JPH01751A - Package sealing device - 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 [Field of Industrial Application] The present invention relates to a package sealing device that connects a cap and a package base using a sealing material made of a eutectic alloy or the like.

[Conventional technology]

Broadly speaking, encapsulation techniques for semiconductor devices can be divided into resin encapsulation techniques and hermetic encapsulation techniques. The former is widely used in DIR (daily in-line packages) and the like because the process is relatively simple and the cost is low. However, for products that require high reliability (particularly humidity resistance), hermetically sealed packages, in which a ceramic or glass package is filled with an inert gas such as nitrogen (N2), are widely used.

FIG. 3 shows an example of a package in which a semiconductor element is mounted. A semiconductor element 3 is die-bonded to a cavity 2 of a package base 1, and pads of the semiconductor element 3 are connected to inner leads 5 by bonding wires 4, respectively. A plurality of external electrodes 6 connected to inner leads 5 are formed on the outer surface of the package base 1, and after assembly is performed in this manner, a cap 7 is adhered to hermetically seal the package. Ru.

Such hermetic sealing is performed using so-called hermetic sealing technology. That is, the package base 1 is made of ceramics from the viewpoint of processability, versatility, heat resistance, etc., and the cap 7 is made of ceramics or metal, and when these are bonded together, a low melting point eutectic metal such as Au-3n is used. Depends on why is optimal. In particular, since it is not preferable to heat gallium arsenide (GaAs) or the like above 300'C, a eutectic metal is used as the sealing material instead of a low melting point glass.

The eutectic metal used as the sealing material 8 is formed into 19 rectangular plates (according to the upper surface shape of the package base 1 as shown in the figure), and this sealing material 8 is formed between the package base 1 and the cap 7. The package base 1 and the cap 7 are bonded together by being sandwiched between them, pressurized, and heated. Here, the package base 1 on which the sealing material 8 is placed is
The upper surface and the lower surface of the cap 7 in contact with the sealing material 8 are pre-metalized with a metal such as AIJ, and when the sealing material 8 melts, a eutectic reaction occurs with these metallized layers, resulting in adhesion. The sealing inside the package is completed.

FIG. 4 shows examples of conventional devices for performing the above-mentioned sealing. In the device shown in FIG. 4(a), a package base 1 covered with a cap 7 via a sealing material 8 is fitted into a recess 10a on the top surface of a heater stand 10 and fixed, and in this state is placed on the cap 7. Press rest 11 descends and cap 7
It is designed to pressurize. The package base 1 is heated to a temperature higher than the melting temperature of the sealing material 8 by a heating element 12 (which may be the heater itself or the heating element) embedded in the heater stand 10, thereby causing the sealing material 8 to heat the package base 1 and the cap 7. The cap 7 is bonded by causing a eutectic reaction with the metallized layer.

On the other hand, the device shown in FIG. 4(b) has a package base 1
@: A stage 13 that is positioned and fixed within the recess 13a, and a heater block 14 that moves up and down in the direction of the stage 13.
The heater block 14 presses the cap 7, and the cap 7 is heated by a heating element 15 (the heater block itself may be a heat generating resistor) 15 disposed inside. The heat of the heating element 15 is locally transmitted from the heater block 14 only to the cap 7, thereby causing a eutectic reaction between the sealing material 8 and the metallized layer.

[Problem that the invention seeks to solve]

However, since the conventional device shown in FIG. 4 (a) has a structure in which the seal vJ8 is heated through the package base 1, the semiconductor element mounted on the package base 1 is affected by heat due to the heating of the package base 1. Moreover, a large amount of thermal energy is required to heat the package base 1. On the other hand, the conventional device shown in FIG. Although the influence is small and the heating efficiency is good, the cap 7 is likely to be misaligned due to stress when the heater block 14 is pressurized, resulting in a high incidence of defective products.

Therefore, the present invention solves the problems of the above-mentioned conventional technology, and
It is an object of the present invention to provide a package sealing device that has less thermal influence on semiconductor elements, has good heating efficiency, and has improved cap positioning accuracy.

(Means for Solving the Problems) The package sealing device according to the present invention is basically based on the technical idea of FIG. 4(b) of heating the sealing material from the cap side, and has a cap positioning function. At least the lower part is composed of a heating element, and
A suction port that suctions the cap is formed at the bottom end.
It is characterized in that it is made of 1M so that the cap can be placed on the package base under pressure while holding the cap.

(Function) Since the package sealing device according to the present invention is configured as described above, the suction port acts to reliably hold the cap and accurately position it to the package base.
The heating element acts to heat the retained cap.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to FIGS. 1 and 2 of the accompanying drawings. In the description of the drawings, the same elements are designated by the same reference numerals, and important descriptions will be omitted.

