JPH1027860A - Manufacture of lid with low melting point glass, and manufacture of solid-state image pick-up semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to make uniform the thickness of low melting point glass by a method wherein low melting point glass powder is pressure-molded into a frame shape in such a manner that the thickness of the four corner parts of the frame body becomes thinner than the circumferential part. SOLUTION: A low melting point glass lid is manufactured by conducting a pressure- molding process, with which low melting point glass powder is formed into frame-like shape by pressing and temporary firing, and an adhesion and firing process with which a frame body 1, formed by the pressure-molding process, is adhered by firing to optical glass. In this case, the low melting point glass powder is formed into frame-like shape in such a manner that the thickness of the four corner parts 1a of the frame body becomes thinner than the circumferential part of the frame body 1, and the formed material is temporary fired. As a result, the fused low melting point glass is gathered to the four corner parts 1a of the frame body 1 by surface tension when the frame body is adhered by firing to the optical glass, and the thickness of the frame body 1 is increased. However, as the thickness of the corner parts 1a becomes thinner than the circumferential part, the thickness of the low melting point glass is made uniform.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a lid with a low-melting glass used for an enclosure of a solid-state imaging semiconductor device such as a CCD linear image sensor, and a solid-state imaging device having the lid with a low-melting glass. The present invention relates to a method for manufacturing a semiconductor device.

[0002]

2. Description of the Related Art As an envelope of a solid-state imaging semiconductor device (CCD), a package in which a semiconductor package is hermetically sealed with a lid made of optical glass has been generally known.

FIG. 4 is a structural diagram showing an example of a conventional solid-state imaging semiconductor device.

The envelope of the solid-state imaging semiconductor device is a base ceramic 101 on which a semiconductor pellet 100 is mounted.
And a wind ceramic 102 provided thereon.
And a ceramic package (body package) having a lead frame 103 installed between them. Wind ceramic 10 of this body package
2, the optical glass 104 is sealed, and the lead frame 1
The semiconductor pellet 100 connected to the semiconductor chip 03 is hermetically sealed. The optical glass 104 is provided with a low-melting glass 105 having a frame shape for sealing with a main package, and is configured as a lid with low-melting glass.

Here, the method of bonding the low-melting glass to the optical glass mainly includes a method of forming the low-melting glass into a paste and screen-printing the optical glass (tentatively referred to as a printing bonding method), and a method of bonding the low-melting glass to gold. There are two types: a method of press-molding with a mold, calcination, and calcination and adhesion to optical glass (tentatively referred to as a calcination adhesion method). Among them, in the printing adhesion method, it is difficult to control the thickness of the low melting point glass, and it is necessary to repeatedly perform screen printing and firing in order to secure a predetermined thickness. On the other hand, in the pressure sintering bonding method, the thickness of the low-melting glass can be adjusted by a mold, so that the repetitive operation such as the printing bonding method is not required.

In the pressure-fired bonding method having such excellent characteristics, first, powder of the low-melting glass 105 is mixed with a binder (organic solvent) to form a paste, which is pressed using a mold. After being formed into a frame shape, it is calcined at about 350 ° C. As a result, a frame of the low-melting glass 105 as shown in FIGS. 5A and 5B is manufactured. FIG.
(A) is a plan view of a frame of the low-melting glass 105, and (b) is a cross-sectional view taken along the line AB.

Next, when the frame of the low melting point glass 105 is placed on the optical glass 104 and baked at 460 ° C., the lid with the low melting point glass as shown in FIGS. can get. Here, FIG. 6A is a plan view of a lid with a low-melting glass, and FIG. 6B is a cross-sectional view taken along line CD.

[0008]

However, in the method for manufacturing a lid with a low-melting glass, the low-melting glass 1
When the frame of No. 05 is placed on the optical glass 104 and subjected to main baking, a force that tends to gather on the corner portion due to surface tension and the like acts on the molten low melting point glass 105, and as a result, FIG.
As shown in (b), only the four corners Ca of the low-melting glass 105 become thicker, and a difference Cb in thickness from the thinner part occurs.

As described above, when the lid with the low-melting glass having a partial difference in the low-melting glass thickness is used for sealing the main package of the solid-state imaging semiconductor device, the main package and the low-melting glass 104 are not sealed. Therefore, there is a problem that the sealing performance and the yield of the solid-state imaging semiconductor device are reduced.

The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a method of manufacturing a lid with a low-melting glass, which can make the thickness of the low-melting glass uniform. It is to be. Another object of the present invention is to provide a method of manufacturing a solid-state imaging semiconductor device that can make the thickness of the low-melting glass of the lid with the low-melting glass uniform and improve the sealing property and the yield using the same. .

