Patent Publication Number: US-4547964-A

Title: Method for the manufacture of a printed-circuit board connector

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a method of making a printed-circuit board connector for connection with a thin, miniaturized multi-connector formed at an end of a printed-circuit board, for example, a flexible printed-circuit board. 
     A conventional printed-circuit board connector for receiving a multi-connector formed at an end portion of a printed-circuit board is such as follows: A housing is formed by molding of an insulating material, such as a synthetic resinous material. An elongated opening is formed in the housing for insertion thereinto of a mating connector, a plurality of contact mounting grooves are formed in the opening at regular intervals in its lengthwise direction thereof, and contact pieces are inserted into and fixed to the contact mounting grooves one by one, thereby making the connector. Accordingly, a precise assembling operation is needed for mounting the contacts in the housing and the reduction of the pitch of arrangement of the contacts or miniaturization of the connector in its entirety would introduce difficulty in the manufacturing and assembling operation. Further, in order to prevent soldering flux, when soldering connector terminals for electrical connection, from flowing into the housing through the terminals, the prior art involves a special step for applying adhesive to terminal leading-out portions of the housing. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide a printed-circuit board connector manufacturing method which permits efficient fabrication, with a simple manufacturing process, of a connector having contact pieces arranged at small pitches. 
     According to the printed-circuit board manufacturing method of the present invention, a contact array plate, which has a plurality of contact pieces formed integrally with substantially parallel first and second coupling pieces to extend therebetween, is made out of a sheet of metal. Then a first housing half is molded integrally with the contact base plate so that its central portion may be buried in the housing half. After this, the first and second coupling portions of the contact base plate are cut out to separate the contact pieces into individual ones. Next, the contact pieces are bent along the peripheral surface of the first housing half to form contact propers. Then a second housing half is fixed to the first housing half with the contact propers inside the housing assembly. Between the first and second housing halves thus fixedly assembled is defined an insertion opening for receiving a mating connector. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a plan view showing an example of a contact array plate; 
     FIG. 2 is a plan view showing the contact array plate molded with a first housing half; 
     FIG. 3 is a cross-sectional view taken on the line 11--11 of FIG. 2; 
     FIG. 4 is a right side view of FIG. 2; 
     FIG. 5 is a front view of FIG. 2; 
     FIG. 6 is a bottom view of FIG. 2; 
     FIG. 7 is a cross-sectional view, corresponding to FIG. 3, showing the state in which contact pieces are bent; 
     FIG. 8 is a plan view showing an example of a second housing half; 
     FIG. 9 is a front view of FIG. 8; 
     FIG. 10 is a left side view of FIG. 8; 
     FIG. 11 is a cross-sectional view taken on the line 11--11 of FIG. 8; 
     FIG. 12 is a front view of a fixture 35; 
     FIG. 13 is a left side view of FIG. 12; 
     FIG. 14 is a cross-sectional view, corresponding to FIG. 3, showing a connector produced according to the present invention; 
     FIG. 15 is a plan view of the connector shown in FIG. 14; 
     FIG. 16 is a front view, partly cut away, of FIG. 15; 
     FIG. 17 is a bottom view of FIG. 15; 
     FIG. 18 is a perspective view illustrating an example of the connector produced according to the present invention, a mating connector and a printed-circuit board on which the connector is mounted; 
     FIG. 19 is a perspective view showing another example of the connector produced according to the present invention, the mating connector and a printed circuit board on which the connector is mounted; 
     FIG. 20 is a perspective view showing another example of the connector produced according to the present invention and a printed-circuit board on which the connector is mounted; 
     FIG. 21 is a plan view illustrating still another example of the connector produced according to the present invention; 
     FIG. 22 is a bottom view of FIG. 21; 
     FIG. 23 is a cross-sectional view taken on the line 23--23 of FIG. 21; 
     FIG. 24 is a front view, partly cut away, of FIG. 21; 
     FIG. 25 is a perspective view showing one part of each of the first and second housing halves assembled together and a coupling block disassembled therefrom; 
     FIG. 26 is a perspective view illustrating another example of the connector produced according to the present invention; 
     FIG. 27 is a perspective view showing the first housing half in FIG. 26; 
     FIG. 28 is a perspective view showing the second housing half in FIG. 26; 
     FIG. 29 is a cross-sectional view, corresponding to FIG. 14, of FIG. 26; 
     FIG. 30 is a perspective view showing a flexible printed-circuit board connector; and 
     FIG. 31 is an exploded perspective view of FIG. 30. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A description will be given, with reference to the drawings, of an example of the printed-circuit board connector manufacturing method of the present invention. 
