JPH047865A - Lead frame and semiconductor integrated circuit device using the same - Google Patents

Abstract

PURPOSE:To facilitate handling and testing, and realize a multipin LSI package, by arranging test pads on one surface of a guard ring. CONSTITUTION:Test pads 7 are arranged on one surface of a frame type guard ring 6 for fixing an outer lead part 3b. Hence, when selection work such as testing and screening is performed, it is not necessary to bring a prove directly into contact with the outer lead part, so that the deformation defect of lead in a selection process can be surely prevented. Further, since the handling of lead frames is facilitated, the deformation defect of lead at the time of carriage or the like can be surely prevented. Thereby, when the plate thickness of a lead frame is extremely reduced, and the width of a lead and the pitch between leads are made small, the warp and the deformation of the lead can be prevented, and handling can be surely performed. Thus a multipin LSI can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a lead frame and a semiconductor integrated circuit device using the lead frame, and particularly to a technique that is effective when applied to increasing the number of pins in an LSI puff cage.

[Conventional technology]

2. Description of the Related Art With the increasing functionality of various electronic devices such as computers, the number of pins in LSI packages that encapsulate semiconductor chips forming integrated circuits such as microcomputers and gate arrays is rapidly increasing. L suitable for multiple bins
Typical SI packages include QFP
(quad flat package) is known.

Guardring is a type of QFP mentioned above.
) QFP (GQFP) (Japan Electronics Industry Association standard BD-7414 general rules for integrated circuit external shapes). GQFP has a frame-shaped guard ring molded on the outside of the outer lead portion of the lead frame to facilitate handling and testing during the assembly process.

This guard ring is cut off from the leads before the package body is mounted on the board, and at this time the outer lead portion is formed.

[Problem to be solved by the invention]

However, because conventional GQFPs have test pads arranged in a row along the outer edge of the guard ring, there is a limit to how narrow the pitch of the test pads can be, and this method cannot be applied to QFPs with a large number of pins. there were.

The present invention has been made in view of the above-mentioned problems, and its purpose is to provide a technique that can promote the increase in the number of pins in LSI packages.

Another object of the present invention is to provide a technique that can facilitate handling and testing of LSI packages.

Another object of the present invention is to provide a technique that can improve the packaging density of LSI packages.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Means for Solving the Problems] Among the inventions disclosed in this application, a brief overview of typical inventions is as follows.

(1) One invention of the present application is a lead frame in which a test pad electrically connected to the outer lead portion is provided on one surface of a frame-shaped guard ring that fixes the outer lead portion.

(2) Another invention of the present application is a lead frame in which the test pads are arranged in a staggered manner.

(3) Another invention of the present application is a lead frame in which the test pads are provided on both sides of the guard ring.

[Effect]

According to the above-mentioned means (1), by providing a test pad on one side of the guard ring, when performing selection work such as testing or screening, there is no need to directly contact the probe with the outer lead part, so the selection process Deformation defects of the leads can be reliably prevented. Further, by providing a guard ring on the outside of the outer lead portion to protect the easily deformable leads, the lead frame can be easily handled, and deformation defects of the leads during transportation can be reliably prevented.

Furthermore, even when the thickness of the lead frame is made extremely thin to reduce the radius of the leads and the pitch between the leads, warpage and deformation of the leads can be prevented and handling can be performed reliably. It is possible to realize multi-bin packaging. Additionally, when mounting an LSI package on a board, the guard ring is left uncut from the leads and the test pads are used as external terminals of the package, thereby eliminating the need for cutting or forming the outer leads. .

According to the above-mentioned means (2), by arranging the test pads in a staggered manner, it is possible to arrange a large number of test pads within a fixed area of the guard ring surface.
It is possible to easily increase the number of pins in a package.

According to the above-mentioned means (3), by providing the test pads on both sides of the guard ring, the test can be placed on a fixed area of the guard ring surface, compared to the case where the test pads are provided only on one side of the guard ring. Since the number of pads can be doubled, it is possible to further increase the number of pins in an LSI package. Further, by using the test pads provided on both sides of the guard ring as they are as external terminals of the package, it is possible to mount the LSI package in multiple stages, thereby improving the packaging density of the LSI package.

[Example 1] Figure 1 is a plan view of the lead frame of Example 1,
The figure is a sectional view taken along the line ■-■ in FIG.

The lead frame l of this embodiment 1 is, for example, a surface mount type L.
This is used for assembling QFP, which is a type of SI package. A rectangular tab 2 on which a semiconductor chip is mounted is provided in the center of the lead frame 1.

