JPH06120300A - Intermediate board for mounting circuit component and production thereof - Google Patents

Abstract

PURPOSE:To produce an intermediate board for mounting circuit component being interposed when a circuit component such as an IC is mounted on a circuit wiring board constituted such that distortion due to differential thermal expansion between the circuit component and circuit wiring board can be absorbed. CONSTITUTION:An insular electrode 11 having a corrosion resistant metal layer 6 is provided on one surface of a dielectric base member 1. A circuit component mounting terminal 9 having one end connected with the insular electrode 11 and the other end connected with a corrosion resistant metal layer 10 projecting through the dielectric base member 1 to the outside constitutes a connecting terminal 12 along with the insular electrode 11. An annular groove 4a is made in the dielectric base member 1 around the connecting terminal 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of flip-chip mounting a circuit component such as an IC on a circuit wiring board using solder bumps or the like, in order to improve the bonding reliability of the bump and the circuit component and the circuit. The present invention relates to an intermediate substrate for mounting circuit components mounted between the substrate and the substrate and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, the area of IC has been increased and the number of electrodes has been increased.
As the density becomes higher, a difference in thermal expansion coefficient between a circuit component such as an IC chip and a circuit board causes distortion in the bump portion, which causes wire breakage in a severe case and adversely affects connection reliability.
For such a problem, a method of increasing the height of the bump by means of disposing the circuit component mounting intermediate substrate of this type between the circuit component and the circuit substrate is effective.

Various conventional structures for such an intermediate substrate with terminals for connecting circuit components have been proposed. For example, an insulating material as disclosed in Japanese Patent Laid-Open No. 60-123093 has a diameter of 0.1 mm. A conductive pin of about 0.2 mm is embedded and formed so as to project from the insulating material, and a hole is provided at a predetermined position of the insulating film as in JP-A-1-72537, and the hole is formed in this hole. A certain amount of
There is one in which the solder paste is held by a printing means. Furthermore,
As shown in JP-A-62-18049, a through hole is formed in a ceramic green sheet and fired, and a copper paste having wettability to solder is inserted into the through hole. Then, a non-wettable tungsten paste or the like is inserted on the copper layer and baked, and then a wettable copper paste or the like is inserted on the tungsten layer and baked. In addition, there is a method of melting and joining a solder ball to the copper portion on the upper surface.

[0004]

In such an intermediate substrate for mounting circuit components, when the wiring density of the IC chip is further increased and the diameter of the solder bump is also reduced accordingly, a high-definition connection terminal is provided. It is difficult to manufacture the circuit component mounting intermediate board that the user has. Further, it is difficult to align the electrodes of the IC chip with the connection terminals of the circuit component mounting intermediate substrate.

On the other hand, in the conventional method, the distortion due to the difference in thermal expansion coefficient between the circuit component and the wiring board is alleviated by the means for increasing the connection terminal. Reliable implementation may be difficult.

[0006]

SUMMARY OF THE INVENTION According to the present invention, when a circuit component such as an IC chip is mounted on a circuit board, a connection terminal on a circuit component mounting intermediate substrate of this kind disposed between them is improved. (EN) An intermediate substrate for mounting circuit components, which can be formed to have a high density, and which suitably absorbs strain caused by a difference in thermal expansion coefficient to enable high-density and highly reliable flip-chip mounting, and a manufacturing method thereof. .

Therefore, in the circuit component mounting intermediate substrate of the present invention, the above-mentioned circuit is used for electrically connecting the electrode of the circuit component such as an IC and the electrode of the circuit wiring substrate arranged facing the electrode. In a circuit component mounting intermediate board, which is provided between a board and a circuit wiring board and has a connecting terminal that is formed so as to project through an insulating base material, it is a peripheral portion of the connecting terminal. And a groove formed on one surface of the insulating base material.

Here, a part of the groove is the insulating base.
The groove may be formed so as to penetrate through the connecting member, and such grooves may be provided in a plurality of lines in the peripheral portion of the connecting terminal.

As a method for manufacturing such an intermediate substrate for mounting circuit components, a metal mask having holes and grooves formed at required positions is formed on one surface of the insulating base material. A conductive layer having a corrosion resistant metal layer formed on the other surface of the insulating base material at a position corresponding to the hole and having a resist layer on the surface other than the surface having the corrosion resistant metal layer formed thereon. A step of forming a metal layer, a step of removing a part of the insulating base material located in the hole and the groove from the metal mask side, and a step of removing all of the insulating base material located in the hole. Removing to partially expose the conductive metal layer, etching to remove the metal mask, and one end of the hole in which the conductive metal layer is partially exposed to the conductive metal. Electrically connected to the layer and the other end of the insulating base material A step of forming a circuit component mounting terminal projecting through to the outside, and removing the resist layer on the surface of the conductive metal layer and excluding the portion where the corrosion resistant metal layer is formed. A process of etching away the conductive metal layer region can be adopted.

