Abstract:
The present invention provides a spreading apparatus with a vibrator and a spreading method. The spreading apparatus includes a pattern plate, a scraper module, and a vibrator. The pattern plate includes at least a hole and carries a material. The scraper module scrapes the material on the pattern plate, causing the material to pass through the hole to a substrate. The vibrator, which is connected to the pattern plate or the scraper module, vibrates the pattern plate or the scraper module.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a spreading apparatus and a spreading method, especially to a spreading apparatus with a vibrator and a spreading method thereof.  
         [0003]     2. Description of the Prior Art  
         [0004]     Generally speaking, a printed circuit board (PCB) has many devices thereon such as IC, resistor, inductor, capacitor, and many others, thereby allowing a circuitry with a certain function to be formed on the printed circuit board. For this reason, there are many welds on a printed circuit board whose locations are corresponding to the locations of the devices disposed on the printed circuit board. These welds are utilized to joint the devices and the printed circuit board. To facilitate the welding effect and to enhance the welding efficiency, the welds on the printed circuit board are often spread with some weld facilitating material before the weld is executed. Solder paste is the most frequently used material among the weld facilitating materials.  
         [0005]     Spreading solder paste on the printed circuit board includes several regular procedural steps. First, a pattern plate is made according to the locations of the welds on the printed circuit board. Steel is often selected as the material for the pattern plate, so this kind of pattern plate is often called a solder spreading steel plate. Once a solder spreading steel plate is made, it is easy to see that the solder spreading steel plate has many holes thereon, which are corresponding to the locations of welds on the printed circuit board, allowing solder paste to pass through and to locate on the corresponding welds on the printed circuit board. Second, during the process of spreading solder paste on the printed circuit board, the solder spreading steel plate is initially placed on the printed circuit board such that the holes on the solder spreading steel plate aim at the welds on the printed circuit board. Third, solder paste is placed on the solder spreading steel plate and a scraper is utilized to scrape solder paste back and forth on the solder spreading steel plate. Therefore, when solder paste spreads over the holes, solder paste passes through the holes and locates on the welds on the printed circuit board. The aforementioned procedures are described in detail with the aid of drawings. Please refer to both  FIG. 1  and  FIG. 2  together.  FIG. 1  illustrates a first operation of a prior art spreading apparatus, and  FIG. 2  illustrates a second operation of the prior art spreading apparatus. At the beginning of the spreading process, a solder spreading steel plate  120  is placed precisely on the printed circuit board  110  such that the holes on the solder spreading steel plate  120  aim at the welds on the printed circuit board  110 . When the steel scraper set  130  starts to scrape the solder paste  140  along the direction A, as shown in  FIG. 1 , the steel scraper  131  lifts up to move off the solder spreading steel plate  120 , and the steel scraper  132  goes down to touch the solder spreading steel plate  120 . When the steel scraper  132  moves along the direction A, it scrapes the solder paste  140  into the holes of the solder spreading steel plate  120 . Thus, the solder paste  140  passes through the holes and locates on the welds on the printed circuit board  110 . It is well known in the industry that during the process of spreading solder paste, the steel scraper set  130  scrapes the solder paste  140  back and forth on the solder spreading steel plate  120 . Therefore, after the steel scraper set  130  moves along the direction A from the right side to the left side, the steel scraper  132  lifts up to move off the solder spreading steel plate  120 , and the steel scraper  132  goes down to touch the solder spreading steel plate  120  (as shown in  FIG. 2 ). Then, the steel scraper  131  moves along the direction B, and it scrapes the solder paste  140  into the holes of the solder spreading steel plate  120 . Thus, the solder paste  140  passes through the holes on the solder spreading steel plate  120  and locates on the welds on the printed circuit board  110 . Because the steel scraper set  130  moves back and forth along the directions A and B, all welds on the printed circuit board  110  are smeared with solder paste.  
         [0006]     As mentioned above, the steel scraper set  130  utilizes the steel scraper  131  and the steel scraper  132  alternatively to scrape the solder paste  140  back and forth on the solder spreading steel plate  120 . When the steel scraper set  130  moves from right to left, as shown in  FIG. 1 , the steel scraper  132  goes down and the steel scraper  131  lifts up such that the steel scraper  132  takes charge of scraping the solder paste  140 . Similarly, when the steel scraper set  130  scrapes from left to right, as shown in  FIG. 2 , the steel scraper  131  goes down and the steel scraper  132  lifts up such that the steel scraper  131  takes charge of scraping the solder paste  140 . However, due to the fact that the solder paste  140  usually adheres to the steel scraper  131  and the steel scraper  132 , when the steel scraper  131  or the steel scraper  132  lifts up, the solder paste  140  is pulled up. Therefore, if there are welds at the location where the steel scraper  131  or the steel scraper  132  lifts up, the solder paste  140  is usually pulled up by the steel scraper  131  or the steel scraper  132  because of the adhesion between the solder paste  140  and the steel scraper  131  or the steel scraper  132 . As a result, there will be no solder paste  140  on these welds or the amount of solder paste  140  on these welds will be deficient. Moreover, due to the adhesion between the solder paste  140  and the steel scraper  131  or the steel scraper  132 , when the steel scraper  131  or the steel scraper  132  scrapes over the holes of the solder spreading steel plate  120 , some solder paste  140  adheres to steel scraper  131  or the steel scraper  132 , resulting in non-uniform spread of the solder paste  140 .  
