I cant remember if the stencil survey has been posted before on SMART E LINK and
Technet. As both contributed to the survey here are the basic results for
further information contact the SMART Group direct or visit the Internet Home
Page.

Bob Willis


SOLDER PASTE STENCIL SURVEY IN THE 
ELECTRONICS INDUSTRY

UK SURVEY RESULTS
October 1996

by 
Bob Willis

THE SMART GROUP
86 EASTON STREET
HIGH WYCOMBE
BUCKS HP11 1LT
ENGLAND

TEL: (+44) 01494 465217  FAX: (+44) 01494 473975
Email: [log in to unmask]
Home Page:http://www.smtuk.demon.co.uk

SOLDER PASTE STENCIL SURVEY IN 
THE  ELECTRONICS INDUSTRY

This survey was conducted with members of the SMART Group in England, Ireland
and Scotland during September and October 1996. A stencil questionnaire was
posted to the membership, placed on SMART-E-, the Group's Email Forum and on
TechNet, the IPC Forum.

A copy of the relevant graphs produced from the responses are included in this
report along with the original questionnaire circulated to members. A copy of
the full report is available from Tony Gordon at The SMART Group office

A total of 35 responses were obtained from the UK and Europe which were included
in the results, the responses from America from TechNet were not included in the
results.

Survey Overview

The survey responses were mainly from Original Equipment Manufacturers (OEM) 23
responses with only four responses from Contract Equipment Manufacturers (CEM)
who are more likely to have a greater number of stencils of different types. The
survey results were mainly from consumer, computer and telecomms businesses.

Comparing the number of products produced and those using stencil printing the
reflow soldering process appears to be growing strongly despite the continued
use of wave soldering.  

Metal stencils are the main method used for printing paste but still six
companies indicated the use of screens for paste application. This was mainly
the case with low volume users probably for prototype builds.

The responses came from a wide range of companies with differing volumes between
50-10,000 SMT boards per week. The number of stencils currently in a company's
library also varied considerably between 5-150 different types. One company
indicated that they had over 800 stencils in their store, this was omitted from
the graphs for clarity. Over the next six months there will be an average
predicted requirement of 2-80 new stencils per company. 
- 2 -


Over the coming months there will be good potential for any of the stencil
suppliers with the predicted use of stencils for new designs. The figures for
the next six months should be used for reference as the 12 month figures may be
misleading. It is not clear from the survey if the figures quoted are in
addition to the first six months.

The main UK suppliers in the industry are indicated in the survey and their
position is probably quite accurate even with the small survey response with
Chemtech being the leading supplier of stencils, as indicated by the number of
companies using the Essex based supplier.

Although the trend in the industry is to finer and finer pitch applications, the
etched stencil is still the most commonly used. With relatively few suppliers in
the industry the quality levels of etched stencils is high. They can achieve a
very good performance for printing paste down to 0.025". The trend for materials
is to stainless steel with the majority of respondents indicating stainless
steel as opposed to the traditional brass.

The price quoted did vary but is difficult to pinpoint an exact figure due to
stencil size variations, etch or laser, frame types etc. As one example, the
cost of a laser cut stencil varied between L200-800. The figures are shown in a
graph and it is left to the reader to draw an average figure from the prices
quoted. Not all respondents provided costs for stencils purchased.

In terms of technology used in new designs only Ball Grid Array (BGA) was
indicated as an active area in the responses. Only a couple of people are using
Tape Automated Bonding (TAB).

The use of framed stencils is still preferred to the frameless systems but this
will probably change over the next twelve months. A limited number of people are
still using photographic artwork, the majority are using data but this is still
a problem area for the stencil suppliers. 


- 3 -



Survey Graphs

1. Company Product Type
2. Different Designs and Surface Mount Only
3. SMT Boards Assembled Weekly
4. Number of Stencils Currently in Library
5. Stencil Requirements for Six/Twelve Months
6. Current Stencil Suppliers Used
7. Types of Stencil Used
8. Stencil Type and Costs

SMART GROUP SOLDER PASTE 
STENCIL QUESTIONNAIRE

The SMART Group are investigating solder paste stencil requirements. Your help
in this exercise will be greatly appreciated. The questionnaire is a further
effort to provide its members and the industry with trends on current production
technology. Survey results are available from the SMART Group on Cleaning
Alternatives and PCB Solder finishes and costs.

Please complete the survey by marking a cross or filling in the required
details.

1. 	Company business: 	
	a)  Military	
	b)  Telecomms	
	c)  Computers and peripherals	
	d)  Consumer	
	e)  Other - please specify:

2. 	Are you a:	
	a)  Original Equipment Manufacturer			
	b)  Contract Equipment Manufacturer	

3. 	How many SMT boards do you produce per week?

4. 	How many different types of PCB do you produce per week?

5. 	How many of these utilise solder paste?

6. 	Do you use:	
	a)  Mesh screens			Yes/No
	b)  Metal mask stencils	Yes/No

7. 	If you use stencils how many different stencils do you have in your
library?

8. 	How many will you obtain in:
	a)  the next six months
	b)  the next 12 months

9. 	Please advise name of companies who supply you with stencils:
	a)
	b)
	c)

10. 	Do you have any specific requirements for stencils:
	a)	chemically etched			Yes/No
	b)	chemically etched nickel plated	Yes/No
	c)	laser cut					Yes/No
	d)	Electrofom					Yes/No
	e)	other - please specify:

11. 	Please indicated the materials you require:
	a) 	S Steel
	b) 	Brass
	c) 	Nickel
	d) 	Other

12. 	What is the price you expect to pay for:
	a)	chemically etched
	b)	chemically etched nickel plated
	c)	laser cut
	d)	other type

	Please state frame type:
	Frame mounted
	Frameless less

13. 	What form of data is provided to your supplier for the production of
stencils:	
	a)	Photographic artwork	
	b)	Digital data	

14.	Are you using or planning to use:
	a)	Tape automated bonding	
	b)	Chip on board	
	c)	Flip chip	
	d)	Ball Grid Arrays


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