JPH0719961B2 - Method for manufacturing enamel board with insert terminal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to connection characteristics (insertability) to an external connector.
The present invention relates to a method for manufacturing an enameled substrate having an insertion terminal portion, which is improved.

[Conventional technology]

The enamel substrate can be used as a high heat resistant circuit substrate in the same manner as an alumina substrate is used as an electronic circuit substrate by forming a circuit on the alumina substrate with a thick film paste.

In addition, the enamel board has a large mechanical strength because it uses a metal as a core material, and therefore an insertion terminal portion is provided on the enamel board itself as disclosed in Japanese Utility Model Laid-Open No. 60-17594 (No. 7).
As a result, it can be directly connected to the connector of the external circuit. In FIG. 7, 4 is a circuit board, 3 is a thick film conductor circuit, and 5 is an insertion terminal portion.

On the other hand, when a through hole is formed in the steel core material of the enamel substrate and then the enamel is applied, it is difficult for the enamel to attach to the corners of the hole, and there is a phenomenon that the enamel thickly builds up around it and this is avoided. In order to achieve this, Japanese Patent Publication No. 59-4880 is disclosed. In this technique, the corners of the openings are pressed from above and below by a pressing die with rounded corners to form the through holes into smooth curved surfaces without corners.

[Problems to be Solved by the Invention]

As shown in FIG. 5, the cross section of the conventional fitting insertion terminal has a thick enamel layer attached to a portion close to the end. This is because when the enameled glass is melted and solidified, the flow gathers at the tip portion to generate a bulge (meniscus), and the bulge is about 100 μm in a normal enamel substrate. The presence of this swell creates resistance when inserted into the connector. FIG. 6 shows an elevation view of an example of a general metal terminal of a connector into which a terminal of an enamel board is inserted. It is made of brass and phosphor bronze. Figure 5 shows
The result (average value) of measuring the thickness at various distances from the end when the conventional metal core is normally cut is shown. 0.8 mm thickest at 0.6 mm from the end
It shows 70 mm.

An object of the present invention is to provide a method of manufacturing a board with an insertion terminal portion that eliminates the rise of the enameled layer of the insertion terminal portion for fitting and can be smoothly inserted into the connector.

[Means for Solving the Problems]

The manufacturing method of the present invention, in the punching of the metal core of the enameled board having the insertion terminal for fitting to the connector for external connection, first leaving the shape of the tip of the insertion terminal portion of the core from the material metal plate, Only the vicinity is punched out,
Next, only the tip of the insertion terminal is pressed in the thickness direction, crushed to give a taper, and finally, the entire substrate is punched together with burrs by the pressing of the tip to form a metal core, which is then coated with enamel coating. It is a method of manufacturing an enamel board with an insertion terminal portion, which is characterized by being performed.

FIG. 1 is a sectional elevation view of an insertion terminal which is the object of the method of the present invention. A metal core 1 is coated with an enamel layer 2. This metal core is in the range of 1.0 to 3.0 mm, preferably in the range of 1.0 to 1.5 mm from the tip of the core (Fig. 1b),
The tip portion is tapered in the thickness direction so that the thickness (Fig. 1a) is 0.10 to 0.30 mm.

C is the thickness of the metal core, which is usually about 0.5 to 0.7 mm.

If the thickness a of the tip portion is less than 0.1 mm, the thickness becomes thinner during pickling in the pretreatment of the enamel glaze, which causes a problem in strength and the tip is easily chipped, which is not preferable. On the other hand, when the thickness is more than 0.3 mm, the thin plate has a small difference from the original core thickness, and the effect of preventing the rise of the enameling is small, and it becomes difficult to insert the enamel without increasing the insertion force.

For the distance b from the tip of the taper start position,
In FIG. 5, when using a conventional metal core, it is necessary to make the taper portion approximately 0.6 mm where the enamel layer becomes the thickest. In this sense, a range of 1.0 mm to 1.5 mm is appropriate, On the other hand, when b is larger than 3.0 mm, the taper angle becomes small in the case of a thin plate and it is difficult to eliminate the bulge, so that problems such as increase in insertion force into the connector are likely to occur, which is not preferable. .

From these viewpoints, b is more preferably 1.5 mm or less.

By making such a taper at the tip of the metal core, as shown in FIG. 1, in the conventional metal core, the thickness of the flat plate portion is 0.6 mm from the tip where the enameled layer is thickest. On the other hand, the average thickness can be reduced to about 55 μm, and there is no problem in inserting the terminals.

The thicknesses of to in FIG. 1 are average values in many measurements.

