JPH0513614A - Plastic pga package - Google Patents

Abstract

PURPOSE:To improve the flatness of external lead-out/in pins by making a structure so that pins are fixed in throughholes only by a brazing material on a board and so that pins in four corners of the board are pressed to fit in throughholes. CONSTITUTION:Throughholes 4 have external lead-out pins 11a inserted by press fit method only at four corners of a board 1 to input electric signal from outside or output it to outside. The remains use loose contact pins 11b. These pins should be longer than those of press fit method and have a form of being kept mechanically on the board 1 by a brazing material 12 such as solder without press-fit into throughholes 4. A loose contact pin 11b comes in a loose contact state with the board 1 due to remelting of the brazing material 12; then, the board 1 lowers to the position of the pins 11a by its own weight, resulting in finish of mounting.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic pin grid array (hereinafter abbreviated as P-PGA) package.

[0002]

2. Description of the Related Art As shown in FIG. 3, a conventional surface mount P-PGA package has at least bonding to a substrate 1a formed by laminating (or only one layer) an insulating base material 2 made of at least glass epoxy or the like. The structure has a pad 3, a through hole, a wiring 5 for electrically connecting the bonding pad and the through hole, and a cavity portion 6. A semiconductor element 8 is fixed in the cavity 6 of the PGA package with an adhesive 7 made of Ag paste or insulating resin. An electrode (not shown) is formed on the upper surface of the semiconductor element 8,
The electrodes of the semiconductor element and the bonding pads formed on the substrate 1 are connected by the bonding wires 9.
The inside of the cavity 6 is a resin 1 such as a liquid epoxy resin.
After potting 0, the encapsulating resin is formed by solidifying. An external lead-out pin 11a is inserted into the through hole 4 by press fitting (press hit) for the purpose of inputting or outputting an electric signal from the outside. After the insertion, the brazing material 12 made of solder or the like is used. It was fixed by.

[0003]

In this conventional surface mount type P-PAG package, it is an important problem how to make the height (coplanarity: flatness) of each pin from the bottom surface of the substrate constant. Is. In this conventional example, since the pins are press-fitted, it is difficult to control the coplanarity between the pins, and there is a problem that the press-fitting of the pins causes warping of the substrate itself. If the coplanarity is poor, there is a problem that soldering cannot be performed because each pin has no flatness at the time of mounting.
Further, even if an attempt is made to mount the mounting board on the mounting board, the mounting cannot be carried out accurately.

[0004]

A surface mount type plastic PGA package of the present invention has at least an insulating substrate, a cavity portion, a bonding pad, a through hole for inserting a pin for introducing and outputting an electric signal to the outside, and In a plastic PGA package having wiring for electrically connecting the through hole and a bonding pad, and a pin for inserting and extracting an electric signal to the outside is inserted in the through hole, the pin is Pins (hereinafter referred to as loose contact pins) fixed to the substrate only by brazing material such as solder in the through hole, and pins at four corners of the substrate are press-fitted into the through hole, or four corners of the substrate. Columns are provided on all the pins, and all pins mounted on the board are fixed only by brazing material such as solder.

[0005]

Embodiments of the present invention will now be described with reference to the accompanying drawings.

FIG. 1 is a vertical sectional view showing a surface mount type P-PGA package according to a first embodiment of the present invention.