In the above step, the corrosion-resistant metal layer formed on the corresponding part of the conductive metal layer is formed on the entire surface of the conductive metal layer after the step of forming the circuit component mounting terminal. It is also possible to form the holes in the corresponding portions of the resist layer formed in step 1 and then form the corrosion resistant metal layer.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be further described below with reference to the illustrated embodiments. In FIGS. 1 and 2, an insulating base material 1 made of polyimide or the like is provided with a gold or the like at a required position on one surface thereof. An island-shaped electrode 11 made of a conductive metal such as a copper foil covered with a metal layer 6 having high corrosion resistance and good solder wettability is formed. A hole 3c is formed in a corresponding portion of the insulating base material 1 where the island-shaped electrode 11 is formed, and one end of the hole 3c is electrically connected to the island-shaped electrode 11 and the other is formed. A circuit component mounting terminal 9 having an end penetrating the insulating base material 1 and protruding to the outside is formed. The surface of the circuit component mounting terminal 9 is covered with a metal layer 10 such as gold having a high corrosion resistance and a good solder wettability. These metal layer 6, island-shaped electrode 11 and circuit component mounting terminal 9 and the metal layer 10,
Although not shown, a connection terminal 12 for electrically connecting the electrode of the circuit component and the electrode of the circuit wiring board is configured. Reference numeral 4a denotes a groove formed in a ring shape from one surface of the insulating base material 1 in the vicinity of the periphery of the connecting terminal 12, and this groove 4a is used when a circuit component such as an IC is mounted on a circuit wiring board. It works so as to preferably absorb the strain caused by the difference in thermal expansion coefficient between the circuit component and the wiring board.

As shown in FIG. 3, the structure of the groove for absorbing the strain due to the difference in the coefficient of thermal expansion is constituted by the through groove 4c which partially penetrates the insulating base material 1 discontinuously. Alternatively, as shown in FIG. 4, it is also possible to form a plurality of grooves so as to include a groove 4b formed near the outer periphery of the groove 4a and formed from the other surface of the insulating base material 1. is there.

(1) to (6) of FIG. 5 are shown in FIGS.
3A to 3D show manufacturing process diagrams of the circuit component mounting intermediate substrate shown in FIG.
First, as shown in FIG. 1A, a metal mask 2 such as a copper foil having a hole 3 and an annular groove 4 is formed at a desired position on one surface of an insulating base material 1 such as polyimide. , Insulation base
A conductive metal layer 5 such as a copper foil is formed on the other surface of the metal material 1. As the insulating base material 1, the metal mask 2 and the conductive metal layer 5, for example, one having an adhesive layer or a non-adhesive double-sided copper clad laminate is prepared, and one side of the copper foil is prepared. It is also possible to form the metal mask 2 having the holes 3 and the grooves 4 by performing an etching process on. Then, a resist layer 7 is formed on the surface side of the conductive metal layer 5 except the portions corresponding to the holes 3, and a corrosion-resistant metal layer 6 such as gold is formed on the portions where the resist layer 7 is not formed. Is formed by means of plating or the like.

Next, as shown in FIG. 2B, the excimer laser light A1 is irradiated from the side of the metal mask 2 to partially expose the insulating base material 1 located in the holes 3 and the grooves 4. The groove 3a and the groove 4a having a required depth are formed by removing the ablation so as not to penetrate the hole. Therefore, as shown in FIG. 3C, the metal mask 2 is formed so as to cover other regions except the hole 3a.
When the excimer laser light A2 is irradiated with the light-shielding metal mask 8 placed on the insulating mask, the insulating base remaining in the hole 3a is exposed.
Since the entire portion of the soot material 1 can be removed, the hole 3c for partially exposing the conductive metal layer 5 can be formed in this portion.

Further, as shown in FIG. 4 (4), the metal mask 2 is removed by etching when the light-shielding metal mask 8 is removed, and then the corrosion-resistant metal layer 6 is first formed as shown in FIG. 5 (5). When the hole 3c is plated with the plating resist layer 13 provided on the opposite side, one end is electrically connected to the conductive metal layer 5 and the other end penetrates the insulating base material 1. Since it is possible to form the circuit component mounting terminal 9 having a shape protruding outward, a metal layer 10 having a high corrosion resistance and a good solder wettability can be formed on the surface of the terminal 9 by means such as gold plating. it can. Therefore, when both resist layers 7 and 13 are removed as shown in FIG.
Of the conductive metal layer 5 excluding the portion where the corrosion-resistant metal layer 6 is provided by etching on the side of the substrate to form the island electrode 11 and form the connection terminal 1.
2 can be configured, and by this, an intermediate substrate for mounting circuit components as shown in FIGS. 1 and 2 can be manufactured.

