JP2006269796A - Pin structure of wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pin structure with enhanced connection reliability in a pin structure of an electric element-mounted wiring board for mounting an I/O pin, on a pad provided on the surface of the wiring board. <P>SOLUTION: A polyimide sheet 5 has a pin aligning hole 6. The I/O pin 7, aligned in the hole 6, includes fine protrusions. The I/O pin-equipped board is obtained by jointing the polyimide sheet 5 and the wiring board. Since the I/O pin 7 includes the fine protrusions, it is possible to form the I/O pin with high reliability. A fine protrusion may be provided on a pin connection pad 2 of the wiring board. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pin structure of a wiring board, and more particularly to a pin structure of a wiring board for attaching an I / O pin to a pad provided on a surface of an electric element mounting wiring board.

  A conventional pin structure of a wiring board will be described with reference to FIGS. Of the four pins shown in FIGS. 1A to 1D, the two on the left are those according to the prior art. In this method, a resin (polyimide) sheet is used, pins are aligned, and this sheet is bonded to a resin layer formed on the substrate surface by thermocompression bonding. In this method, the residual thermal stress is small and almost zero compared with the pin mounting method by soldering. For this reason, there is a high degree of freedom in selecting a metal material of the pin, and there is an advantage that a material having the most advantageous characteristics in each substrate such as low electrical resistance, flexibility, mass, and thermal conductivity can be used. This prior art is described in Patent Document 1.

Japanese Patent No. 2725664 (page 2-3, FIG. 7)

  However, the conventional pin structure described above has the following problems. In this pin mounting method, the pin and the pad on the substrate surface are only pressed against each other, so that they are particularly vulnerable to lateral force. For this reason, there are problems in that electrical and mechanical connection reliability is poor and resistance increases and disconnections are likely to occur.

  An object of the present invention is to provide a pin structure that solves the above-described problems of the prior art and has improved connection reliability.

The pin structure of the wiring board of the present invention is a pin structure of a wiring board in which a resin sheet having a pin alignment hole and a pin inserted into the pin alignment hole is joined to the wiring board.
The wiring board has pin connection pads,
The pin has a protrusion on a surface connected to the pin connection pad.

The pin structure of the wiring board of the present invention is a pin structure of a wiring board in which a resin sheet having a pin alignment hole and a pin inserted into the pin alignment hole is joined to the wiring board.
The wiring board has pin connection pads,
The pin connection pad has a protrusion on a surface connected to the pin.

  The present invention has the following effects. Since there are minute protrusions on the bonding surface of the pins or the pin connection pad surface of the wiring board, the connection reliability is improved.

  The best mode for carrying out the present invention will be described in detail with reference to the drawings. 1A to 1D are cross-sectional views for describing an embodiment of the present invention. Of the four pins, the left two are according to the prior art, and the right two are according to the embodiment of the present invention.

  First, the outline of the present invention will be described. In FIG. 1 (a), a resin (polyimide) sheet 5 has pin alignment holes 6. In FIG.1 (b), the I / O pin 7 aligned with the hole 6 has a microprotrusion. In FIG.1 (c), the resin sheet 5 and a wiring board are joined. In FIG. 1D, a bonded I / O pin-attached substrate is obtained. In this way, in the present invention, since the I / O pin 7 has minute protrusions, it is possible to form an I / O pin with high connection reliability.

  Next, embodiments of the present invention will be described in detail.

  Referring to FIG. 1 (a), a pin alignment polyimide sheet 5 is shown. In the figure, holes 6 align the pins.

  Referring to FIG. 1 (b), a polyimide sheet 5 having pins 7 inserted therein is shown. In the figure, a minute projection is formed on the bonding surface of the pin 7.

  Referring to FIG. 1C, a configuration for bonding the pins 7 and the wiring board is shown. In the figure, the wiring board is formed of a ceramic substrate 1, internal wiring (not shown), a component mounting pad 3, a pin connection pad 2, and a polyimide layer 4. The pin connection pad 2 is formed with minute protrusions.

