JP2577916B2 - High frequency semiconductor device and lead frame for the device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency semiconductor device operated at high speed and a lead frame for the device.

[Related Art] In recent years, with an increase in the speed of an information processing device, the frequency of a semiconductor device used in the processing device has been further increased, and the demand for a semiconductor device having a high frequency characteristic and containing a high frequency semiconductor element has been increasing. Is growing.

Conventionally, this high-frequency semiconductor device includes a package for accommodating a high-frequency semiconductor element, such as a metallization layer or the like constituting a ground plane inside or on a surface of a ceramic insulator, in parallel with an input / output signal line. The one using a ceramic package with a conductor layer and the metal package surrounding a ceramic terminal attaching member with an input / output signal line with a metal member or the signal line surrounded with a metal member via a glass member Some are used.

[Problems to be Solved by the Invention] However, the device using the above-described ceramic package has a conductor layer such as a metallized layer constituting a ground plane inside or on the surface of a ceramic insulator when manufacturing the device. It takes a lot of trouble and time to
It was expensive and lacked versatility.

Also, when manufacturing the above-described device using the metal package, it takes a lot of time and trouble to cut and form a metal member surrounding the periphery of the terminal attachment member provided with the signal line, and is expensive and versatile. Did not.

An object of the present invention is to solve such a problem, and an object of the present invention is to provide an inexpensive and easy-to-manufacture general-purpose high-frequency semiconductor device and a lead frame for the device.

[Means for Solving the Problems] In order to achieve the above object, a high frequency semiconductor device according to the present invention includes a die pad having a high frequency light guide element fixed inside an insulator such as a resin; A semiconductor device in which an internal lead portion electrically connected to the internal lead portion is sealed, the die pad is provided above or below the internal lead portion or below or above and below the internal lead portion so as to be separated from the internal lead portion. An electrically conductive ground plane is provided via a tie bar, and the ground plane covers the internal lead portion above, below, or above and below the internal lead portion.

The lead frame for a high-frequency semiconductor device according to the present invention is a lead frame including a die pad for fixing a semiconductor element, and an internal lead portion for electrically conducting the semiconductor element. A ground plane provided in series through a tie bar provided at a distance from the internal lead portion, by bending the tie bar, so that the ground plane is above or below the internal lead portion or above and below the internal lead portion. And a ground plane capable of covering the internal lead portion above or below the internal lead portion or above and below the internal lead portion with the ground plane.

[Operation] In the high-frequency semiconductor device of the present invention, the ground plane is electrically connected to the die pad via the tie bar, and the ground plane covers the upper or lower part of the internal lead portion or the upper and lower parts thereof. ,
It is possible to prevent the electric signal transmitted through the internal lead portion from leaking to the outside of the internal lead portion and from being mixed into the adjacent internal lead portion.

Further, the potential of the die pad and the potential of the ground plane electrically connected to the pad via the tie bar can be maintained at the same potential. Then, the back potential of the semiconductor element fixed to the die pad and the potential of the ground plane can be maintained at the same ground potential. The ground plane can effectively prevent noise from being mixed into the internal lead portion, and the high frequency characteristics of the internal lead portion can be effectively improved by the ground plane.

In addition, since the tie bar for electrically connecting the ground plane to the die pad is provided separately from the internal lead, it is possible to prevent the electric signal transmitted through the internal lead from entering the tie bar as noise. Can be. Then, it is possible to prevent the noise from being transmitted to the ground plane provided on the tie bar. Then, it is possible to prevent the noise from deteriorating the shielding characteristics of the ground plane or from being transmitted to the ground plane as noise again through the tie bars into the internal lead portion.

In the lead frame for a high-frequency semiconductor device according to the present invention, the tie bar is bent into a U-shape or the like, and a ground plane provided on the die pad via the tie bar is provided above or below the internal lead portion or above the internal lead portion. And below it. Then, the ground plane can cover above or below the internal lead portion or above and below it.

In this case, the ground plane is electrically connected to the die pad via the tie bar, so that the potential of the ground plane can be maintained at the same ground potential as the die pad. The ground plane can effectively prevent noise from being mixed into the internal lead portion, and the high frequency characteristics of the internal lead portion can be effectively improved by the ground plane.