     The manufacture starts with the preparation of a contact array plate 14 of the type as shown in FIG. 1 which is formed by a sheet of metal. The contact array plate 14 comprises first and second thin, rectangular parallel coupling pieces 11 and 12 and a plurality of band-shaped contact pieces 13 1 , 13 2 , . . . which are of the same shape and formed integrally with the coupling pieces 11 and 12 to extend therebetween and are arranged at regular intervals lengthwise thereof. The contact array plate 14 can be obtained by press work or chemical etching of sheet metal. 
     The contact pieces 13 1 , 13 2 , . . . have at one end contact portions 13 r1 , 13 r2 , . . . which are formed by press work to extend lengthwise thereof. 
     A first housing half 10 is formed by molding as a unitary structure with the contact array plate 14 in such a manner that the intermediate portions of its contact pieces may be buried in the housing half 10 as shown in FIGS. 2 to 6. The housing half 10 is a rectangular-parallelepiped-shaped molding of an insulator material, such as, for instance, synthetic resin and a surface 15h of the housing half 15 extending lengthwise thereof is substantially flat. The contact array plate 14 is assembled with the housing half 10 so that the central portions of the contact pieces 13 1 , 13 2 , . . . are buried therein in parallel with the abovesaid surface 15h, with their opposite end portions extending from surfaces 15a and 15b of the housing half 10 adjacent to the surface 15h. One marginal edge of a face 15c on the opposite side from the face 15h is rounded to form a curved face 15 co  towards the face 15h. In the face 15c are cut parallel contact receiving grooves 16 1  , 162, . . . corresponding to the positions of the contact pieces 13 1 , 13 2 , . . . , respectively. The contact receiving grooves 16 1 , 16 2 , . . . are extended at one end to a face 15a of the housing half 10 which is contiguous to the curved face 15 co  and the other end portions of the grooves are cut deep to provide relieves 1 1 , 1 2 , . . . . The contact receiving grooves 16 1 , 16 2 , . . . are a little wider than the contact pieces 13 1 , 13 2 , . . . . 
     A thin, flat projecting base plate 21 is formed integrally with the first housing half 10 on a face 15b opposite from the face 15a to extend at right angles to the face 15c. The projecting base plate 21 has recesses 22 1  and 22 2  at both end portions thereof in the lengthwise direction of the housing half 10. The marginal edge of the projecting base plate 21 is tapered on the projecting end side thereof as indicated by 21a. Both end portions of the face 15c respectively have formed therein grooves 23 1  and 23 2  adjacent to the projecting base plate 21 to extend in parallel to the lengthwise direction of the contact pieces 13 1 , 13 2 , . . . . In order to hold the contact array plate 14 in a molding die during molding, an elongated groove 15l is cut in the face 15h in the direction perpendicular to the contact pieces 13 1 , 13 2 , . . . . 
     From the viewpoint of improving productivity, it is also possible to form the first and second coupling pieces 11 and 12 in a further elongated shape, to form a plurality of sets of contact pieces 13 1 , 13 2 , . . . integrally with the coupling pieces 11 and 12 at regular intervals and to mold a plurality of the housing halves 10 as a unitary structure with the respective sets of contact pieces 13 1 , 13 2 , . . . . 
     Next, the plurality of contact pieces 13 1 , 13 2 , . . . of the contact array plate 14 are severed into individual contact pieces. That is, the first and second coupling pieces 11 and 12 of the contact array plate 14 molded integrally with the first housing half 10 as described above are cut off along broken lines 13A--13A and 13B--13B shown in FIG. 6 by a cutter to separate the interconnected contact pieces 13 1 , 13 2 , . . . into independent ones. 
