JPH0511660B2 - - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) This invention relates to a resin-sealed integrated circuit device in which an integrated circuit fixed on an island of a lead frame is sealed with a resin, and its manufacture. Regarding the method.

(Prior Art) In integrated circuit devices in which an integrated circuit is fixed on an island of a lead frame, the integrated circuit is generally sealed in order to protect the semiconductor chip from dust. ing.
This sealing method includes an airtight sealing method and a resin sealing method.

FIG. 3 shows an example of a resin-sealed integrated circuit device. In the figure, 11 is an island of the lead frame, and 12 is also a lead. 13 is an integrated circuit fixed on the island 11. 14 is a resin that integrally seals the island 11, the base end portion of the lead 12, and the integrated circuit 13.

The integrated circuit 13 is, for example, a hybrid integrated circuit. That is, this integrated circuit 13 is
It has an insulating substrate 131 fixed on the island 11 with an adhesive or the like, and a plurality of semiconductor chips 132 fixed on the insulating substrate 131 with an adhesive or the like. Conductive wiring 133 is provided on the insulating substrate 131.
is formed. The conductor wiring 133, the electrodes of the semiconductor chip 132, and the leads 12 are wires 1 as appropriate.
34.

FIG. 4 is a sectional view showing the structure of another example of the resin-sealed integrated circuit. This resin-sealed integrated circuit device is different from the previous one except that a hole 135 is formed in an insulating substrate 131 and a part of the semiconductor chip 132 is directly fixed to the island 12 through the hole 135 with an adhesive or the like. It has almost the same configuration as the device shown in FIG. Therefore, in Figure 4, the previous third
Parts that perform almost the same functions as those in the figures are given the same reference numerals.

Two configurations of the resin-sealed integrated circuit device have been described above. Although this resin-sealed integrated circuit device can protect the integrated circuit 13 from dust and the like, it has the following problems. Ta.

(1) First, the time required for the integrated circuit device to break down due to moisture intrusion into the package is short.

That is, when moisture enters the package, leakage current may flow between the conductor wiring 133 at the interface between the resin 14 and the insulating substrate 131, but if this leakage current is large, the function of the integrated circuit device may be destroyed. be done. In the case of a resin-sealed integrated circuit device, since a large amount of moisture enters the device, there is a high possibility that the above-mentioned functional breakdown will occur in a short period of time. This problem becomes particularly noticeable when the spacing between the conductor wirings 133 becomes narrower as the integration becomes higher.

For example, in the case of a dual inline package (DIP) type resin-sealed integrated circuit device,
Wire spacing 0.2mm to 1.0mm, applied voltage between wires approximately 30V
When conducting a long-term reliability test using steam pressurization under these conditions, it was confirmed that the leakage current reached the order of 10 μA after about 100 hours, causing functional breakdown. This breakdown time is a time that poses a problem in terms of reliability on the market in surface-mounted thin type resin-sealed integrated circuit devices. Therefore, in order to advance and expand resin-sealed integrated circuit devices, it is essential to extend the breakage time.

(2) Also, one of the problems is that there is a high possibility that the conductor wiring 133 will be disconnected or twisted (or shot in severe cases) due to thermal stress, resulting in functional destruction. This problem is caused by conductor wiring 1
This phenomenon is particularly noticeable when the width of the conductor wiring 133 is narrow or the interval is narrow, or when the conductor wiring 133 is made of a soft material. For example, if the line width is
It has been confirmed that if the wire is 100 μm or less, repeating the -65°/200°C temperature cycle every 30 minutes will cause wire breakage or kinking.

(3) Another problem is that there is a high risk that the wire 134 that the conductor wiring 133 crosses will be deformed, such as sagging, and that a shoot will occur.

(4) Furthermore, one reason is that when the area ratio of the conductor wiring 133 on the insulating substrate 131 increases, the insulating substrate 1
This means that the adhesion rate between 31 and resin 14 decreases. If the adhesion rate decreases, problems such as the above-mentioned (1) will occur.