Further, since the tie bar is provided separately from the internal lead portion, it is possible to prevent the electric signal transmitted through the internal lead portion from entering the tie bar as noise. Then, it is possible to prevent the noise from being transmitted to the ground plane provided on the tie bar. Then, it is possible to prevent the noise from deteriorating the shielding characteristics of the ground plane or from being transmitted to the ground plane as noise again through the tie bars into the internal lead portion.

Example Next, an example of the present invention will be described with reference to the drawings. 1 and 2 show a preferred embodiment of a high-frequency semiconductor device according to the present invention. FIG. 1 is a partially cutaway plan view of the device, and FIG. 2 is a cross-sectional view of the device shown in FIG. The figure is shown. Hereinafter, an embodiment in the above-mentioned figure is explained. In the figure, reference numeral 4 denotes a lead frame having a square plate-shaped die pad 6 which is recessed one step in comparison with other portions at the center, and a plurality of leads 5 on the left and right sides of the die pad toward the outside. The semiconductor element 2 is fixed on the upper surface of the die pad 6 of the lead frame 4, and each electrode 3 of the element is connected to the tip of each internal lead 5 a of the lead frame by a wire 9. A flat ground plane 7 is disposed above and below the die pad 6 to which the semiconductor element 2 is fixed, respectively.
The upper and lower portions of each of the internal lead portions 5a separated from each of the internal lead portions 5a of the lead frame are covered with the flat ground plane 7, respectively. A part of the periphery of each of the ground planes 7 and a part of the periphery of the die pad 6 to which the semiconductor element 2 is fixed are tie bars 8a in the shape of a U-shaped strip, and are provided separately from the internal lead portions 5a. Connected together with tie bar 8a. Then, each ground plane 7 is electrically connected to the die pad 6. Further, the gap 10 between each of the upper and lower ground planes 7 and the lead frame 4 inside and the lead frame 4 around the element including the semiconductor element 2 are sealed with an insulator 1 such as a resin. The high-frequency semiconductor device shown in FIGS. 1 and 2 has the above configuration.

Next, the operation will be described. When an electric signal is applied to each lead 5 of the lead frame protruding outside the insulator 1, the signal is transmitted to each electrode 3 of the semiconductor element connected to each lead 5 by a wire 9, and the signal is transmitted to the insulator 1 such as a resin. The semiconductor element 2 housed inside is operated. At this time, the respective ground planes 7 provided on the surface of the insulator 1 and electrically connected to the die pad 6 via the tie bars 8a cause signals flowing through the respective leads 5 to leak out of the respective leads 5 or to be adjacent to each other. Prevention of mixing in each lead 5 is properly prevented.

3 and 4 show a preferred embodiment of a lead frame for a semiconductor device according to the present invention. FIG. 3 is a plan view of the lead frame, and FIG. It is sectional drawing of this lead frame. Hereinafter, the lead frame in the above-mentioned figure will be described. The lead frame 4 includes a ground plane 7 which is separated from a die pad 6 having a rectangular plate shape to which the semiconductor element 2 is fixed and which is integrally connected to the die pad 6 with a tie bar 8a. The tie bar 8a is provided separately from the internal lead portion 5a. More specifically, a rectangular plate-shaped die pad 6 for fixing the semiconductor element 2 is provided at the center between the upper and lower guide rails 11 of the lead frame, and a narrow band-shaped tie bar is provided from the upper and lower peripheral edges of the die pad toward the outside. When the tie bar 8a is bent, a rectangular plate-shaped ground plane 7 covering the upper and lower sides of the die pad 6 and the respective internal leads 5a around the tie bar 8a is attached to the tip of each tie bar 8a. And are provided integrally with each other. Also, a plurality of leads 5 are provided on the left and right sides of the die pad 6 toward the outside of the die pad 6, respectively. Then, the middle of each of the leads 5 on the left and right sides of the die pad 6 is mutually connected to the upper and lower guide rails 11 via a tie bar 8b by a dam bar 12a which is integrally connected to each other, and each lead 5 is supported between the guide rails 11. In addition, the above dam bar 12
A dam bar 12b surrounding the upper and lower sides of the die pad 6 is extended from the end toward the tie bar 8a which integrally connects the die pad 6 and the ground plane 7 from the end. Further, the ground plane 7 is supported between the guide rails 11 via the tie bars 8b, and the tie bars near the dam bar 12b are so provided that the die pad 6 does not fall off with the ground plane 7 from the lead frame 4 when the tie bars 8b are removed. Die pad support bar 1 between 8a and dam bar 12a
Interconnect with 4 The lead frame shown in FIGS. 3 and 4 has the above configuration.

