Clamp for improving heat dissipation capability of surface-mounted fixed attenuator

Abstract

The utility model discloses a clamp for improving the heat dissipation capability of a surface-mounted fixed attenuator, and belongs to the field of chip component power test tool clamps. Comprising a red copper base back comb-shaped body, a red copper base top cavity, a top cavity side wall, a radio frequency connector, a circuit board, a product mounting hole, a microstrip line and a metal bonding wire. The back comb-shaped body of the red copper base and the top cavity of the red copper base are of an integrated structure, the radio frequency connector is fixedly connected with the top cavity of the red copper base, the circuit board is installed at the bottom of the top cavity of the red copper base, a microstrip line of the circuit board is correspondingly connected with an inner conductor of the radio frequency connector, and a product is mounted in a product mounting hole. And the metal welding layer is connected with the bottom of the top cavity of the red copper base. The problems that the power density borne by a resistor body per unit area is high during the power test of the surface-mounted fixed attenuator, and an existing heat dissipation means is difficult to meet the power test requirement of the surface-mounted fixed attenuator are solved. The device is widely applied to the technical field of power test of surface-mounted planar two-port electronic components.

Description

Technical Field

[0001] The utility model belongs to the field of chip component power test fixtures, and further relates to the field of chip attenuator power test fixtures, and specifically, to a fixture for improving the heat dissipation capacity of a surface-mounted fixed attenuator. Background Art

[0002] Surface mount fixed attenuators (also known as surface mount fixed attenuators, referred to as products) have high integration density and small size. The power density per unit area of ​​the attenuator resistor will be very high, and the requirements for the heat dissipation capacity of the substrate are also very high. The usual heat dissipation means are difficult to meet the requirements of the power performance test of surface mount fixed attenuators. For example, the FAC0707 surface mount fixed attenuator uses an alumina ceramic substrate with a thickness of 0.25mm and an alumina content of 99.6%. The product's dimensions are only 0.76mm×0.76mm×0.25mm. The rated power of this series of products is above 1W, especially the 10dB surface mount fixed attenuator, which needs to withstand a rated power of 2W, while the area of ​​its resistor is only 0.1mm 2 The power energy transmitted by a 10dB surface-mount fixed attenuator is only 10%. By calculation, it can be concluded that the power dissipated on the resistor film layer is 1.8W. Therefore, the average power density that the resistor body needs to withstand is as high as 18W / mm 2 , far exceeding the power density of general high-power thick film resistors.

[0003] At present, surface mount attenuator tests require the use of some special fixtures to complete. Generally, fixtures made of aluminum alloy, stainless steel or gold-plated brass are commonly used. However, the surface mount fixed attenuator of this project uses fixtures made of the above materials that cannot meet the requirements of good heat dissipation, resulting in product failure.

[0004] In view of this, the present utility model is proposed. Summary of the invention

[0005] The technical problem to be solved by the utility model is: to solve the problem that during the power performance test of the existing surface-mount fixed attenuator, the power density per unit area of ​​the resistor body will be very high, and the existing heat dissipation means are difficult to meet the requirements of the power performance test of the surface-mount fixed attenuator.

[0006] The inventive concept of the utility model is: in order to solve the problem of rapid heat dissipation during the power test of the surface-mounted fixed attenuator, a comb-shaped heat dissipation cavity fixture structure made of gold-plated copper material is adopted, the product is installed on the fixture through a conductive adhesive bonding or gold-tin welding process, and the planar two ports of the surface-mounted fixed attenuator are connected to the input and output electrodes of the product to the microstrip line through a gold wire bonding process or a tin-lead welding process, thereby improving the heat dissipation capacity of the surface-mounted fixed attenuator during the power test.

[0007] To this end, the utility model provides a fixture for improving the heat dissipation capability of a surface-mounted fixed attenuator, such as Figure 1-2 As shown. It includes: a comb-shaped body 1 on the back of a copper base, a cavity 2 on the top of the copper base, a side wall 3 on the top cavity, a radio frequency connector 4, a radio frequency connector fixing screw 5, a circuit board 6, a product mounting hole 7, a circuit board fixing screw 8, a microstrip line 9, and a metal bonding wire 11.

