The present invention relates to brackets for mounting large electrical components to circuit boards.
Conventionally, large electrical components (i.e., components such as electrolytic capacitors and inductors that are much larger than common microprocessors) are coupled to a printed circuit board with additional means besides the pins that provide the electrical connection. Often, heat shrinkable tubing and/or thermally conductive glue are used for this purpose.
In one embodiment, the invention provides an apparatus comprising, in combination, an electrical component and a bracket. The electrical component has a first end configured to electrically connect to a circuit board. The electrical component defines an axis and has a width measured in a direction transverse to the axis. The bracket has a body defining a bore shaped to receive the electrical component. The body further includes a break in communication with the bore to allow expansion of the bore. In an at-rest state of the bracket, the bore has a bore width smaller than the width of the electrical component, and when the electrical component is received in the bore, the bracket is elastically deformed such that the electrical component is clamped in the transverse direction solely by the residual stress within the bracket without any additional clamp or fastener.
In another embodiment the invention provides a circuit board assembly comprising a circuit board, a first electrical component electrically connected to the circuit board, a first bracket holding the first electrical component and being coupled to the circuit board, a second electrical component electrically connected to the circuit board, and a second bracket holding the second electrical component and being coupled to the circuit board. The second electrical component has a height in a direction perpendicular to the circuit board that is different than a corresponding height of the first electrical component. The first and second brackets are of substantially identical height in a direction perpendicular to the circuit board when coupled thereto, and the height of the first and second brackets is at least as large as the taller of the two electrical components.
Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways.
As shown in
The bracket 20 includes a plurality of mounting apertures 40 configured to receive corresponding fasteners 44 (
To insert one of the capacitors 36 into the bracket 20 for mounting to the circuit board 48, a spreader tool is inserted into the slit 32 corresponding to the desired bore 28, and the spreader tool is operated to spread apart the adjacent walls of the slit 32. This causes an elastic deformation of the body 24 that increases the size of the bore 28 (i.e., increasing the effective bore width BW to a dimension larger than the at-rest bore width BW and at least as large as the width W1 of the capacitor 36). When the slit 32 is spread, the capacitor 36 can be inserted into the bore 28 with little or no frictional resistance. Once the capacitor 36 is inserted to the desired depth and oriented as desired, the spreader tool is released, and the body 24 tries to return to its natural state. However, due to the width W1 of the capacitor 36 being slightly larger than the at-rest bore width BW, a slight residual stress is maintained in the material of the body 24. This residual stress exerts a clamping force on the capacitor 36 in a direction transverse to the axis A to hold the capacitor 36 firmly in place. Thus, the capacitor 36 is gripped or clamped firmly in place by a self-contained force without any additional components (e.g., movable or adjustable clamp members and/or fasteners).
The difference between capacitor width W1 and bore width BW is large enough to securely clamp the capacitors 36, but small enough that the bracket 20 does not yield while being stretched during assembly and does not exceed a predetermined contact stress on the capacitors 36 after assembly. In some constructions, a thermal fit is used to clamp the capacitors 36 in the bracket 20, and the slits 32 may or may not be necessary. In a thermal fitting process, the assembly is done with the bracket 20 and/or the capacitors 36 at a reduced temperature. When the components reach ambient or elevated temperatures, the capacitors 36 are securely clamped in the bracket 20.
If the bracket 20 includes multiple bores 28, as is the case with the illustrated bracket 20, the above described process can be repeated until capacitors 36 are inserted and clamped in each of the bores 28. Once all of the desired capacitors 36 are within the bracket 20, the bracket 20 is coupled to a first side 48A of the circuit board 48. The pins 52 of the capacitors 36 are received in corresponding apertures of the circuit board to establish the desired electrical connections. The base surface 56 of the bracket 20 makes surface contact with the first side 48A of the circuit board in the area directly surrounding the area of the electrical connections. The fasteners 44, which are screws in the illustrated construction, extend from a second side 48B of the circuit board 48 (i.e., the back side which is opposite the first side 48A) through apertures 64 in the circuit board 48 to engage the apertures 40 in the bracket 20. The bracket 20, along with the capacitors 36 therein, are mounted firmly to the circuit board 48 to avoid damage by vibration without heat shrinkable tubing or gluing. Although screws are illustrated, the bracket 20 may be coupled with the circuit board 48 with snap hooks, rivets, and/or dovetails, among other things.
The three bores 28 of the illustrated bracket 20 are disposed in a single row, although other configurations are optional. The slits 32 are staggered on opposite sides of the body 24 such that adjacent pairs of bores 28 do not have their slits 32 on the same side of the body 24, but rather on opposite sides of the body 24. In some constructions, the body 24 allows only a limited amount of elastic deformation.
The bracket 20 forms a strong thermal coupling with the capacitors 36 therein due to a large amount of surface contact. The thermal coupling allows effective cooling of the capacitors 36 as heat is drawn into the bracket 20. The bracket 20 can be constructed of aluminum or other metals. Alternately, the bracket 20 can be constructed of one or more different types of plastics, including standard and/or heat conductive types.
The illustrated bracket 20 can be manufactured as a one-piece extrusion. The extrusion can be produced to any desired length, and lengths shorter than the extrusion length can be produced by cutting (e.g., sawing) the extrusion to a desired length. Alternately, the bracket 20 can be machined, die-cast, or molded.
Although the bracket 20 can include bores having shapes other than cylindrical, the cylindrical bores 28 in the illustrated construction are well-suited for a variety of electrical components or other items, which may or may not have well-established standardized sizing. For example, the bracket 20 can be particularly useful for all types of battery cells (which are typically cylindrical, have standardized sizing, and benefit from good thermal transfer for cooling). The bracket 20 is especially useful for big battery cells, such as traction batteries for electric vehicles and other high power batteries.
Turning now to
The body 124 has a discontinuous perimeter having breaks therein in the form of a pair of opposed recesses or windows 150 that allow the bore width BW2 to be slightly increased by elastic deformation to match the width W2 of the inductor 136. Thus, residual stress in the body 124 exerts a clamping force on the inductor 136 in a direction transverse to the axis A2 to hold the inductor 136 firmly in place so that it is gripped or clamped firmly in place without any additional components (e.g., movable or adjustable clamp members and/or fasteners). One of the windows 150, shown on the right hand side of
The body 124 further includes a pair of apertures 140 that extend fully through the body 124. In the illustrated construction, the two apertures 140 are positioned diagonally across from each other at opposite ends of the body 124. The bracket 120 is configured to be coupled to the circuit board 48 in much the same way as the bracket 20 of
The overall height H2 of the bracket 120 is measured from the base surface 156 to a top surface 160. A secondary base surface 162 (
Further features of the bracket 120, such as materials, methods of manufacturing, and thermal transfer, among others, are similar to the bracket 20 of
As can be seen in
Thus, the invention provides, among other things, a bracket configured to exert a self-contained clamping force on one or more large electrical components. Multiple brackets mounted to a circuit board define a common plane, parallel to and spaced a distance from the circuit board, that is shared with a housing member. All of the brackets are at least as tall as the tallest electrical component in a given circuit board assembly. Various features and advantages of the invention are set forth in the following claims.