In the above, the connecting terminal 12 as shown in FIG.
To provide the through groove 4c in the vicinity of the periphery of the hole 3c, the excimer laser light A2 is irradiated from the side of the metal mask 2 without arranging the light shielding metal mask 8 in the step (3) of FIG. A groove penetrating the insulating base material 1 discontinuously in the vicinity of the periphery may be formed, and in the step of FIG. 5 (5), the through groove may be changed so as not to be plated. Further, as shown in FIG. 4, a double groove 4 is formed near the periphery of the connecting terminal 12.
To provide a and 4b, an annular groove having a size larger than the diameter of the annular groove 4 is formed by etching on the side of the conductive metal layer 5 shown in FIG. 5A, and as shown in FIG. Similar to the method of forming the holes 3a and the grooves 4a, excimer laser light may be irradiated from the side of the conductive metal layer 5 to form similar grooves on the other surface of the insulating base material 1. The groove 4a, 4b, the through groove 4c, etc. are formed not only in a concentric manner around the connecting terminal 12 but also in a part of the spiral shape around the connecting terminal 12. You can
The corrosion-resistant metal layer 6 may be formed at a predetermined position of the conductive metal layer 5 after the circuit component mounting terminal 9 shown in FIG. 5 (5) is formed. Further, instead of the method of forming the groove as described above by the ablation process using excimer laser light, a wet removal process method using, for example, a hydrazine-based etching solution can be adopted.

[0017]

According to the circuit component mounting intermediate substrate and the method of manufacturing the same according to the present invention, it is possible to form a groove in the insulating base material in the vicinity of the periphery of the connecting terminal.
It is possible to preferably absorb the strain caused by the difference in thermal expansion coefficient between the circuit component such as C and the circuit wiring board.

Further, according to the manufacturing method of the present invention, in the case where the circuit component such as an IC having a large area and a high-density electrode arrangement is mounted on the circuit wiring board, the connection reliability is extremely high. It is possible to stably provide a highly accurate intermediate substrate for mounting circuit components.

[Brief description of drawings]

FIG. 1 is a conceptual partial cross-sectional configuration diagram of a circuit component mounting intermediate substrate configured according to an embodiment of the present invention.

FIG. 2 is an enlarged perspective cross-sectional configuration diagram of a conceptual main part of the circuit component mounting intermediate substrate of FIG.

FIG. 3 is an enlarged perspective cross-sectional configuration diagram showing a similar main part of an intermediate board for mounting circuit components, which is configured to have a through groove in the vicinity of the periphery of a connection terminal according to another embodiment of the present invention.

FIG. 4 is a similar enlarged perspective cross-sectional configuration diagram of a main part of a circuit component mounting intermediate substrate configured to have a plurality of grooves in the vicinity of the periphery of a connection terminal according to still another embodiment of the present invention.

5 (1) to 5 (6) are manufacturing process diagrams of an intermediate substrate for mounting circuit components according to an embodiment of the present invention.

[Explanation of symbols]

 1 Insulating Base Material 2 Metal Mask 3 Hole 3a Hole 3c Hole 4 Groove 4a Groove 4b Groove 4c Through Groove 5 Conductive Metal Layer 6 Metal Layer 7 Resist Layer 8 Light-shielding Metal Mask 9 Circuit Component Mounting Terminal 10 Metal Layer 11 Island electrode 12 Connection terminal 13 Plating resist layer

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[Procedure amendment]

[Submission date] April 13, 1993

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Fig. 2]

[Figure 3]

[Figure 4]

[Figure 5]

Claims (5)

[Claims] 1. A circuit wiring board is provided between the circuit board and the circuit wiring board to electrically connect an electrode of a circuit component such as an IC and an electrode of a circuit wiring board arranged to face the electrode. Also, in an intermediate board for mounting a circuit component, which is provided with a connecting terminal projectingly formed through the insulating base material, in the peripheral portion of the connecting terminal and on one surface of the insulating base material. An intermediate substrate for mounting a circuit component, comprising the formed groove. 2. The circuit component mounting intermediate substrate according to claim 1, wherein a part of the groove is formed so as to penetrate the insulating base material. 3. The circuit component mounting intermediate substrate according to claim 1 or 2, wherein another groove is provided near the groove. 4. A metal mask having holes and grooves formed at required positions is formed on one surface of the insulating base material, and
A conductive metal having a corrosion resistant metal layer formed on the other surface of the insulating base material at a corresponding position corresponding to the hole and having a resist layer on the surface other than the surface having the corrosion resistant metal layer formed thereon. A step of forming a layer, a step of removing a part of the insulating base material located in the hole and the groove from the metal mask side,
A step of partially removing the portion of the insulating base material located in the hole to expose the conductive metal layer; a step of etching and removing the metal mask; and a step of partially removing the conductive metal layer. A step of forming a circuit component mounting terminal having one end electrically connected to the conductive metal layer and the other end penetrating the insulating base material and protruding to the outside in the hole exposed at An intermediate substrate for mounting circuit components, comprising a step of removing the resist layer on the surface of the conductive metal layer and etching away the other corrosion-resistant metal layer regions except the portion where the corrosion-resistant metal layer is formed. Manufacturing method. 5. The resist layer formed on the entire surface of the conductive metal layer after the step of forming the circuit component mounting terminal, wherein the corrosion-resistant metal layer formed on the corresponding portion of the conductive metal layer. 5. The method for manufacturing an intermediate substrate for mounting circuit components according to claim 4, wherein the corrosion-resistant metal layer is formed after forming holes in the corresponding portions.