[0008] The comb-shaped body 1 on the back of the copper base and the cavity 2 on the top of the copper base are an integrated structure. A RF connector 4 fixing hole matching the RF connector fixing screw 5 and a RF connector 4 electrode passing through hole are made on the top cavity side wall 3 of the top cavity 2 of the copper base. A circuit board fixing hole matching the circuit board 6 and the circuit board fixing screw 8 is made on the bottom of the cavity 2 on the top of the copper base.

[0009] The RF connector 4 is fixedly connected to the cavity 2 at the top of the copper base through the RF connector fixing screws 5, the RF connector fixing holes and the RF connector 4 electrode passing through holes.

[0010] The circuit board 6 is fixedly mounted on the bottom of the cavity 2 at the top of the copper base through circuit board fixing screws 8 and circuit board fixing holes.

[0011] The microstrip line 9 of the circuit board 6 is connected to the inner conductor of the RF connector 4 accordingly.

[0012] A product mounting hole 7 is provided on the circuit board 6, and microstrip lines 9 are made at both ends of the product mounting hole 7. The product 10 is mounted in the product mounting hole 7, and the bottom surface of the product 10 is connected to the bottom of the cavity 2 at the top of the copper base through a metal welding layer, and the electrode port of the product 10 is connected to the corresponding electrode interface of the microstrip line 9 through a metal bonding wire 11.

[0013] The material of the copper base may be a material with higher thermal conductivity.

[0014] The utility model reserves a product installation hole 7 for placing the product 10 on the circuit board 6 installed on the top cavity 2 of the copper base, so that the product 10 is directly in contact with the top cavity 2 of the copper base after installation, and the heat generated by the product 10 during the test process is quickly transferred to the top cavity 2 of the copper base with high thermal conductivity. The comb-shaped body 1 on the back of the copper base of the top cavity 2 of the copper base increases the contact area between the top cavity 2 of the copper base and the air, and can quickly transfer heat to the air. Therefore, the use of the copper base top cavity 2 fixture of the utility model for installing the product 10 can meet the requirement of good heat dissipation of the product 10 during the test process.

[0015] The utility model can well fix the product for testing, and can also be connected with a vector network analyzer to test the S parameter electrical performance of the product. The fixture can be used for related power performance tests for planar two-port electronic components similar to the surface-mount fixed attenuator structure, and for products whose input and output electrodes are connected to the microstrip line through the gold wire bonding process or the tin-lead welding process. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The figure is a schematic diagram of the overall structure of the fixture.

[0017] Figure 2 for Figure 1 A partial enlarged view of the product installation area A.

[0018] In the figure: 1 is the comb-shaped body on the back of the copper base, 2 is the top cavity of the copper base, 3 is the side wall of the top cavity, 4 is the RF connector, 5 is the RF connector fixing screw, 6 is the circuit board, 7 is the product mounting hole, 8 is the circuit board fixing screw, 9 is the microstrip line, 10 is the product (surface-mount attenuator), 11 is the metal bonding wire, and A is the product installation area. DETAILED DESCRIPTION

[0019] like Figure 1-2 As shown, taking the power performance test of FAC0707 type surface mount fixed attenuator as an example, the fixture for improving the heat dissipation capacity of the surface mount fixed attenuator is specifically implemented as follows:

[0020] The copper base is a rectangular parallelepiped, and a gold layer is plated on the surface of the copper base.

[0021] The top cavity 2 of the copper base is a U-shaped cavity, and the top cavity side walls 3 at both ends of the U-shaped cavity are rectangular parallelepipeds.

[0022] The metal bonding wire 11 is a gold wire, a silicon aluminum wire or a copper wire.

[0023] The specific structure is:

[0024] The top cavity 2 of the copper base has rectangular top cavity side walls 3 at both ends thereof with a length, width and thickness of 6mm×22mm×12mm, which are used to install and fix the RF connector 4. The RF connector 4 can be connected to a test or experimental cable for corresponding testing or experimentation.

[0025] The back structure of the cavity 2 at the top of the copper base is designed to have a comb-shaped body 1 at the back of the copper base with a spacing of 2 mm. The length, width and thickness of the comb-shaped body 1 at the back of the copper base can be 47 mm×6 mm×2 mm respectively.

