JPH0382148A - Semiconductor device - Google Patents

Abstract

PURPOSE:To make it possible to secure sufficiently the heat transfer paths from a semiconductor pellet to leads and to reduce the heat resistance of a package by a method wherein an insulating layer is interposingly provided between the pellet and the group of the inner parts of the leads, but a metal layer is formed on the whole surface of the insulating layer. CONSTITUTION:When a pellet 14 generates heat, the generated heat of the pellet 14 is transferred to a metal foil 13, on which the pellet 14 is fixed, and is diffused in the foil 13 as a whole. The heat diffused to a very large area in this foil 13 is dissipated in a resin-sealed package 17 with a very large surface area compared to that of the pellet 14 and at the same time, exceeds an insulating sheet 11 with the foil 13 applied thereon and is transferred to a group of central part inner leads 8B, which are positioned directly under the sheet 11. The heat transferred to the group of central part inner leads 8B is transferred to a group of outer leads 7 formed integrally with the central part inner leads 8B and is dissipated in a wiring board and the atmosphere through the group of outer leads 7.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to semiconductor device manufacturing technology, particularly to improvement of lead wiring technology. The present invention relates to a technique effective for use in manufacturing a semiconductor integrated circuit device (hereinafter sometimes referred to as DIP-IC1 or simply IC).

[Conventional technology]

Conventionally, a dual-in-line type resin-sealed package having a bending width of 300 m11 (7.62 m5) has been used in memory-based semiconductor integrated circuit devices.

Recently, as the degree of integration of memory-based semiconductor integrated circuit devices has increased, semiconductor pellets have become larger in the longitudinal direction. Furthermore, memory-based semiconductor integrated circuit devices are characterized in that the bonding pads on the semiconductor pellet are arranged biased toward both short sides of the semiconductor pellet, which is formed into an elongated shape.

Therefore, if the degree of integration of memory semiconductor integrated circuit devices increases further, there is a problem that it will be extremely difficult to maintain a bending width of 3QQmil in a dual-in-line resin-sealed package. . In other words, dual
In an in-line resin-sealed package, when trying to accommodate a semiconductor pellet that is long and has bonding pads biased toward the short side, there is insufficient wiring space for the inner leads within the package. This is because you end up doing it.

Therefore, even when sealing semiconductor pellets that are long and have bonding pads biased toward the short sides, a resin-sealed package can secure sufficient wiring space for the inner leads. It is desired to provide a semiconductor device having the following features.

In order to meet such demands, the following semiconductor devices have been proposed.

That is, a semiconductor pellet, a plurality of leads that are electrically independent from each other and constitute external terminals, bonding wires that are bridged between each lead and the semiconductor pellet, and these. A semiconductor device comprising a semiconductor pellet, a lead, and a package for resin-sealing a group of bonding wires, the inner portion C and below of at least some of the leads of the group of leads,
It is sometimes called an inner lead. ) is wired below the semiconductor pellet within the package, and an insulating layer is interposed between the inner lead and the semiconductor pellet.

According to this semiconductor device, at least some of the inner leads of the lead group are partially wired below the semiconductor pellet within the resin-sealed package.
Sufficient wiring space can be secured for the inner lead.

Thus, for example, dual
In an in-line resin-sealed package, even if you are trying to accommodate a semiconductor pellet that is long and has bonding pads biased toward its short side, it is difficult to keep the inner leads inside the package. Can be wired sufficiently.

Furthermore, since an insulating layer is interposed between the semiconductor pellet and the inner lead wired below the semiconductor pellet, good insulation is maintained between the semiconductor pellet and the lead group, and the semiconductor pellet is It can be firmly fixed within the resin-sealed package.

An example of such a semiconductor device is as follows.
Japan Patent Office Published Patent Publication, JP 57-114261
No., JP-A No. 61-218139, and JP-A No. 61-Sho.
There is No.-258458.

[Problem R that the invention attempts to solve]

However, in the semiconductor device described above, sufficient consideration has not been given to the heat transfer path from the tL semiconductor pellet to the inner part of the lead, so the problem is that the thermal resistance of the buff cage increases as the number of pins increases. The present inventor has revealed that there is.

