are provided with holes 6 corresponding to the land shape of the conductive circuit pattern, and the two (19, 20) are sandwiched by the conductive circuit pattern 2 therebetween. And pressurized from above and below with a mold or a jig heated to the curing temperature of the first insulating resin member 20 and the second insulating resin member 19, and the conductive circuit pattern 2, the first insulating resin member 20, and the The second insulating resin member 19 is integrated (FIG. 4B). Next, the solder resist 10 at the land formation portion of the conductive circuit pattern 2 is dissolved and removed with a solvent (FIG. 4C). When the solder resist 10 is removed, the conductive circuit patterns 2 are exposed to form lands 3.

In place of the solder resist used at this time, a plating resist or a resin material having characteristics similar or close to those of the plating resist can be used.

In the figure, the solder resist 10
Is the same as the size of the hole 6 provided in the first insulating resin member 20 and the second insulating resin member 19, but considering the processing error, the overlap of about 0.2 to 1 mm is not a problem. Rather, it is useful to consider yield improvement.

The lands are protected by holes in the first and second insulating resin members.

In the first to third embodiments, when the insulating resin member is bonded by thermocompression bonding, there is a possibility that the resin of the insulating resin member temporarily softens and oozes out. Although it may be necessary to set the value larger than the design value, in this embodiment, since the solder resist is provided at the land formation portion, the resin can be prevented from seeping out and the substrate can be manufactured more easily and accurately.

(Other Embodiment) As a development of this embodiment, a circuit board shown in FIG. 4D will be further described.

Here, the circuit board shown in FIG. 4C can be mounted by removing the solder resist 10 and exposing the conductive circuit pattern 2. However, the surface of the exposed portion is oxidized as time passes. The joining by the connecting members is incomplete or difficult. In order to solve this problem, as shown in FIG. 4 (d), as an advanced circuit board, the exposed portion of the conductive circuit pattern serving as a land is covered with solder 11 to prevent oxidation.

At this time, various methods of attaching the solder 11 can be considered, such as plating and immersion in a molten bath. Further, plating with another metal may be performed instead of the solder 11.

(Embodiment 5) Another embodiment (mainly a forming method) of the circuit board described in Embodiment 4 will be described with reference to FIG.
This will be described with reference to FIG. Here, the movable pin is a fitting means.

FIG. 5 shows a mold apparatus for forming a circuit board. Reference numeral 12 denotes an upper mold 12a for sandwiching a target circuit board.
And the lower mold 12b.
Movable pins 14 are arranged via 3, and the solder resist 10 of the circuit board arranged in the mold is pressed by urging the movable pins 14 as described later. As described above, the movable pin 14 that matches the position, shape, and size of the land is
The mold 12 attached via 3 is prepared.

On the other hand, the first insulating resin member 20 and the second insulating resin member 19 are provided with holes 6 corresponding to the land positions of the conductive circuit pattern 2, and the first insulating resin member 20 and the second insulating resin member The printed and dried resist 10 is overlaid (the state described with reference to FIG. 4B, in which heating and pressing have not been performed yet). The movable pins 14 of the mold 12 are inserted into the holes 6 of the superposed first insulating resin member 20 and second insulating resin member 19 from above and below, respectively. The distal end portion 14a of the inserted movable pin 14 and the solder resist 10 come into close contact with each other, and a force in the direction indicated by an arrow is applied to the mold 12 so as to sandwich the conductive circuit pattern 2 via the solder resist 10. Further, a force in the direction indicated by an arrow is applied to the mold 12, and the first
The insulating resin member 20 and the second insulating resin member 19 are heated and pressed.

Normally, the land holes 6 of the first insulating resin member 20 and the second insulating resin member 19 are easily deformed by heating and pressing. However, the use of the movable pin 14 prevents deformation. Further, since the tip portion 14a is in contact with the solder resist 10, it is possible to prevent deformation and bleeding of the first insulating resin member 20 and the second insulating resin member 19 from entering the land. It is easy to dissolve and remove with a solvent without being stained or covered with the material. In this embodiment, since the movable pin 14 is fitted in the hole 6, the structure is further prevented from deformation.

(Embodiment 6) Embodiment 6 of the present invention will be described with reference to FIG.

The first insulating resin member 21 is provided with a hole 6 corresponding to the land forming portion of the conductive circuit pattern 2. The conductive circuit pattern 2 and the first insulating resin member 21 are heated and pressurized by the lower mold 16a having the projections 15a in the holes and the upper mold (not shown) of the plane, thereby forming the first insulating resin. The conductive circuit pattern 2 is embedded and integrated in the member 21.

Next, a second portion having a hole 6 (provided so as to correspond to the land) is formed in a portion where the land 3 is formed on the upper surface of the circuit board which is flat and one surface of the conductive circuit pattern 2 is exposed. The insulating resin member 22 is overlaid. At this time, the upper mold of the plane is removed, but the lower mold is kept as it is.