  Referring to FIG. 1 (d), a wiring board formed by the present method is shown. In the figure, the minute protrusions formed on the bonding surface of the pin 7 or the pin connection pad 2 surface of the wiring board improve the connection reliability between the pin and the wiring board.

  Next, the operation (manufacturing process) of the present embodiment will be described with reference to the drawings.

  First, the polyimide sheet 5 of FIG. 1A is formed by a thick film method. Here, the size is 90 square mm and the thickness is 0.1 mm. A hole 6 is drilled in this using a laser method or a photolithography method. The formation pitch is a grid of about 1.8 mm. The size of the hole 6 is a shape having an inclination of about 1 mm on the upper surface and about 0.5 mm on the lower surface. This is in accordance with the head shape of the pin 7 described later.

  Next, the pins 7 are aligned in the holes 6 as shown in FIG. The pin head portion has a taper, and the inserted pin 7 is held in the hole 6 by appropriately matching the diameters of the sheet hole and the pin head. A microprotrusion is formed on the bonding surface of the head portion of the pin 7 (the third from the left, see the pin of the present method (1)). The minute protrusions are formed by thin film etching using photolithography or etching by sputtering. Since this method is not directly related to the present invention, its detailed method is omitted.

  Next, the ceramic wiring board for pin connection shown in FIG. 1C is formed. The main part of the insulating part is alumina and the main part of the wiring part is tungsten. Although it is formed by the green sheet laminating method, it is not directly related to the present invention, and therefore the detailed configuration is omitted.

  Component mounting pads 3 are formed at predetermined positions on the component mounting surface of the ceramic wiring board. On the pin connection surface, pin connection pads 2 having the same pitch as the polyimide sheet 5 are formed. Further, a polyimide layer 4 having a thickness of about 0.01 mm is formed, and the polyimide is removed from the pin connection pad 2 portion by photolithography. Since the method for forming the polyimide layer is not directly related to the present invention, its detailed method is omitted.

  Next, as shown in FIG. 1C, the polyimide sheet 5 in which the pins 7 are aligned and the wiring board are bonded together. Align so that there is no displacement, and thermocompression bond between upper mold 8 and lower mold 9. When the heating temperature at this time is set to be equal to or higher than the glass transition point of the polyimide, very strong bonding can be performed. Specifically, it is performed at a temperature of 350 degrees and a pressure of 15 kg / square centimeter. It is performed in a vacuum of about 10-2 torr to prevent air bubbles from entering. Since the polyimide bonding method is not directly related to the present invention, its detailed method is omitted.

  The pinned wiring board shown in FIG. 1D is formed through the above steps. An integrated polyimide layer 11 is formed on the pin joint surface.

  In the above process example, a minute protrusion was formed on the bonding surface of the pin 7. That is, the shape of the “present method (1)” is the third from the left among the four pins in FIGS. As shown in the fourth “this method (2)” from the left, fine protrusions may be formed on the surface of the pin connection pad 2 of the other wiring board. Otherwise, the process is exactly the same.

1A to 1D are cross-sectional views for describing an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Board | substrate 2 Pin connection pad 3 Component mounting pad 4 Polyimide layer 5 Polyimide sheet 6 Hole 7 Pin 8 Upper die 9 Lower die 11 Polyimide layer

Claims (2)

A pin structure of a wiring board in which a resin sheet having a pin alignment hole and a pin inserted into the pin alignment hole and the wiring board are joined,
The wiring board has pin connection pads,
The pin structure of a wiring board, wherein the pin has a protrusion on a surface connected to the pin connection pad. A pin structure of a wiring board in which a resin sheet having a pin alignment hole and a pin inserted into the pin alignment hole and the wiring board are joined,
The wiring board has pin connection pads,
A pin structure of a wiring board, wherein the pin connection pad has a protrusion on a surface connected to the pin.

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