Electrical connector with flexible circuit and reinforcement

Abstract

The present application discloses an electrical connector having a flexible circuit and a reinforcement. An electrical connector includes a flexible circuit having a flexible material and a trace at least partially embedded in the flexible material. The electrical connector also includes a first group of conductive bumps, a second group of conductive bumps, and a reinforcement. The first group of conductive bumps are coupled to respective first end portions of the traces and extend from a first side of the flexible circuit. The second group of conductive bumps are coupled to respective second end portions of the traces. The reinforcement is coupled to the flexible circuit on a second side of the flexible circuit opposite to the first side.

Description

Summary of the invention

[0001] In certain embodiments, an electrical connector assembly includes an electrical connector. The electrical connector includes a flexible circuit having a flexible material and a trace at least partially embedded in the flexible material. The electrical connector also includes a first set of conductive bumps, a second set of conductive bumps, and a reinforcement. The first set of conductive bumps are coupled to respective first end portions of the traces and extend from a first side of the flexible circuit. The second set of conductive bumps are coupled to respective second end portions of the traces. The reinforcement is coupled to the flexible circuit on a second side of the flexible circuit opposite to the first side.

[0002] In certain embodiments, an electrical connector includes a flexible circuit having a flexible dielectric material and a conductive trace at least partially embedded in the flexible material. The conductive trace includes a pair of traces for transmitting differential signals and a trace for transmitting a ground reference signal. The electrical connector includes a first group of conductive bumps, a second group of conductive bumps, and a reinforcement. The first group of conductive bumps are coupled to respective first end portions of the conductive traces and extend from a first side of the flexible circuit. The second group of conductive bumps are coupled to respective second end portions of the conductive traces. The reinforcement is coupled to the flexible circuit on a second side of the flexible circuit opposite to the first side.

[0003] While multiple embodiments are disclosed, other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the present invention.Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] Figure 1 A top view of an electrical connector assembly according to certain embodiments of the present disclosure is shown.

[0005] Figure 2 Shown is a top view of a flexible circuit according to certain embodiments of the present disclosure.

[0006] Figure 3 According to some embodiments of the present disclosure, Figure 2 A side view of a portion of a flexible circuit.

[0007] Figure 4 A top exploded view of an electrical connector according to certain embodiments of the present disclosure is shown, the electrical connector comprising Figure 2 and Figure 3 Flexible circuits and reinforcements.

[0008] Figure 5According to some embodiments of the present disclosure, Figure 4 A top view of an assembly of an electrical connector.

[0009] Figure 6 According to some embodiments of the present disclosure, Figure 4 and Figure 5 A side view of a portion of an electrical connector.

[0010] Figure 7 A top view of a cover according to certain embodiments of the present disclosure is shown.

[0011] Figure 8 According to some embodiments of the present disclosure, Figure 7 Bottom view of the cover.

[0012] Fig. 9 According to some embodiments of the present disclosure, Figure 7 and Figure 8 Cover Figure 1 Top view of an electrical connector assembly.

[0013] Although the present disclosure may have various modifications and alternative forms, specific embodiments are shown by way of example in the drawings and are described in detail below. However, it is not intended to limit the present disclosure to the specific embodiments described, but is intended to cover all modifications, equivalents and alternative forms falling within the scope of the appended claims. DETAILED DESCRIPTION

[0014] Figure 1 An electrical connector assembly 10 is shown, which includes an electrical connector 100 and a printed circuit board 150. As will be described in more detail below, the electrical connector 100 may include features useful for efficiently transmitting data at high rates. In addition, the electrical connector 100 may include features useful for repeated rapid connection and disconnection.

