RIBBON WIRE BOND
In a described example, an electrical apparatus includes a substrate having a first surface and lead pads on the first surface of the substrate for surface mounting components. A ribbon wire bond is provided having open ends and a central portion between the open ends, the open ends of the ribbon wire bond connected to the lead pads. An electrical component is bonded to the central portion of the ribbon wire bond. The central portion of the ribbon wire bond and the electrical component are spaced from the first surface of the substrate.
This disclosure relates generally to populating substrates with electrical components, and more particularly to a device and method for mounting devices to a substrate.
SUMMARYIn a described example, an electrical apparatus includes a substrate having a first surface and lead pads on the first surface of the substrate. A ribbon wire bond is provided having open ends and a central portion between the open ends, the open ends of the ribbon wire bond are connected to the lead pads. An electrical component is bonded to the central portion of the ribbon wire bond. The central portion of the ribbon wire bond and the electrical component are spaced from the first surface of the substrate.
Corresponding numerals and symbols in the different figures generally refer to corresponding parts, unless otherwise indicated. The figures are not necessarily drawn to scale. As is further described herein below, certain structures and surfaces are described as “parallel” to one another. For purposes of this disclosure, two elements are “parallel” when the elements are intended to lie in planes that, when extended, will not meet. However, the term parallel as used herein also includes surfaces that may slightly deviate in direction due to manufacturing tolerances. If the two surfaces generally lie in planes that are spaced apart and which would not intersect when extended infinitely if the surfaces were made without these deviations, these surfaces are also parallel.
As is further described hereinbelow, certain structures and surfaces are described as “perpendicular” to one another. For purposes of this disclosure, two elements are “perpendicular” when the elements are intended to form a 90-degree angle at their intersection. However, the term “perpendicular” as used herein also includes surfaces that may slightly deviate from 90 degrees due to manufacturing tolerances. Certain elements are described hereinbelow as “sub-PCBs.” A sub-PCB is a printed circuit board that carries components and that has a surface area smaller than a PCB that the sub-PCB is mounted to.
Certain elements are described herein as “surface mount ribbon wire bonds.” A surface mount ribbon wire bond has at least two open ends that are arranged to be soldered to a lead pad on a surface. The open ends have a portion that is parallel to the surface for mounting on the lead pad. The ribbon wire bonds have at least one central portion between the open ends. In some arrangements, the ribbon wire bonds have two or more central portions between the open ends. The central portions include a portion parallel to the surface and formed at an angle to legs that extend from a first open end, to the central portion, which extends to and forms the angle with another leg, and then the ribbon wire bond extends to the second open end. Thus the central portions continue the ribbon wire bond from a leg extending from an open end to form an approximately straight portion displaced from the surface. In some examples, additional portions of surface mount ribbon wire bonds may be arranged to be soldered to a pad on a surface.
Certain elements are described herein as “through-hole mount ribbon wire bonds.” A through-hole mount ribbon wire bond is one that has at least open ends that are arranged perpendicular to a surface of a substrate, such as a printed circuit board (PCB). The through-hole ribbon wire bonds are mounted by insertion into an opening in a surface of the printed circuit board. Through-hole ribbon wire bonds as described herein may also have central portions that are parallel to the surface formed between the open ends.
In some described examples, the ribbon wire bonds shown are coupled to a surface of a PCB. In additional arrangements, the ribbon wire bonds can be coupled to a surface of a lead frame. In the described examples the ribbon wire bonds are shown with a component mounted thereon, with additional components mounted on the substrate. However alternative arrangements include a component mounted on a ribbon wire bond and spaced from a surface of a substrate without additional components. In an example a multi-chip module can be formed using ribbon wire bonds to mount components such as inductors, capacitors, resistors, transformers displaced from a surface of a lead frame, thereby reducing the surface area needed for components on the surface of the lead frame. The ribbon wire bonds can be mounted to any substrate, including a substrate where additional components would be mounted, and thereby reduce the area needed for the components on the surface of the substrate by displacing the components on the ribbon wire bond from the surface. PCBs and lead frames are examples of substrates, other examples include a premolded substrate for use in mounting components in a package, module, or system on a chip (SOC) or system in package (SiP or SIP) arrangement.
In an example arrangement, a bigger device is mounted on a central portion of a ribbon wire bond and is vertically displaced (as oriented in
In
In
A few illustrative examples of ribbon wire bonds useful with the arrangements are shown in
Ribbon wire bonds 420 and 422 illustrated in
The points on the “W” of the W-shaped ribbon wire bond 422 in
U-shaped ribbon wire bonds 420 and W-shaped ribbon wire bond 422 are surface mount ribbon wire bonds as illustrated in
A method for mounting electrical components spaced from a substrate surface and over underlying electrical components on a substrate (such as a lead frame or a PCB) using ribbon wire bonds is described in the flow chart in
In
In
In
In
In
In
In
As illustrated in
Open ends of the through-hole ribbon wire bonds 920 that are arranged approximately perpendicular to the surface of the PCB 900 are inserted in through-holes in the PCB 900, and are soldered. The sub-PCB 950 is then bonded to the central portion of the through-hole ribbon wire bonds 920 above (as PCB 900 is oriented in
In
The ribbon wire bonds can be formed using a stamping die 1030 such as is illustrated in
Similarly, a through-hole ribbon wire bond (examples shown in
A stamping die 1230 for producing one ribbon wire bond with each stamping operation is illustrated in
A stamping die 1330 for producing multiple ribbon wire bonds during each stamping operation is illustrated in
In the first step 1502 of
In step 1504 and illustrated in
In step 1506 and illustrated in
In step 1508 and illustrated in
After step 1508 is completed, the path 1510 illustrates the steps 1504, 1506, 1508 can be repeated to manufacture multiple ribbon wire bonds.