An object of the present invention is to provide a semiconductor device in which a sufficient heat transfer path from the pellet to the lead can be ensured and the thermal resistance of the puff cage can be reduced.

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] Representative inventions disclosed in Book III are summarized as follows.

That is, a semiconductor pellet, a plurality of leads that are electrically independent from each other and each connect an external terminal, and a bonding wire that is bridged between the inner part of each lead and the semiconductor pellet. In a semiconductor device comprising these semiconductor pellets, inner portions of leads, and a puff cage for resin-sealing bonding wires, the inner portion of each lead is located at least near the semiconductor pellet, and the inner portion group A tlA edge layer is formed thereon, a metal layer is formed on this insulating layer, and the semiconductor pellet is bonded onto this metal layer.

[Effect]

According to the above-mentioned means, an insulating layer is interposed between the semiconductor pellet and the inner part group of the leads, but since the insulating layer is entirely covered with a metal layer, the heat generation of the semiconductor pellet is suppressed. After being conducted to this metal layer, it is conducted to the entire lead by the entire surface of this metal layer. Therefore, the heat conduction efficiency is extremely high, and by reducing the thermal resistance from the semiconductor pellet to the lead, the entire semiconductor device is heated. The heat dissipation performance is improved.

[Example 1] Fig. 1 is a partially cutaway perspective view showing a DIP-IC which is an embodiment of the present invention, Fig. 2 is a side view and a central vertical sectional view thereof, and Fig.
The figure is a front view and a central vertical sectional view. FIGS. 4 to 6 are explanatory diagrams illustrating the manufacturing method.

In this example, the semiconductor device according to the present invention is a DIP
It is configured as an ICl3, and constitutes an external terminal electrically independent from the semiconductor pellet 14,
A plurality of wires consisting of an outer part (hereinafter referred to as "outer lead") 7 drawn out to the outside of the resin-sealed package (described later) and an inner part (hereinafter referred to as "inner lead") 8 wired inside the package. 6, bonding wires 16 bridged between each inner lead and the semiconductor pellet, and a package 17 for sealing the semiconductor pellet, inner lead, and bonding wire group with resin. and,
At least some of the inner leads 8B of the group of 8 inner leads are partially wired below the semiconductor pellet in the package, and some of the inner leads 8B of the group of inner leads 8B are wired below the semiconductor pellet. An insulating sheet) 11 as an insulating layer is fixed thereon, and a metal foil 1 as a metal layer is placed on this insulating sheet) 11.
3 is fixed, and a semiconductor pellet is bonded onto this metal foil 13.

Further, on the outside of the package, the outer lead group is bent downward, and the bending width of the opposing leads is set to 300 ml. The DIP IC configured as described above is manufactured by the following manufacturing method.

A method of manufacturing this DIP-IC, which is an embodiment of the present invention, will be explained below. With this explanation, the above [)IP-I
Configuration details for C are revealed.

In this example, the DIP-IC manufacturing method includes a fourth
A multi-lead frame 1 shown in the figure is used. This multi-lead frame is made of a thin (e.g. , a plate material with a wall thickness of 0-0-25a is used, and is integrally formed by suitable means such as punching press processing or etching processing.This multiple lead frame l includes a plurality of unit lead frames 2. are arranged in one row in one direction.

The unit lead frame 2 includes a pair of outer frames 3 each having a positioning hole 3a, and both outer frames 3.3 are parallel to each other at a predetermined interval and extend in series. la
A pair of section frames 4 are disposed parallel to each other between both outer frames 3.3 and are integrally constructed between the unit lead frames 2.2, which are connected to each other. A unit lead frame 2 is constructed within a rectangular frame.

In each unit lead frame 2, a pair of dam members 5 are arranged on both outer frames 3.3, and two dam members 5.5 are arranged parallel to each other and approximately symmetrically at inner positions of both section frames 4.4. A plurality of leads 6 are arranged at regular intervals in the longitudinal direction, are parallel to each other, and integrally protrude perpendicular to the dam member 5. A portion of the dam member 5 between adjacent leads 6.6 substantially constitutes a dam 5a for blocking the flow of package molding, which will be described later, and in particular, the flow of resin, which will be described later.