[0015] The electrical connector 100 includes a flexible circuit 102 that is Figure 2 is shown in more detail in . Figure 2 The side of the flexible circuit 102 shown in FIG. Figure 1 . The flexible circuit 102 comprises a flexible dielectric material 103, such as a polyimide, polyester, or liquid crystal polymer. In certain embodiments, the dielectric constant of the dielectric material 103 is 2.7-3.6. Figure 2As shown, the flexible circuit 102 includes a trace 104 extending between a first end portion 106A and a second end portion 106B. The trace 104 may include a conductive material such as copper and is at least partially embedded in the dielectric material 103. For example, the trace 104 may be embedded in the dielectric material 103, except that the first end portion 106A and the second end portion 106B of the trace 104 may be exposed so that these portions can be electrically connected to other components. In some embodiments, at least some of the traces 104 are arranged in pairs (e.g., a first pair 108A, a second pair 108B, a third pair 108C, and a fourth pair 108D). For example, the electrical connector 100 may be arranged to transmit differential signals across corresponding pairs of traces 104. Alternatively or additionally, the electrical connector 100 may be arranged to transmit single-ended signals across each trace 104. In addition, the trace 104 may include a ground reference trace 110, which is an example of a trace 104 that transmits a single-ended signal.

[0016] The distance between individual traces 104, the distance between pairs of traces 104, the width of the traces 104 themselves, the thickness of the traces 104 themselves, and the thickness of the dielectric material 103 itself can be designed to be useful for efficiently transmitting data at high rates. In certain embodiments, the distance between individual traces 104 is in the range of 2 mils to 20 mils, the distance between pairs of traces 104 is in the range of 2 mils to 20 mils, the width of the traces 104 themselves is in the range of 2 mils to 20 mils, the thickness of the traces 104 themselves is in the range of 0.2 mils to 2 mils, and the thickness of the dielectric material 103 itself is in the range of 1 mil to 10 mils. In certain embodiments, the various distances, widths, and thicknesses of the traces 104 and the dielectric material 103 remain constant along the flexible circuit 102. As an example, the distance between individual traces 104 in one or more pairs of traces 104 (e.g., first pair 108A, second pair 108B, third pair 108C, and fourth pair 108D) can remain substantially constant between first end portions 106A and second end portions 106B of traces 104.

[0017] In some embodiments, conductive bump 112 is coupled to first end portion 106A and second end portion 106B. Figure 2 , the conductive bumps 112 include a first group of conductive bumps coupled to the first end portion 106A of the trace 104 and a second group of conductive bumps 112 coupled to the second end portion 106B of the trace 104. Thus, the conductive bumps 112 and the trace 104 are electrically coupled to each other so that an electrical signal can be transmitted from the first group of conductive bumps 112 to the trace 104 and then to the second group of conductive bumps 112. In some embodiments, the conductive bumps 112 are annular. In some embodiments, the conductive bumps 112 include a conductive material such as gold. Figure 3 1 shows a side view of a conductive bump 112 extending from an end portion 106A of each trace 104. In some embodiments, the conductive bump 112 is Figure 3 The conductive bumps 112 are shown as being circular and are generally semicircular. In some embodiments, the height of the conductive bumps 112 is in the range of 1 mil to 10 mils.

[0018] Utilizing the above features, the flexible circuit 102 can provide an impedance controlled path for signals having a bandwidth of at least up to 22 GHz. For example, the flexible circuit 102 can have a shorter rise time than a flexible circuit that does not use conductive bumps or similar conductive structures. In certain embodiments, the impedance of the signal path (single-ended signal path and differential signal path) is controlled within the range of 25-200 ohms. These characteristics are particularly useful for applications involving high data rate transmission. For example, for a hard disk drive using heat-assisted magnetic recording (HAMR), certain signals are transmitted at a rate of 3 to 4 gigabits per second. These signals include signals transmitted between a preamplifier and a read / write head of a hard disk drive or during testing of such a read / write head (for example, when the read / write head is connected to a spin stand). It may be challenging to transmit signals at such speeds without suffering significant losses on an electrical connector.

[0019] Figure 4 The flexible circuit 102 (with Figure 2 ) and a reinforcement member 114, and Figure 5 The flexible circuit 102 and the stiffener 114 are shown assembled together (eg, laminated together).