A large number of glue sticks 3 are arranged around the tab 2 so as to surround the tab 2. A frame-shaped dam 4 that supports the lead 3 is formed in the middle of the lead 3, and four tab suspension leads 5 that support the tab 2 are installed between the tab 2 and the dam 4. has been done. The lead 3 extends inside the mold line M, which is the boundary between the area sealed inside the package and the area exposed to the outside, as an inner lead part 3as.
The outer sides are respectively referred to as outer lead portions 3b. The tab 2, lead 3, dam 4, and tab suspension lead 5 are patterned by pressing a hoop material made of a conductive material such as 4270 mm or copper.

The lead frame 1 of this embodiment 1 has an outer lead portion 3
A guard ring 6 in the shape of a rectangular frame is provided on the outside of b to fix the outer lead portion 3b. The guard ring 6 is made of an insulating plate made of, for example, epoxy resin (glass epoxy) impregnated with glass fiber. Also, guard ring 6
A test pad 7 electrically connected to the outer lead portion 3b is provided on one surface. The test pad 7 is made of a metal such as copper whose surface is soldered. The number of test pads 7 corresponds to the number of 30 leads, and one test pad 7 is connected to only one lead 3. The electrical connection between the test pad 7 and the lead 3 is made, for example, through a through hole 8 having a plating layer provided therein, as shown in FIG. Although not particularly limited, these test pads 7 are arranged in a staggered manner in the first embodiment as shown in FIG.

As shown in FIG. 3, the lead frame 1 is made up of a plurality (three in the figure) of unit frames each made up of the above-mentioned parts arranged in series in one direction. The guard ring 6 and the outer lead portion 3b are bonded to each unit frame using an adhesive or the like.

FIG. 4 shows a semi-finished QFP assembled using the lead frame 1 described above. A semiconductor chip 9 on which a logic LSI or the like is formed is mounted on the tab 2 of the lead frame 1, and an Au5 (:u
Alternatively, a wire 11 made of Δl is bonded. The chip 9, tab 2, wire 11, and inner lead portion 3a are sealed inside a package body 12 made of synthetic resin such as epoxy resin. Only the outer lead portion 3b and the guard ring 6 for fixing the outer lead portion 3b are left on the outside of the package body 12, and the other members are cut and removed by a press.

In the lead frame 1 of the first embodiment, the test pad 7 is provided on one side of the guard ring 6, so when performing QFP selection work, it is sufficient to bring the probe into contact with the test pad 7. That is, the lead frame 1 of Example 1
Since the probe does not have to come into direct contact with the outer lead part 3b when performing screening work such as testing or screening, it is possible to reliably prevent deformation of the leads 3 during the screening process, and improve the QFP assembly yield. can be improved.

The lead frame 1 of this embodiment 1 has an outer lead portion 3
A guard ring 6 is provided on the outside of b to protect the easily deformable leads 3 inside the guard ring 6, so that it is easy to transport the lead frame 1 sequentially through the pellet attachment process, wire bonding process, molding process, and cutting process. Handling becomes easier. This makes it possible to reliably prevent deformation of the leads 3 during transportation, thereby improving the QFP assembly yield.

The lead frame 1 of this embodiment 1 has an outer lead portion 3
By fixing b with the guard ring 6, even if an extremely thin hoop material with a thickness of 100 μm or less is used to narrow the width of the leads 3 and the pitch between the leads 3, warpage and deformation of the leads 30 can be prevented. Since the problem can be prevented and handling can be performed reliably, it is possible to realize a QFP with a large number of pins.

The lead frame 1 of the first embodiment has a guard ring 6 of a constant area by arranging the test pads 7 in a staggered manner.
QF
It is possible to easily increase the number of pins of P. In the first embodiment, the test pad 7 is connected to the guard ring 6.
Although a case has been described in which the test pads 7 are provided only on one side of the guard ring 6, the test pads 7 are not limited to this, and the test pads 7 may be provided on both sides of the guard ring 6. In this way, the number of test pads 7 that can be placed on a fixed area of the guard ring 6 is doubled compared to the case where the test pads 7 are provided only on one side of the guard ring 6, so the number of pins of the QFP can be increased. can be further promoted.

The semi-finished QFP products shown in FIG. 4 are shipped to, for example, a board mounting manufacturer after selecting good products through testing and screening. In this QFP, since the outer lead portion 3b is protected by the guard ring 6,
Defects in deformation of the board 3 during transportation are reliably prevented. The guard ring 6 is cut and removed from the outer lead portion 3b immediately before mounting the QFP on the board, and at this time the outer lead portion 3b is formed.

