JPS5923486B2 - Crystal oscillator holding device - Google Patents

Description

[Detailed description of the invention] The present invention relates to a holding device for a crystal resonator.

Conventionally, crystal oscillators have two terminal pins that pass through the sealing base, and two leaf springs that are perpendicular to and parallel to the base, which hold the crystal oscillator between them, and are sealed with a cap. Ta.

To configure an oscillator, an integrated circuit with an oscillation circuit, a frequency dividing circuit, a drive circuit, and an example capacitor are required, which not only increases the number of components of the oscillator but also requires connection to the circuit board via terminal pins. Therefore, there were drawbacks such as the troublesome connection process.

Since the present invention is a crystal oscillator holding device in which a capacitor is integrally formed, the number of parts when configuring the oscillator is small, and the capacitor is sealed together with the crystal oscillator. There are few changes.

In addition, it is easy to manufacture and enables mass production and cost reduction.

An embodiment of the present invention will be described.

FIG. 1 is a front view with the thickness exaggerated, and numeral 1 denotes a holder for a crystal resonator, which is made of a flexible substrate.

That is, 2 is a flexible insulating sheet made of polyimide or the like, and has a three-layer structure in which a conductor film, such as a Cu foil 3.4, is adhered to the front and back surfaces of the sheet with an adhesive 5.5.

The thickness of the Cu foil varies, for example, 35μ, 70μ, 105μ, etc., but a thicker one is preferable from the viewpoint of crystal retention.

However, it is not particularly limited.

Using such a flexible substrate, it is pressed into the shape of the holder 1 as shown in the second figure.

That is, the holding arms γ, 8 extend from the substantially circular central portion 6 and the symmetrical position of its opening.

Relief holes 9 and 10° 11 for the terminal pins are drilled in the central portion 6, and holding holes 12 and 13 for the crystal resonator are drilled in the holding arms γ and 8I.

The surface conductor film at the center of the holder 1 is divided into three conductor films by a separation strip 14I from which the conductor film is removed by etching or the like.

That is, the conductor film on the left side is the crystal connection electrode 15, and is continuous with the conductor film 15a drawn out by the holding arm T.

The conductor film on the right side is a crystal connection electrode 16, and is continuous with the conductor film 16al drawn out by the holding arm 8.

The conductor film in the middle is an electrode 1T for die bonding of an integrated circuit.
It is.

Separation strips 18a and 18b are provided on the back conductor film of the holder 1 by removing the conductor film by etching or the like near the boundaries between the holding arms 1 and 8 and the central portion 6, and the middle part of the separation strip is the common electrode. It is 19.

Separation zone 18a. Providing 18b also has the purpose of avoiding cracks when the holding arm is bent.

Then, the crystal connection electrode 15 and the common electrode 19 and the crystal connection electrode 16 and the common electrode 19 overlap with the insulating sheet 2 in between, and load capacitances C, C2 are generated using the insulating sheet 2 and the adhesive 5 as dielectrics. .

The holder 1 thus formed is fixed to the upper surface of the metal base 24 as shown in the fourth and fifth figures.

That is, a conductive adhesive is applied to the common electrode 19 on the back surface of the holder 1, and the terminal pins 20, 21, 22 are inserted into the escape holes 9, 1.
0,11tt and adhere to the upper surface of the base.

That is, the common electrode 19 is grounded to the base 240.

Then, an integrated circuit (IC chip) 25 is die-bonded to the electrode 1γ.

Further, as indicated by a dotted line 26 in FIG. 4, electrical continuity is established between the electrode 1T and the upper surface of the base using a conductive adhesive.

Wire bonding is performed between a predetermined position of the IC chip 25 and the electrodes 15, 16, 17 and the terminal pins 21, 22, and between the electrode 1γ and the terminal pin 20.

Holding arm γ. 8 from the bending lines 2γ, 28 and stand up as shown in the fifth figure.

A crystal resonator 29 is held in the holding holes 12 and 13 of the holding arms 1 and 8.

The crystal resonator and the holding hole 12 or 13 are bonded with a conductive adhesive, and the conductive film 15a or 16a is connected to the drive electrode of the crystal resonator.

A conductive adhesive 30 is applied to the upper ends of the holding arms γ, 8, and the conductive films on the front and back sides thereof are electrically connected.

As a result, the crystal drive circuit shown in FIG. 6 is formed.

After finely adjusting the frequency, it is sealed with a metal cap (not shown) to complete the assembly of the crystal oscillator.

In FIG. 6, 31 is an amplifier circuit, 32 is a buffer, 33 is a frequency divider circuit, 34 is a drive circuit, and 35 is a resistor, each of which is formed within the IC chip 25.

Further, the terminal pins 20, 21, and 22 are respectively a VDD power terminal, an output terminal, and a VSS power terminal.

By using a flexible substrate, the crystal resonator holding device of the present invention can integrate the load capacity and the holding arm,
The number of parts is small, the configuration is simple, and manufacturing is easy.

Furthermore, since the electrode for die bonding of the integrated circuit is formed on the holder, there is no need for a substrate for an IC chip when constructing a crystal oscillator, which simplifies the construction and enables miniaturization.

In a crystal oscillator using this holding device, the load capacitance and IC chip are sealed together with the crystal resonator, so the crystal oscillator is less affected by environmental changes and changes over time, has stable dynamic characteristics, and has high precision.

Moreover, it has many excellent effects such as excellent mass productivity.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, in which FIG. 1 is a front view with exaggerated thickness for explaining the flexible substrate, FIG. 2 is a front view of the holder, and FIG. 3 is a rear view of the same. Fig. 4 is a plan view of the holder fixed to the base, Fig. 5 is a sectional view taken along the line V-V of Fig. 4 with the crystal resonator attached, and Fig. 6 is a plan view of the holder fixed to the base.
The figure is a drive circuit diagram. 1...Holding body, 6...Central part, γ, 8
...Holding arm, 14, 18a, 18b--
--- Separation band, 15° 16... Crystal connection electrode, 1T... Electrode for die bonding of integrated circuit, 19... Common electrode, 25... ...Integrated circuit, 29...Crystal resonator, C□sC2...
...Load capacity.

Claims (1)

[Scope of Claims] 1. A holder for a crystal resonator having a central portion and two holding arms extending laterally from the central portion is provided. The holder is provided with a flexible insulating sheet and provided on both sides of the holder. It consists of a front conductor film and a back conductor film.The front conductor film of the holder has a separation strip (from which two crystal connection electrodes are formed), and the back conductor film of the holder has a separation strip (from which a common electrode is formed). A holding device for a crystal resonator, characterized in that a load capacitance for a crystal drive circuit is generated between the two crystal connection electrodes and the common electrode. In this device, the surface conductor film of the holder is divided into three sections by a separation band, the two sections are crystal connection electrodes, and the central section is an electrode for die bonding of an integrated circuit.