The substrate 1 is at least glass epoxy resin,
Alternatively, the insulating substrate 2 made of triazine resin or the like is laminated (or only one layer). The PAG package is
The substrate 1 is formed with a bonding pad 3, a through hole 4, a wiring 5 for electrically connecting the bonding pad and the through hole, and a cavity portion 6. A semiconductor element 8 is fixed in the cavity 6 of the PAG package via an adhesive 7 made of a conductive resin such as Ag paste or an insulating resin. An electrode is formed on the upper surface of the semiconductor element 8, and the electrode of the semiconductor element and the bonding pad 3 formed on the substrate 1 are connected by a bonding wire. A resin 10 such as a liquid epoxy resin is potted inside the cavity 6 and then solidified to form a sealing resin. Pins 11a for external lead-out are inserted into the through-holes 4 only at the four corners of the substrate by a press hit method for the purpose of inputting or outputting an electric signal from the outside. Loose contact pins 11b are used for the remaining pins. The loose contact pin 11b is longer than the pin of the press hit type, and its shape is mechanically held only by the brazing material 12 such as solder without being press-fitted into the through hole 4 provided in the substrate 1. It has a shape. When the loose contact pin 11b is mounted on the mother board, the solder 12 for mechanically holding the pin with the substrate 1 is re-melted to loosen the contact pin 11b.
And the substrate 1 are in loose contact. Then, the substrate 1 is lowered to the position of the pin 11a by its own weight, and the mounting is completed.

FIG. 2 is a vertical sectional view showing a surface mount type plus chip PGA package according to a second embodiment of the present invention. In this embodiment, the pins 11a inserted by the press hit method at the four corners of the substrate 1 of the first embodiment are replaced by the substrate 4
In the corner, the pillar 15 made of glass epoxy resin or the like is the adhesive 1
Since it is the embodiment bonded by way of 4, the same parts as those in FIG. 1 are designated by the same reference numerals in FIG. 2 and their detailed description is omitted.

All the pins are loose contact pins 11b, and the loose contact pins 11b and the substrate 1 are held only by a remeltable adhesive 12 such as solder, and are electrically connected. Pillars 15 made of glass epoxy resin or the like and having a prismatic shape are fixed to the four corners of the substrate 1 with an adhesive 14.

[0010]

As described above, according to the present invention, the pins are press-fitted into the substrate only at the four corners of the substrate by the press hit method, or the prismatic pillars are provided at the four corners of the substrate through the adhesive. All of the pins are designed so that electric signals can be led in and out by loose contact pins, so if the pins provided only at the four corners of the board or only the height of the pillars match, the P-PGA package can be used. When mounting on a motherboard, loose contact pins have a structure that allows the pins themselves to fluctuate up and down depending on the warp of the board or the warp of the motherboard itself, so there is no need to manage coplanarity for all pins. This has the effect of reducing costs.

[Brief description of drawings]

FIG. 1 is a surface mount type plastic P according to an embodiment of the present invention.
FIG. 3 is a vertical sectional view of a GA package.

FIG. 2 is a vertical sectional view of a second embodiment.

FIG. 3 is a vertical cross-sectional view of a conventional surface mount plastic PGA package.

[Explanation of symbols]

1 substrate 2 insulating substrate 3 Bonding pad 4 through holes 5 wiring 6 cavity 7 adhesive 8 Semiconductor elements 9 Bonding wire 10 resin 11a pin 11b loose contact pin 12 brazing material 14 Adhesive 15 pillars

Claims (2)

[Claims] 1. A cavity portion, which is a semiconductor element fixing portion, a bonding pad connected to an electrode of the semiconductor element, a through hole for inserting a pin for introducing an electric signal to the outside, and at least an insulating substrate. Plastic P having wiring for electrically connecting the through hole and the bonding pad, and a pin for inserting and extracting an electric signal to the outside is inserted into the through hole.
In the GA package, the pin is a pin fixed to the substrate only by a brazing material such as solder in the through hole, and the pins at four corners of the substrate are press-fitted into the through hole. Plastic PGA
package. 2. A cavity portion, which is a semiconductor element fixing portion, a bonding pad connected to an electrode of the semiconductor element, a through hole for inserting a pin for leading and receiving an electric signal to the outside, and at least an insulating substrate. Plastic P having wiring for electrically connecting the through hole and the bonding pad, and a pin for inserting and extracting an electric signal to the outside is inserted into the through hole.
A plastic PGA package characterized in that in the GA package, pillars are provided at four corners of the substrate, and all pins mounted on the substrate are loose contact pins fixed only by a brazing material such as solder.