The semi-finished QFP shown in FIG. 4 can also be used as a finished product. That is, as shown in FIG. 5, when mounting the QFP on the substrate 13, the guard ring 6 is left as it is without being cut or removed from the outer lead portion 3b. Then, the test pad 7 provided on the guard ring 6 may be used as an external terminal of the QFP, and this may be soldered to the electrode (footprint) 14 of the substrate 13. When such a mounting method is used, the step of cutting and removing the guard ring 6 from the outer lead portion 3b and the step of forming the outer lead portion 3 can be omitted.

[Embodiment 2] FIG. 6 shows an example in which a pair of test pads 7.7 are provided on both sides of the guard ring 6, and the pair of test pads 7.7 are connected to one lead 3. In this case as well, the electrical connection between the pair of upper and lower test pads 7.7 and the leads 3 is made through the through holes 8 having a plating layer provided inside.

In this way, as shown in the figure, by using the pair of test pads 7.7 as external terminals of the QFP, it becomes possible to mount the QFP in multiple stages, thereby improving the packaging density.

The invention made by the present inventor has been specifically explained based on Examples above, but the present invention is not limited to Examples 1 and 2, and can be modified in various ways without departing from the gist thereof. Needless to say.

Guard rings are not limited to synthetic resin;
For example, it may be made of an insulating material such as ceramic.

The arrangement of the test pads is not limited to a staggered pattern, but is arbitrary.

The package is not limited to QFP, and can be applied to resin mold packages in general. Further, as shown in FIG. 7, the present invention is applied to a semiconductor integrated circuit device having a package structure in which a semiconductor chip 9 is sealed in a cavity sealed by a package substrate 15 made of an insulating material such as ceramic and a cap 16. You can also do that.

〔Effect of the invention〕

A brief explanation of the effects obtained by typical inventions disclosed in this application is as follows.

(1) According to the lead frame of the present invention, in which a test pad electrically connected to the outer lead portion is provided on one surface of a rod-shaped guard ring that fixes the outer lead portion, Since lead deformation defects can be reliably prevented, the assembly yield of LSI packages can be improved.

Furthermore, even when the thickness of the lead frame is made extremely thin to reduce the width of the leads and the pitch between the leads, warpage and deformation of the leads can be prevented and handling can be performed reliably. A large number of pins can be achieved.

Furthermore, when mounting an LSI package on a board, the guard ring is left uncut from the leads and the test pads are used as external terminals of the package, thereby eliminating the cutting and forming processes for the outer leads. I can do it.

(2) According to the lead frame of the present invention in which the test pads are arranged in a staggered manner, a large number of test pads can be arranged on a guard ring surface of a constant area, so it is easy to increase the number of pins in the LSI package. can be realized.

(3) According to the lead frame of the present invention in which the test pads are provided on both sides of the guard ring, it is possible to arrange the test pads on a constant area of the guard ring surface compared to the case where the test pads are provided only on one side of the guard ring. Since the number of test pads that can be used is doubled, it is possible to further increase the number of bins in LSI packages. Further, by using the test pads provided on both sides of the guard ring as they are as external terminals of the package, it is possible to mount the LSI package in multiple stages, thereby improving the packaging density of the LSI package.

[Brief explanation of drawings]

FIG. 1 is a plan view of a lead frame which is an embodiment of the present invention, FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1, and FIG. 4 is a plan view of a semiconductor integrated circuit device manufactured using this lead frame, FIG. 5 is a cross-sectional view showing a state in which this semiconductor integrated circuit device is mounted on a substrate, and FIG. 6 is a plan view of a semiconductor integrated circuit device manufactured using this lead frame. FIG. 7 is a cross-sectional view showing a semiconductor integrated circuit device according to another embodiment mounted on a substrate. FIG. 7 is a cross-sectional view of a semiconductor integrated circuit device according to still another embodiment of the present invention. l...lead frame, 2...tab, 3... ・
Lead, 3a... Inner lead part, 3b...
Outer lead part, 4...Dam, 5...Tab hanging lead, 6...Guard ring, 7...Test hat,
8...Through hole, 9...Semiconductor chip, 10.
...Ponding pad, 11...Wire, 12...
・Package body, 13...substrate, 14...electrode (
footprint), 15... package board, 16.
...Cap, M...Mold line. Agent Patent Attorney Daiwa Tsutsui

Claims (1)

[Scope of Claims] 1. A lead frame characterized in that a test pad electrically connected to the outer lead portion is provided on one surface of a frame-shaped guard ring that fixes the outer lead portion. 2. The lead frame according to claim 1, wherein the test pads are arranged in a staggered manner. 3. The lead frame according to claim 1, wherein the test pads are provided on both sides of the guard ring. 4. A semiconductor integrated circuit device using a lead frame according to claim 1, 2 or 3, wherein the test pad constitutes an external terminal of a package.