JP2010186813A - Structure for mounting electronic component package and mounting method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the trouble problem caused by an unbalance of heat conduction when performing an electronic component packaging of a surface mount method such as BGA and/or LGA where electrode parts are arranged on the lower surface of the package and soldered to further apply for the packaging of larger electronic component packagings. <P>SOLUTION: A structure is formed as that through-holes are provided at the position corresponding to electrodes of the package and pads of a sheet substrate sandwiched between an electronic component package and a printed-circuit board. The structure filling in a solder paste to the through-holes and sandwiching between the electronic component package and the printed-circuit board fast and uniformly conducts the heat to uniformly heat the unheated solder, satisfactorily solder-bonding. This provides a new packaging method of the electronic component packaging. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electronic component package mounting structure and a mounting method using the same.

  Today, the performance of electronic devices continues to improve dramatically, and the integration of electronic components per unit area is increased by mounting large-scale integrated circuits in smaller packages. As one of the methods, a method using a surface mounting method such as BGA or LGA in which an electrode part of an electronic component package is disposed on the lower surface of the package and soldered is often used.

  When the electrode part is placed on the lower surface of such an electronic component package and solder bonding is performed with the pad portion of the printed circuit board, the heat transferred from the back surface of the printed circuit board cannot be directly heated. In addition, soldering is performed by heating with hot air sent into the gap between the package and the printed circuit board. (For example, Patent Document 1)

 However, in order to further enhance the functionality of electronic component packages, it is necessary to increase the size of the package, and as a result, the heat conduction to the solder joint at the time of mounting becomes unbalanced. It has occurred.

JP 2006-228771 A

  With the enhancement of the functionality of electronic component packages, multilayering and double-sided mounting of printed circuit boards are performed, and in the conventional method, the amount of heat transferred through the circuit board tends to decrease as the printed circuit board becomes thicker. For example, the thermal conductivity of glass or epoxy resin often used for a substrate is about 1 W / (m · K) for glass, and 0.21 W / (m · K) for epoxy resin, which is difficult to transfer heat.

  In addition, even when the hot air is sent to the gap between the package and the printed circuit board, the heat conduction to the solder joint becomes unbalanced due to the increase in the size of the package electrode, resulting in problems such as solder ball unfusion due to insufficient heat during mounting. .

  The present invention solves the problem of defects due to imbalance of heat conduction during mounting of a surface mounting type electronic component package such as BGA or LGA in which an electrode portion is disposed on the lower surface of the package and soldered, and a larger electronic component. It aims to be applicable to packages.

  In order to solve the above-described problems, the first configuration of the structure of the present invention is a sheet-like substrate placed between the electronic component package and the printed circuit board, and at positions corresponding to the electrode portions of the package and the pad portions of the substrate. A structure in which a through hole is provided and solder paste or the like is previously applied and filled in the through hole to hold unheated solder.

  The second structure of the structure of the present invention is a structure having a thickness comparable to the gap between the package and the printed circuit board for use between the electronic component package and the printed circuit board.

  As a third configuration of the structure of the present invention, the heat conductivity is metal (iron 84 W / (m · K), copper 398 W) because heat from the heating device attached to the structure is quickly transferred to the structure. / (M · K)) and a structure made of a material having an electrical resistivity equal to or higher than that of an insulator (1 MΩ or higher).

  The present invention is characterized in that the structure has the above-described first to third configurations in which heat can be transferred quickly and uniformly so that unheated solder can be uniformly heated and good solder bonding can be performed. A new mounting method for an electronic component package.

  According to the present invention, in the solder bonding of the electronic component package, heat is uniformly transmitted to the central portion, and it becomes possible to solve the soldering defect. Further, it is possible to provide a new mounting method capable of good solder bonding of the electronic component package even when the heat conduction condition is further deteriorated due to the enlargement of the package electrode portion due to the high functionality of the electronic component package.

The top view which shows the shape of the structure of this invention Side view showing the shape of the structure of the present invention The top view which shows the heat conduction system from the heat generating body of the mounting method by the structure of this invention The side view which shows the heat conduction system from the heat generating body of the mounting method by the structure of this invention The side view which shows the positional relationship of the structure and board | substrate of this invention The side view which shows the positional relationship of the structure of this invention, a board | substrate, and an electronic component package The side view which shows the conduction system of the heat from a heat generating body at the time of mounting by the structure of this invention The side view which shows the removal condition of the heat generating body after mounting by the structure of this invention The top view which shows the conduction system of the heat from a heat generating body of an example of the mounting method by the enlargement of the structure of this invention The top view which shows the removal condition of the heating element after mounting of an example of the mounting method by the enlargement of the structure of this invention

  FIG. 1 to FIG. 4 are diagrams showing the shape of the structure and the heating element of the present invention and the state of heat conduction in the structure.

  FIG. 1 is a plan view of the structure of the present invention. This structure is characterized in that a through-hole is provided in a sheet-like substrate at a position corresponding to the ball grid of the BGA to be mounted, and the size of the hole is slightly larger than the diameter of the ball grid. FIG. 2 is a side view of the structure of the present invention. The thickness of this structure is characterized by being larger than the radius of the ball grid of the BGA to be mounted and smaller than the diameter.