[0026] The bottom of the cavity 2 at the top of the copper base is also provided with screw holes for installing the circuit board 6. The circuit board 6 is installed at the bottom of the cavity 2 at the top of the copper base using the circuit board fixing screws 8, and corresponding screw holes are left on the circuit board 6 at positions corresponding to the circuit board fixing screws 8 for installing the circuit board 6 on the cavity 2 at the top of the copper base.

[0027] A product mounting hole 7 is reserved at the center of the circuit board 6. The width of the product mounting hole 7 is slightly larger than the size of the product 10, so as to facilitate the placement of the product.

[0028] The thickness of the circuit board 6 is slightly greater than the thickness of the product 10 so that the length of the gold wire 11 can be as short as possible during the wire bonding process.

[0029] A microstrip line 9 is arranged on each side of the product installation hole 7. The product 10 is placed in the product installation hole 7, and the input and output electrodes of the product 10 are connected to the microstrip line 9 through the gold wire 11. The microstrip line 9 is connected to the RF connector 4 installed on both sides of the cavity 2 at the top of the copper base.

[0030] Case 1: Product 10 is bonded with conductive adhesive

[0031] Fix the RF connector 4 and the circuit board 6 to the corresponding positions of the cavity 2 at the top of the copper base using the connector fixing screws 5 and the circuit board fixing screws 8 respectively. Put an appropriate amount of conductive glue in the product mounting hole 7 of the circuit board 6, place the input and output electrodes of the product 10 in the product mounting hole 7 of the circuit board 6 close to the microstrip line, press the product 10 slightly to evenly spread the conductive glue on the back, and form a conductive glue layer between the product 10 and the bottom of the cavity 2 at the top of the copper base. Then place the cavity 2 at the top of the copper base on a hot plate for baking to solidify the conductive glue. After the conductive glue is solidified, use the gold wire bonding process to connect the input and output electrodes of the product 10 to the microstrip line 9 through the metal bonding wire 11. At this point, the product 10 is installed on the cavity 2 at the top of the copper base of the utility model fixture. In this example, the product 10 is a 10dB surface-mount fixed attenuator.

[0032] Feature 1: The fixture is made of gold-plated copper with high thermal conductivity, which can quickly conduct away the heat generated by the product. At the same time, the comb-shaped structure on the back increases the heat dissipation area, allowing the heat generated by the product to dissipate faster. It can be used in tests that require timely conduction of the heat generated by the product.

[0033] Feature 2: The product installed on the fixture of this utility model can be directly connected to the vector network analyzer for product performance testing. The operation is simple, and there is no need to connect expensive probe stations and probes, saving test costs.

[0034] Feature 3: The fixture is highly compatible with products of different types and sizes, and can be used for testing or experiments.

[0035] Case 2: Product 10 uses AuSn solder or AuSn solder paste for eutectic welding

[0036] Fix the circuit board 6 to the cavity 2 at the top of the copper base using the circuit board fixing screws 8. Place a gold-tin solder sheet in the product mounting hole 7, and then place the input and output electrodes of the product 10 on the gold-tin solder sheet or gold-tin solder paste in the product mounting hole 7 close to the microstrip line 9. Place the fixture in a eutectic welding furnace to form a gold-tin alloy layer between the product 10 and the bottom of the cavity 2 at the top of the copper base, so that the product 10 is eutectically welded on the cavity 2 at the top of the copper base. Then install the RF connector 4 at both ends of the cavity 2 at the top of the copper base. Use a gold wire bonding process to connect the input and output electrodes of the product 10 to the microstrip line 9 through the metal bonding wire 11 to complete the product installation. In this example, product 10 is a 10dB surface-mount fixed attenuator.

[0037] Compared with Case 1:

[0038] The operation is simpler. The gold on the back of the product is eutectic welded with the copper cavity to form a whole. The heat energy generated by the product is conducted more directly and quickly to the copper cavity and dissipated into the air through the cavity.

