US 3255299 A
Description (OCR text may contain errors)
June 7, 1966 R. E. HARTSOCK 3,255,299
LE PRINTED CIRCUIT BOARD Filed March 16, 1964 IIIIIIIIII Illlllllllllll 1.\\\\\\1Im\\ w INVENTOR. ROBERT E. HARTSOCK ATTORNEY United States Patent Filed Mar. 16, 1964, Ser. No. 353,022 3 Claims. (Cl. 174-685) This is a continuation-in-part of my abandoned patent application, Serial Number 60,334, filed October 4, 1960.
This invention relates to a conductor-equipped panel, and more particularly to a conductor-equipped panel having sections thereof angularly disposed with respect to each other.
Conductor-equipped panels are most frequently referred to generically as printed wire boards or panels although the conductors may be provided along the panel by techniques other than printing as, for example, etching processes, stencil and spraying techniques, etc.; and consequently wherever this term is used herein, it is intended to apply to' conductonequipped panels generally. Irrespective of the particular process or technique employedfor equipping the panel with conductors, it is generally advantageous to work with a panel that is planar in contrast to one having angular sections or other nonplanar configurations. However, in many installations, it is not feasible to have an entire circuit formed along one planar panel, and as a result it is customary to employ a number of separate panels angularly oriented with respect to each other, and the conductors of the various panels are respectively inter-connected by means of separate connector structures each of which has a plurality of contacts that respectively engage. the conductors of the associated panels to establish an electric connection therebetween.
An object of the present invention is to provide a pair of conductor-equipped integral panels or panel sections which are angularly disposed with respect to each other, and in which the conductors common to each panel section are integral or uninterrupted along the juncture of the panels.
Another object of the invention is in the provision of a printed wire circuit defined along a pair of integral panels or panel sections that are rigidified with respect to each other in an angular orientation, and in which at least certain of the conductors in the circuit extend in tegr-ally from panel to panel.
Still another object of the invention is that of providing a conductor-equipped panel having integral sections thereof rigidified in an angular orientation relative to each other with at least certain conductors extending integrally between the sections along the exterior or outside surface thereof, and in which such integral sections are fabricated from a single planar panel after the circuit has been provided thereon.
Other and additional objects and advantages of the invention will become apparent as the specification develops.
Embodiments of the invention are illustrated in the accompanying drawing, in which- FIGURE 1 is a perspective view of a conductorequipped panel arrangement embodying the invention;
FIGURE 2 is a broken perspective view illustrating a portion of a planar panel after conductors have been provided therealong but prior to formation of the panel into the angularly disposed sections shown in FIGURE 1;
FIGURE 3 is a broken longitudinal sectional view illustrating the step of slitting or notching the conductorequipped panel;
FIGURE 4 is a broken longitudinal sectional view similar to that of FIGURE 3, but showing the panel after the notch has been formedtherein;
FIGURE 5 is a broken longitudinal sectional view similar to that of FIGURE 4, but illustrating a notch of modified configuration; and
FIGURE 6 is an enlarged, broken longitudinal sectional view of the panel structure shown in FIGURE 1.
The panel or board illustrated in FIGURE 1 is des ignated in its entirety with the numeral 10, and comprises integral panel sections 11 and 12 which are angularly related with respect to each other and in the specific illustrative embodiment define a right-angle therebetween. The panel 10 is equipped with a circuit pattern denoted generally as 13, and the circuit comprises a plurality of conductors such as those designated with the numerals 14, 15, 16 and 17 which extend integrally between the sections 1 1 and 12 and are common to each, forminga continuous circuit pattern on the outer surface of the panel sections. The panel sections 11 and 12 meet along a line of mergence 18 which extends transversely thereacross and also traverses the conductors 14-17. Along the line 18 is a corner block or filler 19 which is secured to the adjacent edges of the sections 11 and 12 and rigidifies the Same in the angular disposition thereof.
As .will be noted from the drawings; and particularly in FIGURE 1, panel sections 11 and 12 extend in substantially right angle relationship to one another and are integrally secured to one another by a thin bowed section 22. The bowed section 22 has a depth less than the thickness of the panel sections 11 and 12, and joins the panel sections with its outer surface tangent to the outer surface of the panel sections, thereby forming an integral bridging section therebetween. A continuous circuit pattern 13 is provided on the outer surface of the panel 10 with the conductors 14, 15, 16 and 17 extending from the outer surface of the panel section 12 to the outer surface of the panel section 11 along the bridging surface formed by the outer side of the bowed section 22. It will be noted that with this construction the greater portion of the thickness of the bowed section 22 underlying the conductors 14, 15, 16 and 17 is under slight compression, and that the metal conductors supported thereby are under slight tension but that because of the thinness of the bowed section the compressive and tensile stresses are kept so small that no fracture in the bowed or bridging area occurs. In other words, the relative Width and the thickness of the bowed sections are such that the radius of curvature in the bridging area is attained without exceeding the tensile strength of the conductors 14-17 and of the immediately underlying surface portion of the bowed section 22. The walls of the panel 10 adjacent the bowed section lie in spaced relation to one another forming a notch 21 underlying the bowed section 22. The width of the notch 21 at the sides of the panel remote from the conductors must be great enough so that the lips thereof stand in spaced relation to each other when the panel sections 11 and 12 are bent at the bridging section, whereby the walls of the panel 10 adjacent the bowed section 22 are in spaced relation to one another to form a notch underlying the bowed section 22. The filling or reinforcing material 19 is disposed in the mouth of the formed notch 21, thus rigidifying the panel sections 11 and 12 in angular relationship to one another.