This structure is made of single crystal diamond, polycrystalline diamond or sintered body thereof, cubic boron nitride or sintered body thereof, sintered body of boron nitride, and aluminum nitride in order to increase thermal conductivity and electrical resistivity. Any of these sintered bodies or a structure using two or more of them is desirable.
Further, any of diamond powder or a sintered body thereof, cubic boron nitride powder or a sintered body thereof, a sintered body of a mixture of boron nitride and aluminum nitride, or a structure using two or more thereof. Good.

  A structure that increases the strength and maintains the shape by attaching one or both of glass, epoxy resin, polyimide resin, or two or more of these having high electrical resistivity to one or both of the package surface and the printed circuit board surface of this structure. It can be a body.

  FIG. 3 is a plan view when a heating element is attached to the structure of the present invention. In this structure, an electronic component package is mounted by heating and melting the unheated solder inside by transmitting heat generated by attaching a heating element to the periphery of the structure.

FIG. 4 is a side view when a heating element is attached to the structure of the present invention. In order to realize a stable contact state when the heating element is attached to the peripheral portion of this structure, it is desirable that the structure has a structure in which the thickness of the heating element is made slightly thicker than that of the structure.

  FIG. 5 is a side view showing the positional relationship between the structure of the present invention and the pad portion of the substrate when mounted. The structure is positioned and placed so that the through hole of the structure and the pad portion of the substrate correspond to each other.

  FIG. 6 is a side view showing the positional relationship when the structure of the present invention and the electronic component package are mounted. Positioning is performed so that the through hole of the structure and the electrode part of the electronic component package correspond to each other.

  FIG. 7 is a side view showing the positional relationship when the structure, the electronic component package, and the heating element of the present invention are mounted. A heating element is attached to the periphery, and the generated heat is transferred by the structure to heat and melt the unheated solder inside to mount the electronic component package.

  FIG. 8 is a side view in which the heating element is removed after mounting the structure of the present invention and the electronic component package. The heating element can be used repeatedly one after another.

  When the structure of the present invention is mounted, solder may flow into the gap between the substrate and the structure due to a capillary phenomenon, which may cause electrical problems. As a method for preventing this, a structure is provided in which protrusions are provided at the four corners of the lower portion of the structure body in order to provide a sufficient gap between the substrate and the structure body.

  It is also possible to provide a structure in which a heat sink is attached to the structure and the heat sink is attached to the structure after mounting. As a result, heat generated during actual operation of the electronic component package can be quickly dissipated into the air.

  In order to solve the problem that the heat conduction speed of the structure slows down when the structure of the present invention is enlarged, a structure in which a plurality of structures and heating elements are used in combination with each other can be used. Will be transmitted and good implementation will be possible. The structure is combined with a structure in which the heating element can be inserted and removed.

  FIG. 9 is a plan view showing an example of how to attach the heating element when the structure of the present invention is enlarged. Heat from the heating element attached to the center heats the solder uniformly through the structure.

  FIG. 10 is a plan view showing an example of how to remove the heating element after mounting when the structure of the present invention is enlarged. Move and remove the three heating elements in a fixed direction.

  Those having the same function as the structure of the present invention can be attached in advance to the printed circuit board surface or the electronic component package lower surface. Further, by forming an integrated structure with the printed circuit board surface or the electronic component package, a new mounting method for a higher-functional electronic component package can be established.

  When it is necessary to replace the electronic component package after mounting the structure of the present invention, the electronic component package can be easily removed by reattaching the heating element and reheating the structure.

DESCRIPTION OF SYMBOLS 1 Structure 2 Solder paste 3 Heat generating body 4 Heat conduction from a heat generating body 5 Board | substrate 6 Pad part 7 Electronic component package

Claims (6)

  A through-hole is provided in a sheet-like board that is larger than the radius of the ball grid of the electrode part of the package on which the thickness is mounted and smaller than the diameter, at positions corresponding to the electrode part of the package and the pad part of the printed circuit board. A structure for mounting an electronic component package, characterized by using a material having high resistivity.   The structure material is either single crystal diamond, polycrystalline diamond or sintered body thereof, cubic boron nitride or sintered body thereof, boron nitride sintered body, aluminum nitride sintered body, or two of them. The electronic component package mounting structure according to claim 1, wherein the above is used.   As the structure material, diamond powder or a sintered body thereof, cubic boron nitride powder or a sintered body thereof, a sintered body of a mixture of boron nitride and aluminum nitride, or two or more of them are used. The electronic component package mounting structure according to claim 1, wherein:   4. One or both of glass, epoxy resin, polyimide resin having high electrical resistivity, or two or more thereof are attached to one or both of the package surface and the printed circuit board surface of the structure. 2. A structure for mounting an electronic component package according to item 1.   5. The electronic component package mounting structure according to claim 1, wherein a heat sink is attached to the structure. A through-hole is provided in a sheet-like board that is larger than the radius of the ball grid of the electrode part of the package on which the thickness is mounted and smaller than the diameter, at positions corresponding to the electrode part of the package and the pad part of the printed circuit board. A mounting method using a mounting structure for an electronic component package, characterized by using a material having high resistivity.

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