JPH051999B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method of manufacturing a printed circuit board with terminal pins by injection molding.

(Prior Art) In order to carry out wiring processing on both the front and back sides of the board material of a printed circuit board, there is a structure in which the front side and the back side of the board material are configured to be electrically conductive. For example, in the past, a connection hole was formed in the surface of a board material, and a good conductor layer was formed on the inner wall of the connection hole by means such as plating, so that the circuit pattern of the board and the connection hole could be connected to each other so as to conduct electricity. However, there were some cases in which the front and back sides of the board material were connected by pouring solder or attaching terminal pins through this good conductor layer.

However, since the thickness of the copper foil, etc. that makes up the circuit pattern is extremely thin, when connecting solder or conductor pins through a good conductor layer, the electrical connectivity is not sufficient because there are few contact parts, that is, current-carrying parts. I hated it. Furthermore, since the manufacturing process requires multiple steps, there is a problem that manufacturing and economical efficiency are not good.

(Problems to be Solved by the Invention) This invention has been proposed in view of the above-mentioned problems, and its purpose is to ensure that both the front and back surfaces of the board material are connected to the circuit pattern by the terminal pins. It is an object of the present invention to provide a method for efficiently manufacturing a printed circuit board with terminal pins which are electrically connected and have good connectivity.

(Means for Solving the Problems) That is, in this invention, a terminal pin whose tip is coated with cream solder is arranged in a fixed cavity, and a circuit pattern constituting a printed circuit is provided on the surface of the movable cavity. A circuit film is arranged so that the circuit pattern faces the cavity side, and the mold is clamped to allow the tips of the terminal pins to penetrate the circuit pattern and the circuit film, and the cream solder is moved onto the circuit pattern surface. Next, by injecting the molten resin constituting the board into the cavity, the board material is molded integrally with the circuit pattern and the terminal pins, and the cream solder is melted and soldered, and then the molded product is This method is characterized in that a printed circuit board with terminal pins is obtained by removing the circuit film on the surface.

(Function) The printed circuit board with terminal pins obtained by the present invention has reliable and good connectivity since the terminal pins and the circuit pattern are integrally soldered to the board material part.

According to this invention, the aforementioned printed circuit board with terminal pins is manufactured all at once at the same time as the board material is molded, and the cream solder transferred onto the circuit pattern surface in the cavity by mold clamping is The terminal pins and the circuit pattern, which are melted by the heat of the molten resin constituting the board that is injected into the cavity, are integrally soldered inside the board as the board material is molded.

(Embodiments) Examples of the present invention will be described below with reference to the attached drawings. FIG. 1 is a partially enlarged sectional view showing an embodiment of a printed circuit board obtained by the present invention, and FIG. 2 is an injection molding die for carrying out the method of manufacturing a printed circuit board with terminal pins of the present invention. Fig. 3 is a partially enlarged sectional view of the mold showing the arrangement of terminal pins, Fig. 4 is a partially enlarged sectional view showing the mold in its closed state, and Fig. 5 is another example. FIG. 6 is a cross-sectional perspective view of a main part illustrating the flow of molten resin in a mold cavity in an example, and FIG. 6 is a perspective view of a main part of a printed circuit board with terminal pins according to another embodiment.

Explaining according to the partially enlarged sectional view of FIG. 1, the printed circuit board 10 with terminal pins of this embodiment is as follows:
A circuit pattern 13 made of a conductive material such as copper foil is formed on the surface of a substrate material 11 made of an insulating material such as resin by the following manufacturing method and injection mold. Terminal pins 15 made of a conductive material are penetrated through the substrate material 11 over both sides of the front surface 11A and the back surface 11B of the substrate material 11, and are electrically connected to the circuit pattern 13.

That is, the terminal pin 15 is attached to the substrate material 1, with its soldering portion indicated by reference numeral 17.
1 and is integrally soldered to the circuit pattern 13. Note that the terminal pin 15
In addition to the linear shape shown in the figure, the terminal pin may be a terminal pin of a component or a terminal pin of a socket thereof.

