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EDA Software Review
Altium
Designer 25
Review by Tim Blythman
Altium Designer 25 is the latest version of the EDA (electronics design automation) software
that we use for all of our PCB designs. This new version was released late in 2024, and we
have spent some time putting it through its paces. Here is what we have found.
A
ltium Designer may not be the cheapest
PCB design package, but it certainly is very capable and becoming
quite mature. It has been around for
over 30 years now; it can trace its history back to a software package called
Protel Autotrax.
Like many software packages, Altium
Designer gets frequent updates, including annual major revisions that often
introduce new features. I have been
using Altium Designer for around ten
years now, so I was interested to see
what was new compared to the previous
major version from 2024, Altium Designer 24. As this is a complex piece of
software, I will be concentrating mainly
on the change and additions, rather
than its core functions like schematic
capture, PCB design and simulation.
Renesas Electronics acquired Altium
in August 2024. Renesas is a Japanese
semiconductor manufacturer that includes the semiconductor operations
of Hitachi, Mitsubishi and NEC.
That marks an interesting geographical history for Altium, with Protel Systems Pty Ltd originally founded as an
Australian company. For many years, it
has been headquartered in San Diego,
California.
We’re most familiar with Renesas
Electronics as the manufacturer of the
RA4M1 microprocessor used in the
new Arduino Uno R4 microcontroller
board. The Raspberry Pi 5 also uses a
Renesas power management IC.
AD25 overview
Altium Designer 25 looks and feels
much the same as previous versions,
56
but like many modern applications, it
is constantly evolving. This time we
are looking at version 25.0.2.
The webpage at www.altium.com/
documentation/altium-designer/new
lists details of the various version updates and the versions (and subversions) to which they apply. So you
can easily see which version has a
particular feature.
Some features that are present are
disabled by default but can be turned
on via the Advanced Settings window
of Preferences. Others are available as
Extensions, which can be installed from
the Extensions and Updates window.
Such features may still be at the beta
testing stage.
Beta testing means that the feature
is essentially complete but not fully
tested. It is a good way to get early
access to novel features, and there is
usually the ability to toggle these features on and off.
Just as with previous versions, it is
possible to install multiple versions of
Altium Designer alongside each other.
You might like to do this to try out the
features in a new version without committing to it until you are happy with
the changes.
Amongst other videos, the new
features are also presented at the
Altium Academy YouTube channel
(www.youtube.com/<at>AltiumAcademy).
These and other training materials are
also available on the Home Page of the
Altium Designer application.
Performance
Altium Designer 25 claims to have
much improved performance, especially with large designs. Our designs are
typically on the smaller and less complex side, so we’re not really able to put
this aspect to the test. But we were certainly happy with its responsiveness in
the time we’ve been using it.
This applies to many aspects of
Altium Designer, including the schematic and PCB editors, and Draftsman,
as well as in collaborative tools like
Altium 365 and PCB CoDesign.
Operations like opening documents,
repouring polygons, placing stitching
vias and bulk copying and pasting have
all been sped up. These improvements
have been brought about through better
memory management and caching of
data where possible.
On a related note, recent versions of
Altium Designer (starting with 24.8) use
the newer .NET 6 software framework.
Previously, Altium Designer used Microsoft’s proprietary and now obsolete
.NET Framework 4.8. Unsurprisingly,
.NET 6 is also faster.
Interestingly, .NET 6 is fully opensource. It is intended to be modular and
works across multiple platforms (including Windows, Linux and macOS).
Dare we wonder if this is the first step
of being able to run Altium Designer
on a Linux PC or Mac?
The SI Analyzer by Keysight
Another extension that sounds quite
handy is the Signal Integrity Analyzer
by Keysight, although this is another
one that we probably won’t ever need
to use due to our modest designs. As
the name suggests, it is intended to
Practical Electronics | September | 2025
Altium Designer 25
Fig.1: the Signal Integrity Analyzer by Keysight
can be used post-layout to validate signal integrity
and provide checks on parameters such as
impedance, delay, insertion loss and return loss.
This will be very handy to validate high-speed
designs before committing to PCB manufacture.
