Cavity amplifier

Abstract

The utility model discloses a cavity type amplifier, it includes substrate, amplifier bare chip and plastic film, substrate adopts printed circuit board, and substrate is equipped with circuit, and the front surface of substrate is equipped with the plurality of terminal of protruding, and terminal is connected with circuit, the flip -chip welding of each terminal of amplifier bare chip and substrate front surface, and plastic film combines with substrate and amplifier bare chip, and plastic film covers the front surface of substrate, and the front surface and side of amplifier bare chip, and the closed cavity is formed between plastic film, substrate and amplifier bare chip. The utility model discloses a cavity type amplifier has the advantages of small, high production efficiency.

Description

Technical Field

[0001] This utility model relates to the field of amplifiers, and in particular to a cavity amplifier. Background Technology

[0002] Cooperate Figure 1 As shown, existing cavity amplifiers (such as low-noise amplifiers) generally include a housing 1', an amplifier die 2', and a cover plate 3'. During assembly, die bonding (fixing the amplifier die 2' in the housing 1') and wire bonding (connecting the amplifier die 2' to the housing 1' via metal wires 3') are typically performed first in the cavity 11' of the housing 1'. Then, a cap is applied (the cover plate 3' is connected to the housing 1' to close the opening of the cavity 11' of the housing 1'). Because wire bonding is required, the cavity 11' of the housing 1' needs sufficient space for the bonding operation, resulting in a larger size for the housing 1' and thus a larger overall size for the amplifier. In addition, the cover plate 3' is bonded to the housing 1 using a dispensing process, which has relatively low dispensing efficiency, affecting production efficiency during mass production.

[0003] In view of the above problems, it is necessary to study a cavity amplifier with a small size. Utility Model Content

[0004] The purpose of this invention is to provide a cavity amplifier with a small size.

[0005] To achieve the above objectives, the solution of this utility model is:

[0006] A cavity amplifier includes a substrate, an amplifier die, and a plastic film. The substrate is a printed circuit board with circuits and multiple raised terminals on its front side, which are connected to the circuits. The amplifier die is flip-chip soldered to each terminal on the front side of the substrate. The plastic film is bonded to the substrate and the amplifier die, and covers the front side of the substrate, as well as the front and sides of the amplifier die, forming a sealed cavity between the plastic film, the substrate, and the amplifier die.

[0007] The substrate has terminals installed by ball placement.

[0008] The terminal is made of copper, silver, or gold.

[0009] The height of the terminal is 2 to 18 micrometers.

[0010] The plastic film is bonded to the substrate and the amplifier die.

[0011] The cavity amplifier also includes a plastic encapsulation that is bonded to the front of the plastic film.

[0012] The molding compound is made of epoxy molding compound.

[0013] The plastic film is made of modified polyurethane resin or modified polyimide.

[0014] The back of the substrate has multiple pads, which are connected to circuits.

[0015] The solder pads and circuits of the substrate are integrated.

[0016] By adopting the above solution, in this utility model, on the one hand, the amplifier die is flip-chip soldered to each terminal on the front side of the substrate, which makes the size requirement of the substrate small when the amplifier die is combined with the substrate; on the other hand, the plastic film covers the front side of the substrate, as well as the front and sides of the amplifier die, and a sealed cavity is formed between the plastic film, the substrate and the amplifier die, which makes the volume of the cavity small; combining these two aspects, this utility model can make the cavity amplifier of this utility model small in size. Attached Figure Description

[0017] Figure 1 This is a cross-sectional view of an existing amplifier.

[0018] Figure 2 This is a cross-sectional view of the cavity amplifier of this utility model.

[0019] Background technical reference numerals: tube shell 1', cavity 11', amplifier die 2', cover plate 3', metal wire 4';

[0020] Explanation of reference numerals for specific implementation methods:

[0021] Substrate 1, circuit 11, terminal 12, pad 13, amplifier die 2, plastic film 3, encapsulation 4, cavity S. Detailed Implementation

[0022] To further explain the technical solution of this utility model, the following detailed description is provided through specific embodiments.

[0023] like Figure 2 As shown, this utility model discloses a cavity amplifier, which includes a substrate 1, an amplifier die 2, and a plastic film 3. The substrate 1 is a printed circuit board with lines 11 and a plurality of protruding terminals 12 on the front side of the substrate 1, which are connected to the lines 11. The amplifier die 2 is flip-chip soldered to each of the terminals 12 on the front side of the substrate 1. The plastic film 3 is combined with the substrate 1 and the amplifier die 2, and the plastic film 3 covers the front side of the substrate 1 and the front and sides of the amplifier die 2, forming a sealed cavity S between the plastic film 3, the substrate 1, and the amplifier die 2.

[0024] In this invention, on the one hand, the amplifier die 2 is flip-chip soldered to each terminal 12 on the front side of the substrate 1. This arrangement makes the size requirement of the substrate 1 small when the amplifier die 2 is combined with the substrate 1. On the other hand, the plastic film 3 covers the front side of the substrate 1, as well as the front and side sides of the amplifier die 2, and a sealed cavity S is formed between the plastic film 3, the substrate 1, and the amplifier die 2. This makes the volume of the cavity S small (the size of the cavity S can not exceed the size of the amplifier die 2). Combining these two aspects, this invention enables the cavity amplifier of this invention to be small in size.