     The contact pieces 13 1 , 13 2 , . . . thus separated are bent through using the first housing half 10 as a bending die to form contact propers on the first housing half 10. That is, as shown in FIG. 7, the contact pieces 13 1 , 13 2 , . . . projecting out of the face 15a of the first housing half 10 are bent along curved surfaces of the corresponding contact piece receiving grooves 16 1 , 16 2 , . . . adjacent the top (as illustrated) of the housing half 10, and their free end portions are bent into the relieves 1 1 , 1 2 , . . . at the contact portions 13 r1 , 13 r2 , . . . . Removing the bending force, the contact pieces 13 1 , 13 2 , . . . , owing to their resiliency, spring back with their free end portions far away from the said curved surfaces of the contact piece receiving grooves 16 1 , 16 2 , . . . , providing contact propers 13 c1 , 13 c2 , . . . in position in the contact piece receiving grooves 16 1 , 16 2 , respectively. The contact propers 13 c1 , 13 c2 , . . . are resiliently displaceable in a direction perpendicular to the face 15h. It is also possible to bend the contact pieces 13 1 , 13 2 , . . . at the positions of the contact portions 13 r1 , 13 r2 , . . . first and then bend the contact pieces 13 1 , 13 2 , . . . along the said curved surfaces of the contact piece receiving grooves 16 1 , 16 2 , . . . respectively. Those portions of the contact pieces 13 1 , 13 2 , . . . projecting out of the face 15b of the first housing half 10 are bent towards the bottom of the housing half 10, i.e., along face 15h to form terminals 2 1 , 2 2 , . . . , respectively. 
     Then a second housing half 30 is fixedly assembled with the first housing half 10 having the plurality of contact propers 13 c1 , 13 c2 , . . . . The second housing half 30 is preformed as a molding of an insulator, such as, for instance, a synthetic resin material. For example, as shown in FIGS. 8 to 11, the second housing half 30 has a thick board-like shape and its opposing end portions are extended at right angles to its face on the same side to form end pieces 41 1  and 41 2 . One marginal edge of the second housing half 30 is rounded to form a curved face 30 co  substantially similar to that 15 co  of the first housing half 10 as shown in FIGS. 10 and 11. As illustrated in FIGS. 8 and 9, fixture mounting recesses 42 1  and 42 2  are formed in the face of the second housing half 30 on the inside of the end pieces 41 1  and 41 2  and in contact therewith. The recesses 42 1  and 42 2  intercommunicate through a coupling recess 42 3  on the side of the marginal edge of the second housing half 30 on the opposite side from the marginal edge where the curved face 30 co  is formed. The recesses 42 1  and 42 2  extend towards the curved face 30 co  to form depressions 43 1  and 43 2  thereunder, respectively. 
     Fixtures 35 and 36 are mounted in the recesses 42 1  and 42 2  of the second housing half 30, respectively. The both fixtures are formed by bending sheet metal of, for example, phosphor bronze into the same shape but symmetrical with each other. As shown in FIGS. 12 and 13 which illustrate the fixture 35, one marginal portion of a substantially rectangular plate member 45 is bent at right angles to extend therefrom to form a bent piece 45e. Substantially one half portion of the other marginal portion of the plate member 45 is bent to extend in the same direction as the bent piece 45e to form a coupling piece 45c. One marginal portion of the coupling portion 45c is bent to form an extended portion 45l perpendicular to both the plate member 45 and the coupling portion and its end portion is folded back to form a resilient portion 45f. The resilient portion 45f has at its end a portion bent inwardly and more than a half part of the bent angle in the width direction is pressed flat to form a plateau 45p, leaving a ridge 45r. The fixture 36 is formed into a shape identical but symmetrical with the fixture 35 of such a shape as described above. 
     As illustrated in FIG. 14, the fixture 35 is attached to the recess 42 1  of the second housing half 30 in such a manner that the extended portion 45l abuts against the bottom of the recess 42 1 , the plate member 45 extends along the end piece 41 1  and the bent piece 45c extends along one marginal edge of the second housing half 30 towards its center. In exactly the same manner the fixture 36 is attached to the recess 42 2  of the second housing half 30. The fixtures 35 and 36 mounted on the second housing half 30 are held with their bent pieces 45e facing each other. 
