JPH06314750A - Semiconductor element mounting board and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide a method of easily manufacturing a semiconductor element mounting board at a low cost, wherein a board and a lead are pasted together into one piece and electrically connected together at the same time. CONSTITUTION:A board 1 on which a wiring pattern is formed for mounting a semiconductor element and a lead 8 are bonded together into one piece through the intermediary of a thermal adhesive layer 3 by thermocompression, and the electrode terminal 2 of the board 1 and the lead 8 are electrically connected together through the intermediary of a conductive material 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor element mounting substrate on which a semiconductor element is mounted and a method of manufacturing the same, and more specifically, a semiconductor element mounting substrate and a method of manufacturing the same in which a substrate and leads are bonded together. It is about.

[0002]

2. Description of the Related Art Conventionally, the problems to be solved by the invention
A printed wiring board on which a semiconductor element is mounted and leads (such as a lead frame) are connected by soldering.

However, according to the above-mentioned structure, the electrical connection between the substrate and the lead and the portion for physically fixing the two are only at one soldered portion, so that the lead pitch is narrowed. Adhesion between the substrate and the lead is very difficult and unstable, and there is a drawback that a connection failure between the substrate and the lead is likely to occur later.

The present invention has been made in view of the above-mentioned conventional drawbacks, and an object thereof is a substrate for mounting a semiconductor element having a structure in which a substrate and a lead are bonded and integrated with each other, and at the same time, an electrical connection is possible. Another object of the present invention is to provide a method for inexpensively and easily manufacturing a flexible substrate.

[0005]

In order to achieve the above-mentioned object, the invention of claim 1 is to integrate a substrate and a lead, on which a wiring pattern for mounting a semiconductor element is formed, by thermocompression bonding. The electrode terminal of the substrate and the lead are electrically connected via a conductive material.

According to a second aspect of the present invention, a thermal adhesive layer is provided on the surface of the substrate on which a wiring pattern for mounting a semiconductor element is formed, and the thermal adhesive layer in this portion is exposed so that the electrode terminals of the substrate are exposed. Is removed to form a concave portion, and then the concave portion of the thermal adhesive layer is filled with a conductive material, and then the substrate and the lead fixed to the substrate are thermocompression bonded.

According to a third aspect of the present invention, a thermal adhesive layer is provided on the surface of the substrate on which a wiring pattern for mounting a semiconductor element is provided, and a protective film is attached thereon, and the electrode terminals of the substrate are exposed. As described above, the heat-adhesive layer and the protective film in this portion are removed to form a concave portion, and then the concave portion is filled with a conductive substance, and then the protective film is peeled off, and the substrate and leads fixed to the substrate are formed. It is characterized by aligning and thermocompression bonding.

Further, the invention of claim 4 is characterized in that, in the invention of claim 2 or 3, a concave portion or an uneven portion is formed at a tip portion of a lead which is thermocompression bonded to the substrate.

[0009]

In the invention according to claim 1, the electrode terminal of the substrate and the lead are electrically connected through the conductive material, and the substrate and the lead are fixed and integrated by thermocompression bonding. Therefore, the adhesive force between the substrate and the lead is very strong and strong, and a connection failure between the substrate and the lead does not occur later.

Further, in the invention according to claim 2, a thermal adhesive layer is provided on the surface of the substrate, and the thermal adhesive layer in this portion is removed to form a recess so that the electrode terminals of the substrate are exposed, After filling the concave portion with a conductive material, the substrate and the leads are thermocompression bonded, whereby the substrate and a large number of leads connected thereto are collectively connected, and the substrate and a large number of leads are integrated by thermocompression bonding and A semiconductor element mounting substrate having an electrically connected structure can be manufactured inexpensively and easily.

Further, in the invention according to claim 3, a heat-adhesive layer is provided on the surface of the substrate, and a protective film is further adhered thereon, and the heat-adhesive layer and the protective film of the electrode terminal portion of the substrate are attached. Since the protective film is peeled off after filling with the conductive material in the formed recess, the conductive material attached to the portion other than the recess can be removed cleanly when filling the conductive material in the recess, Moreover, the conductive material is formed slightly higher than the surface of the thermal bonding layer,
Furthermore, the height of the rise can be freely adjusted by changing the thickness of the protective film, so that the connection with the lead becomes more reliable.

Further, in the invention according to claim 4,
By forming a recess or an uneven portion at the tip of the lead, it is possible to prevent problems such as when the lead is thermocompression-bonded with the substrate, the conductive material protrudes from the lead and adheres to the adjacent lead or the like to cause a short circuit. Therefore, it is convenient for narrowing the lead pitch.

[0013]

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

FIGS. 1 to 3 show an embodiment of the present invention. FIG. 1 is a sectional view of a main part of a semiconductor element mounting substrate, FIG.
Is a plan view of relevant parts, and FIG. 3 is a sectional view of relevant parts showing the manufacturing method in the order of steps.

