CN102376666B - A kind of ball grid array package structure and manufacture method thereof - Google Patents

Abstract

The invention provides a kind of ball grid array package structure and manufacture method thereof, this ball grid array package structure comprises: chip, and its upper surface is formed with fixed cell and multiple pad; Substrate, its upper surface is formed with the placement unit corresponding with described fixed cell and the multiple through holes corresponding respectively with pad described in each, described chip makes described fixed cell contact with described placement unit in the mode of upside-down mounting, and makes each described through hole expose the described pad corresponding with this through hole respectively.According to ball grid array package structure of the present invention and manufacture method thereof; by by flip-chip in substrate; and each pad exposed by the through hole being arranged at substrate on chip; and by directly planting ball on pad after electric conducting material protection pad; realize low cost thus, technique is simple, and there is high electrical performance.

Description

Ball grid array package structure and manufacturing method thereof

technical field

The invention relates to a ball grid array packaging structure and a manufacturing method thereof, in particular to a ball grid array packaging structure and a manufacturing method thereof that improve electrical performance by flipping a chip onto a substrate.

Background technique

Ball grid array (BGA) packaging technology is a surface mount package, which replaces traditional leads by making ball bumps (ballbumps) in an array on the back of the substrate, making semiconductor devices more integrated and high performance. better. BGA packaging technology will significantly increase the number of I/O pins of the device and reduce the pad pitch, thereby reducing the size of the package and saving the footprint of the package, so that PC chipsets, microprocessors, etc. performance, miniaturization of multi-pin packaged devices is possible. With the increasing demand for packaging technology and product diversification, high speed, low cost, small size, and excellent electrical performance are important development trends.

In the traditional manufacturing process of BGA package, the chip is fixed on the substrate through its lower surface, and then the pads arranged on the upper surface of the chip are electrically connected to the soldering points on the substrate through a wire bonding process through a wire bonding process. Then, the chip and the substrate are molded to protect the chip and the internal metal wires. Finally, bumps are formed on the lower side of the substrate through a ball planting process, so that the chip can be electrically connected with other external circuits.

However, because the existing BGA package structure needs to be manufactured through a wire bonding process, its cost is relatively high, and the signal integrity is poor due to the long metal wires, and the process steps are relatively complicated.

Contents of the invention

The present invention is proposed to solve the above problems, and its purpose is to provide a ball grid array packaging structure and a manufacturing method thereof, so as to save the wire bonding process and improve the electrical performance of the ball grid array packaging structure.

According to one aspect of the present invention, a ball grid array packaging structure includes: a chip, a fixed unit and a plurality of pads are formed on its upper surface; a substrate, a placement unit corresponding to the fixed unit is formed on its upper surface, and a A plurality of through holes corresponding to the pads, the chip is flip-chip bonded to the fixing unit and the placement unit, and each of the through holes is exposed to the corresponding through hole. pad.

Moreover, the fixing unit and the placement unit are fixed together by adhesive.

Moreover, the adhesive is a thermally conductive adhesive to dissipate heat from the chip.

The ball grid array package structure according to the present invention further includes a plastic package for protecting the chip and the substrate.

The ball grid array package structure according to the present invention further includes: a conductive material for protecting the pad, the conductive material is arranged inside the through hole; a convex ball is arranged at the lower end of the through hole, and the convex ball passes through the conductive Material forms an electrical connection with the pad.

According to another aspect of the present invention, a manufacturing method of a ball grid array package structure includes the following steps: turning the chip upside down, and aligning each of the pads with the through hole respectively; The fixing unit of the chip is fixed to the placement unit of the substrate; filling the through hole with a conductive material for protecting the pad; molding the chip and the substrate; The lower end of the through hole of the substrate forms a bump electrically connected to the pad.

According to the ball grid array package structure and its manufacturing method of the present invention, the chip is flipped on the substrate, and each pad on the chip is exposed through the through hole provided on the substrate, and the pad is protected by a conductive material and directly on the solder pad. The balls are planted on the plate, thereby achieving low cost, simple process, and high electrical performance.

Description of drawings

Fig. 1 is the schematic diagram according to the upper surface of the chip of the present invention;

Figure 2 is a side view of a chip according to the present invention;

3 is a cross-sectional view of a substrate according to the present invention;

4 is a schematic diagram of a ball grid array package structure according to the present invention;

FIG. 5 is a flow chart of the manufacturing process of the ball grid array package structure according to the present invention.

detailed description

Hereinafter, a lead wire heating device according to an embodiment of the present invention will be described in detail with reference to the drawings. However, the present invention can be implemented in many different ways and should not be construed as being limited to the following examples. In the drawings, the dimensions are exaggerated for clarity, and the same reference numerals are used in different drawings to designate the same components.

Fig. 1 is a schematic diagram of the upper surface of a chip according to the present invention, Fig. 2 is a side view of a chip according to the present invention, Fig. 3 is a cross-sectional view of a substrate according to the present invention, and Fig. 4 is a schematic diagram of a ball grid array package structure according to the present invention .

