CN110867636B

CN110867636B - Aluminum nitride micro load sheet

Info

Publication number: CN110867636B
Application number: CN201911168400.2A
Authority: CN
Inventors: 陈建良
Original assignee: Suzhou City Prudential's Electronics Co ltd
Current assignee: Suzhou City Prudential's Electronics Co ltd
Priority date: 2019-11-25
Filing date: 2019-11-25
Publication date: 2021-03-19
Anticipated expiration: 2039-11-25
Also published as: CN110867636A

Abstract

The invention provides an aluminum nitride micro load sheet which comprises a load sheet body, wherein the load sheet body comprises an aluminum nitride ceramic substrate, a silver paste bonding pad and a grounding lead are respectively arranged on two sides of the front surface of the aluminum nitride ceramic substrate, a resistor is connected between the silver paste bonding pad and the grounding lead, and a protective film is covered outside the aluminum nitride ceramic substrate; the back of the resistor is provided with a back conductor which is T-shaped, and a termination ground is connected between the grounding lead and the back conductor. The invention aims to provide an aluminum nitride micro load sheet, wherein a back conductor is designed in a T shape, the reliability and risk points of application are fully considered, the later-stage assembly efficiency is greatly improved, and the reliability risk is reduced.

Description

Aluminum nitride micro load sheet

Technical Field

The invention relates to the technical field of load sheets, in particular to an aluminum nitride micro load sheet.

Background

In the field of radio frequency power amplification, two types of isolators are mainly used, one is a traditional microstrip isolator, and the other is a surface-mounted isolator. The traditional microstrip isolator realizes large-area localization, while the surface-mounted isolator is mainly produced in Japan at present, and the localization is not realized in China.

The biggest advantage of surface mount isolators is their small size, which has now reached the 5mm by 5mm dimension, which is not achievable with current microstrip isolators. Because of the small volume, the load attached by the user puts higher requirements on the size, and the current domestic load product mainstream has the minimum size of 1.27mm 2mm 0.3mm and the power of 3W. The size requirement of the load in the surface mount isolator is smaller than 1.27mm 2mm 0.3mm, the power requirement is 2W, at present, the load product with the tiny size is mainly produced by Japan, and the mass production is not realized in China.

Disclosure of Invention

The invention aims to provide an aluminum nitride micro load sheet, wherein a back conductor is designed in a T shape, the reliability and risk points of application are fully considered, the later-stage assembly efficiency is greatly improved, and the reliability risk is reduced.

The invention provides the following technical scheme:

the aluminum nitride micro load sheet comprises a load sheet body, wherein the load sheet body comprises an aluminum nitride ceramic substrate, a silver paste pad and a grounding wire are respectively arranged on two sides of the front surface of the aluminum nitride ceramic substrate, a resistor is connected between the silver paste pad and the grounding wire, and a protective film is covered outside the aluminum nitride ceramic substrate; the back of the resistor is provided with a back conductor which is T-shaped, and a termination ground is connected between the grounding lead and the back conductor.

Preferably, the aluminum nitride ceramic substrate is 0.8mm by 1.6mm by 0.385mm in size.

Preferably, the protective film is a black protective film, and the protective film is completely covered outside the resistor.

Preferably, the silver thick liquid pad with one side that resistance carried on the back mutually is equipped with the welding part, earth conductor with one side that resistance carried on the back mutually is equipped with wiring portion, the both sides of protection film cover establish extremely the welding part with wiring portion.

Preferably, the back conductor is a T-shaped conductor, and the T-shaped conductor includes a wide portion and a narrow portion perpendicular to the center of the wide portion, the wide portion is close to the termination, and the narrow portion is close to the silver paste pad.

Preferably, the resistance is adjusted by a laser transverse line cutting method.

Preferably, the power of the load sheet body is 2W.

The invention has the beneficial effects that: the whole circuit is covered by a protective film, so that the circuit is protected from being affected by electroplating and is isolated from the influence of external humidity in use; the resistance value is adjusted by adopting a laser transverse line cutting method, so that the required resistance value is ensured to be reached, the area of the resistor is ensured as much as possible, and the designed power meter allowance is ensured; adopt the back conductor of T font, the one end that is close to earth conductor is wider in the one end that is close to silver thick liquid pad, and the width at termination ground is wide to guarantee the large tracts of land contact between product front circuit and the ground connection, and the one end that is close to silver thick liquid pad is narrow when having avoided rewelding the printed product little thin again, leads to bottom soldering tin to extrude the edge after, piles up and front pad formation short circuit, and this design when fully having guaranteed the circuit connection reliability, the risk that probably appears when having avoided the volume production.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

FIG. 1 is a top view of the structure of the present invention;

FIG. 2 is a side view of the structure of the present invention;

FIG. 3 is a rear view of the structure of the present invention;

labeled as: 1. an aluminum nitride ceramic substrate; 2. silver paste bonding pads; 3. a ground lead; 4. a resistance; 5. a protective film; 6, a back conductor; 7. at the termination ground.

