JPH02119168A - Flat-type semiconductor device - Google Patents

Abstract

PURPOSE:To eliminate the necessity of reducing the widths and pitches of outer leads and reduce the manufacturing cost of a container for a semiconductor package by a method wherein a protrusion is formed on the bottom part of the container and the outer leads are attached to the respective steps of the protrusion. CONSTITUTION:A semiconductor element 1 is placed in the cavity 9 of a container 2 made of ceramics and connected to inner wirings 7 provided around it with bonding wires 3. The inner wirings 6 are drawn out of the container 2 as outer leads 6A and 6B provided on the steps of the bottom part of the container 2 which is so formed as to have a protruding shape through side wirings 8. The leads 6B are provided on the protrusion 2A so as to be in parallel with the bottom surface and the tip parts of the leads 6A provided or the upper step are bent so as to be in the same plane with the leads 6B. With this constitution, the outer leads can be provided over the two steps and the necessity of reducing the widths and pitches of the leads can be eliminated, so that the manufacturing cost of the container can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a flat type semiconductor device, and particularly relates to the structure of attaching external leads.

[Conventional technology]

Conventionally, a flat semiconductor device using a laminate type ceramic package has a semiconductor element 1 mounted in a cavity 9 at the center of a container 2 made of ceramic, as shown in FIGS. 3(a) and 3(b). After bonding to the internal wiring 7 metalized around the container 9 using the bonding wire 3, it is hermetically sealed with a metal or ceramic lid 4, and the outer peripheral part of the bottom surface 11 of the container 2 is connected to the side wiring 8. It had a structure in which the external leads 6 were fixed.

[Problem to be solved by the invention]

The external leads 6 of the conventional flat semiconductor device described above are attached to the side or bottom of the semiconductor device so as to form the same plane. As semiconductor devices become smaller, the external leads of flat semiconductor devices have to become finer in order to accommodate the increased number of bins. Therefore, the external leads provided on each side of the same plane are As the lead width and lead pitch become smaller, not only does the manufacturing cost of the container increase and the yield decrease, but it also becomes difficult to handle accurately, including soldering during mounting.

[Means to solve the problem]

The flat semiconductor device of the present invention includes a container having a cavity on the upper surface, a semiconductor element fixed in the cavity, an external lead provided on the outer periphery of the bottom surface of the container in parallel with the bottom surface, and a semiconductor element fixed in the cavity. In a flat semiconductor device having a lid for sealing an element, the bottom of the container is formed in a convex shape, and external leads are fixed to each step of the convex part.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIGS. 1(a) and 1(b) are a sectional view and a bottom view of a first embodiment of the present invention.

In FIGS. 1(a) and 1(b), a semiconductor element 1 is mounted in a cavity 9 of a container 2 made of ceramic, and is connected to an internal wiring 7 provided around the cavity 9 using a bonding wire 3, and from there a conductor is connected. The open side wiring 8 leads to external leads 6A and 6B made of Kovar or the like provided at each step on the bottom of the container 2 which is formed in a convex shape.

The external leads 6A provided around the upper part are the external leads 6A provided on the convex part 2A so as to be parallel to the bottom surface.
The tip is bent so that it is flush with B. Note that 4 is a lid sealed to the container 2 with a brazing material 5.

According to the first embodiment configured in this way, the external leads can be attached in two stages, and there is no need to reduce the width or pitch of the external leads, so the manufacturing cost of the container can be reduced. .

FIGS. 2(a) and 2(b) are a sectional view and a bottom view of a second embodiment of the present invention.

The embodiment of the second embodiment is the same as the first embodiment except that the external electrode 10 is provided on the surface of the convex portion 2A of the container 2, that is, on the lower stage. That is, the external electrode 10 is metallized on the bottom surface of the container 2, and has a structure similar to that of a so-called LCC (leadless chip carrier). The leading ends of the upper external leads 6A provided on the periphery are bent so as to be on the same plane as the external electrodes 10.

According to the embodiment of Sui-Tei 2, compared to the first embodiment, only one stage of external lead frame is required, which not only reduces the number of steps required for bonding the lead frame, but also reduces lead cutting and forming after semiconductor device assembly. There are advantages to being able to do so.

In this way, according to the above embodiment, it is possible to attach the external leads by dividing them into two circumferences, and the lead width and pitch can be reduced by 1.5 to 1.5 mm compared to the conventional external leads of flat type semiconductor devices on the same plane. It becomes possible to expand by 2.0 times. In addition, it is possible to suppress deformation and damage to the external leads due to handling not only in the manufacturing of the container but also in the assembly process and finishing process, and furthermore, it is possible to improve soldering performance and positional accuracy during mounting.

Also, in the above embodiment, the lead frame was attached to the side opposite to the semiconductor element mounting surface, but external leads may be provided in the same direction, and if necessary, a heat sink can be attached to the back side of the element mounting surface. Therefore, it becomes an effective alternative to PGA as a semiconductor device for high power consumption devices compatible with surface mounting.

Furthermore, although the above embodiment is a flat type semiconductor device in which the external lead attachment section is divided into two stages, it may be divided into three or more stages, and the container is not limited to ceramic material. Instead, metal, resin, etc. may be used.

〔Effect of the invention〕

As explained above, the present invention reduces manufacturing costs by forming the bottom of the container constituting the package into a convex shape and fixing external leads to each stage of the convex part, and also reduces manufacturing costs during mounting. A flat semiconductor device that is easy to handle, such as soldering, can be obtained.

[Brief explanation of drawings]

1(a), (b) and 2(a), (b) are sectional views and bottom views of the first and second embodiments of the present invention, and FIG. 3(a), (b) 1A and 1B are a cross-sectional view and a bottom view of a conventional flat type semiconductor device. DESCRIPTION OF SYMBOLS 1... Semiconductor element, 2... Container, 2A... Convex part,
3... Bonding wire, 4... Lid, 5... Brazing metal, 6°6A, 6B... External lead, 7... Internal wiring, 8... Side wiring, 9... Cavity, 10・
...External electrode.

Claims (1)

[Claims] A flat container comprising a container having a cavity on the upper surface, a semiconductor element fixed in the cavity, an external lead provided on the outer periphery of the bottom surface of the container parallel to the bottom surface, and a lid for sealing the semiconductor element. A flat type semiconductor device, characterized in that the bottom surface of the container is formed in a convex shape, and an external lead is fixed to each step of the convex part.