     As shown in FIGS. 14 to 17, the second housing half 30 is assembled with the first housing half 10. That is, as shown in FIG. 17, the projecting base plate 21 of the first housing half 10 is inserted between the end pieces 41 1  and 41 2  of the second housing half 30 and the end portions of the end pieces 41 1  and 41 2  are fitted into the grooves 23 1  and 23 2  of the first housing half 10 and, further, the end edge of the projecting base plate 21 is fitted into the coupling recess 42 3 . The coupling pieces 45c of the fixtures 35 and 36 are positioned in the recesses 22 1  and 22 2  of the projecting base plate 21, the bent portions between the extended portions 45l and the resilient portions 45f of the fixtures 35 and 36 are inserted into and engaged with the depressions 43 1  and 43 2 , respectively, and the fixtures 35 and 36 are held between the depressions 43 1 , 43 2  of the second housing half 30 and the projecting base plate 21 of the first housing half 10. The first and second housing halves 10 and 30 thus assembled are fusion welded by ultrasonic waves as a unitary structure. The tapered face 21a of the projecting piece 21 is formed for facilitating the ultrasonic fusion. By assembling both housing halves in the manner described, their curved faces 15 co  and 30 co  face each other to define therebetween an opening 61 for receving a connector to be connected as shown in FIGS. 14 and 15. 
     With the circuit board connector thus produced, a mating circuit board connector 9 is inserted into the opening 61 for connection therewith, for example, as shown in FIG. 18. In this case, the curved faces 15 co  and 30 co  of the first and second housing halves 10 and 30 facilitate smooth insertion of the circuit board connector 9 into the opening 61. A printed-circuit board 8 is held between the bent pieces 45e of the fixtures 35 and 36 and the faces of the first and second housing halves 10 and 30 on the opposite side from the opening 61, not shown in FIG. 18, and terminals 2 1 , 2 2 , . . . are respectively soldered to circuits on the printed-circuit board 8. Notches 38 1  and 38 2  are formed in both marginal portions of the insertion end of the circuit board connector 9 and when the circuit board connector 9 is inserted into the opening 61 of the connector, the plateaus 45p of the resilient portions 45f of the fixtures 35 and 36 press the circuit board connector 9 against the contact propers 13 c1 , 13 c2 , . . . and the ridges 45r engage with the notches 38 1  and 38 2  to stably lock the circuit board connector 9 in its installed state. Thus the fixtures 35 and 36 serve both to hold the circuit board 8 and to lock the circuit board connector 9 in its installed state. 
     When the circuit board connector 9 is inserted into and held in the opening 61, the contact propers 13 c1 , 13 c2 , . . . respectively make resilient contact with contact portions of the circuit board connector 9 and resiliently displace towards the bottoms of the contact piece receiving grooves 16 1 , 16 2 , . . . . In this case, the overall reaction force of the contact propers 13 cl , 13 c2 , . . . produces an action of curving the first housing half 10 in a direction perpendicular to the direction in which the circuit board connector 9 is inserted into the opening 61. However, the portion of the first housing half 10 forming the contact receiving grooves 16 1 , 16 2 , . . . is made relatively thick; consequently, the first housing half 10 is able to well withstand the abovesaid curving action, ensuring good contact of the contact propers 13 c1 , 13 c2 , . . . with the contact portions of the circuit board connector 9. In addition, the curved surfaces of the contact receiving grooves 16 1 , 16 2 , . . . can be used as the bending dies for bending the contact propers 13 cl , 13 c2 , . . . as described previously. 
     The fixtures 35 and 36 may be omitted but, in such a case, as shown in FIG. 19, engaging pieces 51 1  and 51 2  (51 2  being not illustrated) are formed integrally with both end portions of the first housing half 10 to extend on the opposite side from the opening 61 and, by use of the engaging pieces 51 1  and 51 2 , the connector is fixed to the circuit board 8. Also it is possible to adopt an arrangement of the type shown in FIG. 20 in which engaging grooves 52 1  and 52 2  are formed in both end faces of the first housing half 10, the circuit board 8 is held between the connector and a fixing piece 44, and engaging pieces 53 1  and 53 2  at both ends of the fixing piece 44 are engaged with the engaging grooves 52 1  and 52 2 , respectively. 