As will be described later, the outer portion of each lead 6 protrudes to the outside of the resin-sealed package, and therefore constitutes an outer lead 7, and the tip of each outer lead 7 is mechanically attached to the section frame 4. By being connected to each other, the state is maintained.

On the other hand, since the inner portions of each lead 6 are sealed inside a resin-sealed package as described later, they constitute inner leads 8, respectively. The inner ends, which are the free ends of each inner lead 8, are aligned on a straight line passing through predetermined positions on both short sides within the space of the unit lead frame 2. By being opposed to the bonding pads, each substantially constitutes a wire bonding portion 9.

In this embodiment, the 8 groups of inner leads can be roughly classified into 211 types. That is, one is a normal DIP
- Similar to the inner leads in an IC, the inner leads (hereinafter referred to as peripheral inner leads 8A) are wired using the empty space at the periphery of the unit lead frame 2.
), and the other is a normal DIP-IC
Completely different from the inner leads in , the inner leads C and below are wired using the empty space in the center of the unit lead frame 2, and the center inner leads 8B.
This is the − group of ). Ii1 side inner lead 8A
The wire bonding portion 9A of the inner lead 8B extends from the periphery toward the center, and the wire bonding portion 9B of the center inner lead 8B extends from the center toward the periphery. However, the wire bonding parts 9A and 9B in the inner leads 8A and 8B in both the peripheral part and the central part are also aligned in a straight line at predetermined positions. The central inner lead 8B group will be wired below the semiconductor pellet to be described later.

In this way, the unit lead frame 2 according to this embodiment
In this case, the group of central inner leads 8B are wired in the central region within the empty space of the unit lead frame 2, so the entire empty space can be used extremely effectively, and as a result, the inner leads 8B of the unit lead frame 2 are Even if the space is set to be long and narrow, all eight groups of inner leads can be properly and safely wired without coming into contact with each other.

In this way, each unit lead frame 2 of the lead frame L with the I precept comes with gold i foil! ! An edge sheet bonding operation, a pellet bonding operation, followed by a wire bonding operation is performed. These bonding operations are sequentially performed for each unit lead frame 2 by pinch-feeding the lead frame 1 in the serial direction.

Through these bonding operations, intermediate products shown in FIGS. 5 and 6 are manufactured.

First, by an insulating sheet bonding operation, the insulating sheet 11 with metal foil is bonded onto the group of central inner leads 8B of the unit lead frame 2 with a bonding layer 12 made of adhesive interposed therebetween.

In this embodiment, this Il! The edge sheath 11 is made of a material with good insulation, such as a polyimide resin film. @The green sheet 11 is formed into a rectangular shape that is larger than the planar shape of a semiconductor pellet to be described later. From the correlation between insulation maintenance and mechanical strength,
The thickness of the insulating sheet 1 is preferably about 125 μm. The adhesive for forming the bonding 1i12 is a thermoplastic material such as polyetheramide imide, or a thermosetting material such as epoxy. things are used.

A metal foil 13 is previously applied onto the insulating sheet ll. This metal foil 13 is formed using a metal material with good thermal conductivity such as a copper-based (W4 alloy) material, and is formed by forming the insulation sheet 1-11 by a suitable means such as welding or vapor deposition. It is evenly coated over the entire surface. This metal foil 13 is formed to have a sufficient thickness to effectively diffuse the heat generated by the semiconductor pellet.

Next, a semiconductor pellet (hereinafter referred to as pellet) 14 in which a 4M DRAM integrated circuit was fabricated in the previous process
is bonded to the metal foil 13 attached to the insulating sheet 11 of each unit lead frame 2 with a bonding layer 15 made of Ag paste or the like interposed therebetween. At this time, the pellets 14 are arranged approximately concentrically with respect to the metal 7613. As the adhesive for forming the bonding layer 15 that fixes the pellet 14 to the metal foil 13, it is desirable to use a material with as good thermal conductivity as possible.

A wire 16 is bridged by bonding both ends of the wire 16 between the electrode pad of the pellet 14 bonded to the metal foil 13 on the sheet II and the wire bonding portion 9 of the inner lead 8 in the unit lead frame 2. Ru. As a result, the integrated circuit built into the pellet 14 includes electrode pads, wires 16, and inner leads 8.
And it is electrically drawn out to the outside via the outer lead 7.