FIG. 1 is a perspective view from the bottom of a sealing device according to an embodiment of the present invention. As shown in the figure, a press block 21 is attached to the lower end of the hollow rod 20, which is moved or expanded/contracted in the vertical direction. Press block 2
1, as shown in FIG. 2, a vertical through hole 22 is formed, the lower end of the through hole 22 widens into an inverted funnel shape, and a cap 7 is formed.
It serves as a suction port 23 for vacuum suction. The through hole 22 is connected to a valve and a suction device (both not shown) via a hollow rod 20, and by switching the valve, the suction port 23 can suction the lug 7 or release the suction 6. Therefore, the cap 7 acts to
3, it is attracted to the lower end surface of the press block 21 and moves in the vertical direction together with the press block 21.

In this embodiment, a cap 7 is attached to the lower end surface of the press block 21.
A recess 24 having the same shape and size as the cap 7 is formed, and the cap 7, which is sucked by the suction port 23, fits into the recess 24 and is prevented from shifting. The recessed portion 24 functions to prevent the cap 7 from being displaced during the rubbing drive described later. Note that the recess 24 is formed to be shallower than the thickness of the cap 7, and a sufficient amount of protrusion for the cap 7 to abut against the package base 1 is ensured.

Terminals 26 attached to both sides of press block 21
The electric wire 27 is for supplying current to the press block 21, and the press block 21 is made of a material having a certain resistance.

Therefore, when power is supplied to the press block 21 via these terminals 26 and electric wires 27, the press block 21
It is starting to generate heat itself.

Next, the operation of the above sealing device will be explained with reference to FIG.

As shown in FIG. 3A, the package base 1 is fitted into the recess 31 of the stage 30 and fixed with the sealing material 8 placed thereon in advance. Press block 2
1 is moved directly above the package base 1 by a hollow iron 20 connected to an arm of a transfer device such as a robot.

In this case, the cap 7 is fitted into the recess 24 by the suction action of the suction port 23, and the press block 21 can be rubbed (scrub>driven). The sealing material 8 is heated to a temperature higher than its melting point.

Next, as shown in FIG. 2(b), when the cap 7 comes into contact with the sealing material 8 and is pressurized by the press block 21,
The sealing material 8 melts and causes a eutectic reaction with the metallized layer on the lower surface of the cap 7. The above-mentioned rubbing drive promotes this eutectic reaction, whereby the eutectic reaction occurs quickly and reliably, the cap 7 is firmly adhered onto the package base 1, and the sealing force is increased. It should be noted that if the rubbing drive is performed over a large range, the melted sealing material 8 will flow into the cavity of the package base 1, which is undesirable.
This should be done within an appropriate tolerance to prevent this. In addition, since the cap 7 is inserted one inch into the recess 24 on the lower end surface of the press block 21 during the rubbing drive,
There is no possibility that the cap 7 will be misaligned.

After the cap 7 is adhered to the package base 1 by the sealing material 8, the suction of the suction port 23 is cut off, thereby releasing the cap 7 from the press block 21.

After this, the press block 21 is moved as shown in FIG. 2(C).
It rises and leaves the package base 1, and waits while adsorbing another cap for the next processing.

In this embodiment, since the cap 7 is bonded to the press block 21 while being held by the suction port 23, there is no displacement of the cap 70, and the sealing accuracy is improved. Further, since only the cap 7 is heated and bonded, thermal efficiency is improved, and the influence of heat on the semiconductor element mounted on the package base 1 is significantly reduced.

The present invention is not limited to the above, and various modifications are possible.

For example, it is not necessary to form the recess 25 on the lower surface of the press block 21, and in this case, by tightening the suction horn of the suction port 23, displacement of the cap 7 can be prevented. Further, instead of using the entire press block 21 as a heat generating body, a heat generating body may be provided only at the lower end portion.

〔Effect of the invention〕

As explained in detail above, according to the package sealing device according to the present invention, heating of the cap and zero pressure are performed while the cap is in an adsorbed state, so the attachment of the cap improves accuracy and is free from heat effects. Furthermore, since only the tubes and tubes are heated, thermal efficiency is also improved.

[Brief explanation of the drawing]

FIG. 1 is a perspective view from the bottom of a sealing device according to the first embodiment of the present invention, FIG. 2 is a partially cutaway side view showing the sealing operation in the order of steps, and FIG. Exploded perspective view,
FIG. 4 is a side view of each example of conventional installation. 1...Package base, 7...Cap, 8...
- Sealing material, 21... Press block, 23... Suction port, 25... Heating element. Patent Applicant: Sumitomo Electric Industries, Ltd. Representative Patent Attorney Yoshiki Hase Figure 1 Exploded perspective view of the package Figure 3

Claims (1)

[Claims] 1. Pressure and heat a sealing material inserted between a package base on which a semiconductor element is mounted and a cap placed on this package base, and In a package sealing device for adhering to a package base, at least the lower part is composed of a heating element, and a suction port for adsorbing the cap is formed at the lower end, and the package sealing device is attached to the package base while the cap is adsorbed and held. A package sealing device that is driven to place a cap thereon under pressure. 2. The package sealing device according to claim 1, wherein a recess into which the cap is fitted is formed on the lower end surface. 3. The package sealing device according to claim 1 or 2, wherein when the pressurization is applied, the cap is rubbed while being held.