     Incidentally, the second housing half 30 may also be provided with contact propers. For instance, as illustrated in FIGS. 21 to 25, the intermediate portions of contact pieces are buried in the second housing half 30 and the contact pieces are bent through using the surfaces of contact piece receiving grooves to form contact propers 3 1 , 3 2 , . . . and terminals 4 1 , 4 2 , . . . are led out therefrom. As mainly shown in FIG. 25, fitting recesses 63 1 , 63 2  and 64 1 , 64 2  (63 2  and 64 2  being not illustrated) are formed in the corners of both end portions of the first and second housing halves 10 and 30, respectively. A coupling block 65 made of a synthetic resinous material is fitted into the gap between the first and second housing halves 10 and 30 on the back thereof. As shown in FIGS. 21, 24 and 25, holding members 66 1  and 66 2  are formed integrally with both end portions of the coupling block 65 to extend therefrom in the same direction perpendicular to the major surface thereof, and guide projections 67 1 , 67 2  and 68 1 , 68 2  (67 2  being not illustrated) formed in both side portions of the opposing faces of the holding member 66 1  and 66 2  are fitted into the recesses 63 1 , 63 2  and 64 1 , 64 2 , respectively, thus assembling the first and second housing halves 10 and 30 by the coupling block 65. The first and second housing halves 10 and 30 thus assembled are fusion-welded by ultrasonic waves as required. 
     The second housing half 30 need not always be made of the synthetic resinous material but may also be formed, for example, from a sheet of metal. For instance, as shown in FIGS. 26 through 28, a peripheral wall 69 is formed integrally with the first housing half 10 to extend from the marginal portion of the contact piece housing groove forming face except on the side of the face 15a and through holes 71a and 71b are made in the first housing half 10 in contact with the inner surfaces of opposing portions 69a and 69b and, further, a through hole 71c is made in the first housing half 10 in contact with the inner surface of the intermediate portion 69c of the peripheral wall 69 between the opposing portions 69a and 69b thereof. The second housing half 30 is formed by a rectangular metal sheet as shown in FIGS. 26 and 28 and its opposing end portions are bent in the same direction to form bent portions 72a  and 72b. Formed integrally with the bent portions 72a and 72b are fixing pieces 73a and 73b which extend therefrom into the through holes 71a and 71b of the first housing half 10, holding the bent portions 72a and 72b between the opposing end portions 69a and 69b of the first housing half 10. Projecting end portions of the fixing pieces 73a and 73b are bent to fix the second housing half 30 to the first housing half 10 as seen in FIG. 26. From the intermediate portion of one marginal portion of the second housing half 30 along its lengthwise direction is extended a fixing piece 73c in the same direction as the fixing pieces 73a and 73b and inserted into the through hole 71c of the first housing half 10 and then bent as shown in FIG. 29, thereby preventing the intermediate portion of the first housing half 10 from curving. 
     The mating connector for the connector of the present invention is not limited specifically to a plate-shaped element of the type shown in FIG. 18 but may also be a flexible substrate, that is, a sheet-shaped connector. For example, as illustrated in FIGS. 30 and 31, a reinforcing piece 75 is mounted on one end portion of a flexible printed-circuit board 74 along its marginal edge. An L-shaped engaging piece 76 is formed integrally with the reinforcing piece 75 centrally thereof and is projected out through an aperture 77 made in the flexible printed-circuit board 74, and the end portion of the flexible printed-circuit board 74 is inserted into the connector insertion opening 61 along with the reinforcing piece 75. The L-shaped engaging piece 76 is inserted into an engaging recess 78 formed in the intermediate portion of the front of the first housing half 10, for instance, in the case of the connector shown in FIGS. 26 and 29. 
     As has been described in the foregoing, according to the present invention, since the contact pieces 13 1 , 13 2 , . . . are held integrally with the first housing half 10 and since the contact pieces 13 1 , 13 2 , . . . are formed from a sheet of metal into the contact array plate 14, the contact pieces with a minimum pitch can be accurately positioned relative to the first housing half 10. Further, since the contact pieces are bent along the bending dies formed in the peripheral surface of the first housing half 10, that is, along surfaces of the contact piece receiving grooves 16 1 , 16 2 , . . . , the contact propers can be obtained with high density. All of the contact pieces can be bent simultaneously. Moreover, the size of the connector in the direction of insertion of the mating connector can be reduced. By fusion-welding the second housing half 30 to the first housing half 10, for instance, through ultrasonic welding, it is possible to prevent soldering flux from entering into the housing assemlby. Besides, since the contacts are molded integrally with the first housing half 10, soldering flux is restricted from entering into the first housing half 10 during soldering of the terminals 1 1 , 1 2 , . . . . 
     The connector of the present invention resists deformation thereof upon the insertion thereinto of the mating connector and provides good contact therewith. In addition, means for holding and fixing the printed-circuit board 8 having connected thereto the contact terminals 1 1 , 1 2 , . . . can also be easily assembled with connector during the manufacturing process thereof. 
     It will be apparent that many modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.