JPH09139648A - Surface mounted crystal oscillator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the seal pipe of a crystal oscillator from being exposed on the lower surface of the surface mounted crystal oscillator by providing the injection molding hole (gate hole) of resin mold on the terminal side of the crystal oscillator and on the downside rather than a lead frame. SOLUTION: One part of the lead frame is sandwiched between an upper metal mold 11 of a metal mold and a lower metal mold 12 and a lead frame 3' at the section, where a terminal 2 of the crystal oscillator is fixed (welded), is bent so as to be positioned higher than an abutting plane 7 of the upper metal mold 11 and the lower metal mold 12. This working is performed simultaneously when welding the lead frame 3' and the terminal 2 of the crystal oscillator. Then, a gate hole 13 for injection is provided on the side of the lower metal mold 12, and the upper metal mold 11 is provided with two pins 14 and 15 for holding the crystal oscillator. Since the gate hole 13 for injection is positioned lower than the lead frame 3', the flow of resin is first formed on the lower metal mold 12. Therefore, the crystal oscillator is pushed up toward the upper metal mold 11 and any pin for holding the crystal oscillator is not required for the lower metal mold 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-molded surface mount type crystal unit.

[0002]

2. Description of the Related Art A surface mount type crystal unit in which a terminal of the crystal unit is fixed (welded) to a lead frame and then resin-molded is used. Therefore, the injection molding die is provided with a pin for positioning and fixing the sealing tube of the crystal oscillator to prevent the crystal oscillator from moving during the injection molding.

FIGS. 1 and 2 are perspective views of a surface-mount type crystal unit manufactured by a conventional technique. FIG.
FIG. 2 is viewed from diagonally below. FIG. 3 is a front sectional view showing the positional relationship between the die and the crystal unit during the manufacturing process of the surface mount type crystal unit. The injection-molded resin gate port 6 is formed in the upper mold 4, and when the resin is injected, the welded portion of the crystal resonator terminal 2 is pushed downward, and the crystal resonator sealing tube 1 is also lowered. The sealing tube 1 is exposed to the lower surface when the surface mount type crystal resonator is completed by being pressed by the lower mold 5 to contact the lower surface thereof. If the distance between the lower surface of the sealing tube 1 and the lower die 5 is increased, the sealing tube 1 can be prevented from being exposed, but the thickness of the surface mount type crystal resonator increases. This is a measure that cannot be adopted when it is desired to make electronic parts lighter, thinner and smaller. Therefore, dies are installed above and below the sealing tube 1 of the crystal unit in which the terminals 2 are welded to the lead frame 3, and pins 8 and 9 for positioning and fixing the crystal unit are provided.
10 is placed and injection molded. On the resin-molded surface, marks for positioning and fixing pins 8, 9 and 10 reach the sealing tube 1 of the crystal unit as holes 8 ', 9'and 10'. 1 and 2, there are one hole on the upper surface and two holes on the lower surface.

[0004]

Since there is a hole reaching the sealing tube on the lower surface of the surface mount type crystal unit, when the surface mount type unit is mounted on a circuit, the circuit pattern and the crystal unit are sealed. There was a possibility that the stop tube would become conductive due to the solder, resulting in a short circuit.

An object of the present invention is to prevent the sealing tube of the crystal unit from being exposed on the lower surface of the surface mount type crystal unit, and achieve the above-mentioned purpose without any special process in the manufacturing process. Is intended.

[0006]

[Means for Solving the Problems] In a surface mount type crystal unit in which a terminal of the crystal unit is fixed to a lead frame and then resin-molded, an injection molding port (gate port) of the resin mold is formed on the terminal side of the crystal unit. Provide below the lead frame.

A crystal oscillator fixing pin at the time of resin molding is arranged on the upper part of the crystal oscillator and resin molding is performed. Resin is first filled between the lower mold and the crystal unit, and injection molding is performed so that the crystal unit is pressed against the fixed pin.

The lead frame of the terminal fixing portion of the crystal unit is formed above the other lead frame portions.