A resin-sealed package 17 is molded for each unit lead frame into the multi-blocking partial frame that has been subjected to pellet and wire bonding in this manner using a transfer molding device (not shown). Inside the resin-sealed package 17, there are pellets 14, an insulating sheet 11 with metal foil 13. Inner leads 8 and bonding wires 16 are sealed with resin.

Thereafter, the outer frame and dam of the multiple lead frame are cut off for each unit lead frame in a lead cutting and forming process, and the outer leads are bent downward.

Next, the action will be explained.

V after this DIP-IC is mounted or before shipping.
When the pellet 14 generates heat during a test or the like, the heat generated by the pellet 14 is transmitted to the metal foil 13 to which the pellet 14 is fixed, and is diffused throughout the metal foil 13. In this metal foil 13, the heat is radiated to the resin-sealed package 17 with an extremely large surface area compared to the surface area of the iL beam 14, which is diffused over a very wide area, and also beyond the insulating sheet 11 on which the metal fM 13 is attached. The signal is transmitted to the central inner lead 8B group located directly below it. The heat transferred to the center inner lead 8B group is transferred to the outer lead 7 group integrated with the center inner lead 8B, and is radiated to the wiring board and the atmosphere through the outer lead 7 group. In this way, since the metal foil 13 with low thermal resistance is interposed in the heat transfer path from Pellet [-14 to the group of outer leads 7,
Heat generated by the bellet 14 can be effectively radiated to the outside.

According to the embodiment described above, the following effects can be obtained.

(1) By bonding the pellets onto the metal layer on the insulating layer fixed on the inner lead group, a metal layer with low thermal resistance is interposed in the heat transfer path from the pellets to the outer lead group. Thermal resistance from to the outer lead group can be reduced, and the heat dissipation performance of the semiconductor device can be improved.

(By wiring at least some of the inner leads of the twin lead group below the semiconductor pellet in the resin-sealed package, sufficient wiring space can be secured for the inner lead group, resulting in high integration. Semiconductor pellets that are elongated and have bonding pads biased toward their short sides in dual-in-line resin-sealed packages, as in the case of memory-based semiconductor integrated circuit devices. Even if you are trying to store it, you can use a resin-sealed badge.

(3) As a result of (1) above, even in DIP ICs such as 4M DRAMs, which are equipped with highly integrated pellets, it is possible to maintain the standard of 300 m t l for the bending interval. The desired versatility or compatibility can be maintained in the integrated circuit device.

[Embodiment 2] FIG. 7 is a longitudinal cross-sectional view showing a QFI-1c according to a second embodiment of the present invention, and FIG. 8 is a partially omitted plan view showing the resin-sealed package before molding.

In Example 2, the semiconductor device according to the present invention is an IC equipped with a quad flat I-lead puff cage.
It is configured as. This QF[・ICAO is electrically independent from the semiconductor pellet 21 and constitutes an external terminal, and is included in the resin-sealed package 4(!) described later.
l! A plurality of wires are connected to each other from an outer part C (hereinafter referred to as an outer lead) 23 which is drawn out from one surface to the outside, and an inner part (hereinafter referred to as an inner lead) 24 which is wired radially inside the package. part 22, bonding wires 25 bridged between the middle part of each inner lead and the semiconductor pellet, and a package 26 for resin-sealing these semiconductor pellets, the inner leads, and the bonding wire group. There is. The tips of the inner leads 24 group are wired in the puff cage almost directly below the outer periphery of the semiconductor pellet, and an insulating layer is formed on the tips of the inner leads 24 group wired near the semiconductor pellet. An insulating sheet 27 is fixed via a bonding layer 29, a metal fi2B as a metal layer is fixed onto this insulating sheet 27, and a semiconductor pellet 21 is bonded onto this metal 9M28 via a bonding layer 30. ing.

The second embodiment differs from the first embodiment in that the tip of the inner lead 24M# does not reach the position directly below the semiconductor pellet 21, but is located near the semiconductor pellet 21. In the point where it is ing. That is, it is common to the first embodiment that the insulating sheet 27 and the metal foil 28 are overlapped with a part of the inner lead 24.