[0020] The stiffener 114 includes a main body portion 116 and fingers 118 extending from the main body portion 116. When the stiffener 114 is attached to the flexible circuit 102, the fingers 118 of the stiffener 114 extend from the main body portion 116 so that the distal end portion 120 of each finger 118 is positioned adjacent to the first group of conductive bumps 112 located on the opposite side of the flexible circuit 102. The fingers 118 of the stiffener 114 provide a spring force to bias the first group of conductive bumps 112 so that the first group of conductive bumps 112 contact corresponding electrical contacts (e.g., conductive pads or separate conductive traces) of a separate device (e.g., a printed circuit board or a flexible circuit) to which the electrical connector 100 is coupled. In other words, the fingers 118 of the stiffener 114 help provide a mechanical force to couple the first group of conductive bumps 112 to the corresponding electrical contacts. In certain embodiments, the stiffener 114 is composed of a single piece so that the main body portion 116 and the fingers 118 are integrally formed. In certain embodiments, the reinforcement 114 comprises a material such as metal (eg, copper, beryllium, and other metals and alloys) or plastic.

[0021] Figure 6 A side view of the stiffener 114 and the flexible circuit 102 is shown. A spacer 121 is located between at least a portion of the stiffener 114 and the flexible circuit 102. The spacer 121 is shaped so that the fingers 118 are angled (e.g., forming a contact angle) toward the flexible circuit 102. For example, the spacer 121 can be shaped so that the angle of the fingers 118 toward the flexible circuit 102 is 1-10 degrees (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 degrees).

[0022] As described above, the reinforcing member 114 provides elastic force to bias the first group of conductive bumps 112 against corresponding electrical contacts. Therefore, when a component such as a separate flexible circuit or a head gimbal assembly for a hard disk drive is connected to the electrical connector 100, the conductive bump 112 is pressed against the component in a clamp-like manner, so that the conductive bump 112 starts and maintains the mechanical connection and electrical connection with the component. The connection can be quickly started and maintained without the need for a separate latch or other mechanical components, which is very useful in an automated manufacturing environment. In addition, the connection can be started and maintained without using solder for connection. Therefore, the electrical connector 100 can be electrically connected and disconnected multiple times. In certain embodiments, the electrical connector 100 includes a structure that helps guide the component toward the conductive bump 112 along a desired path. In addition, such a structure can help provide a stopper that helps to clamp the component on the conductive bump 112.

[0023] Although the stiffener 114 is shown as having a plurality of individual fingers 118, the stiffener 114 may utilize other features to provide a spring force to bias the first set of conductive bumps 112. For example, if a stronger spring force is desired, the stiffener 114 may include fewer but wider and / or thicker fingers 118. Furthermore, although the stiffener 114 is shown as having one finger 118 for each pair of conductive bumps 112, the stiffener 114 may include one finger 118 for each conductive bump 112.

[0024] Back to Figure 1 , the electrical connector 100 is mechanically and electrically coupled to the printed circuit board 150. For example, the second set of conductive bumps 112 of the electrical connector 100 can be mechanically and electrically coupled to an electrical pad (not shown) on the printed circuit board 150. The electrical pad can be part of or coupled to a trace 152 on the printed circuit board 150. The trace 152 can be coupled to a chip package 154 so that the electrical connector 100 is electrically coupled to the chip package 154. The chip package 154 can include an integrated circuit, such as a preamplifier used with a data storage component. In some embodiments, the flexible circuit 102 itself can include one or more chip packages that are directly coupled to the traces 104 of the flexible circuit 102.

[0025] Although the electrical connector 100 is described as being connectable to the printed circuit board 150 at one end and to a separate component at the other end, the electrical connector 100 can be used between any number of electrical components. For example, the electrical connector 100 can include another reinforcement member, or the reinforcement member 114 can be modified according to the design shown in the figure, so that both ends of the electrical connector 100 can be quickly connected and disconnected from the electrical components.

[0026] During operation, the chip package 154 may be powered, which may cause the chip package 154 to generate heat. To help maintain the chip package 152 within a desired temperature range, the electrical connector assembly 10 may include a cooling assembly 156 (at Figure 7 and Figure 8 are shown in Fig. 9 The cooling assembly 156 may include a cover 158 coupled to the printed circuit board 150 to form a cavity in which the chip package 152 is located. In some embodiments, the cover 158 includes a material such as a metal or a metal alloy (e.g., steel (including stainless steel), copper, beryllium, and alloys thereof) or a plastic.