       SUMMARY OF THE INVENTION  
       [0007]     It is therefore an objective of the claimed invention to provide a spreading apparatus with a vibrator and a spreading method to solve the problem.  
         [0008]     According to an embodiment of the claimed invention, a spreading apparatus is disclosed. The spreading apparatus includes a pattern plate, a scraper module, and a vibrator. The pattern plate includes at least a hole and carries a material. The scraper module scrapes the material on the pattern plate, causing the material to pass through the hole to a substrate. The vibrator, which is connected to the pattern plate or the scraper module, vibrates the pattern plate or the scraper module.  
         [0009]     According to another embodiment of the claimed invention, a spreading method is disclosed. The spreading method comprises: placing material on a pattern plate; vibrating the pattern plate or a scraper module; and utilizing the scraper module to scrape the material on the pattern plate, causing the material to pass through the pattern plate to a substrate.  
         [0010]     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. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  is a first operation of a prior art spreading apparatus.  
         [0012]      FIG. 2  is a second operation of the prior art spreading apparatus.  
         [0013]      FIG. 3  is a first operation of a solder spreading apparatus according to a first embodiment of the present invention.  
         [0014]      FIG. 4  is a second operation of a solder spreading apparatus according to a first embodiment of the present invention.  
         [0015]      FIG. 5  is a solder spreading apparatus according to a second embodiment of the present invention.  
         [0016]      FIG. 6  is a solder spreading apparatus according to a third embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0017]     Please refer to  FIG. 3 .  FIG. 3  illustrates a first operation of the solder spreading apparatus according to a first embodiment of the present invention. In this embodiment, the steel scraper  131  and the steel scraper  132  are equipped with a vibrator  210  and a vibrator  220  respectively. The vibrator  210  and the vibrator  220  can be any kind of vibrator that is capable of being stably set on the steel scraper  131  and the steel scraper  132 . In general, the most frequently utilized vibrator is the ultrasonic vibrator, because the ultrasonic vibrator is small sized making it ideal for being set on the steel scraper  131  and the steel scraper  132 . Additionally, the ultrasonic vibrator has an extremely high vibrating frequency such that it provides a high efficiency vibration. When the steel scraper set  130  starts to scrape the solder paste along  140  along the direction A, the steel scraper  131  lifts up to move off the solder spreading steel plate  120 , and the steel scraper  132  goes down to touch the solder spreading steel plate  120 . At the same time, the vibrator  220  is activated (i.e., turned on). When the steel scraper set  130  scrapes the solder paste  140  from right to left, the steel scraper  132  keeps vibrating due to the vibrator  220 . Because the steel scraper  132  vibrates, the solder paste  140  would pass through the holes on the solder spreading steel plate  120  uniformly and locates on the welds of the printed circuit board  110  when the solder paste  140  is scraped over the holes on the solder spreading steel plate  120 . The vibrator  220  vibrates the steel scraper  132 , so the solder paste  140  scraped into the holes will not be drawn out by the steel scraper  132  when the steel scraper  132  scrapes transversely apart from the holes. The steel scraper  132  continues vibrating and simultaneously scraping the solder paste  140  until the steel scraper set  130  moves to the left most side of the solder spreading steel plate  120 .  
         [0018]     Please refer to  FIG. 4 .  FIG. 4  illustrates a second operation of the solder spreading apparatus according to a first embodiment of the present invention. In this embodiment, after the steel scraper set  130  moves to the left most side of the solder spreading steel plate  120 , the steel scraper  132  lifts up to move off the solder spreading steel plate  120 , and the steel scraper  131  goes down to touch the solder spreading steel plate  120 . It is noted that when the steel scraper  132  lifts up, the vibrator  220  continues vibrating. Therefore, the solder paste  140  is not easily pulled up off the solder spreading steel plate  120  when the steel scraper  132  lifts up due to the vibration of the steel scraper  132 . If there is a hole at the location where the steel scraper  132  stops, the solder paste  140 , which is already scraped in the hole, will not be affected when the steel scraper  132  lifts up. As a result, the non-uniform spreading problem will not occur. In this embodiment, after the steel scraper  132  lifts up and the steel scraper  131  goes down, the vibrator  220  deactivates (i.e., turns off) and the vibrator  210  turns on. Afterwards, as shown in  FIG. 4 , when the steel scraper  131  scrapes the solder paste  140  along the direction B from left to right, the vibrator  210  vibrates the steel scraper  131 . Similarly, when the steel scraper  131  scrapes the solder paste  140 , the steel scraper  131  keeps vibrating due to the vibrator  210 . Because the steel scraper  131  vibrates, the solder paste  140  would pass through the holes on the solder spreading steel plate  120  uniformly and locates on the welds of the printed circuit board  110  when the solder paste  140  is scraped over the holes on the solder spreading steel plate  120 . The vibrator  210  vibrates the steel scraper  131 , so the solder paste  140  scraped into the holes will not be drawn out by the steel scraper  131  when the steel scraper  131  scrapes transversely apart from the holes. The steel scraper  131  continues vibrating and scraping the solder paste  140  at the same time until the steel scraper set  130  moves to the right most side of the solder spreading steel plate  120 .  