Source: www.altium.com/documentation/altiumdesigner/new?version=24#sianalyzer-by-keysight-openbeta-24-10
Fig.2 (below): this trace is
‘necked down’ to fit through
a narrow gap between other
pads; we did this manually,
using an older version of
Altium Designer. The new
auto-shrink feature allows
this to be done automatically
during interactive routing.
perform signal integrity analysis on
high-speed designs. Fig.1 shows the
phases of such an analysis.
It can calculate things such as impedance, delay, insertion loss and return
loss based on the PCB layout. This can
help to validate the PCB before it is committed to manufacture. Signal Integrity
Analyzer is currently a beta feature and
requires the SI Analyzer by Keysight
extension to be installed; there is a free
14-day trial available for this feature.
Routing
When routing the traces on a board,
it is sometimes necessary to use a track
narrower than the preferred width to
fit through a congested or tight area.
This is often described as ‘necking
down’, where the trace is narrowed
down to a thin neck just long enough
and narrow enough to fit.
Previously, you would have to do
this manually, but there is now an
option to auto-shrink the width to the
minimum you’ve set.
This will be handy, since manually
creating a neck can be a fiddly process,
especially if you want the result to be
Practical Electronics | September | 2025
neat. In addition, a new design rule
allows the neck to have a maximum
specified length, to avoid having too
much resistance or increased fragility.
Currently, both these features are in
beta and need to be activated in Advanced Settings. The auto-shrink feature is enabled with the “PCB.Routing.
EnableAutoShrinking” option, while
the neck-down rule follows the “PCB.
Rules.RoutingNeckdown” setting.
There is also an option to centre
traces when routing. Typically, the
auto-router will place traces at the
minimum allowed clearance from the
nearest track, but spreading the traces
out may be preferred. It can also make
the routing neater, since the traces will
be spread out more evenly.
This is also a beta feature and is set
with the “PCB.EnableTraceCentering”
advanced setting. Fig.2 shows an example of a trace necking down through a
narrow gap on our Thermal Controller
PCB, used in a project published in the
March & April 2021 issues.
Single-layer PCBs
For simple designs, a single-layer
PCB (with copper on just one side)
can be an economical choice, especially for designs on flexible substrates.
Large production runs can warrant the
savings in eliminating a copper layer
where that is feasible.
It’s now possible to lay out single-
layer PCBs by enabling the “PCB.
SingleLayerStack.Support” option
in Advanced Settings, then removing a copper layer from a two-layer
PCB stack.
Constraint Manager
The Constraint Manager unifies
design constraints from both the schematic and PCB layout. It works in place
of the PCB Rule and Constraints Editor
dialog (Design Rules).
A project can be set up (at creation)
to use the Constraint Manager or to use
the older Design Rules. There is also
a tool that can convert a project from
using Design Rules into one that is compatible with the Constraint Manager.
It provides a hierarchical system
that is automatically translated into
the priority in which rules are applied.
Constraint Manager can be enabled by
57
EDA Software Review
Source: www.altium.com/
documentation/altium-designer/
constraint-manager
Fig.3: the Constraint Manager
provides a new interface for
managing design constraints
(design rules) across a project.
Older projects can be upgraded
to use the Constraint Manager.
setting the “System.ConstraintManager” option in Advanced Settings.
Fig.3 shows some views of the Constraint Manager.
Importing
Occasionally, we have to deal with
contributed PCBs that have been designed using a different EDA tool, and
sometimes we need to change them.
This might be as simple as making a
small change to the silkscreen markings or could involve a major revision
of the copper routing layers.
Some changes can be made by directly editing the Gerber files, but having
access to fully editable PCB design files
is better for many reasons. Firstly, that
makes it possible to run design rule
checks to validate that any changes
do not cause a manufacturing issue
like shorted traces. It then becomes
possible to make further revisions if
needed in the future.
Whatever the reason, this means that
we need the ability to import designs
from other EDA tools into Altium Designer so that they can be turned into
native Altium Designer files, such as
SchDoc schematic files or PcbDoc
PCB files.
58
The latest version of the importer
now works with KiCad designs from
KiCad version 7 or 8. This is available
as an extension known as the KiCad
Importer Extension and can be found
in Extensions and Updates.