[0027] Cover 158 may include aperture 160 ( Figure 8 ), which can be connected to tube 162 ( Figure 7 154) or another type of conduit. Tube 162 can be connected between cover 158 and vacuum source 164. During operation of chip package 154, vacuum source 164 can be powered and connected to electrical connector assembly 10 so that air is drawn from the cavity in which chip package 152 is located. Vacuum source 164 removes heat from the cavity and also removes dust, etc. from the cavity. In some embodiments, thermal interface material can be located in the cavity between chip package 154 and cover 158 to further help transfer heat from chip package 154 via thermal conduction. In some embodiments, cover 158 is fastened to printed circuit board 150 via one or more fasteners (e.g., screws).

[0028] Various modifications and additions may be made to the disclosed embodiments without departing from the scope of the present disclosure. For example, while the above embodiments relate to specific features, the scope of the present disclosure also includes embodiments having different combinations of features and embodiments that do not include all of the described features. Therefore, the scope of the present disclosure is intended to include all such alternatives, modifications and variations that fall within the scope of the claims, and all equivalents thereof.

[0029] Further examples

[0030] Example 1. An electrical connector assembly, comprising: an electrical connector, the electrical connector comprising: a flexible circuit, the flexible circuit comprising a flexible material and a trace at least partially embedded in the flexible material, a first group of conductive bumps, the first group of conductive bumps are connected to corresponding first end portions of the traces and extend from a first side of the flexible circuit, a second group of conductive bumps, the second group of conductive bumps are connected to corresponding second end portions of the traces, and a reinforcement member, the reinforcement member is connected to the flexible circuit on a second side of the flexible circuit opposite to the first side.

[0031] Example 2. The electrical connector assembly of Example 1, wherein the conductive bumps in the first set of conductive bumps are annular.

[0032] Example 3. The electrical connector assembly of Example 1, wherein the conductive bumps in the first set of conductive bumps are circular.

[0033] Example 4. The electrical connector assembly of Example 1, wherein the conductive bumps comprise gold.

[0034] Example 5. The electrical connector assembly of Example 1, wherein the trace comprises copper.

[0035] Example 6. The electrical connector assembly of Example 1, wherein the flexible material comprises polyimide, polyester, or liquid crystal polymer.

[0036] Example 7. The electrical connector assembly of Example 1, wherein the flexible material has a dielectric constant of 2.7-3.6.

[0037] Example 8. The electrical connector assembly of Example 1, wherein at least some of the traces have a width of 2 mils to 20 mils.

[0038] Example 9. The electrical connector assembly of Example 1, wherein at least some of the traces have a thickness of 0.2 mils to 2 mils.

[0039] Example 10. The electrical connector assembly of Example 1, wherein the traces are spaced 2 mils to 20 mils from each other.

[0040] Example 11. The electrical connector assembly according to Example 1, further comprising:

[0041] A printed circuit board is coupled to a chip package, the chip package being electrically coupled to the electrical connector.

[0042] Example 12. The electrical connector assembly according to Example 11, further comprising:

[0043] A cover is coupled to the printed circuit board to form a cavity in which the chip package is located, the cover including a hole coupled to the tube.

[0044] Example 13. The electrical connector assembly of Example 11, wherein the second set of conductive bumps are electrically coupled to electrical pads on the printed circuit board.

[0045] Example 14. The electrical connector assembly of Example 1, wherein the stiffener includes a body and fingers extending from the body such that distal portions of the fingers are positioned adjacent to the first set of conductive bumps.

[0046] Example 15. The electrical connector assembly of Example 1, wherein the finger provides a spring force against the first set of conductive bumps.

[0047] Example 16. The electrical connector assembly of Example 1, wherein the stiffener is laminated to the flexible circuit.

[0048] Example 17. An electrical connector, comprising:

[0049] a flexible circuit comprising a flexible dielectric material and conductive traces at least partially embedded in the flexible material, the conductive traces including a pair of traces for transmitting a differential signal and a trace for transmitting a ground reference signal;

[0050] a first set of conductive bumps coupled to respective first end portions of the conductive traces and extending from a first side of the flexible circuit;

[0051] a second set of conductive bumps coupled to respective second end portions of the conductive traces, and

[0052] A stiffener is coupled to the flexible circuit on a second side of the flexible circuit opposite the first side.

