JPH03151656A - Substrate for mounting semiconductor element - Google Patents

Abstract

PURPOSE:To prevent short-circuiting failure between a semiconductor element mounting pad and a conductor layer by forming while shifting the position of an edge surface of an insulation layer opposing to a semiconductor element mounting pad and by providing a stage difference between insulation layers. CONSTITUTION:A semiconductor element mounting pad 6a is provided on a substrate 1, multilayer conductor layers 2a-2c and insulation layers 3a-3c are alternately laminated with this semiconductor element mounting pad 6a as the center, formation is made by shifting the position of an end face of the insulation layers 3a-3c opposing to this semiconductor element mounting pad 6a, and a stage difference is provided among the insulation layers 3a-3c. Thus, when a resist film is applied, space surrounded by the resist film, the end face of the insulation layers 3a-3c, and the surface of the insulation layer 3a-3c on the substrate 1 or directly below becomes nearly equal in any insulation layer 3a-3c so that the resist fully reaches this space, thus preventing a void from occurring easily. Thus, it becomes possible to prevent short-circuiting failure from occurring between the semiconductor element mounting pad 6a and the conductor layers 2a-2c.

Description

[Detailed Description of the Invention] [Summary] Regarding the improvement of a semiconductor element mounting board with a multilayer structure consisting of a conductor layer and an insulating layer, a short circuit failure between the conductor layer and the semiconductor element mounting pad was caused by changing the shape of the insulating layer. With the aim of providing a substrate for mounting semiconductor elements that can prevent the occurrence of the A substrate for mounting a semiconductor element, which is formed by shifting the position of the end face of the insulating layer facing the semiconductor element mounting pad, and providing a step between the insulating layers.

[Industrial application field]

The present invention relates to an improvement of a semiconductor element mounting board having a multilayer structure consisting of a conductor layer and an insulating layer.

In conventional substrates for mounting semiconductor devices, the insulating layers of the multilayer structure have a shape in which the end surfaces coincide with each other without any steps between them, and short circuit failures due to this structure occur during the process of forming the conductor layer. are doing.

Under the above circumstances, there is a need for a substrate for mounting semiconductor elements that can prevent short-circuit failures between conductor layers during the manufacturing process.

[Conventional technology]

A conventional semiconductor element mounting board on which four semiconductor elements are mounted will be explained in detail with reference to FIGS. 4 and 5.

FIG. 4 is a plan view of a conventional semiconductor element mounting board.
FIG. 5 is a view showing the right part from the center of the BB cross section in FIG. 4.

As shown in FIG. 5, a semiconductor element mounting pad 16a is formed at a predetermined position on the substrate 11, and a semiconductor element 6 is fixed to the surface of the pad 16a. Insulating layer 13a.

13b and 13c are formed by stacking them alternately.

Connection vias 14a, 14 passing through the insulating layer are provided between the conductor layers.
b, 14c are provided to connect the conductor layers, and component pads 15 are provided on the surface of the insulating layer 13c to be connected to the connection vias 14c.

Since the end faces of the insulating layers 13a, 13b, and 13c facing the semiconductor element mounting pad 16a are formed at the same position as shown in the figure, in the plan view of FIG. It forms a rectangle surrounding the .

To manufacture such a substrate for mounting a semiconductor element, first, a semiconductor element mounting pad i6a and a conductor layer 12a are formed on the surface of the substrate 11 using photolithography technology.

Then, a film Jl! which becomes the material of the insulating layer 13a is applied to the entire surface. , 13
A thin film of polyimide or the like with a thickness of ~25 μm is applied and formed, and a hole for forming the connection via 14a and the required insulation part are formed using photolithography technology, and plating is performed to form a metal film on the surface of the conductor layer 12a in the hole. Connect via 14 by growing
form a.

