JPH0682903B2 - Manufacturing method of metal core and printed wiring board - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a metal core / printed wiring board having a single-sided, double-sided or multi-layer structure, and particularly to a plurality of units on which electronic parts are mounted. The present invention relates to a method of manufacturing a metal core / printed wiring board in which a wiring board is separably provided.

[Prior Art] FIG. 2 is an exemplary view showing a conventional printed wiring board on which surface-mounted components are mounted. First, referring to FIG. 2 (A), the printed wiring board (10) is provided with a plurality of unit wiring boards (23) that can be cut by predetermined separation lines (25), and appropriate electronic parts are provided for each of them. It is supposed to be equipped with (20). Reference numeral (24) is an ear-like portion, which is used for fixing the printed wiring board (10) to a required cutting pedestal during the cutting operation. Next, referring to FIG. 2 (B), a conductor layer (15) is provided at an appropriate position on an insulating printed wiring board (10B) composed of a single substrate, and a lead wire ( 21) is connected to the conductor layer (15) by solder (22). In the example of FIG. 2 (B), the line BB is the planned separation line. A glass-epoxy type printed wiring board is known as an insulating printed wiring board composed of such a single substrate, which enables division into unit wiring boards after electronic components are mounted. To be However, this glass-epoxy type printed wiring board has a drawback that the heat conductivity in the base portion is not good. Finally, referring to FIG. 2 (C), a conductor layer (15) is provided at an appropriate position of a metal core / printed wiring board (10C) including a metal core (11) and insulating layers (14) on both upper and lower sides thereof. The lead wire (21) of an appropriate electronic component (20) is connected to the conductor layer (15) by solder (22). In the example of FIG. 2 (C), the line CC is a planned separation line. However, when using such a metal core / printed wiring board, special equipment and tools are required to divide the electronic components into unit wiring boards after mounting, which significantly increases the manufacturing cost. There is a drawback that it will end up.

By the way, with the recent development of electronic circuit technology, the degree of integration of electronic components such as so-called semiconductor elements has been considerably advanced. Also, for example, various high-speed electronic devices based on the electronic components are mounted and used in automobiles and various industrial devices. Among them, especially for highly integrated ones such as LSI, it is necessary to increase the speed of the LSI and to transmit signals between LSIs at high speed. The so-called emitter follower type, which is operable and has a high load driving capability, has been used.

Further, in the prior art, the operation speed of the so-called IC chip itself is lower than that of the currently used one, and therefore the circuit configuration has relatively slow switching operation characteristics and low power consumption. Stuff was being used. Furthermore, since the degree of integration of the used LSI was not so large, the scale of the electronic circuit configured per unit area of the IC chip was small, and the amount of heat generated per unit area was small. there were.

By the way, as described above, recently, high-speed operation and highly integrated LSIs have been developed, and the signals to be handled have become high-speed pulse waveforms. For this, LS
The power consumed per unit area is increasing in order to provide high-speed operation inside I and / or high-load driving capability outside thereof.

For this reason, in a printed wiring board on which such an LSI as described above or one including a power IC, a MOS / FET transistor, or the like as a power driving element is mounted, heat generated from the LSI or the like is efficiently transferred. It is required to dissipate well. However, when a normal printed wiring board made of an insulating material as described above is used, it has not been possible to sufficiently meet this demand. On the other hand, in the case of a metal core / printed wiring board having a suitable metal plate as a base, a corresponding heat dissipation effect can be expected.

Therefore, for example, a printed wiring board having a metal core such as an aluminum core is used, but when a large number of unit wiring boards corresponding to a required unit function are simultaneously manufactured on a single metal core at a time. In order to separate the unit wiring board, a step of cutting or punching is required. From this perspective,
For example, Japanese Utility Model Application Laid-Open No. 61-112677 and Japanese Patent Application Laid-Open No. 61-287198 disclose a method for easily separating unit wiring boards. That is, in the former, a large number of core metal plates corresponding to each of the unit wiring boards are arranged side by side, and these metal plates are integrally covered with an insulating film to manufacture an insulating substrate, and after forming a conductor circuit, it is adjacent to each other. The metal plates are separated from each other. In the latter, a space having a size larger than the planned size is provided in the planned separation part so that a sufficient insulating material film remains on the cut or punched cross section.

[Problems to be Solved by the Invention] However, in these methods for manufacturing a metal core / printed wiring board, for example, the method disclosed in Japanese Utility Model Laid-Open No. 61-112677 discloses accurate placement of the metal plate for core. Is difficult, and in the method described in JP-A-61-287198, it is necessary to mount electronic components after separation into unit wiring boards,
There was a problem that it was difficult to implement accurately.