The panel 10 may be formed from any of the conventional materials customarily used in making printed wire circuits boards, such as Bakelite or an epoxy glass composition. As stated hereinbefore, the circuit pattern 13 may be formed along the generally planar panel 10, as shown in FIGURE 2, by any of the well known techniques, and the various conductors defining the circuit are comprised of a conductive material such as copper.
After the circuit pattern 13 has been provided along the generally planar panel 10, the panel is sectioned by notching the same along the surface thereof opposite the surface receiving the circuit pattern 13 by means of a cutting tool 20 such as an abrasive wheel which is capableof forming a relatively wide notch 21.
As hereinbefore indicated, the end walls of the panel sections 11 and 12 and the bowed portion 22 forming the notch 21 are of a suflicient lateral width such that the bowed section will not bend sharply nor will the end walls abut. By having a wide groove or notch 21, an area is provided having a fairly uniform cross-section which permits the distribution of the bending of the panel 10' over a length sutficient to keep the stress in both the conductors 14, 15, 16 and 17 and the panel 10 in the plastic range.
The notch 21 extends transversely or at right angles across the panel and correspondingly across the path of the conductors 14-17, and the depth of the slot is controlled so that it terminates a spaced distance from the conductor-equipped surface of the panel and therefore a spaced distance from the conductors. This uncut incremental panel portion or bowed portion 22 may have any desired thickness which will permit the desired bending under the conditions herein enumerated and will not fracture or break. A preferred thickness is, for example, 0.010 inches.
After the panel 10 has been notched, the sections 11 and 12 thereof are rotated relative to each "other in a direction tending to bring the end walls 23 and 24 of each in close proximity to form the notch 21 and locate the conductors along the outer surface of the sections 11 and 12. It will be appreciated that substantially any angular orientation may be enforced upon the sections 11 and 12, such as the 90 angle illustrated in FIGURES 1 and 6.
The sections 11 and 12 are rigidified in their angular disposition by means of the corner block or filler 19 which has a configurationsuch that it fits into the notch 21 defined between the adjacent edges 23 and 24 and the bowed section 22 after such edges are moved toward each other in establishing the desired angle between the sections. Therefore, the block 19 in the specific form shown, wherein the end walls or edges 23 and 24 are generally arcuate and the angle defined between the sections 11 and 12 is substantially 90, has a generally ovate configuration in transverse section. The edges 23 and 24 of the panel sections are adhesively secured to the block 1-9, such as by means of one of the commercially available epoxy resins; and since the formulation of such commercial epoxy resins affords substantial latitude in the curing procedure to be followed, the time required to effect a bond between the block and panel sections can be selected and controlled through temperature and pressure selection. The incremental panel portion 22 serves as a filler or backing element to confine the bonding material about the block 19 along the line 18, and augments the rigidification afforded by the block 19 in that the bonding agent effectively reunites the cracked or broken edges of the increment 22.
The modified construction shown in FIGURE is essentially the same as the embodiment heretofore described except that the notch has a slightly different configuration, and serves to emphasize the point that the precise configuration of the notch is not critical so long as the width thereof is suificient to permit the sections 11 and 12 to be pivoted toward each other to the desired angular orientation. For purposes of differentiating the structure shown in FIGURE 5 from the prior embodiment, the panel in its entirety is denoted with the numeral 111, the two sections with the numerals 11' and 12', the conductors 14, the notch 21, and the incremental panel portion 22'.
In the structure shown, a conductor-equipped panel is provided having angularly disposed sections wherein at least one conductor extends integrally and without interruption between the sections along the outer surface thereof. Therefore, in many instances a complete printed circuit pattern can be produced on a single planar panel thereby simplifying fabrication procedures and obviating the need for connecting angularly-disposed panel sections one with another through separate connector structures.
While in the foregoing specification embodiments of the invention have been set forth in considerable detail for purposes of making a complete disclosure thereof, it will be apparent to those skilled in the art that numerous changes may be made in such details without departing from the spirit and principles of the invention.
1. A printed wire circuit structure comprising an integral panel having first and second panel sections extending in angular relation to one another, and a thin bowed section of a depth less than the thickness of said panel sections and joining said panel section with its outer surface tangent to the outer surfaces of said panel sections to form a bridging section therebetween, said panel having a continuous circuit pattern on the outer surface thereof having at least one conductor thereof extending from the outer surface of one of said panel sections to the outer surface of the other panel section along the bridging surface formed by the outer side of said bowed section, said panel section underlying said conductor being under compression, the walls of said panel adjacent said bowed section lying in spaced relation to each other thereby forming a notch underlying said bowed section, and reinforcing material disposed at said notch and rigidifying said sections in said angular relation to oneanotner.
2. A printed circuit construction in accordance with claim 1, wherein the first and second panels are at substantially right angles to one another.
3. A printed circuit construction in accordance with claim 1, wherein the walls of the panel adjacent the bowed section converge inwardly to the bowed section.
References Cited by the Examiner UNITED STATES PATENTS 2,542,860 2/1951 Clements.
2,586,854 2/1954 Myers.
2,880,378 3/1959 Lindseth.
2,998,475 8/1961 Grirnsinger 174-68.5
ROBERT K. SCHAEFER, Primary Examiner.
JOHN P. WILDMAN, JOHN F. BURNS, E. JAMES SAX, Examiners.
DARRELL L. CLAY, Assistant Examiner.