After that, a resist film is formed on the entire surface, and the resist film is removed in the part where the conductor layer 12b is to be formed using photolithography technology, and plating is performed to grow a metal film on the surface of the insulating layer 13a in this part to form the conductor layer. 12b is formed, and the resist film is removed.

After this, these steps are repeated to sequentially connect the connecting vias 14b.
, an insulating layer 13b and a conductor layer 12c are formed, and further a connecting via 14c, an insulating layer 13C1 and a component pad 15 are formed, thereby completing the manufacture of a substrate for mounting a semiconductor element.

[Problem to be solved by the invention]

In the conventional semiconductor element mounting substrate described above,
As conductive layers and insulating layers are successively laminated,
As the level difference between the surface of the substrate and the surface of the conductor layer or insulating layer increases, the difference in level between the surface of the substrate and the surface of the conductor layer or insulating layer increases, as shown in Fig. 6 (
The resist does not sufficiently wrap around the portion surrounded by the end face of the conductor layer and the surface of the substrate as shown by al, and a gap 18a is created here.

When the resist is heated in such a state to harden it, the air in the voids expands thermally, as shown in FIG.
When forming a conductor layer, connection via, or component pad on the surface of an insulating layer by plating, plating is performed through this crack, and as shown in the figure, there is no problem of short circuit between the semiconductor element mounting pad 16a and the conductor layer 12a. There was a problem with kudzu.

An object of the present invention is to provide a substrate for mounting a semiconductor element, which can prevent short-circuit failure between a conductor layer and a pad for mounting a semiconductor element by changing the shape of an insulating layer, which can be done simply and easily. This is what I did.

[Means to solve the problem]

The semiconductor element mounting board of the present invention is a semiconductor element mounting board comprising a semiconductor element mounting pad on the substrate, and a multilayer conductor layer and an insulating layer arranged around the semiconductor element mounting pad. The end faces of the insulating layers facing the semiconductor element mounting pads are formed to be shifted in position, and a step is provided between the insulating layers.

[Effect]

That is, in the present invention, a semiconductor element mounting pad is provided on a substrate, and a multilayer conductor layer and an insulating layer are alternately stacked and arranged around this semiconductor element mounting pad, and facing the semiconductor element mounting pad. Since the end faces of the insulating layers are formed at different positions to create a step between the insulating layers,
When a resist film is applied, the space surrounded by the resist film, the end face of the insulating layer, and the surface of the substrate or the surface of the insulating layer immediately below is almost the same and small regardless of the insulating layer. Therefore, when Resis 1- is applied, the resist wraps around this space sufficiently, making it difficult to form voids, and even during heating to harden the resist film, the thermal expansion of the air in these voids will cause cracks in the resist film. Therefore, it is possible to prevent short-circuit failure between the semiconductor element mounting pad and the conductor layer even during the plating process.

〔Example〕

An embodiment of the present invention in which four semiconductor elements are mounted will be described in detail below with reference to FIGS. 1 to 3.

FIG. 1 is a plan view of a substrate for mounting a semiconductor element according to the present invention, and FIG. 2 is a view showing a cloth portion from the center of the AA cross section in FIG. 1.

As shown in FIG. 2, a semiconductor element mounting pad 6a is formed at a predetermined position on the substrate 1, and a semiconductor element 6 is fixed to the surface of the pad 6a. 2C and insulating layers 3a, 3b, and 3c are alternately stacked.

Connection vias 4a, 4b4c penetrating the insulating layer are provided between the conductor layers.
are provided to connect the conductor layers, and component pads 5 are provided on the surface of the insulating layer 3c to connect to the connection vias 4c.

The end faces of the insulating layers 3a, 3b, and 3c facing the semiconductor element mounting pad 6a are formed so that the distance from the semiconductor element mounting pad 6a increases as one goes to the upper layer, as shown in the figure. In the plan view of the figure, this end face forms various squares surrounding the semiconductor element mounting pad 6a.

