JPH0217482Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention relates to a flat package, and more specifically, it is suitable for semiconductor devices and crystal resonators in which a flat package body and a cap are sealed via a low-melting glass. It is something.

2. Description of the Related Art In electronic components such as semiconductor devices and crystal resonators, semiconductor elements and elements such as crystal pieces are packaged because their characteristics change due to moisture or the like. Some products are packaged with resin, but in terms of reliability, they are inferior to those sealed in can cases or ceramic packages, so can cases or ceramic packages are used for applications that require high reliability. There is. However, in devices using can cases and ceramic packages, moisture does not infiltrate, but as disclosed in Japanese Utility Model Publication No. 40-36187, when solder is used for sealing, the elements deteriorate due to flux vapor. Therefore, a glass-sealed structure is being considered as disclosed in Japanese Patent Publication No. 5172/1972.

FIG. 2 shows a plan view of an example of a crystal resonator using a conventional glass-sealed ceramic flat package, with the cap removed. A corresponding cross-sectional view is shown. In the figure, 1 is a package body, and a pair of Kovar, 42 alloy (Fe; 58%,
Leads 5 and 6 made of Ni (42%) or the like are hermetically sealed. Reference numeral 7 denotes a cap made of ceramic such as alumina or steatite, which is hermetically sealed to the frame 3 via a low-melting glass 8. Reference numeral 9 denotes a crystal piece, to which electrodes 9a and 9b on both sides are connected and fixed across the pair of leads 5 and 6 via conductive adhesives 10 and 11.

By the way, in the above configuration, the cap 7
As the sealing glass, a low melting point glass 8 whose melting point is lower than that of the glass 4 used to seal the leads 5 and 6 is used. Due to the heating, if the crystal piece 9 becomes high temperature or if a conductive adhesive 10, 11 containing an organic substance is used to connect and fix the crystal piece 9, gas will be generated from the conductive adhesive 10, 11. This caused the deterioration of the characteristics of the crystal blank 9.

Therefore, the applicant separately adhered low-melting glass to at least the sealing area with the package body on the bottom surface of the cap, pressed a heater against the top surface of the cap, and melted the low-melting glass using the conductive heat of the cap. This paper proposes a method of sealing the package body and the cap.

FIG. 5 shows an exploded sectional view for explaining the above-mentioned sealing method which is the background of this invention. The figure is the same as FIG. 4 except for the following points, so the same parts are given the same reference numerals and their explanation will be omitted. The difference from FIG. 4 is that a heat sink 12 made of a good thermal conductor such as iron, copper, or aluminum is placed under the bottom plate 2 of the package body 1, and a heater such as a ceramic heater is placed on the top surface of the cap 7. 13 is pressed.

According to the above structure, the low melting point glass 8 attached to the lower surface of the cap 7 is heated and melted by the conductive heat of the cap 7 from the heater 13.
is fused and sealed to the frame 3 of the package body 1. At this time, the temperature rise of the leads 5 and 6 is suppressed by the thermal resistance of the frame 3 and the glass 4, and the heat of the leads 5 and 6 is conducted through the glass 4 and the bottom plate 2 and radiated to the heat sink 12. Ru. Therefore, the temperature of the leads 5, 6 is kept low, and the temperature of the crystal blank 9 and the adhesives 10, 11 that connect and fix the crystal blank 9 to the leads 5, 6 is low, so that the crystal blank 9 itself does not deteriorate due to high temperatures. In addition, even if the adhesives 10 and 11 contain organic substances, no harmful gases are generated, and the crystal piece 9 is not deteriorated by the gases generated.

When the above manufacturing method is employed, it is preferable that the bottom plate 2 and the cap 7 be formed of a ceramic having a high thermal conductivity such as alumina, while the frame body 3 is formed of a ceramic having a low thermal conductivity such as forsterite.