(Problems to be Solved by the Invention) As stated above, the resin-encapsulated integrated circuit device
Conventionally, there have been problems such as a short time for functional breakdown due to moisture intrusion, a problem in which wire breakage or shortening is likely to occur due to thermal stress, a problem in which shortening is likely to occur due to wire deformation, and a problem in which resin adhesion occurs due to an increase in the area ratio of conductor wiring. The problem was that the rate decreased.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a resin-sealed integrated circuit device and a method for manufacturing the same, which can solve the above problems and provide high reliability.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides an insulating substrate having a first hole provided on the surface of an island in a lead frame; a semiconductor chip provided on the island exposed through the hole; a conductor layer provided on the insulating substrate; and a portion covering the conductor layer and corresponding to the electrode extraction portion of the conductor layer. an insulating coating made of polyimide having a second hole; a wire connecting the electrode lead-out portion of the conductor layer exposed by the second hole to the semiconductor chip; the wire, the insulating coating, and the semiconductor chip; It has a structure comprising a chip and a resin for sealing the island.

In addition, in order to obtain the above-described structure, the present invention first provides an insulating substrate having a first hole on the island in the lead frame, and then provides an insulating substrate having a first hole on the island exposed by the first hole. A semiconductor chip is provided. Next, a conductor layer is provided on the insulating substrate, and the conductor layer is covered with an insulating film made of polyimide in which second holes are previously formed in portions of the conductor layer corresponding to the electrode extraction portions. Thereafter, the electrode extraction portion of the conductor layer exposed through the second hole and the semiconductor chip are connected by a wire, and the wire, the insulating coating, the semiconductor chip, and the island are sealed with a resin. This is how it was done.

(Function) According to the above configuration, the insulating film covering the conductor layer can prevent moisture that has entered the package from reaching the conductor layer.
Functional damage caused by intruding moisture can be minimized.

Further, since the insulating film can prevent thermal stress from being directly transmitted to the conductor layer, disconnection or shorting of the conductor wiring due to thermal stress can be suppressed to the utmost.

Further, the insulating coating can prevent the wire from coming into contact with the conductor layer, etc., so that shortening due to deformation of the wire can be suppressed as much as possible.

Furthermore, since the insulating coating has better adhesion to the resin than a conductor layer made of metal or the like, a decrease in the adhesion rate to the resin can be suppressed even if the area ratio of the conductor layer increases.

(Embodiments) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view showing the structure of an embodiment of the present invention. In the figure, 21 is an island of the lead frame, and 22 is also a lead.
23 is an integrated circuit fixed on the island 21. 24 is island 21, lead 22
This is a resin that integrally seals the base end portion of the integrated circuit 23 and the integrated circuit 23.

The integrated circuit 23 is, for example, a hybrid integrated circuit. That is, the integrated circuit 23 includes an insulating substrate 231 and a plurality of semiconductor chips 232 fixed on the island 21 with an adhesive or the like.
Some of these semiconductor chips 232 are fixed onto the insulating substrate 231 with adhesive or the like. In addition, some of the holes 23 formed in the insulating substrate 232
3 and is directly fixed to the island 21 with an adhesive or the like. Conductive wiring 234 is formed on the insulating substrate 231. This conductor wiring 23
4. The electrodes of the semiconductor chip 232 and the leads 22 are appropriately connected by wires 235.

Next, the features of this invention will be explained.

In FIG. 1, 25 is an insulating film that covers the conductor wiring 234. In FIG. This insulating coating 25 has holes 2 in the portions corresponding to the electrode extraction portions of the conductor wiring 234.
It has 6. A wire 235 is connected to the electrode lead-out portion of the conductor wiring 234 through the hole 26.

The insulating film 25 is formed of an insulating material such as polyimide and has a thickness of about 50 μm to 100 μm.

