1. Why the name Hybrid which generally means offspring of two varieties?
   
2. Why Hybrid Microcircuit is also sometimes referred as Hybrid IC?
   
3. Brief the difference between thickfilm and thin-film Hybrid Microcircuits (HMCs)?
   
4. State key difference between Monolithic circuits and Hybrid Circuits?
   
5. What is so special about Hybrid Microcircuits (HMC's)?
   
6. How would you classify Hybrid Microcircuits?
   
7. What are the advantages of using a resistor network over discrete parts?
   
8. Do you manufacture and stock Standard Resistor Networks?
   
9. Just like plated through holes (PTH) in PCBs, whether the same is possible in Hybrid Microcircuits?
   
10. Can you use discrete components in Hybrid Microcircuits?
    
11. Can you develop HMC ICs from samples/ photographs?
    
12. Is there any specific package for Hybrid Microcircuits?
    
13. What type of encapsulant you suggest for Hybrid Microcircuits?
14. Why should one buy "Print, Fired and Trimmed" substrates from GENUS?
15. Do you fabricate capacitors in Hybrid Microcircuits?

There are several ways of categorizing IC's as to their use and method of fabrication. The common categories are Linear or Digital according to application, and Monolithic or Hybrid according to fabrication.

ICs (Integrated Circuits) which are included entirely on a single chip of semiconductor are called Monolithic Circuits (literally meaning single stone). Whereas Hybrid IC may contain one or more monolithic IC's or individual components bonded to an insulating substrate having resistors and appropriate interconnections formed through thick or thin film process.

When resistance and capacitors are made external to the monolithic chip basically two types of technologies are used ; thick-film or thin-film processes. The thickness of the interconnections and resistors are typically 0.1 to 0.5 µm in "thin" films and are about 25 µm in "thick" films.

The processing steps for the two hybrid techniques are entirely different. In thick-film circuits the resistors and interconnection patterns are "screen printed" on a ceramic substrate, whereas in thin-film circuits these are realised through vacuum deposition or sputtering.

Monolithic Circuits have the advantage that all components are contained in a single rigid structure, which can be fabricated in large number once proven. On the other hand Hybrid circuits offer excellent isolation between components and allow the use of more precise resistors. Furthermore, Hybrid circuits are often less expensive to build in small numbers.

Hybrid Microcircuits can be broadly classified into

(i) Active type and (ii) Passive Type

Active type Hybrid Microcircuits incorporate active components such as Diodes, Transistors, ICs etc mainly in SMD packages. Passive type Hybrid Microcircuits include Resistive Arrays, Capacitors Network, R-C-network, High Voltage resistor network, High Wattage resistor network etc. Resistive Arrays could be Standard Resistor Network or Custom made networks.

Yes. Standard Resistor Networks are available in three configurations :

• Isolated Resistor Networks
  
• Bussed Resistor Networks
  
• Dual Terminator Networks
  

Some of the low profile resistor networks are available ex-stock. Also these can be manufactured at a short notice if necessary.

The most popular Hybrid Microcircuit packages are SIP (Single-in-line Package) or DIP (Dual-in-line Package). These are also sometimes referred as SIL (Single-in-line) or DIL (Dual-in-line). In SIP/ SIL's ; the leads are projected from one side. These occupy less PCB area but will have a certain height. In DIP/ DIL's, the leads are projected from both sides of the circuits. These may occupy more space but height may be considerably less (i.e, stand off length + Substrate Thickness + Thickness of the component).

We can also supply HMCs without leads with provisions of pads, where wires or cables can be soldered. These can be PFT (Printed, Fired and Trimmed) type with or without components

Overglaze also called coverglaze provides adequate protection to printed resistors and conductor tracks from humidity, reducing atmosphere, dust and to some extent from scratches. In general we encapsulate Resistor Networks with epoxy resin and Hybrid Microcircuits with durez resin.

Print, Fired and Trimmed (PFT) substrates are basically semi-processed Hybrid Microcircuits or Networks, where all the time consuming process such as Substrate Preparation, Printing, Firing and Trimming are done by GENUS. You can refer HMC Process Flow Chart to know exactly at what stage, the substrate become PFTs.

Many overseas customers find it easier to buy PFT substrates from us. They then assemble components on the PFTs at their place, insert leads and give shape to them as final products. This turns out to be cheaper option for them. Moreover this solution enables some of the customers to use proprietary components/ special process at their end. All in some cases the HMC's may not require leads at all. The PFT's are put in special/ odd shaped housing and then wire soldered. GENUS is open to enqueries for PFT substrates and assures quicker delivery of the same.

Capacitors of small value (upto few hundred pico farads) can be fabricated by printing and firing process using dielectric paste of high k values. But these tend to occupy large substrate area. Hence we use only Chip Capacitors which are superior in all respects as compared to fabricated capacitors.