JPS61278196A - Multilayer printed wiring board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to a multilayer printed wiring board.

<Summary of the Invention> The present invention provides a multilayer printed wiring board having component lands on the front surface and connection lands electrically connected to the component lands on the back surface, which are compatible with the connection lands of the multilayer printed wiring board on the front surface. A printed wiring board having connecting lands is surface-adhered using an anisotropic conductive adhesive, thereby achieving a reduction in the area of a multilayer printed wiring board.

<Prior Art> Conventionally, when connecting a flexible printed wiring board to a multilayer printed wiring board, as shown in FIG. They are connected using through-pol soldering or tape-shaped anisotropic conductive adhesive. In the above printed wiring board connection structure,
The multilayer printed wiring 4 requires an extra space for the connection area 41, which increases the area of the printed wiring board.

<Object of the Invention> In view of the above problems, an object of the present invention is to provide a novel multilayer printed wiring board that achieves reduction in area.

<Structure and Effects of the Invention> In order to achieve the above object, the present invention provides a multilayer printed wiring board having component lands on the front surface and connection lands electrically connected to the component lands on the back surface. A printed wiring board having connection lands corresponding to the connection lands of a multilayer printed wiring board is surface-adhered using an anisotropic conductive adhesive. According to the above configuration, in the present invention, a connection land electrically connected to a component land is provided on the back surface of a multilayer printed wiring board, and a connection land on the surface of the printed wiring board is surface-bonded to this, so that unlike the conventional multilayer A special connection area is not required on the printed wiring board, and the area corresponding to the connection area can be reduced.

<Description of an Embodiment> FIG. 1 shows a schematic diagram of an embodiment of a multilayer printed wiring board according to the present invention.

The multilayer printed wiring board of the present invention has a component land 11 on the front surface and a connection land 12 electrically connected to the component land on the back surface of the multilayer printed wiring board 1. A flexible printed wiring board 2 having connecting lands 21 is arranged correspondingly to the connecting lands 12 and 21, and the positions of the connecting lands 12 and 21 are aligned to connect both printed wiring boards 1.
, 2 are surface-adhered using an anisotropic conductive adhesive 3.

The anisotropic conductive adhesive 3 is made by dispersing conductive particles 32 such as carbon fibers into an electrically insulating adhesive 31, and applies the adhesive 3 to the bonding surfaces of both printed wiring boards 1 and 2. By heating and pressing under predetermined conditions, the adhesive 31 is removed between the connecting lands 12 and 12, thereby increasing the dispersion ratio of the conductive particles 32.
Conductivity is established between the upper and lower lands 12 and 21 via 2, and
Between adjacent connection lands, the dispersion ratio of the conductive particles 32 decreases due to the adhesive 31 that has flowed out, and the particles 32 are wrapped in the adhesive 31, and at the same time insulation is maintained.
Both printed wiring boards 1 and 2 are fixed with adhesive.

In practice, it is also possible to print an insulating film on parts of the printed wiring board other than the connection lands (in this case, it is possible to set a conductive pattern on the adhesive surfaces of both printed wiring boards).

As described above, the present invention provides a multilayer printed wiring board 1 having a component land 11 on the front surface and a connecting land 12 electrically connected to the component land 11 on the back surface. Connecting land 2 corresponding to land 12
Since a multilayer printed wiring board is constructed by bonding the printed wiring boards 2 containing the printed wiring boards 1 and 1 with the anisotropic conductive adhesive 3, the present invention provides a method for connecting the multilayer printed wiring boards 1 and 2. Unlike the conventional method, the connecting area is not required, and the area of the multilayer printed wiring board can be made small. This effect is particularly remarkable when the number of electrodes to be taken out from the printed wiring board 2 is large.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing an embodiment of a multilayer printed wiring board according to the present invention, Fig. 2 is an enlarged perspective view of the main part, Fig. 3 is a sectional view taken along the line ■-■ in Fig. 2, and Fig. 4 is Conventional print distribution A
FIG. 3 is a perspective view of the substrate.

Claims (2)

[Claims] (1) For a multilayer printed wiring board that has a component land on the front surface and a connection land that is electrically connected to the component land on the back surface, a printed wiring board that has a connection land on the front surface that corresponds to the connection land. A multilayer printed wiring board made by surface bonding with an anisotropic conductive adhesive. (2) The multilayer printed wiring board according to claim 1, wherein the anisotropic conductive adhesive has conductive particles dispersed in the electrically insulating adhesive resin to provide electrical continuity between the opposing connection lands.