JPH0837274A - Lead frame, semiconductor integrated circuit device equipped therewith, and manufacture thereof - Google Patents

Abstract

PURPOSE:To effectively prevent inner leads from being deformed when a lead frame of tape dam type is clamped by a molding die. CONSTITUTION:A tape dam 7a which functions as a dam to stop a flow of package molding resin when a package main body 2 is molded is provided onto a lead 5 so as to be located outside the package outline of a package molding die or the package main body 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead frame, a semiconductor integrated circuit device using the lead frame, and a manufacturing technique thereof, and particularly to a multi-pin, narrow-pitch LSI such as QFP (Quad Flat Package). And effective technology.

[0002]

2. Description of the Related Art In a logic LSI such as a gate array or a microcomputer, a terminal (input / output pin) for connecting to an external circuit as the number of gates increases.
The number of is increasing year by year.

As the number of input / output pins increases, Q
In resin-molded packages represented by FP and the like, the leads are becoming finer and the pitch between adjacent leads is becoming narrower.

However, due to the miniaturization of the leads and the narrowing of the pitch between the adjacent leads due to the increase in the number of pins, it has become very difficult to drop the dam bar of the outer leads after the resin molding.

The leads are fine and therefore bent at the time of dam cutting, the bent leads come into contact with the adjacent leads due to the narrow space between the adjacent leads, or the cutting caused at the dam cut due to the narrow space between the adjacent leads. This is because the rest easily causes problems such as short-circuiting between leads.

Therefore, instead of a means for integrally forming the dam bar and the lead, for example, in Japanese Patent Laid-Open No. 58-28841, a thin insulating tape is attached to a lead frame,
A so-called tape dam method has been proposed in which this is pressed into between the leads during resin molding to form a dam bar.

According to this tape dam method, since the tape is made of an insulating material, dam cutting after resin molding is unnecessary, and it is possible to promote the increase in the number of pins of leads and the reduction in pitch.

[0008]

FIG. 20 shows a state where the tape dam type lead frame 100 studied by the present inventor is mounted on a molding die.

The mold dies are an upper mold 101a and a lower mold 101.
and the lead frame 100 is a lower mold 101b.
Is positioned on the upper surface of. The lead frame 100 includes a lead 102 and a die pad portion 103,
A thin tape dam 104 made of an insulating material such as a polyimide resin is attached to one surface of a middle portion of the lead 102 (a boundary portion between the inner lead portion and the outer lead portion) with an adhesive. The semiconductor chip 105 bonded to the upper surface of the die pad portion 103 has the bonding wire 1
It is electrically connected to the lead 102 via 06.

To mold the semiconductor chip 105 with resin, first, the upper mold 101a and the lower mold 101b are brought into close contact with each other and the mold is clamped. Then, the tape dam 104 adhered to one surface (the upper surface in the example shown in FIG. 13) of the lead frame 100 is sandwiched between the upper die 101a and the lead frame 100 and crushed, and a part of the tape dam 104 and the lead 1 are formed.
The gap 02 is filled.

Next, a molten resin is injected into the cavity of the mold to mold the semiconductor chip 105. At this time,
Insulating tape 1 is provided in the gap between the leads 102.
Since 04 is filled, the molten resin does not flow out of the mold through this gap.

After that, the lead frame 100 is taken out of the mold, the leads 102 are subjected to solder plating, and unnecessary portions of the lead frame 100 are cut and removed by a press, and then the leads 102 are bent into a predetermined shape. , The LSI package is completed.

By the way, as shown in FIG. 20, the molding die of the LSI represented by QFP is an upper die 101a.
The shape of the lower mold 101b is symmetrical.

However, when the single-sided tape dam type lead frame 100 is mounted in such a molding die and the mold is clamped, the middle portion of the lead 102 (the boundary portion between the inner lead portion and the outer lead portion) is The lower surface is directly clamped by the lower die 101b, while the upper surface is clamped by the upper die 101a via the tape dam 104. Therefore, as shown in FIG. 21, the inner lead portion of the lead 102 serves as the tape dam attachment surface. Bends in the opposite direction (downward). Further, when the tape dam 104 is attached to the lower surface of the lead frame 100, it bends upward.

As a result, the lead 102 and the semiconductor chip 1
The bonding wire 106 connecting with 05 is deformed (twisted) to cause a wire short,
A mold defect occurs in which the die pad portion 103 (and the semiconductor chip 105) is tilted.