From above, an upper mold 16b having a projection 15b is installed to heat and press them (FIG. 6).
(A)). The upper mold 16b has a position corresponding to the hole 6 and a protrusion 15b of a size.

By heating the upper mold 16b, the projection 15b penetrates the hole 6 to heat and press the second insulating member 22 (FIG. 6).
(B)). Thickness of second insulating resin member 22 and protrusion 15
By adjusting the length of b, the tip of the projection 15b is in close contact with the conductive circuit pattern 2 to prevent the resin material from protruding to the portion where the land 3 is formed, and the predetermined land 3 can be formed ( FIG. 6 (c)).

As described above, according to the present embodiment, lands on a large current substrate can be easily formed.

According to each of the above embodiments, the conductive circuit pattern is disposed in the inner layer to form a reinforced insulation structure, and the insulation distance of the high voltage substrate can be reduced.
Further, since the width of the large-current pattern can be reduced, it is possible to manufacture a small-sized circuit board at low cost while securing the safety of the high-voltage / high-current circuit board. In addition, it is compatible with miniaturization and thinning of appliances, air conditioners, televisions, etc. that require multifunctionality in the future.

[0062]

As described above, according to the present invention, in the formation of a land for a large current substrate formed by embedding a conductive circuit pattern in an insulating resin member, a land having an arbitrary shape and size can be easily formed at an arbitrary position. Can be formed.

[Brief description of the drawings]

FIG. 1 is a process chart of land formation according to a first embodiment of the present invention;

FIG. 2 is a process chart of land formation according to a second embodiment of the present invention.

FIG. 3 is a process chart of land formation according to a third embodiment of the present invention.

FIG. 4 is a process chart of land formation according to a fourth embodiment of the present invention;

FIG. 5 is a process chart of land formation according to a fifth embodiment of the present invention.

FIG. 6 is a process chart of land formation according to a sixth embodiment of the present invention.

FIG. 7 is a cross-sectional view of land formation on a conventional molded circuit board.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 insulating resin 2 conductive circuit pattern 3 land 4 first insulating resin member 5 second insulating resin member 6 hole 7 conductive hole 8 cream solder 9 electroplating solder 10 solder resist 11 solder 12 mold 13 spring 14 movable pin 15 protrusion Part 16 Mold

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hiroyuki Uchiyama 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture F-term in Matsushita Electric Industrial Co., Ltd. CC62 DD43 DD63 GG11

Claims (9)

[Claims] A first insulating resin member having a land hole and a second insulating resin member having land holes provided on both sides of the conductive circuit pattern; A method for manufacturing a circuit board, comprising: filling a hole with a conductive member such as cream solder; 2. A method for manufacturing a circuit board, wherein a land hole is also provided in a second insulating resin member, and cream solder is filled to form lands on both sides. 3. A circuit board formed of an insulating resin member and a conductive circuit pattern, wherein a land made of a solder material is provided at a portion where the land of the conductive circuit pattern is formed, and a first hole having a land for protecting the land is provided. A method of manufacturing a circuit board, wherein the insulating resin member and the second insulating resin member are overlapped from above and below and integrated by heating and pressing. 4. In a circuit board formed of an insulating resin member and a conductive circuit pattern, after the first insulating resin member and the conductive circuit pattern are integrated, electroplating of solder is performed on a land forming portion of the conductive circuit pattern. A method of manufacturing a circuit board, comprising: forming a land according to (1), and overlaying and integrating a second insulating resin member provided with a hole for protecting the land. 5. A circuit board formed of an insulating resin member and a conductive circuit pattern, wherein a solder resist, a plating resist, or a resin having equivalent performance is formed in a land forming portion of the conductive circuit pattern in accordance with a land shape. After printing, a first insulating resin member having a land protection hole and a second insulating resin member are overlapped on both surfaces of the conductive circuit pattern, and integrated by heating and pressing, and then a solder resist or a plating resist, Alternatively, a method of manufacturing a circuit board, comprising forming a land by removing a resin having equivalent performance with a solvent. 6. A first insulating resin member having a land protecting hole and a second insulating resin member are superimposed on both sides of a conductive circuit pattern. Then, a fitting means is fitted into the hole, and a solder resist is provided. 6. The circuit board according to claim 5, wherein after the fitting means is brought into pressure contact with a land portion formed of a resin, a plating resist, or an equivalent resin, the whole is heated and pressed to be integrated. Manufacturing method. 7. The circuit board according to claim 5, wherein after removing the solder resist, the plating resist, or the resin having the same performance, solder is adhered to the conductive circuit pattern of the removed portion. Production method. 8. A second insulating resin member provided with a hole for a land after integrating the first insulating resin member and the conductive circuit pattern in a circuit board formed of the insulating resin member and the conductive circuit pattern. A method of manufacturing a circuit board, comprising: superimposing a conductive layer on a conductive circuit pattern; and applying heat and pressure using a mold having a projection fitted into the hole to form a land. 9. The method for manufacturing a circuit board according to claim 1, wherein the circuit board is manufactured with a high voltage or a high current.