[0039] Finally, it should be noted that the above embodiments are only examples for the purpose of clear explanation. The present utility model includes but is not limited to the above embodiments. It is not necessary and impossible to list all implementation methods here. For ordinary technicians in the field, other different forms of changes or modifications can be made on the basis of the above description. All implementation methods that meet the requirements of the present utility model belong to the protection scope of the present utility model.

Claims

1. A fixture for improving the heat dissipation capacity of a surface-mounted attenuator, characterized in that: It includes a comb-shaped body (1) on the back of a copper base, a cavity on the top of the copper base (2), a side wall of the cavity on the top (3), a radio frequency connector (4), a radio frequency connector fixing screw (5), a circuit board (6), a product mounting hole (7), a circuit board fixing screw (8), a microstrip line (9), and a metal bonding wire (11); The comb-shaped body (1) on the back of the copper base and the cavity (2) on the top of the copper base are an integrated structure; a RF connector (4) fixing hole matching the RF connector fixing screw (5) and a through hole for passing the inner conductor of the RF connector (4) are formed on the top cavity side wall (3) of the cavity (2) on the top of the copper base; and a circuit board fixing hole matching the circuit board (6) and the circuit board fixing screw (8) is formed on the bottom of the cavity (2) on the top of the copper base; The radio frequency connector (4) is fixedly connected to the cavity (2) at the top of the copper base via the radio frequency connector fixing screw (5), the radio frequency connector fixing hole and the through hole through which the inner conductor of the radio frequency connector (4) passes; The circuit board (6) is fixedly mounted on the surface of the cavity (2) at the top of the copper base by means of circuit board fixing screws (8) and circuit board fixing holes; The microstrip line (9) of the circuit board (6) is correspondingly connected to the inner conductor of the radio frequency connector (4); The circuit board (6) is provided with a product mounting hole (7), and microstrip lines (9) are formed at both ends of the product mounting hole (7). The product (10) is mounted in the product mounting hole (7), and the bottom surface of the product (10) is connected to the surface of the cavity (2) at the top of the copper base via a metal welding layer, and the electrode port of the product (10) is connected to the corresponding electrode interface of the microstrip line (9) via a metal bonding wire (11).

2. A fixture for improving the heat dissipation capability of a surface-mounted attenuator as claimed in claim 1, characterized in that: The copper base is a rectangular parallelepiped, and a gold layer is plated on the surface of the copper base.

3. A fixture for improving the heat dissipation capability of a surface-mounted attenuator as claimed in claim 2, characterized in that: The back structure of the top cavity (2) of the copper base is designed to have a copper base back comb-shaped body (1) with a spacing of 2 mm, and the length, width and thickness of the copper base back comb-shaped body (1) are 47 mm×6 mm×2 mm.

4. A fixture for improving the heat dissipation capability of a surface-mounted attenuator as claimed in claim 1, characterized in that: The top cavity (2) of the copper base is a U-shaped cavity, and the top cavity side walls (3) at both ends of the U-shaped cavity are rectangular parallelepipeds.

5. A fixture for improving the heat dissipation capability of a surface-mounted attenuator as claimed in claim 4, characterized in that: The length, width and thickness of the rectangular top cavity side walls (3) at both ends of the top cavity (2) of the copper base are 6 mm×22 mm×12 mm.

6. A fixture for improving the heat dissipation capability of a surface-mounted attenuator as claimed in claim 1, characterized in that: The metal bonding wire (11) is a gold wire, a silicon aluminum wire or a copper wire.

7. A fixture for improving the heat dissipation capability of a surface-mounted attenuator as claimed in claim 1, characterized in that: The size of the product mounting hole (7) is slightly larger than the size of the product (10).

8. A fixture for improving the heat dissipation capability of a surface-mounted attenuator as claimed in claim 1, characterized in that: The thickness of the circuit board (6) is slightly greater than the thickness of the product (10).

9. A fixture for improving the heat dissipation capability of a surface-mounted attenuator as claimed in claim 1, characterized in that: A conductive adhesive layer is provided between the product (10) and the bottom of the cavity (2) at the top of the copper base.

10. A fixture for improving the heat dissipation capability of a surface-mounted attenuator as claimed in claim 1, characterized in that: A gold-tin alloy layer is provided between the product (10) and the bottom of the cavity (2) at the top of the copper base.

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