Their website at https://pemag.au/
link/ac41 has more information on
importing designs from other tools.
Fig.4 shows a screenshot from our installation of the Software Extensions
that are on offer.
We have also previously used the
free online Altium 365 Viewer, which
is at www.altium.com/viewer
This now supports KiCad files, and
we had no trouble using it to view some
KiCad PCB files that we found online.
Wire bonding
Altium Designer can be used for
designing much more than just traditional planar substrate PCBs. We
were already aware of Altium Designer’s ability to work with flexible
and hybrid (rigid-flex) PCBs, printed
electronics and 3D-printed substrates
using the 3D-MID (three-dimensional
mechatronic integrated device) process. Another example is the recent
Harness Designer.
One of the technologies supported
by Altium Designer 25 is COB (chipon-board) using wire bonding. COB
involves bare silicon chip dies being
bonded directly to a PCB. Connections
are made from pads on the die (die
pads) to the bond finger pads on the
PCB by means of bond wires.
The bond wires used in COB applications are much the same as the
bond wires used to connect a silicon
chip to its leadframe in a traditionally
packaged integrated circuit. These are
very fine wires of a metal such as gold,
copper or aluminium that are welded
to their pads using heat, pressure or
ultrasonic energy.
The process is typically performed
by an automated robotic system. You
can see some images of a COB design
at www.altium.com/documentation/
altium-designer/wire-bonding while
the photos at upper right shows two
examples of silicon dice bonded to
a PCB.
Creating a COB design involves
adding a Die layer and a Bond wire
layer to a PCB document or library. A
complete footprint ‘package’ including
die pads, bond finger pads, and bond
wires can be created, in which case the
Practical Electronics | September | 2025
Altium Designer 25
Fig.4: numerous Altium Designer extensions can be installed from the
Extensions and Updates tab. This shows just some of the extensions available on
our system.
bond finger pads can be simply routed
to on the copper layers.
Alternatively, a die with die pads
can be placed alongside separate bond
finger pads. The bond wires are then
placed manually. With the current version, wire bonding can be enabled with
the “PCB.Wirebonding” option in the
Advanced Settings dialog. For manufacture, a wire bonding table report
can be generated.
As you can see from Fig.5, Altium
Designer’s 3D rendering allows you
to see all aspects of a wire-bonded
design. For example, you can visually check that crossed bond wires
pass at different heights to avoid collisions. We find the 3D views invalu-
able for making sanity checks on our
PCB layouts.
Licensing
There are three different subscription levels available for Altium Designer: Standard, Pro and Enterprise.
They differ in the number of features
that are included and more information is available at www.altium.com/
altium-designer/licensing
Resources
Altium offers numerous resources
to allow users to make the best use of
Altium Designer. You can view a recent
webinar (recorded in November) at
https://pemag.au/link/ac42
Fig.5: Altium Designer 25
now allows wire bonding
between silicon dies and
PCBs. This image shows
an example of two COB
(chip on board) dies
bonded to the PCB below.
Source: www.altium.
com/documentation/
altium-designer/wirebonding#placing-wirebonds-in-a-pcb
Practical Electronics | September | 2025
Two examples of chips bonded
directly to PCB pads. Source:
www.rocket-pcb.com/rocket-pcbwholesale-wire-bonding-technologybulk-fabrication-for-electronics
In addition to covering the important aspects of a feature (in this case,
Single-layer PCBs), it follows with a
live demonstration of how to use that
feature within Altium Designer.
Altium also has a free trial offer for
new users. It allows you to use a fully
featured trial version of Altium Designer for 15 days; see www.altium.
com/altium-designer/free-trial
Conclusion
Altium continues to make incremental updates to Altium Designer.
While there are some bigger features
that we would struggle to use fully,
such as wire bonding, they are no
doubt useful for larger organisations.
It is good to see that they continue to
improve usability and work on basic
features such as routing.
We hope that the switch to the .NET
6 framework is the beginning of crossplatform support. We’re especially
keen to be able to use Altium Designer on Linux, since so many of the
other programs that we use already
allow that.
For more information on Altium
Designer, visit www.altium.com/
altium-designer
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