         [0019]     After the steel scraper set  130  moves to the right most side of the solder spreading steel plate  120 , the steel scraper  131  lifts up to move off the solder spreading steel plate  120 , and the steel scraper  132  goes down to touch the solder spreading steel plate  120 . It is noted that when the steel scraper  131  lifts up, the vibrator  210  continues vibrating. Therefore, the solder paste  140  is not easily pulled up off the solder spreading steel plate  120  when the steel scraper  131  lifts up due to the vibration of the steel scraper  131 . If there is a hole at the location where the steel scraper  131  stops, the solder paste  140 , which is already scraped in the hole, will not be affected when the steel scraper  131  lifts up. As a result, the non-uniform spreading problem will not occur.  
         [0020]     In short, by equipping the steel scraper set  130  with vibrators  210  and  220 , the steel scraper  131  or the steel scraper  132  scrapes the sold paste  140  and vibrates at the same time, causing the solder paste  140  to pass through the holes on the solder spreading steel plate  120  and locate on the welds on the printed circuit board  110 . In addition, the adhesion between the solder paste  140  and the steel scraper  131  or the steel scraper  132  becomes weaker because of the vibration. When the steel scraper  131  or the steel scraper  132  lifts up, the solder paste is not easily pulled up.  
         [0021]     Moreover, according to the present invention, there is an alternative way to spread the solder paste  140  uniformly on the printed circuit board  110 : setting a vibrator on the solder spreading steel plate  120 . Please refer to  FIG. 5 .  FIG. 5  illustrates a solder spreading apparatus according to a second embodiment of the present invention. The solder spreading steel plate  120  is equipped with a vibrator  310  such that during the process of spreading the solder paste  140 , the solder paste  140  is uniformly spread on the printed circuit board  110  due to the vibration of the solder spreading steel plate  120  rather than the steel scraper  131  or the steel scraper  132 . In other words, the vibrator  310  on the solder spreading steel plate  120  provides the vibration required by the solder spreading steel plate  120  or the steel scrapers  131  and  132  to prevent the adhesion of the solder paste  140  to the steel scrapers  131  and  132 . The vibrator  310  is preferably an ultrasonic vibrator because an ultrasonic vibrator is small sized and light weighted making it ideal for being set on the solder spreading steel plate  120 , and it also has an extremely high vibrating frequency such that it provides a high efficiency vibration.  
         [0022]     Please refer to  FIG. 6 .  FIG. 6  illustrates a solder spreading apparatus according to a third embodiment of the present invention. In this embodiment, the steel scraper  131 , the steel scraper  132 , and the solder spreading steel plate  120  are equipped respectively with vibrators  210 ,  220 , and  310  at the same time. When the steel scraper  132  moves from right to left, the vibrator  220  and the vibrator  310  turn on, causing the steel scraper  132  and the solder spreading steel plate  120  to vibrate. Therefore, the solder paste  140  passes through the holes on the solder spreading steel plate  120  and spreads uniformly on the welds on the printed circuit board  110 . Because the vibrator  220  vibrates the steel scraper  132  and the vibrator  310  vibrates the solder spreading steel plate  120 , the solder paste  140  scraped into the holes will not be drawn out by the steel scraper  132  when the steel scraper  132  scrapes transversely apart from the holes. Similarly, when the steel scraper  131  scrapes from left to right, the vibrator  210  and the vibrator  310  turn on, causing the steel scraper  131  and the solder spreading steel plate  120  to vibrate. Therefore, the solder paste  140  passes through the holes on the solder spreading steel plate  120  and spreads uniformly on the welds on the printed circuit board  110 . Because the vibrator  210  vibrates the steel scraper  131  and the vibrator  310  vibrates the solder spreading steel plate  120 , the solder paste  140  scraped into the holes will not be drawn out by the steel scraper  131  when the steel scraper  131  scrapes transversely apart from the holes.  
         [0023]     In summary, a vibrator is set either on the steel scraper or on the solder spreading steel plate to enhance the efficiency of spreading the solder paste such that the solder paste is uniformly spread on the welds of the printed circuit board. In addition, because of the vibration of the steel scraper, the solder paste is not adhered to the steel scraper, so the amount of solder paste required in the spreading process is reduced.  
         [0024]     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.