The crystal unit has a flat cross section.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION FIG. 4, FIG. 5, and FIG. 6 are surface mount type crystal resonators according to the present invention, and are a front sectional view, a top view, and A.
It is -A sectional drawing. FIG. 4 partially shows the state of the mold at the time of injection molding. Part of the lead frame is sandwiched between the upper mold and the lower mold of the mold, and the terminal 2 of the crystal unit is fixed (welded).
The part of the lead frame 3 ′ is bent so as to be above the mating surface 7 of the upper mold 11 and the lower mold 12. Bending is performed at the same time when the lead frame 3'and the terminal 2 of the crystal unit are welded. The gate port 13 for injection is provided on the lower die 12 side, and the upper die 11 is provided with two pins 14 and 15 for receiving a crystal oscillator.

The flow of resin during injection molding will be described. The resin injected from the gate port 13 is affected by the lead frame 3 ′ bent upward to which the terminal 2 of the crystal unit is welded, so that the resin is injected more than the upper part of the mating surface 7 of the upper mold 11 and the lower mold 12. First, the space between the lower mold 12 and the lower portion of the crystal unit flows so as to fill the space, and the crystal unit is pushed upward. The crystal oscillator is composed of two pins 14, 1 provided with an upper mold 11.
Then, the resin is filled in the gap between the upper mold 11 and the upper part of the crystal unit.

After cooling, the lead frame 1 becomes an external terminal.
FIG. 5 is a top view of the surface-mount type crystal resonator completed by bending 6 of FIG.
Holes 14 ', 15' due to 5 remain. Although two pins are used in this embodiment, since the terminals of the crystal unit are welded to the lead frame, one pin (15) on the right side of the drawing is used.
The purpose can be achieved by itself.

If the crystal resonator is made to have a flat cross section such as an ellipse to make the gap between the crystal and the lead frame small so that the resin flows preferentially under the crystal resonator, The gap between the lower part and the lower die can be made smaller, and the flatter shape of the crystal oscillator enables the manufacture of a thinner surface-mounted crystal oscillator.

[0014]

Since the injection molding port is provided in the lower mold and positioned below the lead frame, the resin flow can be made earlier in the lower mold than in the upper mold. This pushed the crystal oscillator up toward the upper mold, eliminating the need to provide pins for receiving the crystal oscillator in the lower mold. Since there are no pin holes on the lower surface of the surface mount crystal unit, there is no short circuit when mounted. Also, the manufacture of the lower mold has become easier.

By bending the lead frame portion (the portion where the resin is injected into the mold) to which the terminals of the crystal unit are fixed to the upper portion, it becomes easy to prioritize the resin flow to the lower mold side. .

By using a crystal resonator having a flat cross-sectional shape, it was possible to enhance the above-mentioned effect and manufacture a thinner surface-mounted crystal resonator.

[Brief description of the drawings]

FIG. 1 is a top perspective view of a surface mount crystal unit according to a conventional technique.

FIG. 2 is a bottom perspective view of a surface mount crystal unit according to a conventional technique.

FIG. 3 is a front cross-sectional view showing the positional relationship between the mold and the crystal unit during the manufacturing process of the surface mount type crystal unit.

FIG. 4 is a front sectional view showing the positional relationship between the mold and the crystal unit during the manufacturing process of the surface mount type crystal unit of the present invention.

FIG. 5 is a top view of the surface mount type crystal resonator of the present invention.

FIG. 6 is a sectional view taken along line AA.

[Explanation of symbols]

 1 Sealing tube 2 Terminal 3 Lead frame 3'Lead frame 4 Upper mold 5 Lower mold 6 Gate opening 7 Mating surface 8 pins 9 pins 10 pins 8 'Hole 9'hole 10' Hole 11 Upper mold 12 Lower mold 13 Gate port 14 pin 15 pin 14 'hole 15' hole 16 Lead frame

Claims (4)

[Claims] 1. In a surface mount type crystal unit in which terminals of a crystal unit are fixed to a lead frame and then resin-molded, an injection molding port of the resin mold is located on the terminal side of the crystal unit and below the lead frame. Surface mount type crystal unit. 2. The surface mount type crystal resonator according to claim 1, wherein the crystal resonator fixing pin at the time of resin molding is arranged on the crystal resonator and resin-molded. 3. The surface mount type crystal resonator according to claim 1, wherein the lead frame of the terminal fixing portion of the crystal resonator is located above the other lead frame portions. 4. The surface mount type crystal resonator according to claim 3, wherein the crystal resonator has a flat cross-sectional shape.