Problems to be Solved by the Invention However, even if the above structure and cap sealing method are adopted, the crystal blank 9 and the conductive adhesive 1
Since the temperature at 0 and 11 rises to about 200 to 250 degrees Celsius, there was no possibility of deterioration of the characteristics of the crystal piece 9 itself due to the heat and gases generated from the conductive adhesives 10 and 11.

Measures to Solve the Problems Therefore, this invention was developed by providing a part lower than the sealing position of the lead near the connection fixing part of the lead element and fixing it to the bottom plate of the flat package body with glass. This is a characteristic feature.

Effect According to the above method, the heat of the leads when sealing the cap is not only radiated to the bottom plate through the glass that seals the leads as in the conventional case, but also to the parts lower than the sealing position of the leads. Since the latter heat dissipation path has a lower thermal resistance than the former, heat can be dissipated effectively, and the characteristics of the element can be prevented from deteriorating due to heat or gas generated from the conductive adhesive. Deterioration can be prevented.

Embodiment A crystal resonator using a flat package according to an embodiment of this invention will be described below.

FIG. 1A shows a plan view with the cap removed, and FIG. 1B shows a sectional view taken along line 1B-1B in FIG. 1A. Except for the following points, it is the same as in FIGS. 2 to 4, so the same parts as in FIGS. 2 to 4 are given the same reference numerals, and the explanation thereof will be omitted. The difference from FIGS. 2 to 4 is that the arcuate portions 5a, 6a of the leads 5, 6 have a tongue-like shape on the inner periphery near the connection fixing point of the crystal piece 9, and The lower portions 5b, 6b are provided, which are bent toward the bottom plate 2 and bent again parallel to the bottom plate 2, and which are lower than the sealing positions of the leads 5, 6.
are fixed to the bottom plate 2 by glasses 16 and 17. The fixing of the lower portions 5b, 6b to the bottom plate 2 by the glasses 16, 17 is achieved by the leads 5,
This is done simultaneously with the sealing with the glass 4 in step 6.

In some cases, the bases of the arcuate portions 5a, 6a of the leads 5, 6 may be bent to form the arcuate portions 5.
The entire portions a and 6a may be lower than the sealing positions of the leads 5 and 6.

In addition, although the above embodiment has been described with respect to a flat package in which arc-shaped crystal pieces are assembled, the same can be applied to a rectangular flat package in which rod-shaped or strip-shaped crystal pieces are assembled, and it can also be applied to other elements. can also be used.

Effects of the invention According to this invention, the leads, especially near the connection fixation point of the element, are thermally bonded to the bottom plate, so when sealing the cap, the characteristics of the element deteriorate due to the temperature rise of the element and conductive adhesive. can be more reliably prevented.

[Brief explanation of the drawing]

Figure 1A is a plan view of a crystal resonator using a flat package according to an embodiment of this invention, with the cap removed, and Figure 1B is a sectional view corresponding to line 1B-1B in Figure 1A. be. FIG. 2 is a plan view of a conventional crystal resonator using a flat package with the cap removed, and FIGS. 3 and 4 are cross-sectional views corresponding to lines - and - in FIG. 2, respectively. FIG. 5 is an exploded cross-sectional view before sealing for explaining the method of sealing the cap. 2... Bottom plate, 4... Glass, 5, 6... Leads, 5b, 6b... Portion lower than the lead sealing position, 7... Cap, 8... Low melting point glass, 9...
... Element (crystal piece), 10, 11 ... Conductive adhesive,
15...Flat package, 16,17...Glass.

Claims (1)

[Claims for Utility Model Registration] An element is connected and fixed to the leads of a ceramic flat package body whose leads are hermetically sealed through glass, and a cap is attached to the flat package body through low melting point glass. In the sealed flat package, a portion lower than the sealing position of the lead is provided in the vicinity of the connection fixing portion of the element of the lead, and is fixed to the bottom plate of the flat package body with glass. Packaging.