Next, an example of its use will be described. In the above-described lead frame, the die pad 6 is depressed by one step as compared with the lead 5, and the semiconductor element 2 is fixed to the upper surface of the depressed die pad 6, and each electrode 3 of the element and each internal lead portion are formed.
5a The ends are connected by wires 9 such as gold wires. next,
The tie bars 8b that directly support the die pad 6 are cut and removed, and as shown in FIG. 4, each tie bar 8a that integrally connects the die pad 6 and the ground plane 7 is folded in a U-shaped cross section in opposite directions. Each of the ground planes 7 integrally connected to the die pad 6 via a tie bar 8a is disposed above and below the die pad 6 to which the semiconductor element 2 is fixed, and is separated from the internal lead portion 5a of the lead frame. The upper and lower ground planes 7 electrically connected to the die pad 6 above and below the internal lead portion 5a.
Cover. Thereafter, the space 10 between the upper and lower ground planes 7 and the lead frame 4 inside the upper and lower ground planes 7 and the lead frame 4 inside the dam bars 12a and 12b around the element including the semiconductor element 2 are insulated with resin or the like. Seal with body 1. Then, the dam bars 12a, 12b and the guide rail 11 for integrally connecting the respective leads 5 are removed from the respective leads 5 of the lead frame protruding outside the insulator 1, and the respective leads 5 are made independent, and the first The semiconductor device of the present invention as shown in the figures and the like is manufactured.

FIG. 5 shows another preferred embodiment of the lead frame for a semiconductor device of the present invention, and more specifically, shows a plan view of the lead frame. Hereinafter, an embodiment in the above-mentioned figure is explained.
In the figure, the same members as those of the lead frame shown in FIGS. 3 and 4 are denoted by the same reference numerals, and description thereof will be omitted. Upper and lower guide rails of lead frame 4
A plurality of leads 5 are provided around four sides of a square plate-shaped die pad 6 for fixing the semiconductor element 2 provided at the center between the eleventh and the semiconductor element 2, respectively. In addition, die pad 6
Between the diagonal upper and lower guide rails 11, there are provided a rectangular ground plane 7 that covers the die pad 6 and the upper and lower portions of the plurality of internal lead portions 5 a around the die pad 6. Then, two corners located on the diagonal line of the die pad 6 and inner corners of the ground planes 7 around the die pad obliquely above and below are integrally formed by a strip-shaped tie bar 8a provided separately from the internal lead portion 5a. connect. Fifth
The lead frame shown in the figure has the above configuration.

Next, an example of its use will be described. In the above-described lead frame, the semiconductor element 2 is fixed to the die pad 6 in which the lead frame 4 is depressed by one step in the same manner as the lead frame shown in FIG. 3 and FIG. And the tip of each internal lead 5a of the lead frame with a wire 9
After each connection, the tie bars 8a for integrally connecting the die pad 6 and the respective ground planes 7 are bent into a substantially U-shaped cross section, and the ground planes 7 above and below the die pad 6 to which the semiconductor element 2 is fixed. Are disposed above and below the internal lead portion 5a of the lead frame with the ground plane 7, respectively, and the gap 10 between the ground plane 7 and the lead frame 4 inside the ground plane 7 and the semiconductor element 2 are formed. The semiconductor device of the present invention as shown in FIG. 1 and the like is manufactured by sealing the portion of the lead frame 4 around the element with an insulator 1 such as a resin.

In the semiconductor device of each of the above embodiments and the device lead frame, the lead frame 4 is provided between the leads 5 around the die pad 6 as shown in FIG. Using a lead frame 4 in which intermediate leads 13 electrically connected to a die pad 6 constituting a coplanar transmission path are integrally extended, a strip transmission path including a lead 5 and a ground plane 7 of the semiconductor device of the present invention is used. The degree of insulation may be increased. In this case, the coplanar transmission line is connected to each lead 5.
The intermediate lead 13 and the separate intermediate lead 13 may be provided between the die pad 6 and the intermediate lead 13 and the die pad 6 may be connected by wires.