[0025] In an embodiment of this utility model, the back side of the substrate 1 is provided with a plurality of pads 13, which are connected to the circuit 11. The pads 13 and the circuit 11 of the substrate 1 can be integrated by the circuit board printing process.

[0026] In an embodiment of this utility model, the substrate 1 is provided with terminals 12 by means of ball planting. The material of the terminals 12 can be copper, silver or gold (preferably copper, which has low cost), and the height of the terminals 12 can be 2 to 18 micrometers.

[0027] In the embodiments of this utility model, the plastic film 3 is bonded to the substrate 1 and the amplifier die 2, which is a simple bonding method; the material of the plastic film 3 can be modified polyurethane resin or modified polyimide, and the modified polyurethane resin and modified polyimide can contain silicon dioxide.

[0028] In an embodiment of this utility model, a cavity amplifier further includes a molding compound 4 bonded to the front of the plastic film 3. The molding compound 4 can protect the molding film and effectively improve the strength of the entire amplifier. The material of the molding compound 4 can be epoxy molding compound.

[0029] To facilitate understanding of this utility model, the manufacturing process of this utility model is described in detail below, which includes:

[0030] Step 1: Take an empty printed circuit board and print circuits on the printed circuit board so that the printed circuit board forms multiple substrates 1. Each substrate 1 has a line 11 and a pad 13 connected to the line 11. The pad 13 is located on the back of the substrate 1.

[0031] Step 2: Ball-mounting is performed on the printed circuit board so that a raised terminal 12 connected to the line 11 is formed on the front side of each substrate 1;

[0032] Step 3: Flip-chip solder multiple amplifier dies 2 to the terminals 12 of each substrate 1 of the printed circuit board;

[0033] Step 4: Place the plastic film 3 onto the printed circuit board and each amplifier die 2, and send them into a vacuum laminating machine for lamination. This allows the plastic film 3 to adhere to the printed circuit board and each amplifier die 2, covering the front of the printed circuit board and the front and sides of each amplifier die 2. Sealed cavities S are formed between the plastic film 3, the printed circuit board, and each amplifier die 2, thus obtaining the amplifier semi-finished product. (The vacuum laminating machine ensures the sealing of the cavities S.)

[0034] Step 5: Curing the plastic film 3 of the amplifier semi-finished product so that the plastic film 3 is bonded to the printed circuit board and each amplifier die 2;

[0035] Step 6: The amplifier semi-finished product is fed into the injection molding machine for injection molding and encapsulation. The encapsulated body 4 is injection molded on the front side of the plastic film 3 to obtain the amplifier assembly.

[0036] Step 7: Cut the amplifier assembly to obtain multiple cavity amplifiers.

[0037] As described above, this invention can use a vacuum laminating machine to adsorb the plastic film 3 onto the printed circuit board and each amplifier die 2 in one go. The plastic film 3 covers the front of the printed circuit board and the front and sides of each amplifier die 2. A sealed cavity S is formed between the plastic film 3, the printed circuit board and each amplifier die 2, which can greatly improve production efficiency and the cavity S has good sealing performance. In addition, this invention uses a flip-chip bonding process to connect the amplifier die 2 to the substrate 1, eliminating the need for wire bonding and helping to reduce costs.

[0038] The above embodiments and figures are not intended to limit the product form and style of this utility model. Any appropriate changes or modifications made by those skilled in the art should be considered as not departing from the patent scope of this utility model.

Claims

1. A cavity amplifier, characterized in that: This includes the substrate, amplifier die, and plastic film; The substrate is a printed circuit board with circuits. The front side of the substrate has multiple raised terminals that are connected to the circuits. The amplifier die is flip-chip soldered to each terminal on the front side of the substrate. A plastic film is bonded to the substrate and the amplifier die, and the plastic film covers the front side of the substrate, as well as the front and sides of the amplifier die. A sealed cavity is formed between the plastic film, the substrate, and the amplifier die.

2. The cavity amplifier as described in claim 1, characterized in that: The substrate has terminals installed by ball mounting.

3. The cavity amplifier as described in claim 1, characterized in that: The terminal is made of copper, silver, or gold.

4. The cavity amplifier as described in claim 1, characterized in that: The height of the terminal is 2 to 18 micrometers.

5. The cavity amplifier as described in claim 1, characterized in that: The plastic film is bonded to the substrate and the amplifier die.

6. The cavity amplifier as described in claim 1, characterized in that: It also includes the encapsulation that is bonded to the front of the plastic film.

7. The cavity amplifier as described in claim 6, characterized in that: The molding compound is made of epoxy molding compound.

8. The cavity amplifier as described in claim 1, characterized in that: The plastic film is made of modified polyurethane resin or modified polyimide.

9. The cavity amplifier as described in claim 1, characterized in that: The back of the substrate has multiple solder pads, which are connected to circuits.

10. The cavity amplifier as described in claim 7, characterized in that: The solder pads and circuits of the substrate are integrated.

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