The ribbon wire bonds can also be supplied as premade structures. The ribbon wire bonds may be temporarily mounted on an adhesive tape or film and supplied as a spool or reel to a pick and place tool for use with assembly methods as described in
Modifications are possible in the described arrangements, and other alternative arrangements are possible within the scope of the claims.
Claims
1. An electrical apparatus, comprising:
- a substrate having a first surface;
- lead pads on the first surface of the substrate;
- a ribbon wire bond having open ends connected to the lead pads and at least one central portion between the open ends; and
- an electrical component bonded to the at least one central portion of the ribbon wire bond, wherein the at least one central portion of the ribbon wire bond and the electrical component are spaced from the first surface of the substrate.
2. The electrical apparatus of claim 1 wherein the ribbon wire bond is a U-shaped ribbon wire bond having legs at the open ends with ends of the legs bent parallel to the lead pads on the substrate, the legs extending from the open ends to the central portion and the central portion of the U-shaped ribbon wire bond straightened and parallel to the ends of the legs.
3. The electrical apparatus of claim 1 wherein the ribbon wire bond is U-shaped ribbon wire bond with legs at open ends of the U-shaped ribbon wire bond and having ends of the legs bent perpendicular to the first surface and extending into a surface of the lead pads, and the legs extending from the open ends to the central portion, the central portion of the U-shaped ribbon wire bond perpendicular to the ends of the legs.
4. The electrical apparatus of claim 1 wherein the ribbon wire bond is a W-shaped ribbon wire bond with ends of legs at an open end bent parallel to the lead pads on the substrate, and with central portions on points of the W of the W-shaped ribbon wire bond parallel to the ends of the legs.
5. The electrical apparatus of claim 1 wherein the ribbon wire bond is a W-shaped ribbon wire bond with ends of legs at the open ends of the W-shaped ribbon wire bond bent perpendicular to the first surface of the substrate and inserted into a surface of the lead pads, and with points of the W of the W-shaped ribbon wire bond flattened to form central portions that are perpendicular to the ends of the legs.
6. The electrical apparatus of claim 1 wherein the electrical component mounted on the ribbon wire bond is an inductor.
7. The electrical apparatus of claim 1 wherein the electrical component mounted on the ribbon wire bond is a transformer.
8. The electrical apparatus of claim 1 wherein the electrical component mounted on the ribbon wire bond is a bulk acoustic wave device.
9. The electrical apparatus of claim 1, wherein the substrate is a printed circuit board (PCB).
10. The electrical apparatus of claim 9 wherein the electrical component mounted on the ribbon wire bond is a sub printed circuit board (sub-PCB) with one or more electrical components mounted on it.
11. The electrical apparatus of claim 1 wherein the substrate is a lead frame.
12. A method for making an electrical apparatus, comprising:
- making a ribbon wire bond with a shape that is one selected from a group consisting essentially of a U-shape and a W-shape, the ribbon wire bond having at least one central portion between open ends;
- soldering the open ends of the ribbon wire bond to lead pads on a first surface of a substrate; and
- mounting an electrical component to the at least one central portion of the ribbon wire bond, the electrical component and the at least one central portion spaced from the first surface of the substrate.
13. The method of claim 12 wherein the ribbon wire bond is a U-shaped ribbon wire bond with ends of legs of open ends of the U-shaped ribbon wire bond bent parallel to the lead pads and with the central portion of the U-shaped ribbon wire bond parallel with the ends of the legs.
14. The method of claim 12 wherein the ribbon wire bond is a U-shaped ribbon wire bond with ends of legs of an open end of the U-shaped ribbon wire bond bent perpendicular to the first surface of the substrate and inserted into through-holes in the lead pads.
15. The method of claim 12 wherein the ribbon wire bond is a W-shaped ribbon wire bond with ends of legs of an open end of the W-shaped ribbon wire bond bent parallel to lead pads on a surface of the substrate.
16. The method of claim 12 wherein the ribbon wire bond is a through-hole mount, W-shaped ribbon wire bond with ends of legs of the open ends of the W-shaped ribbon wire bond perpendicular to a surface of the substrate and extending into the surface of the substrate through the lead pads.
17. The method of claim 12 wherein mounting an electrical component further comprises soldering a terminal of the electrical component to the central portion of the ribbon wire bond.
18. A method of making a ribbon wire bond comprising:
- opening a stamping die consisting of a first half and a second half configured to bend a wire into a ribbon wire bond;
- inserting a wire between the first half and second half of the open stamping die;
- closing the stamping die and bending the wire to form the ribbon wire bond and to detach the ribbon wire bond from the wire; and
- re-opening the stamping die and removing the ribbon wire bond.
19. The method of claim 18, and further comprising:
- making the stamping die to accommodate at least two wires between the first half and second half when the stamping die is opened;
- inserting at least two bond wires between the first half and second half;
- closing the stamping die to form at least two ribbon wire bonds and to detach them from the wires; and
- opening the stamping die and removing at least two ribbon wire bonds.
20. The method of claim 18 wherein the ribbon wire bond is a surface mount ribbon wire bond.
21. The method of claim 18 wherein the ribbon wire bond is a through-hole ribbon wire bond.
22. The method of claim 18 wherein the ribbon wire bond is a U-shaped ribbon wire bond.
23. The method of claim 18 wherein the ribbon wire bond is a W-shaped ribbon wire bond.
Type: Application
Filed: Mar 20, 2018
Publication Date: Sep 26, 2019
Inventors: Amin Ahmad Sijelmassi (Dallas, TX), Bradley Glasscock (Wylie, TX)
Application Number: 15/926,312