Further, the lead frame 4 is provided with only one ground plane integrally connected to the die pad 6 via the tie bar 8a, and the ground plane 7 covers only one of the upper and lower portions of the internal lead portion 5a. May be.

Further, the space 10 between the ground plane 7 and the lead frame 4 inside the ground plane 7 is provided so that the ground plane 7 provided in the semiconductor device of the present invention does not come into electrical contact with an adjacent semiconductor device or the like during use. The ground plane 7 may be sealed inside the insulator 1 by extending the insulator 1 such as resin filling the portion to the outer peripheral surface of the ground plane 7.

Further, the ground plane 7 is formed in a mesh shape, or small holes or the like are scattered through the surface of the ground plane 7 in a scattered manner, so that the space 10 between the ground plane 7 and the lead frame 4 inside the ground plane 7 is made of resin. When sealed with an insulator 1 such as the one described above, the insulator 1 such as the resin may cut into the ground plane 7 so as not to be easily separated.

Further, the semiconductor element may be fixed to the upper surface of the die pad 6 without leaving the die pad 6 one step lower than the lead 5 to form the semiconductor device for high frequency of the present invention.

Further, an insulator 1 such as a resin, which seals a gap 10 between the ground plane 7 and the lead frame 4 inside the ground plane 7 and a part of the lead frame 4 around the element including the semiconductor element 2, that is, a high-frequency semiconductor element A pre-mold type package in which an insulating base formed by resin molding integrally with the lead frame 4 is previously formed may be used as a package for housing the lead frame 4.

[Effects of the Invention] As described above, according to the present invention, an inexpensive general-purpose insulator such as a lead frame or a resin is used for a circuit pattern or an insulator constituting a package for housing a semiconductor element. A high frequency semiconductor device having a ground plane can be formed. Therefore, according to the present invention, an inexpensive and versatile high-frequency semiconductor device can be provided.

According to the lead frame for a high-frequency semiconductor device of the present invention, a ground plane integrally connected to a die pad provided on the lead frame via a tie bar is formed by bending the tie bar into a substantially U-shaped cross section. The element is disposed above or below the die pad to which the element is fixed, or both, and only one or both of the above and below the internal lead portion of the lead frame is covered with the ground plane. A semiconductor device excellent in high frequency characteristics sealed with an insulator can be easily and inexpensively manufactured.

[Brief description of the drawings]

1 is a partially cutaway plan view of a high-frequency semiconductor device according to the present invention, FIG. 2 is a sectional view taken along line AA of the device of FIG. 1, and FIG. 3 is a plan view of a lead frame for a high-frequency semiconductor device according to the present invention. Figure,
FIG. 4 is an explanatory view of the use state of the lead frame of FIG. 3, FIG. 5 is a plan view of another lead frame for a high-frequency semiconductor device of the present invention, and FIG. 6 is an example of a lead frame having a coplanar transmission line. It is a partial plan view. DESCRIPTION OF SYMBOLS 1 ... Insulator, 2 ... Semiconductor element, 3 ... Electrode, 4 ... Lead frame, 5 ... Lead, 5a ... Internal lead part, 6 ... Die pad, 7 ... Ground plane, 8a ... Tie bar .

Claims (2)

(57) [Claims] 1. A semiconductor device in which a die pad in which a high-frequency semiconductor element is fixed inside an insulator such as a resin and an internal lead electrically connected to said semiconductor element are sealed. Above or below or above and below and above the die pad, a ground plane electrically connected to the die pad is provided via a tie bar provided separately from the internal lead portion. A high-frequency semiconductor device, wherein the semiconductor device covers an upper portion, a lower portion, an upper portion, and a lower portion of the internal lead portion. 2. A lead frame having a die pad for fixing a semiconductor element and an internal lead portion electrically connected to the semiconductor element, wherein the die pad is connected to the die pad via a tie bar provided at a distance from the internal lead part. A ground plane provided in series, wherein the ground plane is disposed above or below the internal lead portion or above and below the internal lead portion by bending the tie bar. And a ground plane capable of covering above or below the internal lead portion or above and below the internal lead portion.