It can be seen from the figure that a plurality of pads 11 and fixing units 12 are formed on the upper surface of the chip 10 according to the present invention. The pads 11 are used as input/output terminals to connect with external circuits so that the chip can perform specific functions. The fixing unit 12 is used for disposing the chip 10 on the substrate 13 to package the chip 10 . The substrate 13 is used to mount the chip 10 , and a placement unit 15 for bonding with the fixing unit 12 of the chip 10 is formed on its upper surface. The fixing unit 12 and the placing unit 15 are fixed by an adhesive 19 . Preferably, the placement unit 15 is formed with a groove with a certain depth for setting the adhesive 19 . The adhesive 19 has a heat conduction function to dissipate heat generated when the chip 10 is running. A plurality of through holes 14 formed through the upper and lower surfaces of the substrate 13 are also formed, and each through hole 14 can correspond to the pad 11 of the chip 10 respectively, so that when the chip 10 is loaded and When fixed on the substrate 13 , the through hole 14 exposes the pad 11 . As can be seen from FIG. 4 , since the pads 11 and the fixing unit 12 of the chip 10 of the present invention are all formed on the upper surface, when the chip 10 is fixed on the substrate 13, the upper surface of the chip 10 and the The upper surface of the substrate 13 is in close contact, that is, the chip 10 is flip-chip bonded to the substrate 13 . Moreover, a conductive material 18 is provided in the through hole 14 of the substrate 13 to protect the pad 10 and prevent the chip 10 from losing its function. Moreover, compared with the prior art, the pad 11 in the present invention is directly electrically connected to the solder ball 17 through the conductive material 18 . That is, in the present invention, the substrate 13 does not need wiring, and only serves as a supporting frame. Symbol 16 represents a plastic package for protecting internal structures such as chips.

Hereinafter, the manufacturing process of the ball grid array package structure according to the present invention will be described in detail with reference to FIG. 1 to FIG. 5 . FIG. 5 is a flow chart of the manufacturing process of the ball grid array package structure according to the present invention. It can be seen from the figure that the manufacturing process of the ball grid array package structure according to the present invention is as follows: first, as shown in FIG. 5 (a), turn the chip upside down and align the pads on the chip with the through holes on the substrate. At this time, when the pads on the chip are aligned with the through holes on the substrate, the fixing unit of the chip is naturally aligned with the placement unit on the substrate. Then, as shown in (b) of FIG. 5 , the chip is fixed to the substrate with an adhesive. At this time, the adhesive is a heat-conducting adhesive to dissipate heat generated when the chip is running. Then, a conductive material is filled into the through hole of the substrate to protect the pad and prevent the chip from losing its function. At this time, a certain distance needs to be kept between adjacent pads, so as to prevent adjacent pads from forming connection points through conductive materials. Then, as shown in (d) of FIG. 5 , molding is performed on the chip and the substrate after the above process to protect the chip. Then, as shown in (e) of FIG. 5 , bumps electrically connected to the pads are formed at the lower ends of the through holes of the substrate. At this time, the bumps are directly electrically connected to the pads through the conductive material, thereby improving the electrical performance.

According to the ball grid array package structure and its manufacturing method of the present invention, the chip is flipped on the substrate, and each pad on the chip is exposed through the through hole provided on the substrate, and the pad is protected by a conductive material and directly on the solder pad. The balls are planted on the plate, thereby achieving low cost, simple process, and high electrical performance. Moreover, the substrate in the present invention does not need to be wired, thereby saving processes and reducing costs.

The present invention is not limited to the above-described embodiments, and various variations and modifications can be made without departing from the scope of the present invention.

Claims (6)

1. a ball grid array package structure, is characterized in that comprising:

Chip, its upper surface is formed with fixed cell and multiple pad, and fixed cell is positioned at the central authorities of the upper surface of chip, and described multiple pad is positioned at around fixed cell;

Substrate, its upper surface is formed with the placement unit corresponding with described fixed cell and the multiple through holes corresponding respectively with described pad,

Described chip makes described fixed cell engage with described placement unit in the mode of upside-down mounting, and makes each described through hole expose the described pad corresponding with this through hole respectively.

2. ball grid array package structure according to claim 1, is characterized in that described fixed cell and described placement unit are fixed together by bonded adhesives.

3. ball grid array package structure according to claim 2, is characterized in that described bonded adhesives is heat-conducting type bonded adhesives, to dispel the heat to chip.

4. ball grid array package structure according to claim 1, characterized by further comprising the plastic-sealed body for the protection of described chip and described substrate.

5. ball grid array package structure according to claim 1, characterized by further comprising:

For the protection of the electric conducting material of described pad, it is inner that this electric conducting material is arranged at described through hole;

Be arranged at the convex ball of through hole lower end, this convex ball is formed by described electric conducting material and described pad and is electrically connected.

6., for the manufacture of a method for ball grid array package structure according to claim 1, it is characterized in that comprising the following steps:

By described chip upside down, and make each described pad respectively with described through-hole alignment;

By bonded adhesives, the described fixed cell of described chip is fixed on the described placement unit of described substrate;

Insert in described through hole for the protection of pad electric conducting material;

Mould envelope is carried out to described chip and described substrate;

Formed in the described through hole lower end of described substrate and form with described pad the convex ball be electrically connected.