The printed circuit board with terminal pins as described above is manufactured by the following manufacturing method.

To explain this according to Figures 2 to 5,
FIG. 2 is a sectional view of a main part of an injection mold for molding a printed circuit board with terminal pins. A fixed mold side cavity 40 having the shape of a printed circuit board is formed in a fixed mold 31 fixedly installed on a fixed platen 30 of this mold. Reference numeral 37 in the figure is an injection nozzle, 3
9 is a sprue bush.

A movable mold 61 fixed to the other movable platen 60 is formed with a movable mold cavity 70 corresponding to the fixed cavity 40 .

The fixed mold 31 on the fixed side is composed of a template main body 33 and a template mounting member 35 that holds the template main body from its back. In the cavity 40 formed in the template body 33, a terminal pin 50 serving as an insert is inserted.
A pin hole 41 for holding is formed.

The depth of the pin hole 41 is the length by which the end of the terminal pin 50 projects toward the back side of the molded product. Needless to say, this pin hole 41 is provided in accordance with the circuit pattern.

FIG. 3 shows a terminal pin 50 held in the pin hole 41, and cream solder 55 is applied to the tip of the terminal pin 50.

The cream solder 55 here is a paste-like solder that is a mixture of powdered solder and flux.

The cream solder 55 is selected in consideration of the temperature of the resin injected into the cavity, and in this embodiment, one that melts at a low temperature is used, and its solidus temperature is around 130°C and its liquidus temperature is around 130°C. It is around 160℃. This cream solder 55 is applied to the terminal pin 50.
Before or after placing the in the cavity 40,
For example, the solder cream 55 can be applied by abutting the tips of the terminal pins 50 with a sponge-like material impregnated with the cream solder 55.

The movable mold 61 on the movable side is composed of a template body 63 and a template mounting member 65 that holds the template body from its back. Cavity 70 of template body 63
A cavity surface 70A is formed in correspondence with the fixed cavity 40, which may be flat or curved or core shaped as required.

A circuit pattern 80 constituting a printed circuit is arranged together with a circuit film 85 at a predetermined position on this cavity surface 70A. The circuit film 85 is made of PET or the like, and is integrally formed with a circuit pattern 80 made of a conductive material such as copper foil. The reference numeral 87 in the figure is a feed roller for the circuit film 85, and the reference numeral 88 is a take-up roller.

Further, the cavity surface 70A of the template body 63
, the movable side pin hole 71 is connected to the fixed cavity 40.
It is provided at a position corresponding to the pin hole 41 of.

This movable side pin hole 71 is connected to the fixed cavity 4.
0, and when the tip of the terminal pin 50 penetrates the circuit pattern and the circuit film by mold clamping, the tip is inserted.

As described above, the terminal pin 50 with the cream solder 55 applied to the tip of the fixed cavity 40
A circuit film 85 having a circuit pattern 80 is placed on the cavity surface 70A of the movable mold so that the circuit pattern 80 faces the cavity 40, and then the mold is clamped.

FIG. 4 illustrates the mold-clamped state.

By clamping the mold, the tip of the terminal pin 50 placed in the fixed cavity passes through the circuit pattern 80 and the circuit film 85, and is further inserted into the movable pin hole 71 provided in the movable cavity surface 70A. .

At this time, this terminal pin 50 is connected to the circuit pattern 8
When penetrating 0, cream solder 5 at the tip
5 is blocked by the circuit pattern 80 and moves and adheres to the surface of the circuit pattern 80.

Next, when the molten resin constituting the substrate material is injected into the cavity through the gate of the sprue bushing 39, the circuit pattern 80 is integrally molded with the substrate material. During this molding, the molten resin is generally approximately
The cream solder 55 is melted by this heat, and as the molten resin is cooled and solidified, the cream solder also solidifies in the resin, and the circuit pattern and terminal pins are bonded together. They are soldered together.