Detailed Description

As shown in fig. 1-3, an aluminum nitride micro-load sheet includes a load sheet body, the power of the load sheet body is 2W, the load sheet body includes an aluminum nitride ceramic substrate 1, the aluminum nitride ceramic substrate 1 is 0.8mm by 1.6mm by 0.385 mm;

silver paste pads 2 and grounding wires 3 are respectively arranged on two sides of the front surface of the aluminum nitride ceramic substrate 1, and a resistor 4 is connected between the silver paste pads 2 and the grounding wires 3, wherein the resistor 4 adopts a laser transverse cutting method to adjust the resistance value, so that the required resistance value is ensured to be reached, the area of the resistor 4 is ensured as much as possible, and the designed power meter allowance is ensured, for example, the transverse line in the middle position of the resistor 4 in fig. 1 is used for adjusting the resistance value of the resistor 4 to the resistance value required by actual design, and the thick film printing cannot ensure that the printed resistance value is the resistance value required by design, so that the resistance adjustment is realized by laser resistance adjustment;

a protective film 5 is coated outside the aluminum nitride ceramic substrate 1, wherein the protective film 5 is a black protective film 5, the protective film 5 is completely coated outside the resistor 4, the whole circuit is covered by the protective film 5, the circuit is protected from being affected by electroplating, and the influence of external humidity is isolated in use; one side of silver thick liquid pad 2 and resistance 4 back of the body is equipped with the welding part, and one side that earth conductor 3 and resistance 4 back of the body carried on the body is equipped with the wiring portion, and the both sides of protection film 5 cover and establish welding part and wiring portion, reserve out and can be used as the area of welded and can be used as the wire area of being connected with back conductor 6.

As shown in fig. 3, the back surface of the resistor 4 is provided with a back surface conductor 6, the back surface conductor 6 is T-shaped, a termination ground 7 is connected between the grounding wire 3 and the back surface conductor 6, specifically, the back surface conductor 6 is a T-shaped conductor, the T-shaped conductor comprises a wide part and a narrow part, the narrow part is arranged perpendicular to the center of the wide part, the wide part is close to the termination ground 7, the narrow part is close to the silver paste pad 2, specifically, the width of the termination ground 7 is designed to be wide, so that the large-area contact between the grounding wire 3 on the front surface of the product and the termination ground, meanwhile, the front end is designed to be narrow close to the front silver paste pad 2, so that short circuit between the accumulated bottom soldering tin and the front silver paste pad 2 after the bottom soldering tin is extruded to the edge is avoided, the circuit connection reliability is fully guaranteed, and meanwhile risks possibly occurring in mass production are avoided.

Specifically, because the product is tiny, the printing process of the terminal part 7 cannot be realized, a vacuum sputtering process is adopted, in the vacuum sputtering process, a jig is shielded on one side, the single-side sputtering of the product is ensured, and the product needs to be baked at 85 ℃ before sputtering to remove moisture and impurities on the surface of the product and provide the bonding force of the vacuum sputtering.

As shown in figures 1-3, the aluminum nitride micro load sheet fills the blank of domestic micro loads, and goes a solid step in the direction of load miniaturization, thereby providing a powerful support for the localization of surface mount isolators. Meanwhile, due to the 6T-shaped design of the back conductor of the product, the reliability and risk points of application are fully considered, the later-stage assembling efficiency of the surface-mounted isolator is greatly improved, and the reliability risk is reduced.

Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An aluminum nitride micro-load plate, wherein the aluminum nitride micro-load plate is used for surface mounting an isolator; the aluminum nitride micro load sheet comprises a load sheet body, the load sheet body comprises an aluminum nitride ceramic substrate, silver paste pads and grounding wires are respectively arranged on two sides of the front surface of the aluminum nitride ceramic substrate, resistors are connected between the silver paste pads and the grounding wires, and a protective film is covered outside the aluminum nitride ceramic substrate; a back conductor is arranged on the back of the resistor, the back conductor is T-shaped, and a termination ground is connected between the grounding lead and the back conductor; the T-shaped conductor comprises a wide part and a narrow part, wherein the wide part is arranged close to the termination ground, and the narrow part is arranged perpendicular to the center of the wide part and close to the silver paste pad; the aluminum nitride ceramic substrate is 0.8mm by 1.6mm by 0.385mm in size; the power of the load sheet body is 2W; the protective film is a black protective film and completely covers the resistor.

2. The aluminum nitride micro-load chip of claim 1, wherein a soldering portion is disposed on a side of the silver paste pad opposite to the resistor, a wiring portion is disposed on a side of the grounding wire opposite to the resistor, and two sides of the protection film are covered on the soldering portion and the wiring portion.

3. The aluminum nitride micro-load chip of claim 1, wherein the resistance is adjusted by laser cross-cut.