JP2000208558A - Printed circuit board for LSI package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a semiconductor chip in the state of a bare chip and to easily and inexpensively mount it without being affected by the difference of a bump specification at every chip manufacture by protrusively installing a bump on the semiconductor chip mounting pad of a printed board. SOLUTION: Wirings 11 corresponding to the electrodes of a bare chip 20 are printed on a printed board for manufacturing an LSI package mounting the bare chip 20 and having a ball grid array terminal. Bumps 13 are protrusively installed on semiconductor chip mounting pads 12 abutted on the electrodes of the bare chip. Through holes 14 connected to the ball grid array terminal of the LSI package are formed on the other end parts of the wirings 11. The bare chip which is generally and easily obtained can be mounted on a bare chip-side without changing it. The LSI package can easily and inexpensively be manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a printed circuit board having an L
The present invention relates to a printed circuit board for an LSI package which can be easily mounted without modifying a semiconductor chip side when an LSI package is manufactured by mounting a semiconductor chip for the SI.

[0002]

2. Description of the Related Art In an LSI manufacturing technique, a semiconductor chip (hereinafter, referred to as a "bare chip") cut from a wafer is connected to a substrate for an LSI package.
2. Description of the Related Art Semiconductor chip mounting technology for manufacturing an SI package is one of the important factors for reducing the mounting area of an LSI, reducing its weight, improving its performance, and improving its production efficiency. In order to satisfy these requirements, various means for connecting a bare chip to a substrate for an LSI package have been developed and put to practical use. For example, the “Hybrid Microelectronics Handbook (issued by the Industrial Research Council)” includes methods for connection by soldering, methods using conductive adhesives, methods using anisotropic conductive sheets,
Then, a method of bringing the electrodes into contact by the contraction force of the adhesive to obtain conduction is introduced. A common feature of these techniques is that the bare chip electrode has a "bump"
Conductive bumps called LSI, and these bumps are
An object of the present invention is to form an electrical connection at a contact portion between the bump on the semiconductor chip side and the semiconductor chip mounting pad on the substrate side by pressing the semiconductor chip mounting pad formed at a corresponding position on the package substrate.

[0003]

However, there are various types of formation of the bumps on the semiconductor chip side, and these types differ depending on the chip manufacturer.
For example, even if an LSI user obtains a semiconductor chip with bumps from a plurality of chip manufacturers and assembles one LSI package, it is extremely difficult to request each chip manufacturer to form bumps having a common specification. Therefore, even if an LSI user obtains a semiconductor chip in a wafer state and tries to form a bump having a common specification independently on the wafer, it is almost impossible to obtain a semiconductor chip in a wafer form by commercial practice. Above, even if it is available, since the dimensions of the wafer, the material of the wafer protective film, etc. differ for each chip manufacturer, it is not only difficult to form bumps with common specifications on these, but also expensive Was not practical. The present invention has been made to solve the above problems, and therefore, the object thereof is to obtain a semiconductor chip in a bare chip state without being affected by differences in bump specifications between chip manufacturers, An object of the present invention is to provide an LSI package substrate that can be easily and inexpensively mounted.

[0004]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a printed circuit board for an LSI package in which bumps are protruded from semiconductor chip mounting pads of the printed circuit board. Printed circuit board for LSI package
By simply protruding the bumps on the side of the "printed circuit board", there is no need to make any changes on the semiconductor chip side, and the bare chip can be mounted as it is by the conventionally used bonding method Becomes
Therefore, a generally available bare chip can be easily and inexpensively mounted on a printed circuit board without being affected by differences in specifications among chip manufacturers.

[0005] In the above, it is preferable that the bump is formed by a plating technique. Plating technology in the manufacture of printed circuit boards is a technology that is very commonly used, for example, when forming through holes,
The formation of the bumps by the plating technique has no technical or equipment problem, and can be performed simultaneously with the formation of the through holes, for example, in the usual substrate manufacturing technique and equipment. Cost can be suppressed.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below with reference to the accompanying drawings. 1 and 2 show one embodiment of a printed circuit board according to the present invention. 1 and 2, a printed circuit board 10 is a printed circuit board for mounting an bare chip 20 to manufacture an LSI package having a ball grid array type terminal, and a wiring 11 corresponding to an electrode of the bare chip 20 is provided on the surface. Printed. In this wiring 11, a bump 13 is provided on a semiconductor chip mounting pad 12 which is in contact with an electrode of a bare chip.
And the other end of the wiring 11 has an LSI
A through hole 14 is formed to connect to a ball grid array type terminal of the package.