The present invention has been made to solve such a problem, and a simple separation into a plurality of unit wiring boards, in which the position of the metal core is accurate and electronic components can be mounted in the correct position. It is an object of the present invention to provide a method for manufacturing a metal core / printed wiring board which can be manufactured.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a method for manufacturing a metal core / printed wiring board in which a plurality of unit wiring boards on which electronic components are mounted are separably provided. ) A step of forming a slit along the planned separation line on the plate-shaped metal core while leaving the connecting metal part; b) A step of forming an insulating layer on the metal core and filling the slit with an insulating material; c) Insulation A step of forming a conductor circuit on the layer; d) a step of cutting off the connecting metal part while leaving the insulating material filled in the slit; e) a step of mounting an electronic component; is there.

Further, after the step d), it is advantageous for easy separation to include a step of forming a V-shaped groove portion along the planned separation line on the insulating material filled in the slit.

[Operation] Since the slits are provided in the plate-shaped metal core while leaving the connecting metal portion, it is not necessary to dispose one metal core corresponding to the unit wiring board one by one, and the position of the metal core becomes accurate. In addition, after forming the conductor circuit on the insulating layer, the connecting metal part is cut off, but each unit wiring board is connected at a certain position by the insulating material filled in the slit, and when mounting electronic parts. Is easy to position.

[Embodiment] Next, the present invention will be described based on an embodiment shown in the accompanying drawings.

FIG. 1 is a sectional view showing an embodiment of the present invention. FIG. 1 (A) is a sectional view showing a state where electronic parts are mounted on a metal core / printed wiring board, and FIG. 1 (B) is a Y-shaped clip attached to a divided unit wiring board. It is sectional drawing of the state.

First, referring to FIG. 1 (A), an insulating layer (14) and a conductor layer (15) are sequentially provided on the upper and lower surfaces of a metal core (11), so that the metal core / printed wiring board (10) as a whole.
C) is configured. The lead wire (21) from the electronic component (20) is connected to the conductor layer (15) on the upper surface of the metal core / printed wiring board (10C) by solder (22),
It is designed to form a circuit device that performs the required function. The metal core / printed wiring board (10C) is provided with a slit (12) having a desired width and length and a through hole (16) having a desired diameter. First, regarding the slit (12), this is provided along the cutting line (see FIG. 2A) for each unit wiring board as in the case of the conventional example. 12) is filled with a suitable filling insulation (13). Further, in order to facilitate the cutting, for example, a V-shaped groove portion (18) is provided in the center line portion of the slit (12). Also,
As for the through hole (16), once the hole is provided with an appropriate filling insulating material (13), the filling insulating material (13) is left to have a required thickness, and the through hole (16) is provided around the periphery. A conductor layer (17) for communication with the upper and lower conductor layers (15) is provided.

Next, referring to FIG. 1 (B), a Y-shaped clip (19) is attached to the end of the unit wiring board cut along the slit (12).
Is attached. This Y-shaped clip (1
9) is electrically conductive, but since the filling insulating material (13) is provided at the end of the unit wiring board, there is no problem in maintaining the electrical insulation. Absent.

Here, an example of a process for manufacturing the above metal core / printed wiring board will be described.

Example of 1st process The thickness of the metal core (11) to be the base is 1.0 mm
Of aluminum plates were used. This metal core (11) is perforated with a diameter of 1.5 mm by etching to form desired through holes (16), and between adjacent unit wiring boards and between unit wiring boards and ear-shaped portions. A 1.0 mm wide slit (12) is connected to the metal part (2
6) was left (see FIG. 1 (C)). next,
An insulating layer (14) is formed on a metal core (11) using a predetermined insulating material, and a filling insulating material (13) containing a predetermined heat-resistant epoxy resin as a main component is formed on the through hole (16) and the slit. It was buried in (12). This filling insulation (1
As 3), 150 parts by weight of α-alumina filler is added to 100
A mixture of parts by weight of resin solids was used.

Then, a copper foil having a thickness of 18 μm is laminated and coated on the surfaces of the upper and lower insulating layers (14), and a hole with a diameter of 0.5 mm is formed near the center of the through hole (16) by drilling or the like. And the inner surface is plated with copper to form the contact conductor layer (17)
Was formed. Further, a desired conductor circuit was formed by appropriately performing an etching process to remove unnecessary portions of the copper foil. Then, solder plating was applied to the necessary portions. Then, in order to obtain the required number of unit wiring boards (11) suitable for mounting, the connecting metal parts (26) at the necessary locations are
The slit filled with the insulating material is punched out and left, and a V-shaped groove is formed on the insulating material filled in the slit along the planned separation line (25). After that, predetermined electronic components are mounted on the metal core / printed wiring board in this state, and separated and used.