Therefore, in the second embodiment, as in the first embodiment, the heat generated by the semiconductor pellet 21 is diffused over a wide range by the metal foil 28 on the insulating sheet 27, and the heat is effectively transferred to the group of outer leads 23. Therefore, the heat dissipation performance of the entire semiconductor device is improved.

According to the second embodiment, in addition to the effects of the first embodiment, even when the groups of inner leads 24 are arranged radially with respect to the semiconductor pellet 21, the insulating sheet 27 and the metal foil 28 are interposed. You can get the effect that you can.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the Examples and can be modified in various ways without departing from the gist thereof. For example, the m-marginal layer is v! ! ,
The construction is not limited to using an insulating sheet made of an insulating resin, but may also be constructed using a plate material made of an insulating material such as a ceramic board, or a metal layer as a metal layer. An insulating resin may be formed on the inner surface of the plate by a suitable thick film forming technique such as screen printing or spray painting.

The metal layer is not limited to being formed using a copper-based material, but may be formed using a metal material with good thermal conductivity such as gold or aluminum.

As a means of bonding pellets onto a metal layer,
The bonding method using Ag paste or the like is not limited, but other means such as gold-silicon eutectic method or soldering may also be used.

Between the pellet and the metal layer, between the metal layer and the insulating layer,
The order in which the insulating layer and the lead are bonded to each other does not matter; the pellet is bonded to the metal layer in advance, an insulating layer is formed on the back side of this metal layer, and this insulating layer is bonded onto the lead. You may.

〔Effect of the invention〕

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

By bonding the pellets onto the metal layer on the insulating layer fixed on the inner lead group, a metal layer with low thermal resistance is interposed in the heat transfer path from the pellets to the outer lead group. It is possible to reduce the thermal resistance up to and improve the heat dissipation performance of the semiconductor device.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view of a D(P-IC) according to an embodiment of the present invention, FIG. 2 is a side view and center vertical sectional view thereof, and 3rd rgJ is a front view center longitudinal sectional view thereof. Figures 4 to 6 are explanatory diagrams for explaining the manufacturing method. Figure 4 is a partially omitted plan view showing a multi-lead frame used therein, and Figure 5 is a resin-sealed package. Fig. 6 is a partially omitted plan view showing the molding part of the QFI/IC, and Fig. 6 is a longitudinal sectional view thereof. 1 is a partially omitted plan view showing a molded part of a stop package. 1...Multiple lead frame, 2...Unit lead frame, 3...Outer frame, 4...Section frame, 5...
Dam member, 5a...Dam, 6...Lead, 7...
Outer lead (outer part), 8... Inner lead, 8
A...Peripheral inner lead, 8B...Central inner lead, 9.9A, 9B...Wire bonding part,
11... Insulating sheet (insulating layer), 12.15... Bonding layer, 13... Metal foil (metal foil, 14...
・Pellet, 16... Bonding wire, 17...
・Resin sealing package, 18...DIP-IC (semiconductor device), 20・-QFI・IC (semiconductor device), 21
...Semiconductor pellet, 22...Lead, 23...
Outer lead, 24... Inner lead, 25... Bonding wire, 26... Resin sealed package, 2
7... Insulating sheet (insulating layer), 28... Metal foil (metal layer), 29.30...-bonding layer.

Claims (1)

[Claims] 1. A semiconductor pellet, a plurality of leads that are electrically independent from each other and each constitute an external terminal, and a bridge between the inner part of each lead and the semiconductor pellet, respectively. In a semiconductor device comprising a bonding wire, and a package for resin-sealing the semiconductor pellet, the inner part of the lead, and the bonding wire, the inner part of each lead is located at least in the vicinity of the semiconductor pellet. . A semiconductor device, wherein an insulating layer is formed on the inner part group, a metal layer is formed on the insulating layer, and the semiconductor pellet is bonded onto the metal layer. 2. The semiconductor device according to claim 1, wherein an inner portion of each lead is located below the semiconductor pellet. 3. The inner part of each lead is located near the bottom of the semiconductor pellet, and the bonding wire is bonded to the inner part near the outside of the insulating layer and the metal layer. The semiconductor device according to item 1.