The bumps 13 and the through holes 14 are formed at the same time by a substrate plating technique. At this time, the formation of the bumps is prevented by masking the unnecessary wiring on the circuit with a plating resist or the like in advance.

As shown in FIG. 3, for example, as shown in FIG. 3, a printed circuit board 10 having bumps 11 formed thereon is anisotropically conductive sheet (A) between the printed circuit board 10 and a bare chip 20.
CF) 30 interposed, pressurized and heated,
The printed circuit board 10 and the bare chip 20 are electrically connected between the bumps 13 and the electrodes 21 of the bare chip 20 through the conductive particles in the anisotropic conductive sheet, and at the same time, the resin of the anisotropic conductive sheet 30 is cured. Can be physically joined.

Next, if necessary, as shown in FIG.
If the surface of the printed circuit board 10 is sealed with a resin mold 31 to protect the bare chip 20, and solder balls 32 as external electrodes are formed on the back surface of the through holes 14, a ball grid array (BGA) type LSI package is completed. .

As in the above embodiment, the printed board of the present invention has bumps 13 protruding from its semiconductor chip mounting pads 12, so that the printed board is exactly the same as a conventional LSI package having bumps formed on the LSI chip side. Thus, the connection between the printed circuit board and the bare chip becomes possible. Therefore, it is not necessary to form bumps on conventional LSI chip electrodes, and it is possible to mount a semiconductor chip without bumps, that is, a bare chip, which is generally available from various chip manufacturers, on a printed circuit board. Further, since the bumps of the printed board are formed simultaneously by plating for forming the through holes, it is possible to suppress an increase in the cost of manufacturing the printed board.

In the above description, the printed circuit board of the present invention is used for mounting a bare chip using an anisotropic conductive sheet, but other means for mounting a bare chip may be applied. For example, a method in which a photocurable insulating resin is used instead of the anisotropic conductive sheet, and the bumps on the printed circuit board and the electrodes of the bare chip are electrically connected and physically joined by the contraction force at the time of curing thereof can also be applied. . Further, a conductive paste, solder, or the like may be supplied on the bumps and used as an auxiliary material for connection. In the above embodiment, the case where one semiconductor chip is mounted on the printed circuit board has been described.
It goes without saying that the printed circuit board of the present invention can be mounted on a single printed circuit board by mixing a plurality of semiconductor chips from different manufacturers. Further, the printed circuit board of the present invention may include not only the semiconductor chip connection circuit described above but also circuits and elements for general electronic devices mounted thereon.

[0012]

The printed circuit board for an LSI package according to the present invention has bumps projecting from the semiconductor chip mounting pads of the printed circuit board, so that a commonly available bare chip can be used without any modification on the bare chip side. LSI packages can be easily and inexpensively manufactured without being affected by differences in specifications among chip manufacturers. Further, if the bumps are formed by a plating technique, they can be formed simultaneously with the formation of through holes and the like, so that processing can be performed without providing a special step, and an LSI package can be manufactured at lower cost. .

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line XX of FIG. 1;

FIG. 3 is a cross-sectional view showing one use mode of the embodiment.

FIG. 4 is a cross-sectional view illustrating an example of an LSI package manufactured using the embodiment.

[Explanation of symbols]

 10: Printed circuit board 11: Wiring 12: Semiconductor chip mounting pad 13: Bump 14: Through hole 20: Bare chip 21: Electrode 30: Anisotropic conductive sheet 31: Resin mold 32: Solder ball

Claims (2)

[Claims] An LSI is mounted on a semiconductor chip for an LSI.
A printed circuit board for manufacturing an I package,
A printed circuit board for an LSI package, wherein bumps are projected from semiconductor chip mounting pads of the printed circuit board. 2. The printed circuit board for an LSI package according to claim 1, wherein said bumps are formed by a plating technique.