JPH03280606A - Small-sized crystal oscillator for surface mount use - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Industrial Application Field) The application field of the present invention is a small crystal oscillator for surface mounting.
In particular, it relates to a structure that reduces its overall shape.

(Background of the Invention) Crystal oscillators are widely used in various communication devices and digital control devices because of their excellent electrical characteristics. in recent years,
Surface mount type devices have been developed based on the trend toward miniaturization through high-density mounting. For example, one of these is one by the present applicant (patent@ dated March 22, 1990).

(Prior Art) FIG. 4 is a diagram of a crystal oscillator illustrating a conventional example of this type, in which FIG. 4(a) is an exploded view and FIG. 4(b) is a sectional view.

The crystal oscillator contains a crystal resonator (crystal piece) 1 and a C-M
It is made by enclosing an OS type IC2. IC2 includes inverters 3 and 4 for oscillation and amplification, feedback resistor 5, and capacitor 6.7
An inverter oscillation circuit is constructed using the crystal resonator 1 as an oscillator (FIG. 5). The container 8 consists of a container body 9 and a cover 10. The container body 9 is formed by forming a weld ring 12 on the upper surface of a concave laminated ceramic 11. and,
Weld ring 12 and cover 10 are joined by seam welding. At both corners of the container body 9 there are divided stepped portions 13 (a).
b), and one end side of the crystal piece 1 is electrically and mechanically connected and held. The IC chimp 2 is located and fixed in the gap between the crystal piece 1 and the bottom surface of the container body 9, and is connected to the conductive path by bonding. Further, on the outer surface of the container body 9, a conductive path (not shown) extends from the ceramic laminated surface and is formed as an external terminal. By doing this, the number of components in the circuit is reduced to only the crystal resonator and the IC, thereby reducing the area occupied by them. Further, since the container body 9 and the cover 10 are joined by seam welding, the dimension in the plane direction can be reduced without requiring a flange on the outer periphery. As a result, the overall shape can be made into the world's smallest size with a length of 7.5 mm, a radius W of 5.1 mm, and a height H of 2°0 mm.

(Problems with the Prior Art) However, in the above configuration, the bonding lead wire 14 is connected from the electrode exposed portion (not shown) of the IC chip 2.
is derived. For this reason, the gap between the crystal blank 1 and the IC chip 2 to avoid contact with the central part of the crystal blank 1, which undergoes large vibrational displacement, hinders the reduction in height dimension.

(Objective of the Invention) An object of the present invention is to provide a small crystal oscillator for surface mounting with a further reduced height dimension.

(Solution Means) The present invention provides the following solutions: An IC chip is fixed by face-down bonding, and the IC chip is also used as a holder for a crystal piece. An embodiment of the present invention will be described below.

(Embodiment) Fig. 111 is a diagram of a crystal oscillator for explaining an embodiment of the present invention, in which Fig. 111 is an exploded view and Fig. 111 (b) is a cross-sectional view.

Note that the same parts as those in the previous embodiment drawings are given the same numbers and the explanation thereof will be simplified.

The crystal oscillator is constructed by enclosing a crystal piece 1 constituting an inverter oscillation circuit and a C-MOS type IC chip 2 in a container 8 formed by seam welding as described above. and,
In this embodiment, the container body 8 is made of a concave laminated ceramic, and step portions 13 (ab) are provided at both corners of one end. Then, the IC chip 2 is fixed to the bottom surface of the other end by face-down bonding. That is, the electrodes exposed on the one surface 7 side of the + IC chip are directly connected and fixed to electrode lands (not shown) on the bottom surface. One end of the extended electrode of the crystal blank 1 is electrically and mechanically connected to and held by the stepped portion 13 (ab), and the other end is placed on the other surface of the IC chip. .

In such a device, bonding using a wire from the exposed electrode of the IC chip 2 is eliminated and face-down bonding is used, so that the gap with the crystal blank 1 can be made as small as possible. Furthermore, since the other end of the crystal piece 1 is placed on the IC chip 2, it helps in holding the crystal piece 1 and improves impact resistance.

(Other Embodiments) FIG. 2 is an exploded view of a crystal oscillator excluding the cover, explaining another embodiment of the present invention. Note that the same parts as those in the previous embodiment drawings are given the same numbers and their explanations are omitted.

In this embodiment, the container body 9 has a concave laminated ceramic 1
5, and a stepped portion 13b is provided only at one corner on one end side. Then, the IC chip 2 is fixed to the other corner by face-down bonding.

One end of the crystal piece 1 from which the lead electrode extends is electrically and mechanically connected to and held on the stepped portion 13b and the IC chip 2.

Therefore, even in this case, the dimension in the height direction can be reduced because face-down bonding is used as in the previous embodiment, and this is also used as a holding stand for the crystal blank l.

(Other Embodiments) FIG. 3 is an exploded view of a crystal oscillator excluding a cover, illustrating still another embodiment of the present invention.

In this embodiment, a stepped portion 13 is provided at one end of the container body 9, and the IC chip 2 is fixed to the other end by face-down bonding. The lead electrodes of the crystal piece 1 are extended to both ends, and each end is electrically and mechanically connected to and held on the stepped portion 13 and the IC chip 2. Therefore, even in such a device, since the IC chip 2 is also used as a holder for the crystal blank 1, the dimension in the height direction can be reduced.

(Effects of the Invention) The present invention provides a small crystal oscillator for surface mounting with a further reduced height dimension, since the IC chip is fixed by face-down bonding and the IC chip is also used as a holder for the crystal piece. can.

[Brief explanation of drawings]

FIG. 311 is a diagram of a crystal oscillator for explaining an embodiment of the present invention, in which FIG. 311 (a) is an exploded view and FIG. 311 (b) is a sectional view. FIGS. 2 and 3 are exploded views of a crystal oscillator with the cover removed, illustrating another embodiment of the present invention. FIG. 4(a) is an exploded view of a crystal oscillator explaining a conventional example.
Figure (b) is a cross-sectional view. FIG. 5 is an inverter oscillation circuit diagram. Ml zo Figure 2 'v, Figure 3 Figure 4

Claims (1)

[Claims] A crystal piece and a C-M are placed inside the concave container body made of ceramic.
In a small crystal oscillator for surface mounting in which an OS-type IC chip is placed and sealed by seam welding a weld ring provided on the upper surface of the side wall of the container body and a metal cover, the IC chip is face-down bonded. 1. A surface-mounted crystal resonator, characterized in that the IC chip is fixed to the surface by a crystal resonator, and the IC chip is also used as a holder for a crystal piece.