A method of surface grinding of planar member

Abstract: The invention relates to a method of surface grinding of a planar member (2). An upstream side rectangular brush (10) and a downstream side rectangular grinding means (15) are moved simultaneously.

Description: The present invention relates to a grinding device for grinding a planar member, comprising grinding means and driving means for moving said grinding means Description of the Prior Art An article abrading apparatus having an article carrier belt and arms including abrading members moving across the belt with abrasive reciprocating motion is already known (US-A-3 734 700). This apparatus which may be used for abrading circuit boards and the like comprises lifting means associated with said arms for orienting the elevation of each arm above an article on the belt to make abrading contact with the surfaces of said circuit boards under each arm. Technical Problem The object of the present invention is to solve the above mentioned problem, and to provide an improved grinding method to perform two grinding functions continuously by one device which may have a brush and a grinding stone. Solution of the Technical Problem According to the present invention, the above problem is solved by a grinding device according to claim 1 and, respectively, by a method according to claim 8. A conventional rotary grinding head can never have two functions, and only the surface grinding device of the invention having a rectangular grinding member of substantially planar grinding surface supported through an eccentric shaft to perform plane eccentric motion can allow a constructional possibility. Advantageous Effects of the Invention The grinding member having two different grinding means and driven by one eccentric shaft, according to the present invention, performs two grinding processes on one table so that surface finishing process of planar member is simplified. Brief Description of the Drawings Figure 1 is a perspective view of a surface grinding apparatus for surface grinding printed wiring boards, according to one embodiment of the method of the present invention. Figure 2 is a schematic front view of a portion of Fig. 1. Figure 3 is a perspective view of a portion of Fig. 1 showing surface grinding of a printed wiring board. Figure 4 is a plan view of a brush and a grinding stone, according to another embodiment of the present invention, and Figure 5 is an end view of Fig. 4. Detailed Description of the Preferred Embodiments Fig. 1 illustrates a surface grinding apparatus 1 including a conveyor device 3 to convey printed wiring boards 2 as shown in Fig. 2. Also shown is a grinding device 4 for grinding a surface 2a of the printed wiring board 2 which is conveyed by the conveyor device 3 as well as an apparatus body 5 receiving the conveyor device 3 and the grinding device 4. The conveyor device 3 includes rotatably supported two conveyor rolls 6 and 7, and an endless belt 8 around the rolls 6 and 7. Guide rolls 9 guide the printed wiring boards 2 on the belt 8. An eccentric shaft 12 drives a brush support 11 with a brush body 10 eccentrically on one plane so that every portion of the brush body 10 receives the same kinetic energy. According to the present invention, the grinding device 4 includes the brush body 10, the brush support 11, a grinding stone 15 which is downstream from and parallel with the brush body 10, and the eccentric shaft 12 secured with the brush support 11. The brush body 10 is attached under the relatively long and rectangular planar brush support 11. The brush support 11 and the grinding stone 15 are driven eccentrically through the eccentric shaft 12. The brush support 11 and the grinding stone 15 are supported such that the urging forces to grind the surface 2a of the printed wiring board 2 can be regulatable. However, the brush support 11 and the grind stone 15 may be secured with each other as desired when only the urging force of the grinding stone 15 is to be regulated. As the brush support 11 and the grinding stone 15 are driven by the eccentric shaft 12 on one plane, the upstream side brush body 10 forms grinding traces on the surface of the printed wiring board 2 uniformly and the downstream side grinding stone 15 forms smooth ground surface smoothing out of the ground traces of the brush 10. On both sides of the apparatus body 5, inlet and outlet openings 13 and 14 are formed to supply and discharge the printed wiring boards. Now, the method of grinding the surface 2a of the printed wiring board 2 by the surface grinding apparatus 1 will be described. At first, printed wiring boards 2 to be surface finished are supplied through the opening 13. The supplied printed wiring boards 2 are fed sequentially through the conveyor device 3 to the grinding device 4. The brush body 10 and the grinding stone 15 are driven eccentrically on a plane through the eccentric shaft 12 to grind the surface 2a of the printed wiring board 2. The eccentric motion of the brush body 10 and the grinding stone 15 forms generally spiral brush traces on the surface 2a by the upstream side brush 10, and then the brush traces are ground off by the downstream grinding stone 15. Then, the surface finished printed wiring board 2 is conveyed by the conveyor belt 8 to the discharge outlet 14. Figs. 4 and 5 show another embodiment which is preferable to surface grind relatively soft material, e. g. copper clad on the printed wiring board 2. Same reference numeral shows same or similar part or portion with the first embodiment. The brush 10 includes many brush bundles 16 and the fibers forming the bundle 16 contain grinding material. The brush body 11 has many water feed openings 18 to inject water from water supply, not shown. The grinding stone 15 which is parallel with the brush body 11 is a rubber grinding stone in the embodiment shown. The arrangement can be used as parallel two different grinding means without necessitating a precise relative position regulating device to obtain the required surface finish. As described in detail, according to the present invention, planar brush body 10 and the parallel grinding stone 15 are simultaneously and eccentrically driven by one eccentric shaft 12 on one plane so that uniform brush traces are formed upstream side by the brush 10 and the brush traces are smoothed out by the downstream side grinding stone 15. Thus, the surface 2a of the printed wiring board 2 can be surface finished by one process, and the finished surface is sufficient to perform later processes of good laminate adhering, good printing ink border and good fine pattern forming. Further, as the brush is planar, in contrast to conventional circular brush, the brush can be manufactured easily to reduce manufacturing cost. Also, as the apparatus is essentially an apparatus to perform one grinding function so that simple and cheap construction and short working line can be realized. Also, in the embodiment shown in Fig. 1, the grinding brush device 4 may include water injection means, not shown, to inject high pressure water into the brush body 10 to wash out copper powder and debris from the surface 2a of the printed wiring board to obtain clean finish. As described, according to the present invention, two different kinds of plane finishing processes can be performed by only one work shaft simply and accurately. Thus, simple apparatus, easy working, low cost, and accurate finishing can be realized.