Thereafter, by removing the circuit film on the surface of the molded product, a printed circuit board with terminal pins is obtained.

Note that depending on properties such as viscosity of the resin and conditions during molding such as injection speed, the cream solder may be washed away by the molten resin injected into the cavity. In such cases, it is preferable to take the following measures.

That is, as shown in each figure of the embodiment, a cylindrical core portion 49 is provided in the fixed cavity 40.
The terminal pin 50, that is, the cream solder 55 is placed on the weld line, which is the confluence of the divided flows of molten resin generated by the core portion 49. As shown in FIG. 4, this core portion 49 has a height such that it comes into close contact with the circuit film 85 during mold clamping. This core portion 49 is formed into a circular shape having a diameter three to five times the diameter of the terminal pin 50.
0 is preferably about the same as the diameter of the core portion 49. FIG. 5 is an explanatory diagram showing the flow of the molten resin near the core portion 49. As shown by the arrow in the figure, the flow of the resin is shown in the core part 49.
The cream solder 55 adhering to the terminal pins 50 and the circuit pattern 80 placed on the weld line where the resin separated by the flow joins is melted by the substantially non-flowing resin, but is not washed away. do not.

A printed circuit board 90 with terminal pins shown in FIG. 6 is manufactured by the above method, and in this board 90, a through hole 99 is formed by the core part 49. This through hole 9
9 may be a through hole, but may also be used as a mounting hole for the board 90. Code 91 in the figure
93 is a circuit pattern, and 95 is a terminal pin.

(Effects) As illustrated and explained above, according to the present invention, the terminal pins that connect the front side and the back side of the printed circuit board are integrally soldered together with the circuit pattern inside the board, so that the present invention can be reliably achieved. electrical connectivity.

In addition, since the soldering between the terminal pin and the circuit pattern is done inside the board, the soldered part is not oxidized by the outside air, which prevents deterioration of electrical characteristics due to oxidation and improves its durability. Now I can improve my sexuality.

As described above, according to the present invention, the highly advantageous printed circuit board with pins as described above can be manufactured all at once, simultaneously with the molding of the board material, and the manufacturing and economic advantages are extremely large.

[Brief explanation of the drawing]

FIG. 1 is a partially enlarged sectional view showing an embodiment of a printed circuit board with terminal pins obtained according to the present invention, and FIG. 3 is a partially enlarged sectional view of the mold showing the arrangement of terminal pins, FIG. 4 is a partially enlarged sectional view of the mold showing the clamped state, and FIG. 5 is a sectional view of the main parts of the mold. FIG. 6 is a cross-sectional perspective view of a main part illustrating the flow of molten resin in a mold cavity in another embodiment, and FIG. 6 is a perspective view of a main part of a printed circuit board with terminal pins according to another embodiment. 10...Printed circuit board with terminal pins, 11
...Substrate material, 13...Circuit pattern, 15...Terminal pin, 17...Soldering part, 31...Fixed type, 40...Fixed type cavity, 41...Pin hole, 50...Terminal pin, 55 ... Cream solder, 61 ... Movable type, 70A ... Cavity surface,
71... Pin hole, 80... Circuit pattern, 85...
...Circuit film.

Claims (1)

[Claims] 1. A terminal pin whose tip is coated with cream solder is arranged in a fixed cavity, and a circuit film having a circuit pattern constituting a printed circuit is placed on the surface of the movable cavity, and the circuit pattern is arranged in the cavity. the terminal pins are placed so that they are on the same side, and the mold is clamped to allow the tips of the terminal pins to pass through the circuit pattern and the circuit film to move the cream solder onto the circuit pattern surface, and then to form a board in the cavity. By injecting the molten resin, the board material is molded integrally with the circuit pattern and the terminal pins, and the cream solder is melted and soldered. After that, the circuit film on the surface of the molded product is removed. A method for producing a printed circuit board with terminal pins, the method comprising obtaining a printed circuit board with terminal pins.