To manufacture such a substrate for mounting semiconductor elements, first, as shown in FIG. A thin film 2 is formed by a vapor deposition method, and a resist film 7 is formed on the entire surface of this 1llu2.

Next, a resist film 7 is formed using photolithography technology.
After patterning and removing unnecessary metal thin films by etching, the resist film 7 is removed to form semiconductor element mounting pads 6a and conductor layers 2a as shown in FIG.

Next, as shown in FIG. 3 (C1), a thin film of polyimide or the like with a thickness of 13 to 25 μm, which will be the material of the insulating layer 3a, is coated on the entire surface, and holes and necessary holes for forming the connection vias 4a are formed using photolithography technology. An insulating portion is formed and plating is performed to grow a metal film on the surface of the conductor layer 2a at the bottom of the hole to form a connection via 4a.

After that, as shown in FIG.
A conductor layer 2 is formed using photolithography technology.
The resist film 8 is removed from the portion where the conductor layer 2b is to be formed, and a metal film is grown on the surface of the insulating layer 3a in this portion by plating.
b is formed, and the resist film 8 is removed.

After this, the process from FIG. 3(c+) to FIG. 3(dl) is repeated to sequentially form the connecting via 4b, insulating layer 3b, and conductor layer 2c, and further forming the connecting via 4c, insulating layer 3c, and component pad 5. Finally, the manufacturing of the semiconductor element mounting board is completed.

In the present invention, as shown in FIG.
The end face of the insulating layer 3c is formed farther from the semiconductor element mounting pad 6a than the end face of the insulating layer 3b, and the end face of the insulating layer 3c is formed farther from the semiconductor element mounting pad 6a than the end face of the insulating layer 3b.
The insulating layers are formed at a large distance from a to provide a step between the insulating layers.

If a step is provided between the insulating layers in this way, when a resist is applied, the space surrounded by the resist film, the end face of the insulating layer, and the surface of the substrate or the surface of the insulating layer immediately below will be affected by which insulating layer. When the resist is applied, it will be almost the same and smaller, so when the resist is applied, the resist will fully wrap around this space, making it difficult to create voids, and even when heating to harden the resist, the thermal expansion of the air in these voids will 0 prevents cracks from forming in the resist film, making it possible to prevent short-circuit failures between the semiconductor element mounting pad and the conductor layer during plating processing.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the insulating layer has an extremely simple shape in which the end face of the insulating layer facing the semiconductor element mounting pad is shifted in position and a step is provided between the insulating layers. By changing the above, it is possible to prevent a short-circuit failure between the semiconductor element mounting pad and the conductor layer, and it is possible to provide a substrate for mounting a semiconductor element, which can be expected to significantly improve reliability.

FIG. 4 is a plan view of a conventional substrate for mounting semiconductor elements, FIG. be.

In the figure, ■ is the substrate, 2 is the thin film, 2a is the conductor layer, 2b
is a conductor layer, 2c is a conductor layer, 3a is an insulating layer, 3b is an insulating layer, 3c is an insulating layer, 4a is a connection via, 4b is a connection via, 4c is a connection via, 5 is a component pad, 6 is a semiconductor element, 6a indicates a semiconductor element mounting pad, 7 indicates a resist film, and 8 indicates a resist film.

[Brief explanation of the drawing]

FIG. 1 is a plan view of one embodiment of the present invention, and FIG. 2 is a plan view of an embodiment of the present invention.
3 is a side sectional view showing the manufacturing process of the semiconductor element mounting substrate of the present invention in the order of steps,

Claims (1)

[Claims] A semiconductor element mounting comprising a semiconductor element mounting pad (6a) on a substrate (1), and a multilayer conductor layer and an insulating layer arranged around the semiconductor element mounting pad (6a). A substrate for mounting a semiconductor element, characterized in that the position of the end face of the insulating layer facing the semiconductor element mounting pad (6a) is shifted, and a step is provided between the insulating layers. .