CN103317203A - Welding technology for microwave substrate - Google Patents

Abstract

The invention discloses a welding technology for a microwave substrate, relates to the electronic technical field and aims at solving the technical problems of poor stability, high technological difficulty and the like caused by the fact that substrates are bonded on cavities directly traditionally. The welding technology comprises the steps of a) cleaning the microwave substrate, and placing the microwave substrate on a steel mesh with the welding surface upward; b) coating a layer of solder paste on the welding surface of the microwave substrate, and avoiding a tube core bonding hole during coating; c) putting the solder paste coated microwave substrate in a product cavity, compressing the microwave substrate through a compression block and fixing the compression block and the microwave substrate with a clamp; and d) putting the product in a reflow oven for welding, taking down the clamp after welding, checking the welding quality, and cleaning the microwave substrate.

Description

Microwave substrate weldering knot technique

Technical field

The present invention relates to electronic technology field, particularly a kind of microwave substrate weldering knot technique that is applied to microwave communication, satellite communication, radar.

Background technology

Along with the development of microwave technology, the frequency of microwave product is more and more higher at present, and volume is more and more less, and a lot of products at least all will reach Ku, K, Ka wave band and above wave band.And for fear of signals leakiness and electromagnetic interference, and product can for a long time reliable and stable work under adverse circumstances, it is particularly important whether the ground connection of printed board substrate well reaches reliability.The most general general printed board substrate welds method is to adopt conducting resinl and alloy sheet to weld at present, but conducting resinl and alloy sheet generally all need import at present, therefore procurement cycle is longer, cost is higher, after the simultaneously conducting resinl welding, if product is worked under adverse circumstances for a long time, the conducting resinl easily aging product reliability that causes reduces.Arise at the historic moment accordingly and researched and developed the welding technique of optimizing, in order to reduce the production time of product, reduce cost, improve reliability, reduce production difficulty.

Microwave product particularly frequency reaches the product of Ku, K, Ka wave band and above wave band, the substrate of radio frequency part (sheet material is generally Rogers5880,4350,6010, potsherd etc.) all requires substrate directly is bonded on the cavity for avoiding signals leakiness, electromagnetic interference and dispelling the heat badly etc. usually.And the adhesive technology that usually adopts at present mainly contains following two kinds:

One adopts conductive adhesive.The method generally is that conducting resinl is coated in printed board substrate back solder side uniformly, then substrate is bonded on the cavity, and presses briquetting, and the incubator of then putting into about 150 ℃ toasted about 2 hours.Although the method is simple to operate, conducting resinl all can only be bought basically in import at present, and procurement cycle is long, and cost is high.If simultaneously for a long time (such as high temperature, high humidity, low temperature, open-air, salt fog) work under adverse circumstances, conducting resinl is easily aging, causes substrate to come off and imperfect earth, machine failure occurs, and particularly potsherd easily comes off.If high-power product also can occur dispelling the heat bad and the initiation machine failure.

Its two, adopt the alloy sheet welding.The method generally is that alloy sheet is processed into the printed board substrate shape, is coated with an amount of weld-aiding cream in the cavity welding position, then in warm table heating welding.The method can solve the easily aging and bad problem of dispelling the heat of conducting resinl, but alloy sheet also all needs import to buy basically at present, and procurement cycle is long, and cost is high.The shape size of alloy sheet is wayward, particularly must avoid the die bonding hole, and technology difficulty is very large.

  

Summary of the invention

The present invention is intended to solve traditional substrate and directly is bonded on the cavity technical problems such as the poor or technology difficulty of existence and stability is very large, the microwave substrate weldering knot technique of the advantage such as have to provide that product cost is low, reliability is high, welding material procurement cycle is short, technology difficulty is low.

The objective of the invention is to be achieved through the following technical solutions.

Microwave substrate weldering knot technique of the present invention comprises the steps:

A) clean microwave substrate, the solder side with microwave substrate upwards places on the steel mesh afterwards;

B) solder side in above-mentioned microwave substrate brushes one deck tin cream, need avoid the die bonding hole during brushing;

C) microwave substrate behind the brushing tin cream is packed in the cavity of product, and compress microwave substrate by briquetting, re-use anchor clamps briquetting and microwave substrate are fixed;

D) product is put into reflow ovens and weld, welding is taken off anchor clamps after finishing, and checks welding quality, it is cleaned up at last to get final product again.

Microwave substrate weldering knot technique of the present invention, described by briquetting compression microwave substrate, briquetting is stressed everywhere must uniformity.

  

The beneficial effect of microwave substrate weldering knot technique of the present invention: reduce product cost, improve reliability, shorten the procurement cycle of welding material, reduce technology difficulty.

  

Description of drawings

Fig. 1 process chart of the present invention

The specific embodiment

Detailed structure of the present invention, application principle, effect and effect with reference to accompanying drawing 1, are explained by following embodiment.

The present invention includes following steps:

A) use absolute ethyl alcohol or acetone etc. to clean microwave substrate, the solder side with microwave substrate upwards places on the steel mesh afterwards;

B) solder side in above-mentioned microwave substrate brushes one deck tin cream, need avoid the die bonding hole during brushing, avoids after the reflow soldering in the scolding tin ostium;

C) microwave substrate behind the brushing tin cream is packed into need in the cavity of welding product, and compress microwave substrate by briquetting, re-use anchor clamps briquetting and microwave substrate are fixed;

D) according to the size of specific product, the temperature curve that thickness is set reflow ovens, after furnace temperature is stable, product is put into reflow ovens weld, take off anchor clamps after welding is finished, and check welding quality, use absolute ethyl alcohol to clean up it more at last and get final product.

This technique should be noted following three key points when producing enforcement: first, the control of tin amount, particularly keep away the control of tin distance around the tube core hole, cavity adopts different surface treatment mode (being generally gold-plated or silver-plated) and different steel mesh thickness, then keep away the tin distance different, need specifically to arrange according to specific product; The second, briquetting is stressed necessary uniformity everywhere, avoids microwave substrate wire end mouth welding injustice or cavity and affects earthing effect; The 3rd, the furnace temperature of Reflow Soldering arranges the different of size, thickness and caloric receptivity that need according to product and arranges.

  

Claims (2)

1. microwave substrate weldering knot technique is characterized in that comprising the steps:

A) clean microwave substrate, the solder side with microwave substrate upwards places on the steel mesh afterwards;

B) solder side in above-mentioned microwave substrate brushes one deck tin cream, need avoid the die bonding hole during brushing;

C) microwave substrate behind the brushing tin cream is packed in the cavity of product, and compress microwave substrate by briquetting, re-use anchor clamps briquetting and microwave substrate are fixed;

D) product is put into reflow ovens and weld, welding is taken off anchor clamps after finishing, and checks welding quality, it is cleaned up at last to get final product again.

2. microwave substrate as claimed in claim 1 is welded knot technique, it is characterized in that: described by briquetting compression microwave substrate, briquetting is stressed everywhere must uniformity.

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