Covering the conductor wiring 234 with the insulating film 25 and connecting the wire 235 are performed in the following manner.

First, the insulating coating 25 is prepared in advance as a film in which holes 26 are formed in portions corresponding to the electrode extraction portions of the conductive wiring 234. and,
This insulating film is attached to the electrode extraction part and hole 2.
Covering of the conductor wiring 234 is completed by placing it on the insulating substrate 234 while aligning with the conductor wiring 234 and fixing it with an adhesive or the like. After this, the hole 2
The wire 235 is connected to the electrode lead-out portion of the conductor wiring 234 via the wire 6.

With the above steps, the covering of the conductor wiring 234 and the connection of the wire 235 are completed.

Note that, for forming the holes 26 in the insulating film, for example, chemical etching treatment, mechanical pressing treatment, or treatment using photoreaction can be used.

Further, the adhesive for fixing the insulating film to the conductor wiring 234 may be applied to the insulating film in advance, for example.

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

(1) First, the insulating coating 25 can prevent moisture that has entered the package from reaching the conductor wiring 234 as much as possible. Thereby, leakage current between the conductor wirings 234 can be reduced, and functional breakdown due to intruding moisture can be suppressed. As a result of experiments, current leakage current is on the order of μA, whereas in this example,
It was confirmed that this could be suppressed to nA order and even PA order. As a result, the range of application and application of the resin-sealed integrated circuit device can be greatly expanded. In addition, blocking moisture not only reduces leakage current, but also increases the applied voltage, and in this sense,
The range of application and application of the resin-sealed integrated circuit device can be expanded.

(2) Furthermore, since the insulating film 25 can prevent thermal stress from being directly transmitted to the conductor wiring 234, it is possible to minimize disconnection and shorting of the conductor wiring 234 due to thermal stress.

Furthermore, the insulating coating 25 allows the wire 23 to
Since the wire 235 can be prevented from coming into contact with the conductor wiring 234, shortening due to deformation of the wire 235 can be suppressed as much as possible.

(3) Furthermore, since the insulating coating 25 has better adhesion to the resin 24 than the conductor wiring 234 made of metal or the like, even if the area ratio of the conductor wiring 234 increases, the adhesion rate of the resin 24 will decrease. can be suppressed.

(4) Furthermore, since covering the conductor wiring 234 with an insulating material and forming the insulating film 25 can be easily performed using a normal film forming process,
Resin-sealed integrated circuits can be manufactured without any reduction in productivity.

(5) Also, in order to cover the conductor wiring 234 with the insulating film 25 having holes 26, an insulating film with holes 26 is prepared in advance, and this is coated on the conductor wiring 234.
4, there is an advantage that the conductor wiring 234 is not damaged and complicated etching control is not required. That is, as a method for covering the conductor wiring 234 with the insulating coating 25 having the holes 26, there is another method, for example, in which the conductor wiring 234 is covered with the insulating coating 25 and then the holes 26 are formed. However, in this method, the conductor wiring 234 is damaged when forming the hole 26, and when the hole 26 is formed by etching, it is difficult to control the etching rate to avoid damaging the conductor wiring 234. On the other hand, in this embodiment, since the insulating film in which the holes 26 are formed in advance is covered, such a problem does not occur.

(6) Furthermore, in order to connect the wire 235 to the electrode extraction portion of the conductor wiring 234, the conductor wiring 234 is covered with the insulating coating 25 in which the hole 26 is formed, and then the wire 235
It is possible to prevent wire breakage, etc. That is,
To obtain the conductor wiring 234 covered with an insulating film, first connect the wire 235 to the electrode extraction part of the conductor wiring 234, and then connect the conductor wiring 234.
One possible method is to apply an insulating material to the surface. However, with this method, there is a high risk that the wire 235 will break when applying the insulator. In contrast, in this embodiment, the wire 235 is connected after the conductor wiring 234 is covered with the insulating coating 25 having the hole 26, so such a problem does not occur.