This is the tip manufacturing method, but when punching a substrate from a metal plate, it is most preferable in process to crush the tip of the terminal in the thickness direction on the same stage of the punching die to taper it. Is. This step is shown in FIGS.

First, in FIG. 2, the shape of the tip portion of the insertion terminal portion 5 is left, and only the shaded portion of the vicinity portion 6 is punched out.

Next, in FIG. 3, only the hatched portion of the tip portion 7 of the protruding terminal portion 5 is pressed in the thickness direction to be crushed and tapered. At this time, burr appears around the tip. Finally, in FIG. 4, the entire substrate 4 and the burr formed in the second step are punched at once (the hatched portion of 8 is punched) to obtain the metal core of the enamel substrate of the present invention.

In this way, the punched and crushed core undergoes the pickling process as a pretreatment of the enamel glaze, so the core thickness is 0.03 to 0.
05mm becomes thinner. From this point of view, as described above, it is appropriate that the core thickness a of the tip portion is 0.1 to 0.3 mm, and when it is 0.1 mm or less, the tip core thickness after pickling becomes 0.05 mm or less, which is a problem in terms of strength. Comes out.

The enamel substrate with an insertion end portion of the present invention is obtained by performing glaze glazing through such an acid washing step and firing.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

As the metal core, a 0.6 mm thick steel plate shown in Fig. 1 was used. As taper processing, enamel was glazing 0.12 mm thick (one side) on a core of a = 0.25 mm and b = 1.0 mm. After firing, the thickness of the enamel substrate was measured at positions of 0.3 mm, 0.6 mm, 1.2 mm, and 2.0 mm from the tip. The substrate of the invention of FIG. 1;
FIG. 5 shows the average value of many measured values for the conventional substrate of FIG.

(Present invention) (Conventional example): 0.600mm: 0.84mm: 0.765mm: 0.87mm: 0.835mm: 0.83mm: 0.820mm: 0.82mm Comparison of insertion force between the circuit board of the present invention and the conventional metal terminal did. The insertion force was measured for four metal terminals and four circuit board terminals using a TCM-200 type tester. The insertion force is shown when tested at n = 5.

(Invention) (Kg · f) (Conventional product) (Kg · f) 1. 8.8 1. 11.2 2. 9.2 2. 13.0 3. 7.3 3. 14.5 4. 6.8 4. 10.9 5. 8.5 5. 13.8 Average 8.1 Average value 12.7 [Effect of the invention] As in the present invention, by using a metal core with a tapered tip at the core tip, it becomes possible to prevent the enamel from rising after glazed enamel, and to the actual metal terminal. The insertion force of was also reduced by about 36%, and during insertion, smooth insertion was possible without damaging the conductor circuit or board. In the manufacturing method, taper processing of the tip of the terminal portion can be incorporated in the board punching step, and deburring of the board and the board can be performed all at once, and the tapering step can be simplified.

[Brief description of drawings]

FIG. 1 shows a sectional elevation view of an insertion terminal portion of an enameled board having an insertion terminal portion manufactured by the method of the present invention. FIG. 2 is a plan view in which the metal core is punched out, leaving only the shape of the tip of the terminal portion and punching only the vicinity thereof. FIG. 3 is a plan view in which only the tip end portion of the terminal is pressed in the thickness direction to form a taper. FIG. 4 is a plan view in which burrs are punched out by tapering the entire substrate and the tip. FIG. 5 shows a sectional elevation view of a terminal portion of a conventional enamel substrate with a terminal portion. FIG. 6 is an elevation view of an example of a connector into which an enameled board with a terminal portion is inserted. FIG. 7 is a plan view showing the relationship between the circuit board and the insertion terminal portion.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kenichi Uruga 1-5-1 Kiba, Koto-ku, Tokyo Fujikura Electric Wire Co., Ltd. (72) Inventor Okuyama 1-5-1 Kiba, Koto-ku, Tokyo Fujikura Electric Wire Co., Ltd. (56) Reference JP-A-2-232984 (JP, A) JP-A-2-232985 (JP, A) Actually open 63-131161 (JP, U) Actually open 60-79768 ( JP, U) Actually opened Sho 60-17594 (JP, U) Japanese Patent Sho 59-4880 (JP, B2)

Claims (1)

[Claims] 1. When punching a metal core of an enameled board having an insertion terminal for fitting to a connector for external connection, the shape of the tip of the insertion terminal portion of the core is left from the material metal plate and its vicinity is left. Only the tip of the insertion terminal is pressed in the thickness direction, crushed to give a taper, and finally the entire board is punched together with the burrs by the pressing of the tip. And a method for manufacturing an enamel substrate with an insertion terminal portion, which comprises subjecting the enamel coating to this.