JPH02192197A - Multilayer interconnection board - Google Patents

Abstract

PURPOSE:To reduce a multilayer interconnection board in cost by a method wherein a bonding pad is composed of two or more pad sections connected with each other through contact via-holes and a bonding pad layer consisting of two adjacent pad sections out of the pad sections and an insulating layer interposed between them. CONSTITUTION:A bonding pad 11 connected to a lead 7 is composed of three pad sections 13 connected with each other though contact via-holes 12 and a bonding pad layer provided with two adjacent pad sections 13 out of the pad sections 13 and an insulating film 14 of polyimide resin interposed between the adjacent pad sections 13, which is provided onto a wiring layer 1. And, an electronic component 6 is mounted on the wiring layer 1 of a multilayer interconnection board in such a manner that the corresponding lead 7 is connected to a second pad section 13b. On the other hand, when the electronic component is dismounted from the wiring layer 1, the lead 7 is disconnected from the second pad 13b. By this setup, when the electronic component 6 is re-mounted, an additional multilayer interconnection board can be dispensed with, so that a multilayer interconnection board of this design can be reduced in cost.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a multilayer wiring board used in electronic devices such as computers.

[Conventional technology]

In recent years, insulating materials used in multilayer wiring boards are required to have heat resistance and high reliability due to the diversification of electronic component mounting and connection methods, and for this reason polyimide resins have been widely adopted.

Conventionally, this type of multilayer wiring board has been constructed as shown in FIG. This will be explained based on the figure. In the figure, what is indicated by reference numeral 1 is a wiring layer 5 provided on a substrate 2 and consisting of a polyimide resin insulating film 3 and an inner layer wiring 4.
is provided on this wiring layer 1, for example, gold (Au), copper (
A large number of bonding pads 6 consisting of Cu) etc. are connected to this bonding pad 5, and a large number of bonding pads 7 (
For example, it is an electronic component such as an LSI having a T10 terminal).

Furthermore, in this type of multilayer wiring board, one equipped with a bonding pad made of a composite film of copper, nickel (Ni), gold, etc., is also used.

Electronic components 6 are mounted on wiring layer 1 of the multilayer wiring board configured in this way by connecting leads 7 corresponding to each bonding pad 5.

On the other hand, the electronic component 6 can be removed from the wiring layer I by separating the leads 7 from the bonding pads 5.

[Problem to be solved by the invention]

By the way, in this type of multilayer wiring board, when a failure occurs in the electronic component 6 as a mounted component, the failure occurs in the wiring layer 1.
However, since the bonding pad 5 corresponding to each lead 7 is single-valent, the bonding pad 5 may peel off from the polyimide resin insulating film 3 due to the tensile force applied when removing the component, or when the component is remounted. The electronic component 6 could not be reattached on the wiring layer 1 because the adhesion strength decreased due to the applied thermal stress and the like. As a result, when remounting the electronic component 6, a new multilayer wiring board is required, resulting in an increase in cost.

The present invention has been made in view of the above circumstances, and provides a multilayer wiring board that can mount as many electronic components on wiring layers as there are band parts, thereby reducing costs. It is something.

[Means to solve the problem]

The multilayer wiring board according to the present invention includes bonding pads for connecting leads of electronic components, and a plurality of pad portions each connected to each other by a via hole for contact, and two adjacent pad portions among these pad portions. The bonding pad layer is composed of a bonding pad layer and an insulating film interposed therebetween.

[For production]

In the present invention, even if one pad section is peeled off from another pad when removing an electronic component on a wiring layer, the lead of the electronic component can be connected to the other pad section.

〔Example〕

EMBODIMENT OF THE INVENTION Hereinafter, the structure etc. of this invention will be explained in detail by the Example shown in the figure.

FIG. 1 is a cross-sectional view showing a multilayer wiring board according to the present invention. In the figure and subsequent figures, the same members as in FIG. 3 are denoted by the same reference numerals, and detailed explanations are omitted.

In the same figure, the reference numeral 11 indicates a bonding pad connected to the lead 7, each of which has three pad portions 13 connected to each other through via holes 12 for contact, and adjacent pad portions 13 of these pad portions 13. An insulating film 14 made of polyimide resin interposed between the two pad parts 13
The bonding pad layer is provided on the wiring layer 1.

The pad portion 13 of the bonding pad 11 includes a first pad portion 13a connected to the inner layer wiring 4, a second pad portion 13b connected to the lead 7, and a second pad portion 13b and the first pad portion 13b. 13a, and a third pad portion 13c interposed between the pad portions 13a.

Further, the polyimide resin insulating film 14 has the via holes 12 in each of the first band portion 13a and the third band portion 13a.
It is composed of a first insulating film 14a and a second insulating film 14b, each covering the pad portion 13c.

Mounting of the electronic component 6 on the wiring Nl of the multilayer wiring board configured in this way is carried out by connecting the corresponding leads 7 to the second pad portions 13b.

On the other hand, in order to remove the electronic component 6 from above the wiring layer 1, the second
This is done by separating the lead 7 from the pad portion 13b. At this time, as shown in FIG.
is the first pad portion 13 together with a part of the second insulating film 14b.
a. Even if the third pad portion 13c is peeled off due to tensile force or the like, the lead 7 of the electronic component 6 can be connected to the third pad 13c.

Therefore, in the present invention, since the electronic components 6 can be remounted on the wiring layer 1 by the number of pad portions 13, a new multilayer wiring board that was conventionally required when remounting the electronic components 6 is no longer necessary. .

In this embodiment, a case is shown in which there are three pad sections, but the present invention is not limited to this. For example, it may be composed of four, five, etc., and the number Of course, can be changed as appropriate.

〔Effect of the invention〕

As explained above, according to the present invention, bonding pads for connecting leads of electronic components are formed by a plurality of pad portions each connected to each other by via holes for contact, and two adjacent pad portions among these pad portions. Since the structure is composed of a bonding band layer consisting of an insulating film interposed between pad parts, even if one pad part is peeled off from another pad part when removing electronic components on the wiring layer, these pad parts will not be damaged. You can connect the leads of electronic components.

Therefore, since the electronic component can be reattached to the wiring layer, a new multilayer wiring board that is conventionally required when remounting the electronic component is no longer necessary, and costs can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a multilayer wiring board according to the present invention, and FIG.
The figure is a cross-sectional view showing a state in which electronic components are removed from a multilayer wiring board according to the present invention, and FIG. 3 is a cross-sectional view showing a conventional multilayer wiring board. 1... Wiring layer, 6... Electronic component, 7... Lead, 11... Bonding pad, 12...
Via hole, 13... Pad portion, 14... Insulating film. Patent applicant: NEC Corporation

Claims (1)

[Claims] A multilayer wiring board including a wiring layer having bonding pads thereon for connecting leads of electronic components. A multilayer wiring board comprising a bonding pad layer comprising an insulating film interposed between two adjacent pad portions.