FPC process :
A ) a flexible insulating substrate constituting the multilayer PCB, which can be defined as deflection of the finished product : This structure is generally the many -sided or double-sided flexible microstrip PCB bonded to both surfaces of the end , but its center and bonding together the end portions , so as to have a high degree of flexibility. This is most suitable for multi-layer flexible PCB required flexibility, high reliability and high density designs.
2 ) a multilayer PCB on soft insulating substrate , the end of its provisions can be finished flexing : These multilayer flexible PCB is soft insulating material. When the design requirements to maximize the insulating properties of the film , such as low dielectric constant , the thickness of the homogeneous medium , lighter weight and other characteristics of continuous processing , the use of such a flexible PCB.
3) is formed on a multilayer PCB flexible insulation material , the finished product can be formed instead of the continuous flexing : These soft multi-layer flexible PCB is made of insulating material .
Hard board process :
1, the effect of the hole , the different types and Plating : hard board plated through hole and electrically connected with the through holes in multilayer boards . In the multilayer flexible board is electrically connected to the through hole portion , there is used as the positioning holes for the latter nip circuit . Soft copper plate with black holes ways to achieve inner and outer layers of electrical circuit.
2 , the purpose of the copper foil surface treatment is different : hard board is the use of polished copper surface so rough surface evenly. FPC is to remove surface oxides and contaminants , easy to cover the late film developing circuits.
3 , the process of forming a circuit different: the inner layer with a hard board image transfer , etching, stripping , stripping , lamination , exposure and development . FPC is the use of light exposed , i.e. by way of UV irradiation under a circuit is formed on the dry film . And then developed to remove the unexposed , photosensitive retention circuit .
4 , post- processing of PCB are different: the latter after a hard board also has a secondary copper , etching, solder , Goldfinger , HAL (Gold Finger & HAL), the other pad surface treatment methods . Soft cover film plate is used to strengthen the sheet metal stamping ; adhesive cover film ( insulating film paste ) is equivalent to the hard multilayer board in cooperation with the press . Printed hole that hit SR printing positioning holes , hot co screen printing, a secondary hole positioning holes , namely on contouring die stamping out circuit boards required flatness ; partially fit it with double-sided tape , reinforcing plates plus other parts of the product. Part of the process and the positioning hole final shape plasma cleaning .