As shown in FIG. 1, according to the structure of the present embodiment, the semiconductor element mounting substrate 10 has the substrate 1 and the leads 8 fixed by thermocompression bonding via the thermal adhesive layer 3, and The electrode terminals 2 of the substrate 1 and the leads 8 are electrically connected to each other via a conductive material 7 such as solder.

The board 1 is a printed wiring board on which a semiconductor element is mounted, on which wiring patterns of various circuits are formed. The substrate 1 may have a single-layer structure or a multi-layer structure obtained by laminating insulating layers having an inner layer pattern in layers, but in the present invention, either structure may be used. Such a printed wiring board is conventionally known.
For example, it can be manufactured using a pattern plating method or the like.

The leads 8 are in the form of lead frames generally used for semiconductor device packages. That is, such a lead frame is a frame that supports a large number of leads 8 that are electrically connected to the electrode terminals 2 of the substrate 1 and that are arranged substantially radially around the substrate 1, and that integrally support the plurality of leads 8. And. The lead frame having the leads 8 is manufactured by processing a single metal plate into the above-described shape by mechanical punching or etching.

Next, a method of manufacturing the semiconductor element mounting substrate 10 will be described.

As shown in FIG. 3A, first, the thermal adhesive layer 3 is provided on the surface (the surface to which the leads 8 are to be connected) of the substrate 1 manufactured as described above. A thermosetting resin, for example, a mixed resin of epoxy and nylon (such as BX-60 manufactured by Toagosei Co., Ltd. as a commercially available product) is used for the thermal adhesive layer 3. As the method for providing the thermal adhesive layer 3, the substrate 1 may be directly applied, or a sheet-shaped product may be attached to the substrate 1. The thermal adhesive layer 3
It suffices that it is provided at least in a portion where the leads 8 are fixed, but it can also be provided on the entire surface of the substrate 1. In this way, when it is provided on the entire surface of the substrate 1, there is an effect that other circuits can be protected at the same time.

A protective film 4 which can be peeled off later is further provided on the thermal adhesive layer 3. The protective film 4 is made of, for example, polyethylene terephthalate, and it is easy to use a sheet bonded to the thermal adhesive layer 3 in a sheet form.
That is, a laminate in which the protective films 4 are bonded to both surfaces of the thermal adhesive layer 3 in advance is prepared, and one protective film 4 of the laminate is peeled off at the time of use, and the thermal adhesive layer 3 is bonded to the substrate 1 side. .

Next, as shown in FIG. 3B, the thermal adhesive layer 3 and the protective film 4 in this portion are formed, for example, so that the electrode terminals 2 of the substrate 1 for electrically connecting the leads 8 are exposed. A concave portion 6 is formed by removing it using a means 5 such as an excimer laser or plasma etching. As a method of forming such a recess 6, a portion corresponding to the electrode terminal 2 of the substrate 1 is previously attached to the laminate in which the protective films 4 are attached to both surfaces of the thermal adhesive layer 3 before being attached to the substrate 1. It can also be formed by punching with a die or the like.

Next, as shown in FIG. 3C, the recess 6 thus formed is filled with, for example, a solder paste as a conductive material 7. The conductive material 7 may be filled using a dispenser or a hole filling printing method. Further, instead of the solder paste, other heat-fusible conductive material may be filled by the above method, and further electrolytic plating method, electroless plating method, super solder method or the like may be used. In short, the type of conductive material 7 used and the filling method are not particularly limited.

For example, when the conductive material 7 is filled by the hole filling printing method, the conductive material 7, for example, a solder paste is applied on the protective film 4 and scraped off with a squeegee or the like so that only the concave portion 6 is conductive. The substance 7 is filled. At this time, a very small amount of the conductive material 7 may adhere to and remain on the portions other than the recess 6, but as shown in FIG.
There is no inconvenience because the clean surface is exposed by peeling off the uppermost protective film 4. Further, by doing so, the conductive substance 7 in the recess 6 is formed so as to be slightly raised above the surface of the thermal bonding layer 3.

Next, as shown in FIG. 3E, the substrate 1
And lead 8 are connected. In order to connect the substrate 1 and the lead 8, first, the substrate 1 and the lead 8 are aligned, and for example, the above-mentioned epoxy-nylon mixed resin BX-6 is applied to the thermal adhesive layer 3.
When 0 (manufactured by Toagosei Co., Ltd.) is used as the conductive material 7, the solder paste can be temporarily fixed by pressure bonding while heating to around 140 ° C. Then set the temperature to 180
The temperature of the lead 8
The adhesive paste is secured, and the solder paste is melted by raising the temperature to around 200 ° C.
Filled inside without any gaps.

In this way, the semiconductor element mounting substrate 10 in which the substrate 1 and the leads 8 are integrated by bonding by thermocompression and electrically connected to each other is completed.

