Patent Application
20190275600
The invention relates to a flux transfer tool and a flux transfer method and, more particularly, to a flux transfer tool and a flux transfer method for improving a flux transfer process of a ball grid array (BGA) package and Chip Scale Package (CSP).
BGA and CSP techniques have become more common in recent years for connecting high-density IC components onto circuit boards. In BGA and CSP techniques, a flux transfer tool is used to transfer flux to a plurality of bond pads of a substrate to remove oxidized film and to provisionally fix solder balls before the solder balls are mounted on the bond pads by a reflow process.
Referring to
As demand for electronic devices that are smaller and more powerful continues to increase, the size of the solder ball and the pitch between two adjacent solder balls in a BGA and CSP package become smaller and smaller accordingly. However, due to the limitation of the spacing S between two adjacent flux transfer pins 10, the size of the solder ball cannot be smaller than about 0.15 mm and the pitch between two adjacent solder balls cannot be smaller than about 0.3 mm, such that the development of the electronic devices is limited.
The invention provides a flux transfer tool and a flux transfer method for improving a flux transfer process of a BGA and CSP package, so as to solve the aforesaid problems.
According to an embodiment of the invention, a flux transfer tool comprises a flux tray, a baseplate, a flux transfer head and a flexible member. The baseplate is disposed on the flux tray. The baseplate has a plurality of holes formed thereon. The flux transfer head is arranged corresponding to the flux tray and configured to move with respect to the flux tray. The flexible member is disposed on the flux transfer head. The flexible member faces the baseplate when the flux transfer head is located above the flux tray. When the holes are filled with a flux, the flux transfer head moves towards the flux tray, such that the flexible member adsorbs the flux from the holes.
According to another embodiment of the invention, a flux transfer method is performed by a flux transfer tool. The flux transfer tool comprises a flux tray, a baseplate, a flux transfer head and a flexible member. The baseplate is disposed on the flux tray. The baseplate has a plurality of holes formed thereon. The flux transfer head is arranged corresponding to the flux tray and configured to move with respect to the flux tray. The flexible member is disposed on the flux transfer head. The flux transfer method comprises steps of filling the holes with a flux; moving the flux transfer head towards the flux tray, such that the flexible member adsorbs the flux from the holes; moving the flux transfer head to a position above a substrate, wherein the substrate has a plurality of bond pads and the holes of the baseplate are arranged corresponding to the bond pads of the substrate; moving the flux transfer head towards the substrate to transfer the flux from the flexible member to the bond pads of the substrate.
As mentioned in the above, the invention utilizes the flexible member of the flux transfer head to adsorb the flux from the holes of the baseplate and then transfers the flux from the flexible member to the bond pads of the substrate by the flux transfer head. Since the holes on the baseplate can be adjusted in accordance with the size of the solder ball and the pitch between two adjacent solder balls, the BGA and CSP package can be miniaturized according to practical demand. Accordingly, the invention can improve the flux transfer process of the BGA and CSP package and save the cost of manufacturing the flux transfer pin of the prior art.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
Referring to
As shown in
As shown in
The flux transfer method of the invention shown in
When the holes 320 of the baseplate 32 are filled with the flux 40, the flux transfer head 34 moves towards the flux tray 30, such that the flexible member 36 contacts and adsorbs the flux 40 from the holes 320 of the baseplate 32, as shown in
Then, the flux transfer head 34 moves to a position above the substrate 5, as shown in
In this embodiment, the holes 320 on the baseplate 32 can be adjusted in accordance with the size of the solder ball and the pitch between two adjacent solder balls, so the BGA and CSP package can be miniaturized according to practical demand.
As mentioned in the above, the invention utilizes the flexible member of the flux transfer head to adsorb the flux from the holes of the baseplate and then transfers the flux from the flexible member to the bond pads of the substrate by the flux transfer head. Since the holes on the baseplate can be adjusted in accordance with the size of the solder ball and the pitch between two adjacent solder balls, the BGA and CSP package can be miniaturized according to practical demand. Accordingly, the invention can improve the flux transfer process of the BGA and CSP package and save the cost of manufacturing the flux transfer pin of the prior art.
Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.
