Cos'è il circuito Fr4: ultima guida passo passo 2020

Un ultimo prezzo e vantaggi del circuito stampato fr4 per principianti

Introduzione alla scheda di circuito Fr4

La produzione di assiemi elettronici ha cessato da tempo di essere il dominio di circuito stampato Fr4 . Gli strumenti, i componenti ei materiali oggi disponibili sono diventati migliori e più economici per gli utenti privati. cosicché la produzione professionale di circuiti stampati è diventata ormai un hobby per molti.

Planning, manufacturing and trying out electronic circuits is part of the large area of ​​do-it-yourself. It not only includes seasoned men. School children are also becoming more and more enthusiastic about the world of:

• Diodes
• transistors and

In order for the self-soldered circuito stampato Fr4 to remain safe and operational for a long time, a suitable base material is crucial. Here, FR4 has developed into a new standard in recent years. We introduce the most popular material for printed circuit boards

What an FR4 circuit board has to do?

You can still find it in old radios: the cardboard circuit board. In the technical language “FR-2 hard paper” was said to be. However, it is what it is: Pressed pulp.

In the tube televisions of the 1960s, the cardboard was replaced by temperature-resistant. But very brittle Bakelite. But today’s highly sensitive components need a material for the production of circuito stampato Fr4.

It remains durable and reliable within the set parameters. The FR4 plate is ideally suited for this. It is durable up to 100 ° C and does not delaminate. The plate offers excellent breaking strength and can withstand good mechanical and static loads.

Their most important advantage, however, is their resistance to leakage current and insulation. The special properties of circuito stampato Fr4 make the material particularly suitable for etching circuit boards.

What is printed circuit?

A printed circuit is a set of copper tracks represented on an insulating support.

These tracks are used to connect the various components that make up the electronic circuit.

The insulating support can be made with two different materials:

1. Bakelitewhich is a yellow / brown phenolic resin, used a lot in the past.
2. circuito stampato Fr4

circuito stampato Fr4 has better electrical characteristics than Bakelite. But it is more expensive and spoils the bits more quickly when drilling.

Material for the circuit board

In the past, Pertinax was often used as the base material. Nowadays it is only used for cheap, mass-produced items. Glass fiber mats soaked in epoxy resin called FR4 have better tracking resistance and better high-frequency properties as well as lower water absorption than hard paper.

Material designations for the circuit board:

• FR1 = phenolic resin + paper (cheap type)
• FR2 = phenolic resin + paper (standard quality)
• FR3 = epoxy resin + paper
• FR4 = epoxy resin + fiberglass fabric
• FR5 = epoxy resin + fiberglass fabric (heat-resistant)

FR stands for flame retardant

For special applications, other materials are used in circuito stampato Fr4. Such as:

• Aluminum
• Teflon
• or ceramic and polyester films for flexible printed circuit boards.

In the case of circuito stampato Fr4 with high demands on heat dissipation, base materials with electrically insulated metal cores are used. For instance, in the field of lighting technology with high-performance light emitting diodes. This material is also called Direct Bonded Copper, or Insulated metal substrate (IMS).

circuito stampato Fr4 looked into the core

The designation “FR” means “Flame Retandant” – that is, flame retardant. In practical terms, this means that no fire can establish itself on a circuit board made of this material. The number indicates a resistance class.

Essentially, a FR4 printed circuit is a GRP composite material. It consists of a multi-layer mat made of glass roving fabric impregnated with epoxy resin.

In the course of its special use as a mounting plate for electronic assemblies, great importance is attached. It is to complete saturation of the fabric mats in the manufacture of the FR4 plate.

Usually a vacuum pressing process is used for this. It also allows the resin to flow around the last fiber.

Advantages of Fr4 Circuit Board

Il circuito stampato Fr4  ha dimostrato il suo valore soprattutto per l'uso come base per schede per due motivi:

• Resistenza al calore
• Resistenza al cortocircuito

La scheda FR4 non è assolutamente infiammabile. Ma offre una resistenza alla fatica termica fino a 100 ° Celsius. La temperatura massima di esercizio può arrivare anche fino a 140 °.

Tuttavia, per motivi di sicurezza, i produttori di solito danno un valore inferiore a 100 ° C. Se il carico termico è superiore al limite specificato, il circuito Fr4 non prende fuoco immediatamente.

Tuttavia, se il materiale GRP inizia a delaminare, i componenti elettronici non aderiscono più al materiale di base. Pertanto, la resistenza al cortocircuito soffre.

La rigidità dielettrica di una normale piastra FR-4 è di ca. 20 kV / mm. Questo di per sé è un valore davvero sorprendente. perché, come dice l'unità, si applica per millimetro.

I pannelli economici e tecnicamente molto resistenti sono quindi disponibili a partire da spessori molto bassi. Anche i pannelli sottilissimi, ad esempio di 0,2 mm di spessore, possono resistere a 4 kV.

I formati disponibili in commercio vanno fino a 20 millimetri di spessore. Qui sei già nella gamma di 400 kV. Sebbene le schede abbiano uno spessore di soli due centimetri, gli hobbisti devono lavorare molto duramente per entrare nelle aree limite durante la produzione del circuito stampato Fr4.

circuito stampato Fr4  è economico, anche in termini di qualità industriale

What is also not entirely irrelevant for hobby and semi-professional electronic manufacturer. As an example: a plate with a thickness of 1mm, a width of 100mm and a height of 300mm is available at very low cost.

The panels are therefore absolutely inexpensive overall. The semi-finished circuito stampato Fr4 are offered in the standard dimensions of 500 millimeters wide and 300 millimeters long. Since printed circuit board production usually requires much smaller formats, boards of this size last a long time.

For experiment circuits in the range up to 24 volts, plates with low thicknesses are sufficient. They are ideal for student experiments and beginner circuits. A thin plate also means that a lot of weight is saved.

With thicker boards, the production of a circuito stampato Fr4 can be approached much more courageously and progressively. The strongest GRP panel made of FR4 is 20 millimeters thick, but 14mm panel thickness is common for many applications.