[0011]

In order to achieve the above-mentioned object, a feature of the method for manufacturing a lid with a low-melting glass according to the first invention is that a powder of the low-melting glass is formed into a frame by pressing and calcining. In a method of manufacturing a lid with a low-melting glass having a pressure molding step of molding and a sintering adhesion step of sintering and bonding the frame formed by the pressure molding step to optical glass, the pressure molding step includes: The present invention is characterized in that a low-melting-point glass powder is press-formed into a frame shape so that the thickness of the four corner portions of the frame body is smaller than the peripheral portion thereof, and this is a step of pre-baking.

According to the first aspect of the invention, when the frame of the low melting point glass formed by the pressure forming step is bonded to the optical glass for the solid-state imaging semiconductor device by firing, the molten low melting point glass has a surface tension. It gathers at the four corners of the frame body and increases its thickness, but the thickness of these four corners is thinner than the surrounding area in advance. Uniform.

A feature of the method for manufacturing a solid-state imaging semiconductor device according to the second invention is that the low-melting glass frame is formed so that the thickness of the four corners of the low-melting glass frame is smaller than its peripheral portion. After forming the frame of the low melting point glass by press-molding the powder into a frame shape and preliminarily firing to form a frame of the low melting point glass, the frame of the low melting point glass is fired and adhered to optical glass to produce a lid with a low melting point glass. In advance, a semiconductor chip for solid-state imaging is mounted in the main body package, leads of the main body package are connected to electrodes of the semiconductor chip, and the optical glass of the lid with the low melting point glass is framed by the low melting point glass. And sealing the semiconductor chip by adhering to the body package.

According to the second aspect of the invention, the lid with the low melting point glass of the optical glass is sealed in the main body package of the solid-state imaging semiconductor device by the frame of the low melting point glass whose thickness is made uniform by the above process. Since the semiconductor chip can be sealed by being attached, there is no gap between the body package of the solid-state imaging semiconductor device and the low-melting glass frame,
The sealing performance of the device is improved.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1A and 1B are views showing a pressure forming step of a method for manufacturing a lid with a low-melting glass according to an embodiment of the present invention. FIG.
FIG. 1B is a sectional view taken along the line I-II. FIG.
(A), (b) is a figure which shows the sintering adhesion process after a press molding process, FIG. (A) is a top view, FIG.
It is II-IV sectional drawing.

In the method of manufacturing the lid with low-melting glass according to the present embodiment, first, powder of the low-melting glass 1 is mixed with a binder to form a paste, which is loaded into a mold (not shown). Press molding is performed with this mold to obtain a frame-shaped molded product as shown in FIG. At this time, as shown in FIGS. 1 (a) and 1 (b), this molded product has four corner portions 1
A step is provided at each corner 1a in such a manner that the thickness of “a” becomes thinner than its peripheral part. The step size 1b is determined, for example, by the size of an optical glass described later, and is set to about 0.1 mm in the present embodiment.

Thereafter, in order to increase the strength of the molded product, calcination is performed at a temperature of, for example, 350 ° C., and the pressure molding step is completed.

The frame of the low-melting glass 1 thus formed is set on the optical glass 2. The dimensions of the optical glass 2 are, for example, a longitudinal dimension T1 of 39 mm,
The width T2 is 7 mm, the thickness T3 is 0.7 mm,
The overall size of the frame of the low melting point glass 1 in the pressure molding step is set according to the dimensions of the optical glass 2 (that is, the longitudinal direction: 39 mm, the width: 7 mm).

The frame of the low melting point glass 1 set on the optical glass 2 in this manner is subjected to main firing at, for example, 430 ° C. to complete a lid with a low melting point glass. At this time, the low-melting glass 1 is once melted and adheres to the optical glass 2, but the low-melting glass 1 tends to gather at the four corners 1a of the frame due to the surface tension and the like at the time of melting. As a result, the 4
The two corners 1a increase in thickness, and the thickness of the corners 1a becomes uniform.

Thus, the thickness of the low-melting glass 1 of the lid with the low-melting glass is made uniform as a whole as shown in FIG. The thickness T of the low-melting glass 1 at this time
4 is, for example, about 0.35 mm in the present embodiment.

Next, a method of manufacturing a solid-state imaging semiconductor device using the lid with a low-melting glass manufactured by the above process will be described with reference to FIG.

First, a ceramic package (cerdip package) is prepared as a main body package. This ceramic package includes a base ceramic 11, a wind ceramic 12 and a lead frame 13, and the wind ceramic 12 is assembled on the base ceramic 11. A lead frame 13 is provided between the base ceramic 11 and the wind ceramic 12, and the lead frame 13 is made of a low melting glass 14.
It is adhered by.