[0053] Example 18. The electrical connector assembly of Example 17, wherein the conductive bumps in the first set of conductive bumps are annular, circular, and comprise gold.

[0054] Example 19. An electrical connector assembly according to Example 17, wherein the flexible material comprises polyimide, polyester, or liquid crystal polymer; and wherein the conductive trace comprises copper; wherein the width of the conductive trace is 2 mils to 20 mils; wherein the thickness of the conductive trace is 0.2 mils to 2 mils; and wherein the conductive traces are spaced 2 mils to 20 mils from each other.

[0055] Example 20. The electrical connector assembly of Example 17, wherein the stiffener provides a spring force against the first set of conductive bumps.

Claims

1. An electrical connector assembly, comprising: An electrical connector, comprising: a flexible circuit comprising a flexible material and traces at least partially embedded in the flexible material, a first set of conductive bumps coupled to respective first end portions of the traces and extending from a first side of the flexible circuit, a second set of conductive bumps coupled to respective second end portions of the traces, and A stiffener is coupled to the flexible circuit on a second side of the flexible circuit opposite the first side, the stiffener comprising a body and fingers extending from the body such that the fingers provide a spring force against the first set of conductive bumps. 2 . The electrical connector assembly of claim 1 , wherein the conductive bumps in the first set of conductive bumps are annular. 3 . The electrical connector assembly of claim 1 , wherein the conductive bumps in the first set of conductive bumps are circular. The electrical connector assembly of claim 1 , wherein the conductive bumps comprise gold. The electrical connector assembly of claim 1 , wherein the traces comprise copper.

6. The electrical connector assembly of claim 1, wherein the flexible material comprises polyimide, polyester, or liquid crystal polymer.

7. The electrical connector assembly according to claim 1, wherein the dielectric constant of the flexible material is 2.7-3.

6.

8. The electrical connector assembly of claim 1, wherein at least some of the traces have a width of 2 mils to 20 mils.

9. The electrical connector assembly of claim 1, wherein at least some of the traces have a thickness of 0.2 mils to 2 mils.

10. The electrical connector assembly of claim 1, wherein the traces are spaced 2 mils to 20 mils from each other.

11. The electrical connector assembly according to claim 1, further comprising: A printed circuit board is coupled to a chip package, the chip package being electrically coupled to the electrical connector.

12. The electrical connector assembly according to claim 11, further comprising: A cover is coupled to the printed circuit board to form a cavity in which the chip package is located, the cover including a hole coupled to the tube.

13. The electrical connector assembly of claim 11, wherein the second set of conductive bumps are electrically coupled to electrical pads on the printed circuit board.

14. The electrical connector assembly of claim 1, wherein distal portions of the fingers are positioned adjacent the first set of conductive bumps.

15. The electrical connector assembly of claim 1, wherein the stiffener is laminated to the flexible circuit.

16. An electrical connector, comprising: a flexible circuit comprising a flexible dielectric material and conductive traces at least partially embedded in the flexible dielectric material, the conductive traces including a pair of traces for transmitting a differential signal and a trace for transmitting a ground reference signal; a first set of conductive bumps coupled to respective first end portions of the conductive traces and extending from a first side of the flexible circuit; a second set of conductive bumps coupled to respective second end portions of the conductive traces, and A stiffener is coupled to the flexible circuit on a second side of the flexible circuit opposite the first side and is arranged to provide a spring force against the first set of conductive bumps.

17. The electrical connector of claim 16, wherein the conductive bumps in the first set of conductive bumps are annular, circular, and comprise gold.

18. The electrical connector of claim 16, wherein the flexible dielectric material comprises polyimide, polyester, or liquid crystal polymer; and wherein the conductive traces comprise copper; wherein the width of the conductive traces is 2 mils to 20 mils; wherein the thickness of the conductive traces is 0.2 mils to 2 mils; and wherein the conductive traces are spaced 2 mils to 20 mils from each other.

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