In this case, if the tape dams 104 are attached to both sides of the lead frame 100, even loads are applied to the middle portions of the leads 102 from both upper and lower directions, so that the inner lead portions are not bent. When the mold die is clamped, the insulating tape 104 is pressed into the gaps between the leads 102 from above and below the lead frame 100. Therefore, in the case of the lead frame 100 having a narrow pitch, the leads 102 are spread laterally. It will be transformed.

It is an object of the present invention to provide a technique capable of effectively preventing inner lead bending when a tape dam type lead frame is clamped by a molding die.

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

[0019]

Of the inventions disclosed in the present application, a representative one will be briefly described below.
It is as follows.

That is, in the lead frame of the present invention, the insulating tape for forming the insulating tape dam is attached to the outside of the package outline of the mold for molding the package.

Also, in the method for manufacturing a semiconductor integrated circuit device of the present invention, when the semiconductor chip mounted on the die pad of the lead frame is resin-molded, the insulating tape attached on the lead frame is used. A step of forming an insulating tape dam by pressing the insulating tape between the leads by crushing by the outer flat portion of the package outline of the mold for molding the package; And a step of resin-molding the semiconductor chip by introducing a resin into the cavity.

[0022]

According to the above-mentioned means, the insulating tape for forming the insulating tape dam is attached to the outside of the package outline of the molding die on the lead frame so that the insulating tape can be used during the resin molding process. When crushed by a molding die and press-fitted between leads, sandwich the insulating tape between the entire upper surface and the entire lower surface with the outer flat surface of the package outline of the molding die and in the upper surface and the lower surface. It can be crushed with a uniform pressure applied.

[0023]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a sectional view of a semiconductor integrated circuit device which is an embodiment of the present invention, FIG. 2 is a perspective view of a main part of the semiconductor integrated circuit device of FIG. 1, and FIG. 3 is a schematic view of the semiconductor integrated circuit device of FIG. 4 is a sectional view of a part of the semiconductor integrated circuit device of FIG.
5 is a plan view of a main part of a lead frame used in the semiconductor integrated circuit device of FIG. 1, FIG. 6 is a perspective view of a main part of the lead frame of FIG. 5, and FIG. 7 is a perspective view of a main part of the lead frame of FIG.
5 is a sectional view of an essential part of the lead frame in FIG. 5, FIG. 9 is an enlarged sectional view of an essential part of the lead frame in FIG. 5, FIG. 10 is an enlarged sectional view of an essential part of the lead frame in FIG. 5, and FIG. 11 is a semiconductor integrated circuit of FIG. FIG. 12 is a process diagram for explaining a manufacturing process of the circuit device, FIG. 12 is a sectional view of the semiconductor integrated circuit device of FIG. 1 after a die bonding process, and FIG. 13 is a sectional view of the semiconductor integrated circuit device of FIG. 1 after a wire bonding process. 14 is a cross-sectional view of the semiconductor integrated circuit device of FIG. 1 during a molding step, FIG. 15 is a cross-sectional view of a main part of the semiconductor integrated circuit device of FIG. 1 during a tape dam forming step, and FIG. 16 is a semiconductor integrated circuit device of FIG. 17 is a cross-sectional view of the main part during the tape dam forming process of FIG.
A cross-sectional view of an essential part of the semiconductor integrated circuit device after the molding step,
FIG. 18 is a cross-sectional view of the semiconductor integrated circuit device of FIG. 1 after the molding process.

The semiconductor integrated circuit device of this embodiment will be described with reference to FIGS. The semiconductor integrated circuit device of this embodiment is, for example, QFP1.

In the QFP 1, a die pad portion 3, a semiconductor chip 4 made of silicon (Si) single crystal, and inner lead portions of leads 5 are sealed inside a package body 2 made of an epoxy resin.

The semiconductor chip 4 is adhered onto the die pad portion 3 with, for example, an epoxy resin adhesive.
The semiconductor chip 4 and the inner lead portion of the lead 5 are, for example, gold (Au), copper (Cu) or aluminum (A
It is electrically connected via the bonding wire 6 consisting of 1).

By the way, in this embodiment, the lead 5 is used.
A tape dam 7a made of an insulating material such as a polyimide resin is provided outside the package main body 2 at a middle portion.
Are provided so as to extend along the direction adjacent to the lead 5.

The tape dam 7a is a member that functions as a resin flow stop when the semiconductor chip 4 is sealed with a resin, and the lead 5 is partially filled between the adjacent leads 5 and 5. It is pasted on with adhesive 7b.

Next, a lead frame used for manufacturing the semiconductor integrated circuit device of this embodiment will be described with reference to FIGS. Note that FIG. 8 is a sectional view of FIG. 7, and FIG.
FIG.

