Backside encapsulation of tape automated bonding device
US5834336A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 12, 1996 |
| Grant date | Nov 10, 1998 |
| Priority date | — |
| Expiry date | Mar 12, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49144
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A TAB device (10) is coupled to a circuit board (12). The TAB device (10) includes a semiconductor die (11) having leads (18) extending therefrom. A material layer (30), typically a polyimide layer, covers the inward portion of the leads (18) to maintain leading position during attachment of the TAB device (10) to the circuit board (12). Prior to attachment, a backside encapsulation region (40) is applied to the backside of the TAB device (10), sealing the backside of the leads (18). The backside encapsulation material is selected to have a coefficient of thermal expansion similar to the coefficient of thermal expansion of the first material layer (18). The backside encapsulation material is selected to have a coefficient of thermal expansion similar to the coefficient of thermal expansion of the first material layer (30), to prevent excessive warpage. During attachment, migration of the die attach layer (22) towards the leads will be stopped by the backside encapsulation region (40), preventing the die attach material from shorting the leads (18) of the device (10).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.