Next, in order to perform die bonding, a conductive die bond paste 15 (for example, a mixture of an epoxy resin and Ag powder) is applied to the die pad portion of the base ceramic 11 by a stamping method or the like, and the solid-state image pickup paste is applied thereto. After the semiconductor chip 16 is pressed and temporarily fixed, the paste is hardened by heating and bonded.

Subsequently, in order to perform wire bonding,
For example, using a thermocompression bonding method or an ultrasonic bonding method, the lead frame 13 of the ceramic package and the electrode of the semiconductor chip 16 are connected by bonding wires 17.

After that, in the ceramic package,
The lid with the low-melting glass produced by the above process is capped and passed through a sealing furnace to seal the optical glass 2 to the ceramic package with the frame of the low-melting glass 1. In this way, if the semiconductor chip 16 in the ceramic package is hermetically sealed, a solid-state imaging semiconductor device having the structure shown in FIG. 3 can be obtained.

According to the above-described method for manufacturing a solid-state imaging semiconductor device, the lid with the low-melting glass to which the frame of the low-melting glass 1 having a uniform thickness is bonded is sealed in the main body package to seal the semiconductor chip 16. The stoppage improves the sealing performance and yield of the device.

[0027]

As described above in detail, according to the method for manufacturing a lid with a low-melting glass according to the first invention, the thickness of the four corners of the frame is smaller than that of the periphery. Then, the powder of the low melting point glass is press-formed into a frame shape, which is preliminarily baked, and the frame formed by this pressure forming step is baked and adhered to the optical glass. In a state where the body is baked and adhered to the optical glass, it is possible to reduce a difference in thickness of the frame of the low melting point glass and to make the thickness uniform. Thus, by sealing the lid with the low-melting glass of the present invention to, for example, a main body package of a solid-state imaging semiconductor device by the frame of the low-melting glass and sealing the semiconductor chip, the sealing performance and the yield of the device are improved. improves.

According to the method for manufacturing a solid-state imaging semiconductor device of the second invention, a lid with a low-melting glass is manufactured by the manufacturing method of the first invention, and a semiconductor chip for solid-state imaging is mounted in a main body package. Mounting, connecting the lead of the main package to the electrode of the semiconductor chip, sealing the optical glass of the lid with the low melting glass to the main package by the frame of the low melting glass, and sealing the semiconductor chip. As a result, the thickness of the low-melting glass of the lid with the low-melting glass is uniform, so that the sealing property and the yield of the device are improved.

[Brief description of the drawings]

FIG. 1 is a view illustrating a pressure forming step of a method for manufacturing a lid with a low-melting glass according to an embodiment of the present invention.

FIG. 2 is a view showing a sintering bonding step of the method for manufacturing a lid with a low-melting glass.

FIG. 3 is a structural diagram of a solid-state imaging semiconductor device using the lid with low-melting glass of the present invention.

FIG. 4 is a structural diagram showing an example of a conventional solid-state imaging semiconductor device.

FIG. 5 is a view showing a configuration of a low-melting glass frame in a conventional lid with low-melting glass.

FIG. 6 is a view showing a configuration of a conventional lid with low melting point glass.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Low melting glass 1a Corner of low melting glass frame 2 Optical glass 11 Base ceramic 12 Wind ceramic 13 Lead frame 14 Low melting glass 15 Conductive die bond paste 16 Semiconductor chip 17 Bonding wire

Claims (2)

[Claims] 1. A pressure forming step of forming a powder of a low-melting glass into a frame by pressing and pre-baking, and a firing bonding step of firing and bonding the frame formed by the pressure forming step to an optical glass. In the method for manufacturing a lid with a low-melting glass having the following, the pressure molding step includes forming a powder of the low-melting glass into a frame shape such that the thickness of the four corners of the frame is smaller than its peripheral portion. A method for producing a lid with a low-melting glass, comprising a step of pressure-molding and temporarily baking the molded article. 2. A low-melting glass frame is press-molded into a frame shape and then calcined so that the thickness of the four corners of the low-melting glass frame is smaller than that of its peripheral portion. After forming the low-melting-point glass frame, the low-melting-point glass frame is fired and bonded to optical glass to produce a lid with low-melting-point glass, and a semiconductor chip for solid-state imaging is mounted in the main body package. Connecting the lead of the main package and the electrode of the semiconductor chip, sealing the semiconductor chip by sealing the optical glass of the lid with the low melting glass to the main package by a frame of the low melting glass; A method for manufacturing a solid-state imaging semiconductor device.