Claims: Grinding device for grinding a planar member (2) comprising grinding means (15) and driving means (12) for moving said grinding mean (15), characterized by : a) a brush support (11) having a substantially rectangular brush body (10) on its lower side; b) a substantially rectangular grinding means (15) connected to the brush support (11), the lower end of said grinding means (15) being arranged substantially on the same level as the lower end of said brush body (10); c) a shaft (12) being connected to said driving means (12) and to both said brush support (11) and said grinding means (15) and being arranged eccentrically with respect to the center axis of said brush support (11) and said grinding means (15). Grinding device according to claim 1, characterized in that said brush support (11) and said grinding means (15) are slabs having rectangular cross-sections, the longer sides of said slabs being arranged parallel to each other. Grinding device according to claim 1, characterized by a conveyor device (3) for supplying a planar member (2) to said brush body (10) and said grinding means (15). Grinding device according to claim 3, characterized by a housing (1) having a first slot (13) for introducing said planar member (2) into said housing (1) and a second slot (14) for removing said planar member (2) from said housing, the conveyor device (3) being arranged between said first and said second slot (13, 14). Grinding device according to claim 1, characterized by high pressure water means for injecting water into said brush body (10) to wish out copper powder and debris from the surface (2a) of the grinded planar member (2). Grinding device according to claim 1, characterized in that the planar member is a printed wiring board (2) and that said printed wiring board is grinded on the conveyor device (3) by grinding means (15). Grinding device according to claim 1, characterized in that the brush support (11) and a grinding stone (15) are supported such that the urging forces to grind the planar member (2) are regulatable. Method for grinding a planar member (2) with a grinding means (15) and with driving means (12) for moving said grinding means (15), characterized by the steps: a) moving a planar member (2) to be grinded from a first position (13) to a second position (14); b) grinding and cleaning said planar member (2) between said first position (13) and said second position (14) by eccentrically moving said grinding means (15) together with a brush means (10) by a shaft (12) being arranged eccentrically with respect to the center of said grinding means (15) over the surface of said planar member (2), whereby said grinding means (15) is arranged between said second position (14) and said brush means (10), whereby the grinding means is connected to the brush support and whereby both the grinding means and the brush means are substantially rectangular. Method according to claim 8, characterized in that a plurality of planar members (2) to be grinded are successively supplied to the grinding and cleaning means (15, 10).

Inventors: KUBO ISAMU, SEKI KAMEHARU, KUBO, ISAMU, SEKI, KAMEHARU
Applicants: NIPPON CMK KK, NIPPON CMK CORP.
Application year: 1989
Main classification: B24B7
IPC codes: B24B7, H05K3, B24B41