The lead frame 8 includes a die pad portion 3, suspension leads 9 provided at the four corners of the die pad portion 3 to support the die pad portion 3, and a plurality of leads 5 arranged around the die pad portion 3. The lead 5 is composed of a rectangular frame-shaped insulating tape 7 attached in the middle of the inner lead portion and the outer lead portion, an outer frame 10 supporting the leads 5 and the suspension leads 9.

The lead frame 8 is made of 42 alloy or Cu, and each member such as the die pad portion 3, the lead 5, the suspension lead 9 and the outer frame 10 is integrally formed by pressing or etching.

As an example, the plate thickness of the lead frame 8 is about 0.1 mm, the width of the inner lead portion of the lead 5 is about 0.13 mm, and the pitch is about 0.3 mm. The insulating tape 7 has a thickness of about 50 μm and a width of 0.5 to 2.0 mm.
The thickness of the adhesive 7b for attaching the tape dam 7 to the lead 5 is about 25 μm.

The insulating tape 7 is the tape dam 7 described above.
This is a tape for forming a, and the insulating tape 7 is not filled between the adjacent leads 5 at this stage.

Next, a method of manufacturing the semiconductor integrated circuit device of this embodiment will be described with reference to FIGS.

First, as shown in FIG. 12, the semiconductor chip 4 is bonded to the die pad portion 3 of the lead frame 8 (die bonding step A), and subsequently, as shown in FIG. 13, the lead 5 and the semiconductor chip 4 are joined together. Are electrically connected by a bonding wire 6 (wire bonding step B).

The tape dam 7 does not have to be attached to the same surface as the semiconductor chip 4, but may be attached to the same surface as the semiconductor chip 4 or the opposite surface depending on the application.

Subsequently, as shown in FIG. 14, the lead frame 8 is mounted on the molding die 11. The molding die 11 is composed of a pair of an upper die 11a and a lower die 11b. The lead frame 8 is positioned on the upper surface of the lower mold 11b.

Here, in the present embodiment, as shown in the figure, the insulating tape 7 is arranged outside the package outline L in the molding die 11. That is, the insulating tape 7 is arranged in the flat portion region of the molding die 11.

Thereafter, as shown in FIGS. 15 and 16, the lower surface of the upper mold 11a and the upper surface of the lower mold 11b are brought into close contact with each other to perform mold clamping. Then, the insulating tape 7 adhered to the upper surface of the lead frame 8 has the lower mold 11b and the upper mold 11
It is sandwiched between a and and is crushed, and part of it is lead 5 and lead 5.
It is pressed into the gap between. Then, the tape dam 7a is formed by this.

At this time, the entire lower surface of the insulating tape 7 on the lead 5 is clamped by the flat surface of the lower mold 11b, and the entire upper surface is clamped by the flat surface of the upper mold 11a via the lead 5, and the inside of the upper surface is clamped. Since the pressure applied to the lower surface and the lower surface can be crushed in a uniform state, the inner lead portion of the lead 5 does not bend in the vertical direction.

Then, a molten resin is injected into the cavity of the molding die 11 to mold the semiconductor chip 4 (molding step C). At this time, since the tape dam 7a is filled in the gap between the leads 5 and 5, the molten resin does not flow out of the mold through this gap.

Then, when the lead frame 8 is taken out from the mold, a QFP having the tape dam 7a arranged on the outside of the package body 2 on the lead 5 is obtained as shown in FIGS.

After that, the outer lead portions of the leads 5 are solder-plated, the unnecessary portions of the lead frame 8 are cut and removed by a press, and the leads 5 are bent into a predetermined shape. The QFP1 shown in is completed.

As described above, according to this embodiment, the following effects can be obtained.

(1). Insulating tape 7 for forming a tape dam
Is attached to the outside of the package outline L of the molding die 11 on the lead frame 8, so that the insulating tape 7 is attached to the molding die 1 during the molding step C.
Since the flat portion 1 can press and squeeze between the leads, it is possible to effectively prevent inner lead bending that occurs when the tape dam type lead frame 8 is clamped by the molding die 11.

(2) Due to the above (1), it is possible to prevent wire short-circuit defects and die pad tilt defects due to inner lead bending. Therefore, the yield and reliability of the QFP 1 using this lead frame 8 can be improved.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the embodiments and various modifications can be made without departing from the scope of the invention. Needless to say.

For example, as shown in FIG. 19, the heat dissipation plate 12 may be attached to the upper surface of the package body 2. As a result, the heat of the semiconductor chip 4 is transferred to the die pad 3
Since it can be released to the heat dissipation plate 12 via the, it is possible to provide the QFP1 having a small thermal resistance.