Next, another embodiment of the present invention will be described using the sectional view of FIG.

In the previous embodiment, the case where the present invention is applied to a resin-sealed integrated circuit device having a hybrid type integrated circuit has been described, but this embodiment applies to a resin-sealed type integrated circuit device having a monolithic type integrated circuit. This invention is applied to an integrated circuit device.

In FIG. 2, 31 is an island of the lead frame, and 32 is also a lead. 33
is a semiconductor chip fixed on the island 31 with adhesive or the like.

The electrodes of the semiconductor chip 33 are electrically connected to the leads 32. In this case, generally, since the distance between the electrodes of the semiconductor chip 33 and the leads 32 is long, the two are not directly connected, but the pads 3 provided between the island 31 and the leads 32 are
Connected via 4. This pad 34 is formed on a support base 35 made of, for example, an insulator, and is connected to the leads 32 and the electrodes of the semiconductor chip 33 via wires 36. And this pad 34
is integrally sealed with a resin 37 along with the semiconductor chip 33 and the like.

In such a configuration, in this embodiment, the pad 34 is connected to the insulating coating 3 while leaving the electrode extraction portion 38.
9.

According to this configuration, it is possible to obtain the same effects as in the previous embodiment, such as prevention of shortening between adjacent pads 38 due to moisture.

As described above, the coating with the insulating film, which is a feature of the present invention, is applicable not only to the conductor wiring on the insulating bonded board, but also to general conductor layers sealed with resin, such as the above-mentioned pads.

In addition, in the above explanation, the case where all parts of the conductor layer except the electrode extraction part are covered with an insulating film is explained, but the covered part should be reduced to the extent that the purpose of the invention can be achieved. It's okay.

Moreover, the present invention is of course applicable to a device formed by integrally resin-sealing a plurality of insulating bonded plates.

It goes without saying that this invention can be modified in various other ways without departing from the gist of the invention.

[Effects of the Invention] As described above, according to the present invention, it is possible to improve the moisture resistance characteristics, thermal stress characteristics, and resin adhesion rate of a resin-sealed integrated circuit device, and to prevent shortening due to wire deformation. can do.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the structure of one embodiment of the present invention, FIG. 2 is a sectional view showing the structure of another embodiment, and FIGS. 3 and 4 are respectively conventional resin-sealed integrated circuits. FIG. 3 is a cross-sectional view showing different configurations of the device. 21, 31... Island, 22, 32... Lead, 23... Integrated circuit, 24, 37... Resin,
25, 39... Insulating coating, 26, 38... Electrode extraction portion, 23, 232... Semiconductor chip, 34...
... Pad, 35 ... Support stand, 36, 235 ... Wire, 231 ... Insulating board, 233 ... Hole, 23
4... Conductor wiring.

Claims (1)

[Scope of Claims] 1. An insulating substrate having a first hole provided on the surface of an island in a lead frame, a semiconductor chip provided on the island exposed by the first hole, and the semiconductor chip provided on the island exposed by the first hole. a conductor layer provided on an insulating substrate; an insulating coating made of polyimide that covers the conductor layer and has a second hole in a portion of the conductor layer corresponding to the electrode extraction portion; A wire connecting the exposed electrode lead-out portion of the conductor layer and the semiconductor chip; and a resin sealing the wire, the insulating film, the semiconductor chip, and the island. Resin-encapsulated integrated circuit device. 2. Providing an insulating substrate having a first hole on the island in the lead frame; Providing a semiconductor chip on the island exposed by the first hole; and Providing a conductor layer on the insulating substrate. a step of covering the conductor layer with an insulating film made of polyimide in which a second hole is previously formed in a portion of the conductor layer corresponding to the electrode extraction portion; connecting the electrode lead-out portion of the conductor layer and the semiconductor chip with a wire; and sealing the wire, the insulating film, the semiconductor chip, and the island with a resin. A method for manufacturing a resin-sealed integrated circuit device.