Second process example The thickness of the metal core (11) to be the base is 0.5 mm
Of aluminum plates were used. This metal core (11) is subjected to a punching process with a diameter of 1.5 mm by etching to form a desired through hole (16) portion, and a slit (12) having a width of 1.0 mm is provided between adjacent unit wiring boards. Was formed. Next, a filling insulating material (13) containing a predetermined heat-resistant epoxy resin as a main component was embedded in the through hole (16) and the slit (12). As the filling insulating material (13), a mixture of 150 parts by weight of α-alumina filler and 100 parts by weight of resin solid content was used.

Then, a copper foil having a thickness of 35 μm was laminated and covered on the surface of the insulating layer, and etching treatment was appropriately performed to remove unnecessary portions of the copper foil to form a desired conductor circuit.
Next, a laminated copper foil having a thickness of 18 μm is coated on the front and back of the inner layer printed wiring board in the multi-layer structure part with a 0.5 mm diameter hole near the center of the through hole (16). The portion was formed by drilling or the like, and the inner surface of the portion was plated with copper to form the connecting conductor layer (17). Further, a desired conductor circuit was formed by appropriately performing an etching process to remove unnecessary portions of the copper foil. Then
Solder plating was applied to the necessary parts. Then, in order to obtain the required number of unit wiring boards (11) suitable for mounting,
The connecting metal part (26) at a required location is punched out while leaving a slit filled with an insulating material, and a V-shaped groove is formed on the insulating material filled in the slit along a planned separation line. Form. After that, predetermined electronic components are mounted and separated for each unit for use.

According to these process examples, the metal core in the unit wiring board can be arranged at an extremely accurate position, and at the same time, when mounting the electronic component, the positioning of the electronic component is easy and the work is automatically performed. I was able to proceed.

EFFECTS OF THE INVENTION According to the method of the present invention, the positions of the metal cores of the unit wiring board can be accurately matched, so that the heat dissipation effect of the unit wiring board is uniform and the electronic component of the electronic component at the time of mounting is mounted. Since it is easy to position and can be mounted accurately, it is possible to obtain a metal core print with excellent heat dissipation and easy division.

Further, according to the present invention, when the metal core / printed wiring board is divided into unit wiring boards, it is possible to avoid the exposure at the end surface of the metal core, and to enhance the reliability of its electrical insulation. At the same time, by using the Y-shaped clip shown in FIG. 3, it is possible to use it as a so-called hybrid type wiring board.

[Brief description of drawings]

1 (A) and 1 (B) are sectional views of a main part of a metal core / printed wiring board showing an embodiment of the present invention, FIG. 1 (C) is a plan view of the metal core, and FIG. 2 is a conventional electronic component. It is an illustration figure which shows the printed wiring board by which was mounted. (10C) is a metal core / printed wiring board, (11) is a metal core, (12) is a slit, (13) is a filled insulating material, (14) is an insulating layer, (15) is a conductor layer, and (16) is Through holes, (17) conductor layer for communication, (18) V-shaped groove, (19) Y clip, (20) electronic component, (21) lead wire, (22) solder.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nao Sugiyama 3-200 Kawama-cho, Ogaki-shi, Gifu Ibiden Co., Ltd. (56) References JP-A-54-80566 (JP, A) JP-A-61- 287198 (JP, A)

Claims (2)

[Claims] 1. A method of manufacturing a metal core / printed wiring board in which a plurality of unit wiring boards mounted with electronic components are provided in a separable manner: a) A metal plate for connection is left in a plate-shaped metal core. Providing a slit along the separation line; b) forming an insulating layer on the metal core and filling the slit with an insulating material; c) forming a conductor circuit on the insulating layer; d) filling the slit. A step of cutting off the connecting metal part while leaving the insulating material; e) a step of mounting electronic parts; f) a step of dividing the wiring board into unit wiring boards along a predetermined separation line after the step e). A method of manufacturing a metal core / printed wiring board, comprising: 2. The metal according to claim 1, further comprising the step of forming a V-shaped groove along the planned separation line on the insulating material filled in the slit, after the step d). Manufacturing method of core and printed wiring board.