In the above description, the invention made mainly by the present inventor is the field of application which is the background of the invention.
However, the present invention is not limited to this, and various other applications are possible, such as DIP (Dual Inline Pack).
age), SIP (Single Inline Package) or SOJ
(Small Outline J-Lead Package), etc. can be applied to a semiconductor integrated circuit device having another package structure.

[0051]

Advantageous effects obtained by typical ones of the inventions disclosed in the present application will be briefly described.
It is as follows.

(1) According to the above-mentioned means, the insulating tape for forming the insulating tape dam is attached to the outer side of the package outline of the molding die on the lead frame, so that the resin molding step is performed. When the insulating tape is crushed by the mold and press-fitted between the leads, the entire upper surface and the lower surface of the insulating tape are sandwiched by the outer flat surface of the package outline of the mold, and Since the pressure applied to the lower surface and the lower surface can be crushed in a uniform state, it is possible to effectively prevent inner lead bending that occurs when the tape dam type lead frame is clamped by the molding die.

(2). Due to the above (1), it is possible to prevent a wire short circuit defect and a die pad inclination defect due to inner lead bending. Therefore, the yield and reliability of the semiconductor integrated circuit device using this lead frame can be improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a semiconductor integrated circuit device that is an embodiment of the present invention.

FIG. 2 is a perspective view of a main part of the semiconductor integrated circuit device of FIG.

FIG. 3 is a cross-sectional view of essential parts of the semiconductor integrated circuit device of FIG.

FIG. 4 is a cross-sectional view of main parts of the semiconductor integrated circuit device of FIG.

5 is a main-portion plan view of a lead frame used in the semiconductor integrated circuit device of FIG. 1;

6 is a perspective view of a main part of the lead frame of FIG.

FIG. 7 is a perspective view of a main part of the lead frame of FIG.

8 is a cross-sectional view of a main part of the lead frame of FIG.

9 is an enlarged cross-sectional view of a main part of the lead frame of FIG.

10 is an enlarged cross-sectional view of a main part of the lead frame in FIG.

FIG. 11 is a process drawing for explaining a manufacturing process of the semiconductor integrated circuit device of FIG.

12 is a cross-sectional view of the semiconductor integrated circuit device of FIG. 1 after a die bonding process.

13 is a cross-sectional view of the semiconductor integrated circuit device of FIG. 1 after a wire bonding process.

14 is a cross-sectional view of the semiconductor integrated circuit device of FIG. 1 during a molding process.

15 is a cross-sectional view of essential parts in the tape dam forming step of the semiconductor integrated circuit device of FIG.

16 is a main-portion cross-sectional view of the semiconductor integrated circuit device of FIG. 1 during a tape dam forming step.

17 is a cross-sectional view of essential parts in the semiconductor integrated circuit device of FIG. 1 after a molding step.

18 is a sectional view of the semiconductor integrated circuit device of FIG. 1 after a molding step.

FIG. 19 is a sectional view of a semiconductor integrated circuit device according to another embodiment of the present invention.

FIG. 20 is a cross-sectional view of a lead frame showing a method for manufacturing a semiconductor integrated circuit device examined by the present inventor.

FIG. 21 is a cross-sectional view of a lead frame showing a method for manufacturing a semiconductor integrated circuit device examined by the present inventor.

[Explanation of symbols]

 1 QFP (semiconductor integrated circuit device) 2 package body 3 die pad part 4 semiconductor chip 5 lead 6 bonding wire 7 insulating tape 7a tape dam 7b adhesive 8 lead frame 9 suspension lead 10 outer frame 11 mold die 11a upper die 11b lower die 12 heat sink 100 lead frame 101a upper die 101b lower die 102 lead 103 die pad portion 104 tape dam 105 semiconductor chip 106 bonding wire

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location H01L 23/28 A 6921-4E

Claims (4)

[Claims] 1. A lead frame, wherein an insulating tape for forming an insulating tape dam is attached to the outside of a package outline in a mold for molding a package. 2. A semiconductor integrated circuit device using a lead frame according to claim 1, wherein the semiconductor chip mounted on the die pad of the lead frame is sealed with a package made of resin. 3. The QFP according to claim 2, which is a QFP.
13. The semiconductor integrated circuit device according to claim 1. 4. When a semiconductor chip mounted on a die pad of the lead frame is resin-molded, an insulating tape attached on the lead frame is used as a package contour line in a mold for molding the package. By pressing the insulating tape between the leads by crushing by the outer flat part of the insulating tape dam, and by introducing a resin into the cavity formed by the molding die, the semiconductor 4. The method of manufacturing a semiconductor integrated circuit device according to claim 2, further comprising a step of resin-molding the chip.