In this embodiment, the protective film 4 is attached onto the thermal adhesive layer 3, the concave portion 6 is filled with the conductive substance 7, and then the protective film 4 is peeled off. Depending on the filling method, it is not always necessary to use such a protective film 4.

Further, in order to prevent the conductive material 7 in the recess 6 from protruding from the lead 8 and adhering to an adjacent lead or the like to cause a short circuit when the lead 8 is thermocompression-bonded to the substrate 1 as described above, FIG. As shown in (a) to (c), it is also a preferable embodiment to form holes 8a, grooves 8b, 8c, etc. at the tip portion of the lead 8.

Further, as shown in FIG. 5, the lead 8 fixed to the substrate 1 may be coated with a resin 9 such as epoxy to protect the connection portion between the substrate 1 and the lead 8. Furthermore, the electrical connection points between the substrate 1 and the leads 8 do not necessarily have to be arranged in a line as shown in FIG. 2 of the present embodiment, and considering the recent tendency of increase in electrode density, for example, as shown in FIG. It is also desirable to stagger them in a staggered manner.

[0029]

As described in detail above, according to the present invention, since the adhesive force between the substrate and the lead is extremely strong and integrated, the semiconductor having a structure in which the electrical connection between the two is highly reliable. A device mounting board can be provided.

Further, according to the present invention, a thermal adhesive layer is provided on the surface of the substrate, and the thermal adhesive layer in this portion is removed so that the electrode terminals of the substrate are exposed to form a concave portion. After filling the substrate, the substrate and the leads are bonded by thermocompression bonding, so that the semiconductor element mounting substrate having the above structure can be manufactured inexpensively and easily.

Further, by sticking a protective film on the heat-bonding layer, it is possible to cleanly remove the conductive substance adhering to the portion other than the concave portion when the concave portion is filled with the conductive substance, and further the conductive property of the concave portion is improved. Since the substance is formed to be slightly raised, the connection with the lead becomes more reliable.

Furthermore, by forming a concave portion or a concave-convex portion at the tip end portion of the lead connected to the substrate, the conductive substance sticks out from the lead and adheres to the adjacent lead when the lead and the substrate are thermocompression bonded. It is possible to prevent problems such as short circuit.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of a semiconductor element mounting substrate showing an embodiment of the present invention.

FIG. 2 is a plan view of an essential part thereof.

FIG. 3 is a cross-sectional view of a main part showing the manufacturing method in the order of steps.

FIG. 4 is a diagram showing another embodiment of the present invention.

FIG. 5 is a diagram showing another embodiment of the present invention.

FIG. 6 is a diagram showing another embodiment of the present invention.

[Explanation of symbols]

 1 Substrate 2 Electrode Terminal 3 Thermal Adhesive Layer 4 Protective Film 5 Etching Means 6 Recess 7 Recess 7 Conductive Material 8 Lead 9 Overcoat Resin 10 Semiconductor Element Mounting Substrate

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[Procedure amendment]

[Submission date] December 22, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction content]

The board 1 is a printed wiring board on which a semiconductor element is mounted, and wiring patterns of various circuits are formed. The substrate 1 may have a single-layer structure or a multi-layer structure obtained by laminating insulating layers having an inner layer pattern in layers, but in the present invention, either structure may be used. The substrate 1 is a power supply layer or a ground layer.
(Grounding layer), or both to provide electricity
It is also possible to use a substrate having improved optical characteristics. Such a printed wiring board can be manufactured using a conventionally known method such as a pattern plating method.

Claims (4)

[Claims] 1. A substrate on which a wiring pattern for mounting a semiconductor element is formed and a lead are fixed by thermocompression bonding to be integrated with each other, and an electrode terminal of the substrate and the lead are electrically connected via a conductive substance. A semiconductor element mounting substrate characterized by being connected. 2. A thermal adhesive layer is provided on the surface of a substrate on which a wiring pattern for mounting a semiconductor element is formed, and the thermal adhesive layer is removed to form a recess so that the electrode terminals of the substrate are exposed. Then, after filling the concave portion of the thermal adhesive layer with a conductive material, the substrate and the leads to be fixed to the substrate are thermocompression bonded, and the method for manufacturing a semiconductor element mounting substrate. 3. A thermal adhesive layer is provided on the surface of a substrate on which a wiring pattern for mounting a semiconductor element is provided, and a protective film is attached on the thermal adhesive layer so that the electrode terminals of the substrate are exposed to heat. After removing the adhesive layer and the protective film to form a concave portion, and then filling the concave portion with a conductive material, the protective film is peeled off, and the substrate and the leads to be fixed to the substrate are aligned and thermocompression bonded. A method of manufacturing a substrate for mounting a semiconductor element, comprising: 4. A concave portion or a concave-convex portion is formed at a tip portion of a lead which is thermocompression-bonded to the substrate.
Alternatively, the method of manufacturing a semiconductor element mounting substrate according to the item 3 above.